So I am making a gravel hack bike..( old rocky mtn hammer race front triangle) the back end of this bike had a accident back in the day so I just cut it off.. I have some 5/8 straight gage that I usually use for seat stays that is 0.035 thick and I have some that is 0.049 that have gone on a bmx race bike for chain stays.
do you think the 5/8 x 0.049 would be sufficient enough for chain stays on a 1990 mtn bike…cough I mean a gravel bike. haha are they are kind of the same ?? I also have the dies on my cobra toob bender for this tube, so it makes it easy to do what the heck I want and not be stuck with stock tube bends any thoughts
I suspect the .035” wall stays will be fine as long as the other aspects are dealt with well, like the disk caliper mounting. But you can weigh the difference between the two and judge for yourself if the added few ounces are worth the peace of mind.
It sounds like this is your first frame modding project. I would be more concerned about the joining skills and the joints being the location of any failures to come. Andy.
not my first rodeo modding a frame but my first gravel bike back end.. just don’t want it to be to much a noodle.. the 0.049/ 1.24 mm thick tubes are stiff!! but at 444 mm length stays and regular qr rear wheel just wondering if it will wonder.. I am also 6’2” 170lbs and raced/ jumped most bikes.
the frame will be tig welded or brazed if it feels best to do..
If the tubing is DOM CrMo or better then I think that’s fine. If it’s just ERW mild steel then maybe it’s a bit sketchy depending on the heavy sends you have in mind.
its nice German chromoly . and the bike will be graveled, road biked, and gentle, single tracked, maybe like bike packing?? not sure… its just going to be a experiential bike to see if I am into another genre of cycling.. or will there be time as there is dh, freeride, xc, trail hardtail, freestyle bmx, race bmx (class and cruzer) single speed road bike, fat bike, and commuter,
The second bike I made was a long-low-slack hardtail on which I used the fairly lightweight Zona tubes. The chainstays are 0.8mm wall and 22.2mm diameter (which is .032 and 7/8in). Regular CrMo, cold-drawn seamless. Its owner has been happily smashing it down big rock gardens in the North West of England with no issues.
