Is it necessary to face your bb before installing outboard bearings?

Triathlon Forum
1

I’ve read somewhere that the new style outboard bearing cranksets work best if the bb shell has been faced prior to installation. I have the original 2000 model year aluminum P3 and it does have paint on the bb shell. Should I get the shell faced or just slap the new cranks on and ride?

Thanks

Chris

2

Get the BB shell faced, regardless of the BB type. While you CAN just slap the cranks on and ride, there is a difference between just doing something and doing it properly.

3

Gerard answered you on the “other forum”.

Aloha,

Larry

4

Dumb question, what does getting the bottom bracket shell faced mean?

5

Facing a BB shell entails a few things:

  1. Making certain the threads are clean of paint and/or corrosion.

  2. Making certain that the face of the BB is flat and square.

Basically, chasing (#1) and facing (#2) entails cleaning paint and/or other debris from the shell, as well as making certain that the BB is installed straight with no strain on the bearings.

These are things shops who sold new bikes would do before assembling a bike in the old days. A few bike companies actually bother to do these things on a bike frame before shipping it. Yes, facing and chasing a BB shell are two separate operations; however, they should go hand-in-hand. Usually, if the BB sell is not faced, the threads are not chased, either.

This also goes with facing the head tube and cleaning/reaming the seat tube. Hardly anyone does this anymore, it seems.

6

Whoops, I forgot I had the Cervelo forum set up in digest mode. I’ll have to log in and get Gerard’s input.

Chris