TLDR: is it possible to run a 30 mm spindle crank in your IA or AR? If so, which BB do you use? Is it BB30 or PF30? Is there one that’s relatively easy to install? My new-to-me crank (SRM Origin) has a 30 mm spindle, but I’m not sure if it’s a BB30 crank. Ideally, I would be able to swap easily from 30 mm bearings to 24 mm bearings and vice versa; has anyone used this BB kit by Token that allows swapping (see below)?
Below is the current BB on my bike (Felt AR). I think this would be a BB30, right? If so, how do I swap it for bearings that would accommodate a 30 mm spindle?
Long story. Felt’s customer service has taken a turn for the worse since Felt’s takeover by Pierer Mobility/ KTM. In 2019, it took two days for Felt to get back to me, but now, the main CS email address goes unanswered. I finally had someone reach out after I submitted an inquiry online (using a very poorly-designed form that mentions VIN, as if a bike were an automobile).
My question should be very easy to address, given that they should know what BB is needed once they have my bike’s serial number. But it’s taken the rep 5+ days, and I still have no idea if the BB shell is set-up for BB30 or PF30.
These standards are always confusing. Both use 30mm bearings. But BB30 are installed directly into the frame. So, frame I.D. 42mm same as bearing O.D. PF30 has a bearing shell carrier with the same 42mm O.D. bearing and the carrier is 46mm O.D. which is frame shell I.D.
Your second photo appears to show the bearings outside of the frame. So, this is not a BB30. Likely a PF30 conversion to 24mm I.D. Shimano crank bearings. But to be sure you need to measure the approx frame shell inner diameter because there are also PF41 BB’s made to use a 24mm shell carrier for pressing into a 41mm frame I.D.
As long as you have a frame shell with 46mm I.D. There are 30mm crank options. The only other caveat is the “BB30†crankset. It looks like the Origin is 30mm vs a true BB30 designation so you should be alright. In the past there were true BB30 cranks (SRAM/Quarq) that had spindles too short to use for anything wider than a BB30 BB frame shell width.
The Token kit you show is pretty nice. The downside to Token is that the carrier flanges are very thin. It can be tough to tighten or loosen these if that’s a concern. The BB cup install tools with a threaded rod clamp are a big help. Thread together BB’s such as the Token or WMFR are recommended vs straight pressin. I’ve gone all in using one-piece BBInfinity BB’s.