Facing a Brompton BB shell

[Jurek]

I'm about to fit external (Shimano) bearings to the BB on the Brompton (and cranks to suit).
I think I already know the answer to this question, but I'll ask it anyway - How critical is it to have the BB shell faced?
There's currently the standard square taper / Isis type of arrangement in there, so my guess is that it will not have been faced as there is no need.
*Looks at cost of facing tools* 

[jsabine]

Chasing'n'facing tools available in SE7 if that would be helpful. A 10 minute diversion from the foot tunnel ...

[LittleWheelsandBig]

I thought Brompton BB shells were faced at the factory. If there is paint on the ends of the shell, then it probably hasn't been faced before.

[Jurek]

I see paint / powdercoat on the non-drive side - so I'm assuming as you say, LWAB, not faced.

John, that's a very kind offer, thank you, and I may take you up on it.
I'll know more once the various components have turned up from far and wide on the globe and I have dismantled what I currently have.
The optimist in me may give Brompton a call to ask the question.... but I think I know what their answer will be.

[jsabine]

If you can see powdercoat on the end of the shell, I'd do it anyway, just to clean off any irregularities.

(I tend to do it as a matter of course when fitting any BB unless I know I've done it before - but having the tools in the cellar does make that an easy default choice.)

[Jurek]

If you can see powdercoat on the end of the shell, I'd do it anyway, just to clean off any irregularities.

(I tend to do it as a matter of course when fitting any BB unless I know I've done it before - but having the tools in the cellar does make that an easy default choice.)

Looks like I may be in touch once the remaining bits turn up.
Thanks again.
BTW, I rarely borrow tools - I'm generally well equipped with my own - but if I do, it is on the basis of 'If I trash it, I'll replace it'.

Heh! I've just read your PM which (I think) this post covers - tell me if you think it doesn't.
J

[jsabine]

Once you've got the bits, drop me a line - we can either arrange a meeting point or I'll let you know where to come.

[Jurek]

Once you've got the bits, drop me a line - we can either arrange a meeting point or I'll let you know where to come.

Thanks.
PM sent.

[chriscross1966]

I thought Brompton BB shells were faced at the factory. If there is paint on the ends of the shell, then it probably hasn't been faced before.

Nope, I've just put a Campagnolo Ultratorque in mine and you have both paint and thread extrusion to deal with to get a clean face. With the Campy I had to delete the wavy washer and put 2mm of shim under the drive-side cup to get clearance, plus can only use the outer chainring mount and I had to make the single-ring conversion chainring nuts (I used the bolts from a KCNC set)... This has worked with both the original triangle and gears, and now with an Alfine 11-speed on a kinetics frame with a 60T chainring... video here:

https://www.youtube.com/watch?v=Ue6qk9fD5RA

Yes, that's a 38mm carbon fibre rim on the back...

[Jurek]

........

Yes, that's a 38mm carbon fibre rim on the back...

I had a look at a pair of those from a firm in China in the New Year.
Price including shipping is close to that of an entry level Brompton. Chances are that you'd get to cough some duty on them as well.

[chriscross1966]

I had a look at a pair of those from a firm in China in the New Year.
Price including shipping is close to that of an entry level Brompton. Chances are that you'd get to cough some duty on them as well.

Wasn't too bad, just over 400 dollars and I got charged about 25 quid for the customs clearance, most of which was UPS handling charge... Of course the pound was worth rather more dollars back then.... Anyway, there's a pile more stuff to go on Henrietta yet and in the mid-term future an attempt to get a 25mm Campy crank into a 24mm Chris King bottom bracket