Which size bottom bracket do I need?
Which size bottom bracket do I need?
To find out the size of bottom bracket needed, measure the inside of the bottom bracket shell in your frame, it will be 73mm, 70mm or 68mm. Some older frames may have Italian threaded bottom brackets, instead of the more modern English.
Are all BB30 bottom brackets the same?
Generally, your replacement cranks may have the same or smaller spindle diameter, and the same or longer spindle length than the system your bottom bracket is designed around. For example, a BB30/PF30 bottom bracket has the narrowest shell width of any of the standards, whilst being designed for large 30mm spindles.
How wide is a BB30 bottom bracket?
The BB30 bottom bracket shell is typically 68mm (road) or 73mm (mtb) wide with an inside diameter of 42mm. Originally the BB30 system was designed to use 30mm diameter crank spindles. However, frame’s with BB30 shells can be used many other sized crank spindles.
What does the 30 in BB30 refer to?
The term PF42 refers to the inside diameter of the shell. The term BB30 was an early term in the history of this standard and refers to the 30mm diameter of the spindle used at that time.
What is a BB30 bottom bracket?
The BB30 bottom bracket allows you to pair 30mm spindle cranks to 42mm inner diameter bottom bracket shells. Cannondale pioneered this standard along with specially designed cranks and many have found the benefits to them. Road versions have a 68mm width, MTB has 73mm.
Why does my BB30 creak?
The leading cause of BB30 bottom bracket creaking is bearing migration within the frame bb shell during use. The bearings shift around a minute amount, resulting in the dreaded creaking sounds. Typically somebody greases the bearings to fix it. This only masks the problem, or more often, exacerbates the problem.
What is the difference between BB30 and PF30?
A PF30 frame has a shell slightly larger than BB30 (46mm compared to 42mm). The bearings are pressed into cups which are then pressed into the frame. In the case of the PF30 systems the bearing cups rely on flanges to ensure that both cups are pressed the proper depth into the frame.
Is press fit 30 same as BB30?
Is BB30 the same as BB92?
Nope. The spindle on a BB30 crankset is too large (30mm) to fit through the hole in a BB92 BB shell and still have room for bearings. The spindle size on a crankset that is compatible with a BB92 is 24mm. You can go the otherway though…