Wheels Manufacturing BSA Angular Contact External Bearing Bottom Brackets:

Wheels Manufacturing makes 3 versions of it’s threaded external bottom brackets, known as BSA bottom brackets.  BSA just means Birminham Small Arms, and it’s a bottom bracket threading standard that’s existed for 100+ years.  If you have a steel bike with a threaded bottom bracket shell, chances are it’s BSA threading.  Exceptions are few, and mainly exist on Italian race bikes and old French bikes.   Although there are three grades of bearings of the Wheels Manufacturing BSA bottom bracket, you only want one.  The lowest cost unit is less than 25 dollars cheaper than the middle of the line, and has an inferior bearing system.  The balls are contacted on two sides, which means they’re set up for forward pedaling motion just fine, but can not take side loads easily, like landing a jump a bit sideways, or hammering hard out of the saddle while escaping a deranged beaver.   The middle grade is the grade for you, unless you enjoy lighting money on fire and watching the winds of fate take i