What is the common width on the BB of Downhill, Dirt-jumper, and Trials bikes? Specifically I'm curious if there are any ChroMoly frames that have a low seat-tube, so that a Thudbuster suspension seat-post would fit. The GNG kit is designed to use a 68mm wide BB, and then inserting a 73mm BB-cartridge so the excess threads can provide a mount for the two side-plates. And what are the BB-cartridge options where two stout aluminum plates could securely attach?
A 1-1/8th head-tube is desirable (to allow a wide variety of suspension forks), but not essential.
I know its "possible" for a bike shop to narrow a wider BB-tube using a "facing" tool, but I'm hoping to identify an easy-to-copy combination, with minimal mods needed.
Spring is almost upon us, and I'm looking for a hardtail project frame as a base to develop a BB-drive using a converted BMC/MAC hub as a non-hub. Thanks in advance...
A 1-1/8th head-tube is desirable (to allow a wide variety of suspension forks), but not essential.
I know its "possible" for a bike shop to narrow a wider BB-tube using a "facing" tool, but I'm hoping to identify an easy-to-copy combination, with minimal mods needed.
Spring is almost upon us, and I'm looking for a hardtail project frame as a base to develop a BB-drive using a converted BMC/MAC hub as a non-hub. Thanks in advance...