Once the seat post is rewelded it should be OK. I ran it almost as hard as the worst places I can go. I will continue to watch the welds, but I think they are OK. The rear wheel might be a problem. I needed 268mm spokes but only had 265 so to compensate I used 16 mm brass nipples. One of the mountain bike forums had a discussion about using short spokes and long brass nipples and the consensus was that they had held up for all the people that tried it, except one guy that got a stick stuck in the spokes and it sheared off a bunch of the nipples. His lasted for a good while before they were sheared off. I always treat these posts as hearsay anyway and will be a little careful initially. I will have to wait and see if I can get the 2 speed working and if I like it I might get proper spokes in the future. I hope the Bendix manual 2 speed has a wide gear ratio, lo for steep hills and hi for the rest. I am also toying with the idea of changing the front coaster brake cable mounts. If I can't get the braking action I need then I will weld a lever on the fork to double the pulling distance, but then the mechanical advantage (force) will go down by half. It won't be hard to do the but dang, I want to ride it, not continue to fuss with it.