Viewing 26 posts - 1 through 26 (of 26 total)
  • GXP BB Replacement (i knew it was coming)
  • escrs
    Free Member

    So the new to me gravel bike’s GXP bb has started clicking

    I know these are prone to failure so its no surprise

    So what’s the best replacement for a reasonable price? the bike gets used once a month at the moment but come winter it will be my work bike so needs something that is going to last

    Annoyingly i have 3 brand new Shimano BB’s sat here

    I know the GXP uses a 24mm driveside cup/bearing so i could use a Shimano one on that side (just fitted one to test, all seemed good) obviously the non driveside is 22mm so a Shimano cup/bearing is no good unless someone makes a 2mm spacer?

    Edit: just found these, would using one of these on the non drive side with Shimano cups work?

    https://www.sjscycles.co.uk/bottom-brackets/hope-bottom-bracket-truvativ-gxp-conversion-kit/

    whitestone
    Free Member

    The Hope conversion kit only works with Hope BB cups. There is one for Shimano but don’t know who does it.

    escrs
    Free Member
    BillOddie
    Full Member

    When my GXP BB went on my Gravel Bike, I looked at the prices of a new BB and then I looked at the price of some nice new Tiagra cranks which came with a BB and there was about 30 quid in it.  I bought the cranks, they are stiffer than the FSA ones they replaced, shift better and were shinier.

    thisisnotaspoon
    Full Member

    There is a shimano converting spacer on ebay, from an engineering perspective it’s suspect as shimano BB’s aren’t radial bearings, they’re ACB like your headset and rely on a little preload. But it seems to work for a lot of people. I suppose it might work with other aftermarket BB’s that do have radial bearings. But you’ll run int the problem I had below.

    I wouldn’t recommend any aftermarket GXP BB, I’ve tried Hope, Gusset, Superstar and some others and none had a cir clip to hold the bearings in, so they just fell out after a while! Because GXP doesn’t squeeze the bearings in any way it needs something to hold them in the shell! Infact even SRAM don’t retain the plastic top hat ont he drive side well enough so that walks out and a spacer needs bodging to hold it in (old Race face X-type 24mm x-rings work well for this but any old 24mm o-rings or spacers should work, just add 1mm shims until it starts to bind then take one off).

    I’d either get a new SRAM GXP BB (I tended to find they lasted long enough to be reasonable) or buy a shimano chainset.

    weeksy
    Full Member

    TBH i’ve been impressed with the GXP on the G-160, it’s done better than i expected, i have a spare just in case, but not needed it yet.

    escrs
    Free Member

    Cheers for the replies

    No point in buying another GXP BB as i know it wont last, this one has had light, dry use from me and the previous owner

    Not interested in changing the cranks, Ive got spare Shimano cranks here but want to keep the groupset all Sram

    Ill give the £5 spacer a go and see what happens

    joebristol
    Full Member

    Try the spacer I guess – what’s the worst that can happen?

    I’ve tended not to have major issues with gxp to date – although I have 2 mtb’s so it’s hard to say how many miles the gxp actually gets (the other one has dub).

    The last one which got a good amount t of use on an enduro bike through all sorts of filth lasted 18 months before it started creaking. New one cures the creak and no dramas since. Given they’re about £20 I can live with that.

    kiwijohn
    Full Member

    Wheels Manufacturing.
    Sorts out the worst bits of GXP, the top hat is replaced with bearings the proper size with a spring washer between it & the crank.

    andybrad
    Full Member

    im thinking uberbike might be my next purchase. or hope.

    i cant see how your walking the bearings out of them. very strange.

    thisisnotaspoon
    Full Member

    i cant see how your walking the bearings out of them. very strange.

    The drive side bearing just sits on a machined bit of the axle so just walks out of the cup. Seems to be amplified on the fat bike which will do it in <50 miles from new with most BB’s. The normal 68/73 BB’s seem to last a little better.

    The Hope one on my other fat bike has now walked the non drive side bearing out instead as the plastic shield that sits in the groove in the cup has worn!

    I’ve actually got an old FSA Mega EXO BB on my road bike (admittedly the ludicrous expensive £200+ ceramic version) and it’s much better thought out, with plastic shields that actually fit around the bearing, o-ring seals on the axle etc. It makes other manufacturers efforts look completely half arsed.

    andybrad
    Full Member

    but theres a washer to stop it walking out. its not like you can wobble your cranks once fitted.

    daern
    Free Member

    Wheels Mfg, or Praxis all the way. As you say, don’t bother with the OEM ones.

    dovebiker
    Full Member

    +1 on Wheels Mfg – well made and has good secondary seals, not just relying on the cartridge bearing seals. I bought a new Specialized gravel bike with a GXP crank / BB 4 weeks ago – it’s already making noises and only been ridden in the dry – I’ll replace it with a Wheels when it starts annoying me too much.

    hamishthecat
    Full Member

    I’ve used that spacer from Ebay and it’s worked ok so far.

    thisisnotaspoon
    Full Member

    but theres a washer to stop it walking out. its not like you can wobble your cranks once fitted.

    SRAM have a cir clip that stops it, but the plastic top hat walks out. Worse on the fat bike I think because the chainline grows more than the BB so there’s room for it to come out entirely.

    Other brands have a smaller ID bearing, but no circlip, so the whole things walks out.

    Hope are a special case where the plastic shield kinda acts like a circlip, for about 500 miles then wears out and the bearings fall out.

    andybrad
    Full Member

    ah yes you are correct about the clip.

    spursn17
    Free Member

    I’ve got GXP on 5 bikes (6 if you count the garage turbo bike) and have never had a problem with them, I can’t remember the last time I replaced one. The only one I had that creaked was a new PF30 one, regreased and tightened up it’s been ok for 5000 miles now.

    When I service my bikes I always pop the bottom bracket oil seals off and slap in some marine grease, and always tighten up the crank allen bolt with a torque wrench (54nm). I much prefer SRAM cranks and GXP BB’s to Shimano.

    lewzz10
    Full Member

    Happens on my BXP bb within half a ride. Ungood.

    paton
    Free Member

    GolfChick
    Free Member

    I’ve just ditched my hope BB, replaced the bearings very recently and it was creaking like a right sod. My fella bought one brand new and it also lasted five minutes before creaking. Have never been a fan of it being a regular shimano BB with an adapter, we’ve replaced with a nukeproof BB which is specific to GXP so we’ll see. If it goes again I’ll be ditching the cranks completely and getting a DUB crankset instead because at least you can adjust the preload properly.

    wzzzz
    Free Member

    The genuine sram ones do last well these days.

    I bought the converters to run 1x hope and 1x shimano now in my bikes because I had them laying round from previous bikes. I will replace with genuine sram when these go.

    If you run shimano with converters you need to be careful of chainline and overall width of the mounted BB, it can get confusing.

    I stick an O ring on the drive side of axle to stop the outer seal wandering out on my hopes and converted shimano too.

    wzzzz
    Free Member

    Who is that guy in the video? Awful language immediately obscures anything he has to say.

    I’ve never had play on the axle like he shows on about 5 cranksets.

    I had one once with damaged splines, but that was previous owner error using a shimano BB with no adapter.

    Seems he has a bee in his bonnet for some reason. Oh I see he sells £300 bottom brackets, of course nothing else is as good.

    boblo
    Free Member

    Who is that guy in the video?

    That’ll be our sweary friend Hambini the self professed Professor of Engineering and more mighty than all the Engineering and R&D Depts of all the bike manufacturers… in the world. See other thread.

    Works from his garage so success hasn’t spoiled him…

    andybrad
    Full Member

    i was going to purchase a hope bb but this is putting me off

    kerley
    Free Member

    I have found GXP okay. I change the BB every spring (gets an easy time in Spring, Summer, Autumn and the 3 months of riding in winter finish it off.
    The downside to GXP for me is that they are about twice the price of a Shimano BB.

Viewing 26 posts - 1 through 26 (of 26 total)

The topic ‘GXP BB Replacement (i knew it was coming)’ is closed to new replies.

Thanks for popping by - why not stay a while?IT'S FREE

Sign up as a Singletrack Member and you can leave comments on stories, use the classified ads, and post in our forums, do quizzes and more.

Join us, join in, it’s free, and fun.