Face bb for Hollowtech II ?

FelaKuti
Posts: 8
Joined: Thu Jul 06, 2017 1:27 pm

Face bb for Hollowtech II ?

Postby FelaKuti » Sat Jun 16, 2018 1:27 pm

I have an '80s steel bike which I want to put a road Hollowtech II crankset on. My understanding is that it's necessary to have the bb faced to help smooth operation of the bearings, however my LBS has specifically told me that it's not necessary and to just install the bb as is. How big of a risk is it of early bearing wear if I followed the LBS advice?

User avatar
queequeg
Posts: 5286
Joined: Thu Dec 17, 2009 10:09 am

Re: Face bb for Hollowtech II ?

Postby queequeg » Sat Jun 16, 2018 1:34 pm

FelaKuti wrote:I have an '80s steel bike which I want to put a road Hollowtech II crankset on. My understanding is that it's necessary to have the bb faced to help smooth operation of the bearings, however my LBS has specifically told me that it's not necessary and to just install the bb as is. How big of a risk is it of early bearing wear if I followed the LBS advice?


Bearings are in external cups, which screw into the threaded BB shell. The facing is to ensure the two sides of the shell are aligned so that when you insert the crank, it can go in without putting any stress on the bearings. So, it will really depend on whether you frame is already aligned. I'd assume it is, but getting it fixed shouldn't be a huge issue if it needs doing.
'11 Lynskey Cooper CX, '00 Hillbrick Steel Racing (Total Rebuild '10), '15 Cervelo S5

User avatar
find_bruce
Moderator
Moderator
Posts: 7642
Joined: Mon May 09, 2011 8:42 pm
Location: Sydney

Re: Face bb for Hollowtech II ?

Postby find_bruce » Sat Jun 16, 2018 2:01 pm

Yep - screw the bearings in & see how accurate the face is. I have done it on 3 bikes now - 2 80s steel, 1 naughties aluminium, none of them needed facing

User avatar
10speedsemiracer
Posts: 912
Joined: Sat Feb 11, 2017 7:38 pm
Location: Melbourne, Eastern Suburbs, near the hills,

Re: Face bb for Hollowtech II ?

Postby 10speedsemiracer » Sat Jun 16, 2018 2:27 pm

find_bruce wrote:Yep - screw the bearings in & see how accurate the face is. I have done it on 3 bikes now - 2 80s steel, 1 naughties aluminium, none of them needed facing


Same as Find_Bruce, have thrown Hollowtech into a random assortment of steelies and a 90s alloy Kennedy, none needed re-facing, all worked perfectly.

Put it in, you'll soon know if there's an issue when you fit the cranks.
Mmm, SunTour

User avatar
Duck!
Expert
Posts: 6863
Joined: Tue May 21, 2013 8:21 pm
Location: On The Tools

Re: Face bb for Hollowtech II ?

Postby Duck! » Sat Jun 16, 2018 6:42 pm

I haven't come across any frames that have needed facing. What is more likely to be beneficial or sometimes necessary is chasing the threads with the appropriate taps, because if they're rough and worn they can bugger the threads on the comparitively soft bearing housings.
I had a thought, but it got run over as it crossed my mind.

FelaKuti
Posts: 8
Joined: Thu Jul 06, 2017 1:27 pm

Re: Face bb for Hollowtech II ?

Postby FelaKuti » Tue Jun 19, 2018 2:48 pm

Thanks for the replies. It's a high end frame from Japan and the finish is very good, so I'll have a go at installing the bearings without facing the BB.

User avatar
Mulger bill
Super Mod
Super Mod
Posts: 28997
Joined: Sun Sep 24, 2006 2:41 pm
Location: Sunbury Vic

Re: Face bb for Hollowtech II ?

Postby Mulger bill » Sat Jun 23, 2018 6:18 pm

Only time I've seen it as an issue involved a rough as guts rattle can job.

Bit of stanley knife scrapeage and it went in easy as
...whatever the road rules, self-preservation is the absolute priority for a cyclist when mixing it with motorised traffic.
London Boy 29/12/2011

Who is online

Users browsing this forum: Google [Bot]