Ask a Mechanic | Best Bottom Bracket Adaptor

Question: George wants to know: I am installing a Shimano crankset on a PF30 bike, which is the best adaptor system out there for my application? From: George

Answer: Bottom bracket standards and adaptors is a category that is in constant flux, which makes my job a whole lot harder.

Your situation is the most common adaptor question that most people face. My best advice is not to use adaptors at all. Choose an adaptor bottom bracket, like this PF30 to 24mm bottom bracket from Wheels Manufacturing, so that you won’t need anything between your bottom bracket bearings and your crank spindle. The two cups thread together while simultaneously pressing into your frame’s bottom bracket. It’s an incredibly solid and reliable setup.

If you are going to use an adaptor, I like this SRAM PF30 to BSA adaptor because you can thread in regular outboard bearing cups into the adaptor. Then just press the plastic cups into the frame. It’s simple and cheap. Best of all, the crank spindle rides on the bottom bracket bearings make by the crank manufacturer to ensure a good fit.

The cheapest and easiest route is to use the Wheels Manufacturing Delrin bottom bracket adaptors. They just press into a standard PF30 bottom bracket, which you probably already have. These adaptors take about 30 seconds to install and we’ve never had any real problems with them.

That’s my 2 cents on the adaptor game. Just remember to do what you can to avoid using adaptors at all, and you’ll be able to avoid problems before they start.

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