Junior Member
I'd like to hook up my son's trail-a-bike to my Dahon, helios P-8 with 20 inch wheels. The Trail-a-Bike owner's manual recommends against using the trail-a-bike with 20inch wheels because the pedals many not clear the ground. Has anyone ever tried this? I don't understand why it wouldn't work if you just raised the attachment to a higher point on the seat post.
Redredrider,
You would indeed neet to raise the attachment to a higher point on the seatpost. However, there are two problems with that:
1. The Trail-a-bike attachment will slide down fairly quickly, unless you put a couple of tight pipe collars or a metal sleeve to prevent the attachment from sliding down.
2. Even if you solve the first problem, there is a question of leverage. Because the child may be leaning on one side or the other, the Trail-a-bike imposes a fairly high bending moment on the seatpost. If the Trail-a-bike is attached 15-20 cm above the seatpost clamp, the bending moment will induce fairly serious stress constraints in the seatpost and it will snap.
You would indeed neet to raise the attachment to a higher point on the seatpost. However, there are two problems with that:
1. The Trail-a-bike attachment will slide down fairly quickly, unless you put a couple of tight pipe collars or a metal sleeve to prevent the attachment from sliding down.
2. Even if you solve the first problem, there is a question of leverage. Because the child may be leaning on one side or the other, the Trail-a-bike imposes a fairly high bending moment on the seatpost. If the Trail-a-bike is attached 15-20 cm above the seatpost clamp, the bending moment will induce fairly serious stress constraints in the seatpost and it will snap.
Junior Member
Tried it this morning for the three mile ride and it seemed to work just fine. I made sure to attach the trail-a-bike so it was roughly the same height from the ground as when its on my 26in wheeled mtn bike and this solved any problem of the pedals not clearing the ground. I also don't take many sharp or fast turns with my 5 year old on the bakc. In terms of the seat post bending, Dahon Helios comes with a very sturdy seatpost of substantially greater diameter than the standard. don't see it bending. clamping a thin piece of rubber underneath the mounting mechanism, keeps it from slipping down the post.
