PF30 Hell For A BB92 Guy

My new bike is going together. More on that later…

Working on PF30 for the first time is not going well. I’m a known BB92 guy. I know it’s the best way of doing things. The world, it seems, doesn’t agree with me. Thus, PF30 is taking over. Grrr…

The new bike has a PF30 BB with a width of 68mm. That’s a problem for a mountain bike. Mountain bikes with this setup should have a 73mm wide BB. The market has produced several shim kits to make up the difference. These don’t work the way I like with Shimano Hollowtech II cranks. Shimano likes a 96.5mm width at the crank faces for MTB, offset 2.5mm to the drive side. That means 2.5mm of shim on the non drive side and 5mm of shim on the drive from 68mm.

I prefer any bearing configuration that gets the bearings as far apart as possible, thus my dislike for BB30/PF30. Of the adapters on the market, the Parlee unit is the only one to take advantage of increased bearing spacing. The problem is that these also don’t fix the MTB spacing issue. To get some of that off of the spindle, I made these little shims. 46mm ID x 49.25mm OD x 2.5mm. This way I only have to shim the spindle 2.5mm.

I don’t like this solution. I’m working on something else that’s pretty sweet but I figured that I could whip these up quick and get things rolling before investing in a final solution.

These parts were installed into the frame using Loctite 680 ‘Slip Fit’ Retaining Compound. Adapters in PF30 shells that are made of aluminum are known to make some noise as they shift. I assume this is due to a greased interface. By using a retaining compound, I hope to create a structural buffer between the two parts and eliminated any shifting. We will see.