Wheels Manufacturing BBKT and Cannondale System Six

Wheels Manufacturing BBKT and Cannondale System Six. Wheels MFG make many bottom brackets among other products, allowing cyclist to remove the BB30 / press ft bottom brackets to install a more traditional creak free system. Very nicely made components with fairly detailed instructions. However I am about to fit for the third time the “PF30A Outboard Angular Contact BB for 22/24mm Cranks (SRAM) – Black” simply because as detailed as the instructions are the company send out the component with lots of axles spacers and cup spacers. Now that might sound handy but seeing as this BBKT has been made specifically to fit a GXP to a System six frame you’d think that they would inform you of which ones to use.

But unfortunately WheelsMFG don’t, so the already flawed GXP system now adds in some new factors

Of course the Q-factor of the system should be correct for the chainset to be fitted. And the asymmetrical Cannondale design means the cups are different for both sides. So on the first attempt we fitted 1mm cup spacers on both sides and some axle spacers to take up the slack. This did not work to our liking as the axle was not as smooth as desired. We measured the donor bike at the bottom bracket and worked out that with a 2.5MM spacer on one side and a 1MM spacer on the other the Bottom bracket would be the correct length. It worked perfectly and no spacers on the axle were needed…. (Why did they send them in the first place). However after two rides on the bike and happy with the result we decided to measure the crank distance from frame, only to find out that it is 3MM out.

Fitting a Wheels Manufacturing PF30A bottom bracket to a Cannondale System Six

So simple maths, change the spacers from one side to the other and the job should be correct. I just don’t understand why the drive side cup did not have the extra 2.5MM designed into it and the off side an extra 1MM no spacers would be needed anywhere, remember this is designed for this bike….