Originally Posted by
alhedges
Here's the issue: most folding bikes are compact in part because they have a low step-through frame and the rider is supported on a saddle attached to a very long seatpost. The seatpost acts like a long lever on the small seat tube. (And when there are frame problems on a folder, it is often because the seat tube cracks).
Most trail-a-bikes attach near the top of the seatpost, which, when combined with the weight of the rider, can potentially put a lot of levered force on the seat tube. Obviously, this is a bigger problem if you weigh 220 lbs and the bike has a weight limit of 240 lbs than it is if you weigh 140 lbs.
Listen to this man, he is correct.
A folding bike has a maximum rider weight limit largely because his weight tugs on that long seatpost. A trail-a-bike adds quite a bit more force to tug on that seatpost. This is potentially dangerous.
I suggest that you do *not* use a trail-a-bike with a long-seatpost folding bicycle.