Bicycle front forks with lubricant distribution features

Abstract

Disclosed herein are bicycle front forks having features for distributing lubricant.An exemplary front fork includes a lower tube having a first upper end and a first lower end, the lower tube defining an interior region for receiving a volume of oil, a bushing coupled to an interior surface of the lower tube, and an upper tube having a second upper end and a second lower end opposite the second upper end, the second lower end disposed within the lower tube, the upper tube in sliding contact with the bushing, the upper and lower tubes telescopically disposed and movable between a fully extended and a fully retracted position, the upper tube having a recess, the recess serving to collect oil when the upper tube is moved into the lower tube and to distribute the oil to the bushing when the tubes are moved to the fully extended position.

Description

Area of ​​Revelation

[0001] This disclosure relates generally to bicycle components and, more particularly, to bicycle front forks having lubricant distribution features. background

[0002] Bicycles are known to be equipped with suspension components. Suspension components are used for various purposes, such as dampening shocks, vibrations, or other disturbances to which the bicycle is subjected during use. A common application for suspension components on bicycles is to dampen shocks or vibrations felt by the rider when riding the bicycle over bumps, ruts, rocks, potholes, and / or other obstacles. These suspension components include components for the rear and / or front wheel suspension. For example, some bicycles include a front fork with telescopic legs equipped with a spring and / or damper system. General summary

[0003] An exemplary front fork for a bicycle includes a lower tube having a first upper end and a first lower end opposite the first upper end. The lower tube defines an interior region. The interior region is for receiving a volume of oil. A bushing in the lower tube is coupled to an interior surface of the lower tube. An upper tube has a second upper end and a second lower end opposite the second upper end. The second lower end of the upper tube is disposed within the lower tube. The upper tube is in sliding contact with the bushing. The upper and lower tubes are telescopically arranged and movable between a fully extended position and a fully retracted position. The upper tube has a recess that extends partially into an exterior surface of the upper tube.The recess serves to collect a quantity of oil when the upper tube is moved into the lower tube. The recess serves to distribute the quantity of oil to the bushing when the upper and lower tubes are moved to the fully extended position.

[0004] An exemplary front fork for a bicycle includes a lower tube having an inner surface extending from a first upper end of the lower tube to a first lower end of the lower tube. The first upper end is disposed opposite the first lower end. The lower tube is for receiving a volume of oil. A bushing in the lower tube is coupled to the inner surface. An upper tube has an outer surface extending from a second upper end of the upper tube to a second lower end of the upper tube. The second lower end is disposed opposite the second upper end. The upper tube and the lower tube are telescopically arranged with the second lower end of the upper tube inserted into the lower tube. The upper tube and the lower tube are movable between a loaded position and a fully retracted position.The upper tube has a feature on its outer surface to guide a quantity of oil when the upper and lower tubes are moved to the fully retracted position. The feature is located on or above the bushing in the loaded position. Short description of the drawings Fig. 1 is a side view of an exemplary bicycle in which one of the exemplary front forks disclosed herein may be employed. Fig. 2 is a perspective view of an exemplary front fork that may include the exemplary features disclosed herein. Fig. 3A is a cross-sectional view of the exemplary front fork of Fig. 2 along line AA from Fig. 2 in a fully extended position. Fig. Figure 3B is an enlarged view of the section in Fig. 3A and shows an exemplary upper tube positioned relative to an exemplary lower tube. Fig. 3C is another cross-sectional view of the exemplary front fork of Fig. 2 in a fully retracted position. Fig. 3D is an enlarged view of the section in Fig. 3C and shows an example lubricating oil between the example upper tube and the example lower tube. Fig. Figure 4A illustrates the example upper tube, example features, and example bushings in the fully extended position. Fig. 4B is an enlarged view of the section in Fig. 4A and shows the example features positioned relative to one of the example sockets. Fig. 5 illustrates the example upper tube, example features, and example bushings in the fully retracted position. Fig. Figure 6A is a side view of the exemplary upper tube of Fig. 3A-5. Fig. 6B is an enlarged view of the section in Fig. 6A and shows an arrangement of the exemplary features. Fig. Figure 7A is a side view of the exemplary upper tube with an arrangement of features that is smaller than that shown in Fig. 6 shown arrangement. Fig. 7B is an enlarged view of the section in Fig. 7A and shows the exemplary features arranged in an array. Fig. 8A, Fig. 8B, Fig. 8C, Fig. 8D, Fig. 8E and Fig. 8F illustrate example features of different shapes and / or sizes that may be implemented on the example top tube. Fig. 9A and Fig. 9B illustrate tube sections with additional features that can be implemented on the example upper tube.

[0005] In general, the same reference numerals are used in the drawing(s) and the accompanying written description to refer to the same or similar parts. The figures are not necessarily to scale. Instead, the thickness of the layers or regions in the drawings may be exaggerated. Although the figures depict layers and regions with clear lines and boundaries, some or all of these lines and / or boundaries may be idealized. In actuality, the boundaries and / or lines may be indistinguishable, blended, and / or irregular.

[0006] The terms "first," "second," "third," etc., are used herein to refer to multiple elements or components that may be referred to separately. Unless otherwise stated or apparent from the context of use, these terms have no significance as to priority or chronological order, but merely serve to identify multiple elements or components to facilitate understanding of the disclosed examples. According to some embodiments, the term "first" may be used to refer to one element in the detailed description, while a different term, such as "second" or "third," may be used for the same element in a claim. In such cases, such terms are used to refer to multiple elements or components merely for convenience. Detailed description

[0007] Disclosed herein are example front forks that may be used in a vehicle such as a bicycle. An example front fork disclosed herein connects a front wheel and handlebars to the frame of the bicycle (e.g., via a head tube). The front fork is a suspension component having a first leg and a second leg formed by first and second upper tubes (sometimes referred to as leg portions) telescopically disposed with first and second lower tubes, respectively. The first and second upper tubes are coupled to the frame (e.g., via a crown and steerer tube), and the first and second lower tubes are coupled to the front wheel. The upper tubes and lower tubes extend and retract as the bicycle travels over bumps and obstacles. The front fork has bushings inside the lower tubes.The bushings serve to align the upper and lower tubes and provide a low-friction sliding surface between the upper and lower tubes. The front fork may include a damper and a spring, such as an air spring, that cooperate to absorb shock impulses. According to some embodiments, the damper is disposed in the first upper and lower tubes of the first leg, and the air spring is disposed in the second upper and lower tubes of the second leg.

[0008] A suspension fork acts as a filter between rough terrain and the rider's body. Fine-tuning the suspension fork's filter includes controlling damping, spring rate, and stiffness / vibration. With suspension forks, increased system friction can change the damping force, making the filter less effective and creating an unnecessarily harsh ride. A major factor in system friction in a suspension fork is the interface between the upper tubes and the bushings. This interface creates a certain breakaway force that must be overcome before the upper and lower tubes move. Over time, this friction can loosen the fit between the upper tubes and their bushings. The friction at these interfaces (between the upper tubes and their bushings) can be felt by the rider on the handlebars. Therefore, some front forks require a certain amount of lubricant, e.g.Oil is applied to the inside of the fork's lower tube. The oil lubricates the sliding surfaces to ensure smooth sliding movement between the upper and lower tubes. However, as a structural interface, the upper tubes and bushings are designed to fit tightly together, leaving only a small (i.e., minimal) space for the lubricating oil. Therefore, the oil in the lower tube(s) is not always distributed effectively enough to properly lubricate the interface between the upper tubes and the bushings.

[0009] Disclosed herein are example front forks having one or more features (e.g., recesses, indentations, cavities, grooves, etc.) that enhance the distribution of lubricant (e.g., oil) at the interface between the upper tube and an associated bushing. These example features are defined by a discontinuous and / or interrupted geometry on the outer surface of the upper tube that can contain a specific amount of lubricating oil. An interior region of the lower tube can hold or otherwise contain a volume (e.g., a pool) of the lubricating oil. When the upper and lower tubes compress or move to a fully retracted position (e.g., in response to a pressure application to the front fork), the upper tube is submerged in the lubricating oil, and the features on the upper leg collect and retain a specific amount of lubricating oil.For example, the features described herein may be indentations shaped to retain a specific amount of oil (e.g., the oil flows / overflows into the indentations). The features (on the outer surface of the upper tube) retain a specific amount of oil as the upper tube moves relative to the lower tube. Therefore, as the upper and lower tubes expand or move to a fully extended position, the portion of the upper tube with the features slides along the bushing, transferring the amount of lubricating oil to the inner surface of the bushing. This ensures proper lubrication at the interface between the bushing and the outer surface of the upper tube. Over time, as the front fork continues to extend and retract, the exemplary features disclosed herein may continuously supply lubricating oil to the interface between the upper tube and the associated bushing.Such a lubrication effect can mitigate frictional effects that could otherwise deteriorate the bushing's fit when the top tube moves relative to the down tube. In return, the rider enjoys a smoother ride throughout the life of their bike.

[0010] About the characters: Fig. 1 is a side view of an exemplary human-powered vehicle in which the exemplary front forks disclosed herein may be employed. According to this embodiment, the vehicle is a possible type of bicycle 100, e.g., a mountain bike. In the illustrated example, the bicycle 100 includes a frame 102 and a front wheel 104 and a rear wheel 106 rotatably coupled to the frame 102. In the illustrated example, the front wheel 104 is coupled to the front end of the frame 102 via a front fork 108. A frontward and / or forward direction of travel or orientation of the bicycle 100 is indicated by the direction of arrow A in Fig. 1. A forward direction of movement for the bicycle 100 is therefore indicated by the direction of arrow A.

[0011] In the example shown by Fig. 1, the bicycle 100 includes a saddle 110 coupled to the frame 102 (e.g., near the rear end of the frame 102 relative to the forward direction A) via a seat post 112. The bicycle 100 further includes a handlebar 114 coupled to the front fork 108 (e.g., near a front end of the frame 102 relative to the forward direction A) to enable the bicycle 100 to be steered. The bicycle 100 is shown on a riding surface 116. The riding surface 116 may be any riding surface, such as the ground (e.g., a dirt path, sidewalk, road, etc.), a man-made structure above the ground (e.g., a wooden ramp), and / or another surface.

[0012] In the illustrated example, the bicycle 100 has a drivetrain 118 including a crank assembly 120. The crank assembly 120 is operatively coupled via a chain 122 to a sprocket assembly 124 attached to a hub 126 of the rear wheel 106. The crank assembly 120 includes at least one, typically two, crank arms 128 and pedals 130, and at least one front sprocket or chainring 132. A rear gear-changing device 134, e.g., a derailleur, is disposed on the rear wheel 106 to move the chain 122 onto various sprockets of the sprocket assembly 124. Additionally or alternatively, the bicycle 100 may include a front gear-changing device to move the chain 122 through the gears on the chainring 132.

[0013] The exemplary bicycle 100 includes a suspension system with one or more suspension components. According to this embodiment, the front fork 108 is embodied as the front suspension component. The front fork 108 is or includes a shock absorber with a spring and a damper. In the illustrated example, the bicycle 100 further includes a rear suspension component 136, which is a shock absorber, referred to herein as a rear shock absorber 136. The rear shock absorber 136 is coupled between two portions of the frame 102, including a swingarm 138 coupled to the rear wheel 106. The front fork 108 and the rear shock absorber 136 absorb shocks and vibrations during travel of the bicycle 100 (e.g., when traveling over rough terrain).According to further embodiments, the front fork 108 and / or the rear shock absorber 136 may be integrated into the bicycle 100 in other configurations or arrangements. Furthermore, according to further embodiments, the suspension system may utilize only one suspension component (e.g., only the front fork 108) or more than two suspension components (e.g., an additional suspension component on the seatpost 112) in addition to or alternatively to the front fork 108 and the rear shock absorber 136.

[0014] Although the Fig. 1 is a mountain bike, the example front forks disclosed herein may also be used on other types of bicycles. For example, the disclosed front forks may be used on road bicycles, as well as bicycles with mechanical (e.g., cable, hydraulic, pneumatic, etc.) and non-mechanical (e.g., wired, wireless) drive systems. The disclosed front forks may also be used on other types of human-powered two-, three-, and four-wheeled vehicles. Furthermore, the example front forks may be used on other types of vehicles, such as motor vehicles (e.g., motorcycles, cars, trucks, etc.).

[0015] Fig. 2 is a perspective view of an exemplary front fork 200 (a suspension component) used as front fork 108 on the bicycle 100 of Fig. 1 can be used. In the Fig. 2, the front fork 200 comprises a steerer tube 201, a crown 202, a first leg 203 and a second leg 205. The first leg 203 comprises a first tube 204 and a second tube 208, and the second leg 205 comprises a third tube 206 and a fourth tube 210. Based on the Fig. 2, the first and third tubes 204, 206 are referred to herein as the first and second upper tubes 204, 206 (sometimes referred to as leg sections or stanchions), respectively, and the second and fourth tubes 208, 210 are referred to herein as the first and second lower tubes 208, 210 (sometimes referred to as leg sections or down tubes). The first and second upper tubes 204, 206 may collectively be referred to as the upper tube assembly, and the first and second lower tubes 208, 210 may collectively be referred to as the lower tube assembly. The steerer tube 201 is connected to the frame 102 ( Fig. 1) and the handlebar 114 ( Fig. 1). The first and second upper tubes 204, 206 are coupled via the crown 202. The first and second lower tubes 208, 210 are coupled via an elbow 211 (sometimes referred to as a fork stay or stabilizer). The first and second lower tubes 208, 210 each have a front wheel attachment portion 212, 214, e.g., holes (e.g., eyelets) or dropouts, to mount the exemplary wheel (e.g., the front wheel 104 ( Fig. 1)) to the front fork 200. The first and second upper tubes 204, 206 are slidably received within the first and second lower tubes 208, 210, respectively. Thus, the first and second upper tubes 204, 206 form a telescopic assembly with the first and second lower tubes 208, 210, respectively. During a compression stroke, the first and second upper tubes 204, 206 move into or toward the first and second lower tubes 208, 210, respectively (e.g., to a fully retracted position). During a rebound stroke, the first and second upper tubes 204, 206 move out of or away from the first and second lower tubes 208, 210, respectively (e.g., to a loaded or fully extended position).

[0016] Fig. 3A is a cross-sectional view of the exemplary front fork 200 taken along line AA of Fig. 2 in a fully extended position. Fig. 3B is an enlarged view of section 300 of Fig. 3A and shows the second upper tube 206 relative to the second lower tube 210. Fig. Figure 3C is another cross-sectional view of the exemplary front fork 200 in a fully retracted position. Fig. 3D is an enlarged view of section 301 of Fig. 3C and shows lubricating oil 302 between the second upper tube 206 and the second lower tube 210. The front fork 200 can be moved to any position between the fully extended ( Fig. 3A) and the fully retracted position ( Fig. 3C). When installed on a bicycle, the front fork 200 typically does not reach the fully extended position, but instead is always slightly retracted due to the weight of the frame 102 and / or the rider. This slightly retracted position is referred to herein as the loaded position, but may also be referred to as the normal operating position or sag position. The front fork 200 therefore typically extends and retracts between the loaded position and the fully retracted position. According to some embodiments, the front fork 200 includes one or more internal stops or structures that limit movement of the tubes 204, 206, 208, 210 beyond the fully extended and retracted positions.

[0017] As in Fig. 3A and Fig. 3C, the first upper tube 204 includes a first end 303, referred to herein as a first upper end 303, and a second end 304 opposite the first upper end 303, referred to herein as a first lower end 304. The first upper tube 204 is coupled (e.g., press-fit) to the crown 202 at or near the first upper end 303. The first lower tube 208 includes oppositely disposed first and second ends 306, 308, referred to herein as a second upper end 306 and a second lower end 308 opposite the second upper end 306. The first lower end 304 of the first upper tube 204 is disposed within the first lower tube 208. The first upper end 303 of the first upper tube 204 and the second lower end 308 of the first lower tube 208 form the first and second distal ends of the suspension component. In the compression stage (e.g., movement toward the fully retracted position in Fig. 3C), the first upper end 303 (the first distal end) and the second lower end 308 (the second distal end) are moved towards each other, and during extension or rebound (e.g., movement toward the fully extended position in Fig. 3A), the first upper end 303 and the second lower end 308 are moved away from each other. In this way, the first upper and lower tubes 204, 208 form a telescopic arrangement. The first upper and lower tubes 204, 208 are movable along a first translation axis 310 between the fully extended position ( Fig. 3A) and the fully retracted position ( Fig. 3C). The first upper and lower tubes 204, 208 define an interior region 312. In the illustrated example, the front fork 200 has a volume of oil 302 in the interior region 312. The volume of oil 302 is located near the second lower end 308 of the first lower tube 208. Further, an inner surface 314 of the first lower tube 208 extends from the second upper end 306 to the second lower end 308, and an outer surface 316 of the first upper tube 204 extends from the first upper end 303 to the first lower end 304. The front fork 200 includes one or more bushings, disclosed in detail herein, that form a seal between the inner surface 314 of the first lower tube 208 and the outer surface 316 of the first upper tube 204.

[0018] The second upper and lower tubes 206, 210 are similarly arranged. The second upper tube 206 has a first upper end 318 (e.g., a first end) and a first lower end 320 (e.g., a second end) opposite the first upper end 318. The second lower tube 210 has a second upper end 322 (e.g., a first end) and a second lower end 324 (e.g., a second end) opposite the second upper end 322. The second upper tube 206 is coupled to the crown 202 at or near the first upper end 318, and the first lower end 320 of the second upper tube 206 is disposed within the second lower tube 210 (e.g., inserted therein, extending into it, etc.). In this way, the second upper and lower tubes 206, 210 form a telescopic arrangement. The second upper and lower tubes 206, 210 are movable along a second translation axis 326.The second upper and lower tubes 206, 210 define an interior region 328 containing a volume of oil 302. The volume of oil 302 is located adjacent the second lower end 324 of the second lower tube 210. Further, an inner surface 329 of the second lower tube 210 extends from the second upper end 322 to the second lower end 324, and an outer surface 330 of the second upper tube 206 extends from the first upper end 318 to the first lower end 320. The front fork 200 includes one or more bushings, disclosed in detail herein, that form a seal between the inner surface 329 of the second lower tube 210 and the outer surface 330 of the second upper tube 206.

[0019] As in Fig. 3A and Fig. 3C, the front fork 200 includes upper and lower bushings 332, 334 in the first lower tube 208. The upper and lower bushings 332, 334 are coupled to the inner surface 314 of the first lower tube 208. For example, the upper and lower bushings 332, 334 may be press-fitted into corresponding glands on the inner surface 314. The upper and lower bushings 332, 334 thus remain in a fixed position relative to the first lower tube 208. The upper bushing 332 is positioned between the second upper end 306 of the first lower tube 208 and the lower bushing 334. Furthermore, the upper and lower bushings 332, 334 are axially spaced apart from each other along a longitudinal axis (e.g., the first translation axis 310) of the first lower tube 208. The upper and lower bushings 332, 334 are in contact with the outer surface 316 of the first upper tube 204.The upper and lower bushings 332, 334 form two contact points to ensure that the first upper and lower tubes 204, 208 remain axially aligned and provide a low-friction interface to allow the upper and lower tubes 204, 208 to slide smoothly relative to each other. Similarly, the front fork 200 includes upper and lower bushings 336, 338 in the second lower tube 210 that are coupled to the inner surface 329 of the second lower tube 210. The upper bushing 336 is positioned between the second upper end 322 of the second lower tube 210 and the lower bushing 338. Further, the upper and lower bushings 336, 338 are axially spaced apart from each other along a longitudinal axis (e.g., the second translation axis 326) of the second lower tube 210. The upper and lower bushings 336, 338 are in contact with the outer surface 330 of the second upper tube 206.

[0020] In the illustrated example, the front fork 200 includes both a spring 340 and a damper 342. According to this embodiment, the spring 340 is disposed in and / or otherwise integrated with the second upper and lower tubes 206, 210, and the damper 342 is disposed in and / or otherwise integrated with the first upper and lower tubes 204, 208. According to further embodiments, the spring 340 may be disposed in and / or otherwise integrated with the first upper and lower tubes 204, 208, and the damper 342 is disposed in and / or otherwise integrated with the second upper and lower tubes 206, 210. The spring 340 is configured to resist compression of the first and second upper ends 303, 318 toward the first and second lower ends 308, 324 and to compress the tubes 204, 206, 208, 210 after compression ( Fig. 3C) towards the fully extended position ( Fig. 3A). The damper 342 is configured to limit the rate at which the compression / expansion occurs and / or otherwise absorb vibrations.

[0021] As shown in the enlarged views of Fig. 3B and Fig. 3D, the second upper tube 206 includes features that improve oil distribution. In particular, the second upper tube 206 according to this embodiment includes a plurality of recesses 344 that extend partially into the outer surface 330 of the second upper tube 206. The recesses 344 may have various shapes, sizes, and / or patterns, as disclosed in detail herein. As shown in Fig. 3D, the recesses 344 collect (e.g., guide, contain, accumulate, etc.) an amount of the oil 302 when the second upper tube 206 is moved into the second lower tube 210 (e.g., toward the fully retracted position). The second lower tube 210 contains a predetermined amount or level of the oil 302 such that the lower portion of the second upper tube 206 is at least partially submerged in the oil 302 when the second upper tube 206 is moved into the second lower tube 210. Inserting the second upper tube 206 moves at least some of the oil 302 into the annular space or gap between the inner surface 329 of the second lower tube 210 and the outer surface 330 of the second upper tube 206. Thus, the portion (with the recesses 344) of the second upper tube 206 is coated or covered with the oil 302.Accordingly, the oil 302 can flow / overflow into the recesses 344 when the second upper tube 206 is inserted into the second lower tube 210.

[0022] The recesses 344 can individually retain an amount of the oil 302 when the front fork 200 moves back toward the fully extended position. For example, when the second upper tube 206 and the second lower tube 210 return / move toward the fully extended position ( Fig. 3A), the second upper tube 206 guides the oil 302 retained in the recesses 344. As in the embodiment of Fig. 3B, at least some of the recesses 344 move past the upper and lower bushings 336, 338 as they move to the fully extended position or a loaded position, thereby wetting the bushings 336, 338 with the oil 302. Thus, the recesses 344 help convey (e.g., distribute, spread, guide, etc.) the oil 302 to the bushings 336, 338, ensuring that the bushings 336, 338 remain lubricated and can provide a smooth interface for sliding. In the fully extended position or another loaded position, the lower bushing 338 at least partially covers at least one of the recesses 344. In the fully extended position or other loaded position, at least one of the recesses 344 is located at (e.g., at the same radial location) or above the lower bushing 338.This ensures that at least one of the recesses 344 meets or moves past the lower bushing 338 to distribute the oil to the lower bushing 338 when the front fork 200 extends. According to some embodiments, in the fully extended position or other loaded position, at least one of the recesses 344 may be located at or above the upper bushing 336. This ensures that at least one of the recesses 344 meets or moves past the upper bushing 336 to distribute the oil to the upper bushing 336 when the front fork 200 extends.

[0023] Although the recesses 344 are described in connection with the second upper tube 206 and the second lower tube 210, the first upper tube 204 may also include the recesses 344 to guide and distribute the oil 302 to the bushings 332, 334. Therefore, according to some embodiments, both lower tubes 208, 210 may include recesses. Over time, as the front fork 200 continues to be subjected to impacts that move the upper tubes 204, 206 and the lower tubes 208, 210 between the fully extended position ( Fig. 3A) and the fully retracted position ( Fig. 3C), the recesses 344 continuously supply the oil 302 to the bushings 332, 334, 336, 338. As in Fig. 3B and Fig. 3D, the recesses 344 extend radially from the outer surface 330 to a central axis (e.g., the second translation axis 326) of the second upper tube 206. In the illustrated example, the recesses 344 taper or decrease in size radially toward the central axis of the second upper tube 206. Cross-sections of the recesses 344 are thus generally triangular or conical. According to one embodiment, the recesses 344 may have other shapes, cross-sectional shapes, orientations, sizes, etc., as described below in connection with Fig. 4A-9B are explained in more detail.

[0024] Fig. 4A illustrates the second upper tube 206 and the upper and lower bushings 336, 338 in their respective positions relative to the second upper tube 206 in the Fig. 3A and Fig. 3B shown fully extended position. The second lower tube 210 ( Fig. 2) has been removed for clarity. Fig. 4B is an enlarged cross-sectional view of section 400 in Fig. 4A and illustrates some of the recesses 344 positioned relative to the upper bushing 336. Fig. 5 illustrates the second upper tube 206 and the upper and lower bushings 336, 338 in their respective positions relative to the second upper tube 206 in the Fig. 3C and Fig. 3D shown fully retracted position. The oil level line is also in Fig. 5 shown.

[0025] According to the embodiment of Fig. 4A, Fig. 4B and Fig. 5, the recesses 344 are arranged in an array distributed over the outer surface 330 of the second upper tube 206. According to some embodiments, the second upper tube 206 may include only one of the recesses 344. According to one embodiment, as shown in Fig. 4A, Fig. 4B and Fig. 5, the second upper tube 206 may include a plurality or array of recesses 344. For example, the second upper tube 206 includes a plurality of recesses 344 distributed around the circumference of the outer surface 330 of the second upper tube 206. According to some embodiments, the plurality of recesses 344 are positioned at various locations around the circumference of the outer surface 330. The second upper tube 206 may include any number of recesses 344 (e.g., 10, 20, 30, 100, 500, etc.). According to some embodiments, the array of recesses 344 is arranged in a pattern. As shown in Fig. 4A and Fig. 5, the arrangement of the recesses 344 is arranged, for example, in a spiral pattern 402. In particular, the recesses 344 are distributed circumferentially around and axially along the outer surface 330 of the second upper tube 206. The pattern 402 ensures that a sufficient number of recesses 344 are present to distribute the oil to the upper and lower bushings 336, 338 at all or most locations along the circumference. According to some embodiments, the arrangement of the recesses 344 extends a distance along a length of the second upper tube 206 in a direction from the first lower end 320 to the first upper end 318, as described in connection with Fig. 6A and Fig. 6B. According to one embodiment, according to further embodiments, the second upper tube 206 includes a plurality of recesses 344 positioned at a location along the circumference between the first lower end 320 and the first upper end 318, as described in connection with Fig. 7A and Fig. 7B.

[0026] According to Fig. 4A, the pattern 402 of the recesses 344 extends along a portion of the second upper tube 206 from the lower bushing 338 (e.g., a lower edge 404 of the lower bushing 338) to the upper bushing 336 (e.g., an upper edge 406 of the upper bushing 336) when the second upper tube 206 and the second lower tube 210 ( Fig. 2) are in the fully extended position. The recesses 344 can thus direct the oil 302 ( Fig. 3A, Fig. 3C and Fig. 3D) to both the upper bushing 336 and the lower bushing 338 when the second upper tube 206 and the second lower tube 210 ( Fig. 2) to the fully extended position. In particular, the recesses 344 can distribute the oil 302 to an interface between the outer surface 330 of the second upper tube 206 and the inner surfaces of the bushings 336, 338. As shown in Fig. 4B, the upper bushing 336 is radially aligned with or overlaps at least one of the recesses 344. When the second upper tube 206 and the second lower tube 210 ( Fig. 2) move to the fully extended position, the recesses 344 can therefore spread the oil 302 along the inner surfaces (e.g., an inner surface 408) of the bushings 336, 338. When the second upper tube 206 and the second lower tube 210 ( Fig. 2) to the fully retracted position ( Fig. 5), the recesses 344 can drain the oil 302 from the interior 328 of the second lower tube 210 ( Fig. 3C). According to some embodiments, the arrangement of the recesses 344 does not extend beyond the upper bushing 336 ( Fig. 4A) when the second upper tube 206 and the second lower tube 210 ( Fig. 2) in the fully extended position. According to such embodiments, none of the recesses 344 are removed from the wiper at the second upper end 322 ( Fig. 3) of the second lower tube 210 ( Fig. 3A) out or beyond and exposed to the atmosphere.

[0027] In the illustrated embodiment, the recesses 344 are arranged such that at least two of the recesses 344 overlap along a radial plane. For example, in Fig. 5 illustrates an exemplary plane 500 extending in a radial direction perpendicular to the central axis of the second upper tube 206. At least two of the recesses 344 are intersected by the radial plane 500. The bushings 336, 338 typically form discrete annular contact rings with the outer surface 330 of the second upper tube 206. For example, the lower edge 404 of the lower bushing 338 forms an annular contact ring with the outer surface 330 of the second upper tube 206. The fact that the recesses 344 are spaced apart as mentioned above ensures that one of the recesses 344 exits the annular contact ring and simultaneously another of the recesses 344 enters the contact ring. This reduces or eliminates the possibility of audible noise being generated in the event of discrete discontinuities or gaps between the recesses 344.

[0028] Each recess 344 is formed by an edge on the outer surface 330 and an inner surface that extends radially inward to an indentation depth. The edge may be a continuous edge, e.g., in a circular recess 344, or may comprise multiple individual edges (e.g., an upper edge, a lower edge, a side edge), e.g., in a triangular or square recess. Likewise, the inner surface of the recess 344 may be a continuous surface or multiple individual surfaces. According to the Fig. 5, the recesses 344 are embodied as depressions, which are small individual troughs in the outer surface 330 of the second upper tube 206. According to this embodiment, the recesses 344 are circular, but may be shaped differently according to further embodiments. According to some embodiments, the recesses 344 may have a diameter of 0.2 to 3 millimeters (mm) and a depth that is approximately half the diameter. For example, the recesses 344 may have a diameter of approximately 1 mm (e.g., ± 0.1 mm) and a depth of approximately 0.5 mm (e.g., ± 0.1 mm). According to some embodiments, the above range ensures that the recesses 344 are large enough to capture an amount of oil, but not too large that the oil is not adequately retained.According to further embodiments, the recesses 344 may be larger or smaller than the above-mentioned range. According to some embodiments, the depth of the recesses 344 may be based on the wall thickness of the first and / or second upper tubes 204, 206. For example, if the second upper tube 204 has a wall thickness of 2 mm, the depth of the recesses 344 may not be more than 2 mm. According to some embodiments, the depth of the recesses 344 may be proportional to the wall thickness of the first and second upper tubes 204, 206. For example, the depth of the recesses 344 is designed to be a certain percentage, e.g., 10%, of the wall thickness of the second upper tube 206, so that it is large enough to collect an amount of oil. The second upper tube 206 with a wall thickness of 5 mm can therefore have recesses 344 with a depth of 0.5 mm (e.g. (5)(0.1) = 0.5).According to some embodiments, the recesses 344 are formed by an indentation process, e.g., with a ball press, a peening machine, a rotary press, or a punching machine. According to further embodiments, the recesses 344 may be formed by a subtractive machining process, e.g., with a drilling machine, a laser etching machine, or a waterjet machine. According to further embodiments, the recesses 344 may be formed by casting during the manufacture of the second upper tube 206.

[0029] Fig. 6A is a side view of the second upper tube 206 of Fig. 3A-5. Fig. Figure 6B is an enlarged view of section 600 of Fig. 6A. In particular, Fig. 6B shows the arrangement of the recesses 344 arranged in the spiral pattern 402. As in Fig. 6A, the second upper tube 206 has an overall length 601. According to this embodiment, the arrangement of the recesses 344 is formed on a lower portion of the second upper tube 206 starting at the first lower end 320 and extending a length (e.g., spacing, extent, etc.) 602. The length 602 is less than the length 601. Therefore, only a portion of the second upper tube 206 has the recesses 344, while the remainder of the second upper tube 206 is smooth and has no recesses. According to this embodiment, the recesses 344 are distributed over approximately one-third (1 / 3) of the length 601 of the second upper tube 206. According to further embodiments, the recesses 344 may be distributed over approximately half (1 / 2) of the length 601, three-quarters (3 / 4) of the length 601, or another amount or portion of the length 601.Alternatively, according to some embodiments, the entire length 601 of the second upper tube 206 may include recesses 344.

[0030] Fig. Figure 7A is a side view of the second upper tube 206 having a smaller section or shorter length with cutouts 344. Fig. Figure 7B is an enlarged view of section 700 of Fig. 7A. According to this embodiment, the arrangement of the recesses 344 does not extend to the lower end 320 of the second upper tube 206. The second upper tube 206 thus has a section 701a without recesses above the arrangement and a section 701b without recesses below the arrangement. According to this embodiment, the arrangement of the recesses 344 extends over a length 702 of the total length 601, which is less than the length 602 of the Fig. 6A and Fig. 6B. A first portion of the outer surface 330 thus has the arrangement of the recesses 344. A second portion of the outer surface 330 extends in a first direction (e.g., along the second translation axis 326 ( Fig. 3A)) away from the first portion, and a third portion of the outer surface 330 extends in a second direction away from the first portion, the second direction being opposite to the first direction.

[0031] Fig. 8A, Fig. 8B, Fig. 8C, Fig. 8D, Fig. 8E and Fig. 8F illustrate tube sections 800, 802, 804, 806, 808, 810 having various cutout shapes and patterns formed on the first upper tube 204 and / or the second upper tube 206 of Fig. 3A-3D. According to some embodiments, the tube sections 800, 802, 804, 806, 808, 810 represent the entire length of a tube (e.g., of the second upper tube 206 from the first lower end 320 to the first upper end 318). According to further embodiments, the tube sections 800, 802, 804, 806, 808, 810 may represent a partial length of a tube. For example, the tube sections 800, 802, 804, 806, 808, 810 may represent a portion of the second upper tube 206 extending from the first lower end 320 to the first upper end 318. According to one embodiment, the tube sections 800, 802, 804, 806, 808, 810 may, according to further embodiments, represent a portion of the second upper tube 206 at a location along the circumference between the first lower end 320 and the first upper end 318. Similar to the embodiments described above in connection with Fig. 6A, Fig. 6B, Fig. 7A and Fig. 7B, the array of regions or plurality of recesses (e.g., recesses 344) may extend only along a portion of the upper tubes 204, 206.

[0032] The pipe section 800 in Fig. 8A illustrates an arrangement of oval recesses 812. Further, the recesses 812 are arranged in a first orientation (e.g., angle, inclination, etc.) with respect to an outer surface 814 of the tube section 800. In particular, the recesses 812 are oriented in a direction in which the oval shapes are aligned with the axial direction of the tube section 800. According to Fig. 8B, the tube section 802 has an arrangement of oval recesses 816 which correspond to the recesses 812 of Fig. 8A. In this illustrated embodiment, each of the recesses 816 of Fig. 8B in a second orientation relative to an outer surface 818 of the tube portion 802, wherein the second orientation differs from the first orientation. In particular, the recesses 816 are oriented in a direction in which the oval shapes are angled relative to the axial direction of the tube portion 802 (e.g., by 45 degrees (°)). According to the Fig. 8B, a first 820 of the recesses 816 and a second 822 of the recesses 816 at least partially overlap or are intersected by a radial plane 824 associated with the tube section 802. According to some embodiments, the radial plane 824 can be defined by the annular contact ring of one of the bushings 336, 338 ( Fig. 3A, Fig. 3B, Fig. 3C, Fig. 4A and Fig. 5) and the outer surface 818 of the tube section 802. According to some embodiments, both the first 820 of the recesses 816 and the second 822 of the recesses 816 can direct the oil 302 to the lower bushing 338 ( Fig. 3A, Fig. 3B, Fig. 3C, Fig. 4A and Fig. 5) which defines the annular reference line or radial plane 824 when the tube section 802 is in the fully extended position ( Fig. 3A and Fig. 4A). The oil 302 ( Fig. 3A, Fig. 3C and Fig. 3D) may leak (e.g., overflow, flow, etc.) from the first 820 of the recesses 816 before leaking from the second 822 of the recesses 816. Alternatively, the first and second 820, 822 of the recesses 816 may retain different amounts of the oil 302 when the first and second 820, 822 contact / reach the radial plane 824.

[0033] Pipe section 804 of Fig. 8C illustrates an arrangement of hexagonal recesses 825. The tube section 806 of Fig. 8D illustrates an arrangement of differently sized circular recesses 826. For example, a first set of recesses 826 has a first size (e.g., circumference, depth, etc.) that is larger than a second size of a second set of recesses 826. The recesses 826 of the first set are paired with the recesses 826 of the second set, and the pairs are distributed across an outer surface 828 of the tube portion 806. For example, each of the recesses 826 of the first set is adjacent to one of the recesses 826 of the second set.

[0034] Pipe section 808 of Fig. 8E includes a first set of recesses 830 arranged in an array, a second set of recesses 832 arranged in an array, and a third set of recesses 834 arranged in an array. The recesses 830, 832, 834 have different sizes and / or shapes. For example, the first set of recesses 830 and the second set of recesses 832 are circular (e.g., a circular opening). The recesses 830 of the first set have a smaller diameter than the recesses 832 of the second set. The third set of recesses 834 has an oval shape (e.g., an oval opening) that is different from the shapes of the first and second sets of recesses 830, 832. The third set of recesses 834 in Fig. 8E is similar to the recesses 812, 816 in Fig. 8A-8B, but the third set of recesses 834 in Fig. 8E is arranged in a third orientation that differs from the first orientation of the recesses 812 ( Fig. 8A) and the second alignment of the recesses 816 ( Fig. 8B). In addition, the third orientation associated with the third set of recesses 834 is approximately perpendicular (e.g., at 2 degrees) to the first orientation of the recesses 812 in Fig. 8A.

[0035] Furthermore, the first set of recesses 830 is positioned at a first location on an outer surface 836 of the tube portion 808, the second set of recesses 832 is positioned at a second location on the outer surface 836, and the third set of recesses 834 is positioned at a third location on the outer surface 836. The first location associated with the first set of recesses 830 is adjacent to the second location associated with the second set of recesses 832 (in an axial direction along a longitudinal axis of the tube portion 808). Similarly, the second location associated with the second set of recesses 832 is adjacent to the third location associated with the third set of recesses 834 (in the axial direction along the longitudinal axis of the tube portion 808). According to some embodiments, the first location may be spaced from the second location. In other words, a portion of the outer surface 836 may separate the first set of recesses 830 from the second set of recesses 832.According to some embodiments, the first set of recesses 830 may extend a first length 837a along a length of the tube portion 808, the second set of recesses 832 may extend a second length 837b along a length of the tube portion 808, and the third set of recesses 834 may extend a third length 837c along a length of the tube portion 808. According to some embodiments, the first length 837a, the second length 837b, and the third length 837c are approximately equal (e.g., + / - 1 mm). According to some embodiments, the first length 837a differs from the second length 837b, the second length 837b differs from the third length 837c, and so on.

[0036] Pipe section 810 of Fig. Figure 8F illustrates an arrangement of first recesses 838 and second recesses 840. According to this embodiment, the first recesses 838 are circular and the second recesses 840 are oval. The first and second recesses 838, 840 of Fig. 8F are similar to the recesses 826 of Fig. 8D, however, two of the first recesses 838 are paired with two of the second recesses 840 to define a group of recesses 838, 840. The groups of recesses 838, 840 are distributed over an outer surface 842 of the tube portion 810.

[0037] Fig. 9A and Fig. 9B illustrate tube sections 900, 902 with additional features provided on the first upper tube 204 and / or the second upper tube 206 of Fig. 3A-3D can be implemented. According to Fig. 9A, the tube portion 900 includes an array or plurality of annular recesses 904 (e.g., grooves, trenches, etc.) that extend circumferentially around (e.g., describe, traverse, etc.) an outer surface 906 of the tube portion 900. The annular recesses 904 are arranged in an array distributed across the outer surface 906. Furthermore, the annular recesses 904 are axially spaced from one another along a longitudinal axis of the tube portion 900. As shown in Fig. As shown in Figure 9A, the annular recesses 904 are generally circular (surrounding the outer surface 906). According to further embodiments, the annular recesses 904 may have any general shape or path (e.g., curved, curved, zigzag, etc.) around the outer surface 906.

[0038] Pipe section 902 of Fig. 9B has an annular recess 908 that traverses an outer surface 910 of the tube section 902 in an oblique direction. In other words, the annular recess 908 forms a continuous spiral along the outer surface 910. According to further embodiments, the tube section 902 may have a plurality of annular recesses 908 that form an interrupted (e.g., dashed) spiral across the outer surface 910. According to the Fig. In the embodiment illustrated in Figure 9B, the annular recess 908 spirals around the outer surface 910 in a clockwise direction. According to one embodiment, the annular recess 908 may spiral around the outer surface 910 in a counterclockwise direction.

[0039] All in connection with Fig. The exemplary features disclosed in Figures 8A-8F and 9A-9B (e.g., recesses, grooves, etc.) may be formed by indentation processes, such as with a ball press, a peening machine, a rotary press, or a punching machine. According to further embodiments, the features may be formed by a subtractive machining process, such as with a drilling machine, a laser etching machine, or a waterjet machine. According to further embodiments, the features may be formed by casting during the manufacture of the second upper tube.

[0040] While the exemplary front fork 200 of Fig.2 comprises two legs, the front fork 200 may, according to further embodiments, be configured as a single-sided fork with only one of the legs. According to such an embodiment, the single leg may include a damper, a spring, or a combination of spring and damper. Any of the exemplary oil distribution features disclosed herein may be implemented in such a single-leg fork configuration. Although the oil distribution features disclosed herein are described in connection with a front suspension fork, any of the embodiments disclosed herein may also be implemented in connection with a different type of suspension component, e.g., the rear shock absorber 136. For example, rear shock absorbers having two tubes or body sections that are telescopically arranged may be employed. Any of the exemplary oil distribution features may also be implemented on one of the tubes of the shock absorber.

[0041] The terms "approximately" and "about" are used herein to account for potential deviations from actual items / values ​​that occur in real-world applications. For example, "approximately" and "about" may modify dimensions that may not be exact due to manufacturing tolerances and / or other real-world imperfections, as would be understood by those skilled in the art. For example, "approximately" and "about" may indicate that such dimensions may be within a tolerance range of + / - 10%, unless otherwise stated herein.

[0042] From the foregoing, it will be appreciated that exemplary systems, devices, articles of manufacture, and methods have been disclosed that reduce friction in a front fork of a bicycle by delivering lubricating oil to the interface between the upper tube(s) and the associated bushing. The disclosed embodiments reduce friction effects that might otherwise degrade the bushing fit as the upper tube moves relative to the lower tube. In turn, the rider experiences a smoother ride.

[0043] Exemplary front forks for bicycles are disclosed herein. The following sections provide various examples and example combinations of the examples disclosed herein.

[0044] Example 1 is a front fork for a bicycle. The front fork includes a lower tube having a first upper end and a first lower end opposite the first upper end, the lower tube defining an interior region, the interior region receiving a volume of oil, a bushing in the lower tube coupled to an interior surface of the lower tube, and an upper tube having a second upper end and a second lower end opposite the second upper end, the second lower end of the upper tube being disposed in the lower tube, the upper tube being in sliding contact with the bushing, the upper and lower tubes being telescopically arranged and movable between a fully extended position and a fully retracted position, the upper tube having a recess extending partially into an exterior surface of the upper tube, the recess serving to collect a volume of oil,when the upper tube is moved into the lower tube, and to distribute the amount of oil to the bushing when the upper and lower tubes are moved to the fully extended position.

[0045] Example 2 includes the front fork of Example 1, wherein the bushing at least partially covers the recess in the fully extended position.

[0046] Example 3 includes the front fork of any of Examples 1-2, wherein the recess is a depression.

[0047] Example 4 includes the front fork of any of Examples 1-3, wherein the recess is hexagonal, triangular, oval, or circular.

[0048] Example 5 includes the front fork of any of Examples 1-4, wherein the recess extends radially toward a central axis of the top tube, and wherein the size of the recess tapers radially toward the central axis.

[0049] Example 6 includes the front fork of any of Examples 1-5, wherein the recess is a first recess in an array of recesses, the array of recesses being distributed around the circumference of the outer surface of the top tube.

[0050] Example 7 includes the front fork of Example 6, wherein the array of recesses is arranged in a spiral pattern.

[0051] Example 8 includes the front fork of any of Examples 6-7, wherein the first recess and a second recess of the array of recesses have different shapes.

[0052] Example 9 includes the front fork of any of Examples 6-8, wherein the first recess and a second recess of the array of recesses are intersected by a radial plane perpendicular to a central axis of the top tube.

[0053] Example 10 includes the front fork of Example 9, wherein the bushing overlaps the first and second recesses in the fully extended position.

[0054] Example 11 includes the front fork of any of Examples 1-2, wherein the recess is an annular recess extending circumferentially around the outer surface of the top tube.

[0055] Example 12 includes the front fork of Example 11, wherein the annular recess is a first annular recess in an array of annular recesses, the array of annular recesses distributed over the outer surface of the top tube, the annular recesses being axially spaced from one another along a longitudinal axis of the top tube.

[0056] Example 13 includes the front fork of any of Examples 1-11, wherein the bushing is a first bushing, the front fork further comprising a second bushing coupled to the inner surface of the down tube, the second bushing positioned between the first bushing and the first upper end, the first and second bushings being axially spaced apart from each other along a longitudinal axis of the down tube, the recess being operable to distribute the amount of oil to the second bushing when the upper and lower tubes are moved to the fully extended position.

[0057] Example 14 includes the front fork of Example 1, further comprising at least one damper or spring in the upper and lower tubes.

[0058] Example 15 includes a front fork for a bicycle. The front fork includes a lower tube having an inner surface extending from a first upper end of the lower tube to a first lower end of the lower tube, the first upper end being disposed opposite the first lower end, the lower tube being operable to receive a volume of oil, a bushing in the lower tube, the bushing being coupled to the inner surface, and an upper tube having an outer surface extending from a second upper end of the upper tube to a second lower end of the upper tube, the second lower end being disposed opposite the second upper end, the upper and lower tubes being telescopically arranged, the second lower end of the upper tube being inserted into the lower tube, the upper and lower tubes being movable between a loaded position and a fully retracted position.wherein the upper tube has a feature on the outer surface for guiding a quantity of oil when the upper and lower tubes are moved towards the fully retracted position, the feature being located on or above the bushing in the loaded position.

[0059] Example 16 includes the front fork of Example 15, wherein the bushing is a first bushing, the front fork further comprising a second bushing coupled to the inner surface of the down tube, the second bushing positioned between the first bushing and the feature in the fully retracted position, the first and second bushings being axially spaced apart from each other along a longitudinal axis of the down tube.

[0060] Example 17 includes the front fork of any of Examples 15-16, wherein the feature is a groove in the outer surface, the groove traversing the outer surface in a slanted direction.

[0061] Example 18 includes the front fork of any of Examples 15-16, wherein the feature includes an array of recesses distributed to circumferentially surround the outer surface.

[0062] Example 19 includes the front fork of Example 18, wherein the array of recesses comprises a first set of recesses having a first shape and a second set of recesses having a second shape, the first set of recesses positioned at a first location on the outer surface and the second set of recesses positioned at a second location on the outer surface, the second location axially adjacent to the first location along a longitudinal axis of the top tube.

[0063] Example 20 includes the front fork of any of Examples 18-19, wherein a first portion of the outer surface includes the array of recesses, the front fork further including a second portion of the outer surface extending in a first direction away from the first portion and a third portion of the outer surface extending in a second direction away from the first portion, the second direction opposite the first direction.

[0064] The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not a complete description of all elements and features of devices and systems employing the structures or methods described herein. Many other embodiments will be apparent to those skilled in the art upon review of the disclosure. Other embodiments may be utilized and derived from the disclosure, so that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Furthermore, the illustrations are merely representative and may not be drawn to scale. Certain proportions in the illustrations may be exaggerated, while other proportions may be reduced.Accordingly, the disclosure and the figures are to be considered as illustrative rather than restrictive.

[0065] While this description contains numerous details, these should not be construed as limitations on the scope of the invention or the claimed subject matter, but rather as descriptions of features specific to particular embodiments of the invention. Certain features described in this description in connection with individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in connection with a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.Furthermore, where features are described above as operating in certain combinations and even originally claimed as such, one or more features from a claimed combination may in some cases be taken out of the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[0066] Although specific embodiments are illustrated and described herein, any arrangement that achieves the same or a similar purpose may be substituted for the illustrated embodiments. This disclosure is intended to cover all subsequent adaptations or variations of the various embodiments. Combinations of the above embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art upon review of the specification.

Claims

[1] Front fork for a bicycle, comprising: a lower tube having a first upper end and a first lower end opposite the first upper end, the lower tube defining an interior region for receiving a volume of oil; a bushing in the lower tube coupled to an inner surface of the lower tube; and an upper tube having a second upper end and a second lower end opposite the second upper end, the second lower end of the upper tube being disposed within the lower tube, the upper tube being in sliding contact with the bushing, the upper and lower tubes being telescopically disposed and movable between a fully extended position and a fully retracted position, the upper tube having a recess extending partially into an outer surface of the upper tube, the recess serving to collect an amount of oil when the upper tube is moved into the lower tube and to distribute the amount of oil to the bushing when the upper and lower tubes are moved to the fully extended position. [2] A front fork according to claim 1, wherein the bushing at least partially covers the recess in the fully extended position. [3] A front fork according to claim 1 or 2, wherein the recess is a depression. [4] A front fork according to any one of the preceding claims, wherein the recess is hexagonal, triangular, oval or circular. [5] A front fork according to any one of the preceding claims, wherein the recess extends radially toward a central axis of the upper tube and wherein the size of the recess tapers radially toward the central axis. [6] A front fork according to any one of the preceding claims, wherein the recess is a first recess in an array of recesses, the array of recesses being distributed around the circumference of the outer surface of the top tube. [7] A front fork according to claim 6, wherein the array of recesses is arranged in a spiral pattern. [8] A front fork according to claim 6 or 7, wherein the first recess and a second recess of the arrangement of recesses have different shapes. [9] A front fork according to any one of claims 6 to 8, wherein the first recess and a second recess of the array of recesses are intersected by a radial plane perpendicular to a central axis of the upper tube. [10] A front fork according to claim 9, wherein the bushing overlaps the first and second recesses in the fully extended position. [11] A front fork according to any one of the preceding claims, wherein the recess is an annular recess extending circumferentially around the outer surface of the upper tube. [12] A front fork according to claim 11, wherein the annular recess is a first annular recess in an array of annular recesses, the array of annular recesses being distributed over the outer surface of the upper tube, the annular recesses being axially spaced from one another along a longitudinal axis of the upper tube. [13] A front fork according to any one of the preceding claims, wherein the bushing is a first bushing, the front fork further comprising a second bushing coupled to the inner surface of the lower tube, the second bushing being positioned between the first bushing and the first upper end, the first and second bushings being axially spaced apart from each other along a longitudinal axis of the lower tube, the recess serving to distribute the amount of oil to the second bushing when the upper and lower tubes are moved to the fully extended position. [14] A front fork according to any one of the preceding claims, further comprising at least one damper or spring in the upper and lower tubes. [15] Front fork for a bicycle, comprising: a lower tube having an inner surface extending from a first upper end of the lower tube to a first lower end of the lower tube, the first upper end being disposed opposite the first lower end, the lower tube being operable to receive a volume of oil; a bushing in the lower tube, the bushing being coupled to the inner surface; and an upper tube having an outer surface extending from a second upper end of the upper tube to a second lower end of the upper tube, the second lower end being disposed opposite the second upper end, the upper and lower tubes being telescopically disposed, the second lower end of the upper tube being inserted into the lower tube, the upper and lower tubes being movable between a loaded position and a fully retracted position, the upper tube having a feature on the outer surface for guiding a quantity of oil when the upper and lower tubes are moved towards the fully retracted position, the feature being disposed on or above the bushing in the loaded position. [16] The front fork of claim 15, wherein the bushing is a first bushing, the front fork further comprising a second bushing coupled to the inner surface of the down tube, the second bushing being positioned between the first bushing and the feature in the fully retracted position, the first and second bushings being axially spaced apart from each other along a longitudinal axis of the down tube. [17] A front fork according to claim 15 or 16, wherein the feature is a groove in the outer surface, the groove traversing the outer surface in an oblique direction. [18] A front fork according to any one of claims 15 to 17, wherein the feature comprises an array of recesses distributed so as to circumferentially surround the outer surface. [19] A front fork according to claim 18, wherein the array of recesses comprises a first set of recesses having a first shape and a second set of recesses having a second shape, the first set of recesses being positioned at a first location on the outer surface and the second set of recesses being positioned at a second location on the outer surface, the second location being axially adjacent to the first location along a longitudinal axis of the upper tube. [20] A front fork according to claim 18 or 19, wherein a first portion of the outer surface has the arrangement of recesses, the front fork further comprising a second portion of the outer surface extending in a first direction away from the first portion and a third portion of the outer surface extending in a second direction away from the first portion, the second direction being opposite to the first direction.

Images