It is important to understand there are several different crank specs combined with several different frame specs.
First are the popular crank types, we will cover the 4 most popular:
Each of these require it's own type of BB.
1. Shimano 10 Speed.
2. SRAM (GXP)
3. Campy Ultra Torque
4. FSA Mega Exo.
We get a lot of questions asking if one of the above cranks is compatible with another crank's BB. The short answer is no. The first three are strictly incompatible with each other, but some have had success using a Shimano 10 BB with a FSA Mega Exo crank and vice versa. Although this is not recommended as the two specs are not 100% compatible without some modifications (as we have done to our VCRC FSA BB).
Add in the confusion of FSA having a standard model of cranks and a "Light" model of cranks (with each requiring it's own type of BB) and it gets quite complicated.
Each of the above manufacturers use a slightly different version of the same design. They all use integrated spindles. But they all implement it differently. This is in part because of patent issues and partly to be different from each other. For example, Shimano doesn't want you to use their crank with a SRAM BB and so on.
In the past few years, many frame companies decided that having a normal thread in type BB was not optimal. This led to the industry moving to press in type systems. There are many different press in designs now being used by most top manufacturers. They are:
1. BB90 (found on Trek mostly but also others)
2. BB86 (found on some Giant and Scott frames)
3. BB30 (developed by Cannondale and now adopted by quite a few companies).
Now it starts to get confusing. The 4 crank types listed above all need their own implementation of the BB90 or BB86 system. So if you have a Shimano 10 crank with BB90 or BB86 and want to switch to a SRAM crank, you can't use your BB90/Shimano or BB86/Shimano kit. You'd need a BB90/SRAM or BB86/SRAM kit.
What about BB30? Well it was first developed for use with Cannondale cranks using a 30mm spindle (most road spindles are 24mm). So none of the 4 cranks listed above work directly with BB30. You can buy a specific BB30 crank from FSA and SRAM (not available with Shimano or Campy cranks). You can also convert a BB30 frame to work with the 4 cranks above by purchasing our VCRC BB30 adapter.
Confused? We didn't even get into MTB and their slight variations on things. Maybe next time.
