Hi folks, I have a 2006 giant XTC composite hardtail. The Truvativ ISIS BB needs changing and i’d like to upgrade to an hollow tech II external bottom bracket and cranks.
Will my frame readily accept this type of bottom bracket? I can’t imagine that it is possible to reface the thread in a composite bottom bracket housing.
Any advice would be gratefully received.

Many thanks, Tim

You don’t need to face the bb/threads to fit HTII. I’ve never done it and have no issues with longevity.

Works on my carbon road bike (Giant TCR).

I’d be very suprised if the threads are cut into the carbon, there’ll be a aluminium sleve in there for that job.

Maybe worth phoneing Giant about the faceing part though, no idea how carbon reacts to being cut up like that.

You can usually face carbon frames, just need a nice sharp facing tool and a very gentle touch.

somone does external BB’s that have ‘floating’ bearings I think – you don’t need tohave the frame faced as the bearing just align themselves inside the cups. Might be worth looking at if you’re concerned about expense/risk of facing the bb (wlthough it’ll probably have an Ali insert that the bearign will sit on anyway).

I have a HT2 on my 2006 XTC Composite. I never faced the threads and I still have the same BB fitted. No issues at all. The BB fits into an alloy insert. You should have no problems.

Hi folks,
Thanks for all the advice and comments. It’s time for me to make an investment (v excited).
Tim