Alright, I have an azonic steelhead, which is not a bmx. I have bmx cranks on it currently however. And my bottom bracket is shot. So I was looking at getting a new one, but I don't know if there are certain bmx specific bottom brackets that I will have to get or not. The crank arm has 10 grooves, or splines on it. I already tried an isis bb but it was too thick. The crank arm didn't even fit over the spindle and the grooves look different. The isis has rounded valley's while the crank arm's are squared off. The shell is threaded too, so it doesn't take won't accept "American" bottom brackets, but I am not sure if European are the same shell diameter as a regular mountain bike. I believe mine is a 62. But there's one other catch, the spindle length is like 148. And the longest I've seen so far is a 120. Any tips would be greatly appreciated.