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BB size help - Race Face/Hope 24 or 30?

Aug. 10, 2019, 12:41 a.m.
Posts: 113
Joined: Oct. 18, 2016

Hey everyone, thanks in advance for your help.

I have a 2018 RM Slayer C50, and am looking to replace the BB. The Rocky site lists the spec for the BB as "Race Face BB92", and the crank as "Race Face Aeffect Cinch 32T Steel". I want to replace the stock RF BB with a Hope BB, but can't figure out which size. The RF site lists the BB92 as a 30mm spindle, but the Aeffect crank as being a 24mm spindle.

Which one is compatible, if any?

https://www.hopetech.com/products/drivetrain/bottom-bracket/press-fit-41-30mm-bottom-bracket/

https://www.hopetech.com/products/drivetrain/bottom-bracket/press-fit-pf41-bottom-bracket/

Aug. 10, 2019, 5:17 a.m.
Posts: 2301
Joined: Sept. 5, 2012

It would be the bottom one. I just replaced my cranks and was looking at the Affect but choose to stay with the 30mm BB .

I would pull a crank arm too confirm if you are gonna mail order the BB. Also consider the ceramic bearing option. I have heard the bearing will outlast the bike.

The RF BB is crap, I still need to replace mine and it has roughly 1200km on it. There is a company that makes a threaded BB that adapts to the press-fit frame. A option to consider as well.

Aug. 10, 2019, 7:28 a.m.
Posts: 876
Joined: June 26, 2012

The first BB is a good option for 30 mm spindle cranks (e.g. Race Face Turbine Cinch). Fitting a 30 mm spindle in a BB92 bb shell, which was originally conceived for smaller-diameter spindles, makes the bearings thin and prone to wearing out quickly, so a bb like that where the bearings press directly into the frame results in more room for bigger bearings. Enduro Bearings makes a similar one.

The Aeffect cranks have a 24 mm spindle, same as Shimano cranks. So you need the second bb.


 Last edited by: D_C_ on Aug. 10, 2019, 7:30 a.m., edited 1 time in total.
Aug. 11, 2019, 9:25 a.m.
Posts: 875
Joined: March 18, 2017

I have a Hope SS BB on my DH bike and a Hope Ceramic BB on my Surface. No issues wth either. Shimano cranks on one bike. SRAM on the other.

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