Bottom brackets are measured two ways; by height (floor to center of BB) and drop (horizontal line thru axles to center of BB). So, BB height = ~ 28cm and BB drop = 5-5.5mm Americans usually measure BB drop; Italians BB height. So, 28mm makes no sense for a drop or height measurement. 52mm is ok, but the standards are 50mm or 55mm for a drop. To be on the safe side, use 50mm drop.
My bad. I always think in terms of drop and when I saw 28, I thought that someone was play'n with me
Threadless is the new standard at the track. Trackies are running OS or road handlebars these days. Its easy enough to switch out stems and handlebars.
Yeah, we make a lot of forks and people are split down the middle now, half 1"/tread, the other half 9/8" threadless. So we make both. The other thing we're testing is using thinner walls in the steerer on the 9/8" threadless. Turns out 1.6mm walls made sense when you threaded the steerer but not when you don't. We talked to BMX builders who have been using thin-wall 9/8" steel steerers forever and they have zero problems. The kool part is that the thinner-walled steerers are lighter than the 1"/threaded.
If you are going to tig weld to keep costs down, might as well go OS, since you will be using 9/8" HT.
OS is pretty standard these days and we don't get many serious requests for 1" T/T or 28.6mm D/T.
Also, the issue of good track ends are way important.
We've made big leaps in D.O. design. We now have good laser/CNC plate dropouts that are very nice.
Thanks a ton for your careful collaboration. -Matthew