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Discussion Starter · #1 ·
Bearing dimensions in Chris King PressFit bottom brackets & use of press-in adaptors

Hi, for the purpose of figuring out whether an existing tool is fit for the purpose:

I am looking for information on the outer/inner diameter of the ball bearingraces of both the PressFit24 as well as the PressFit30 bottom bracket.

(In order to avoid any confusion: I am aware that the spindle diameter is 24 or 30 mm, respectively; however the ID of the inner race must be sightly larger due to the plastic spindle sleeves. Further, I know that the ID of the related BB shell is 41 or 46 mm, respectively, but the OD of the ball bearingmust be smaller due to the aluminium cups.)

In addition, I would appreciate if someone who has actually used the specific Chris King press-in adaptors could briefly explain how these are meant to be used: Pressure on outer bearing race or pressure on aluminium cup.

Many thanks for any information,
Markus
 

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You can press in CK BB cups by applying the pressing force to just the outside of the cups like with the Park headset press with no step-down adapters in place. However....the correct way with the CK specific adapters is to use the decreased diameter side of the adapter, not the the flat side, so as the smaller diameter portion of the adapter fits inside the inner race where the spindle would fit. Press in with quality press.
 

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Discussion Starter · #3 ·
Thank you - I will certainly not use just flat adaptors with no centering guide. However, the CK adaptors will not fit the spindle of the press (and are pretty expensive).

I will use existing ones or machine some new ones that perfectly fit.

I only need to know the ID of the bearing inner race and (with reference to the original CK adaptors) whether the adaptor should apply pressure on the cup or the outer bearing race. If the outer race, I 'd need the OD of the outer bearing race.
 
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