This arrangement is satisfactory of carrying or pulling one bag in each hand, however, not preferable, as having both hands tied up in carry luggage is inconvenient in any case.
However, many of these attempts are often ad-hoc in that they are attempts at merely
strapping on the carry-on bag to the larger piece of luggage, wherein the carry-on bag can shift position, knock the larger luggage off balance where it can tip over, or the carry-on can slide off the larger piece of luggage and possibly damage the valuable contents of the carry-on bag.
Another issue is that frequently occurs, is that the traveler will wait in line for check-in, to purchase food or drink, or another reason, thus setting the ad-hoc combined larger luggage and carry-on bag upon the surface in a static manner, where the combined larger luggage and carry-on are unbalanced and tip over, thus adding the inconvenience and hassle of potentially harming the bags contents, especially the high value contents of the smaller carry-on bag.
Further issues that exacerbate the dynamic stability problem with the larger piece of luggage trying to carry the ad-hoc attached smaller carry-on bag is that the smaller bag is typically quite dense in
mass, meaning that if it is full of electronic devices, it is quite heavy, especially due to the
laptop and battery, chargers, and so on, thus this denser
high weight carry-on bag is placed in the worst possible position being the typically on top of the larger lower weight density luggage, meaning that the top
heavy weight instability is made worse, that is especially noticeable when the traveler is making a turn and the larger bag on the bottom wants to tip over.
In addition, the stability of the combination low weight density lower larger bag is made worse by this larger bag typically having a two wheel setup typically puts the ad-hoc attached heavy carry-on bag at a greater distance from the surface due to the
hypotenuse effect of angling the larger bag on two wheels (as opposed to a four wheel arrangement), that does not have the
hypotenuse effect of increasing the distance of the carry-on bag weight from the surface.
Another issue is the pacing
cadence or stride of the traveler when they are walking and pulling the two wheeled tilted or angled luggage behind them, as when an individual normally walks, their arms naturally move in a counterbalancing
pendulum effect, which results in the two wheeled bag tending to oscillate back and forth as an individual pulls the angled two wheeled bag forward across a surface, this can effectuate a
pendulum effect upon causing the highest movement of the oscillating motion to occur at the carry-on bag, as it is the furthest from the pivot point, being the two wheels and surface interface.
What this results in is the
high density mass weight of the carry-on experiences the maximum movement leading to an ever higher potential dynamic
instability of the combination larger bag and the ad-hoc placed on top of the carry-on bag while being pulled across the surface by the traveler, leading potentially to increased potential for tip over's.
Note that in Thomas, all of the previously mentioned
instability issues are present, being the two wheeled design, placing the
high weight density items at the furthest distance from the surface, and the
cadence oscillating
pendulum issue.