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I must admit i'm confused as hell
Need the bottom bracket out as its creaking and clunking. Hollowtech II (its a 2017 Bronson)
There are no discernible markings on the BB its-self but assuming its SRAM like the cranks.
As i understand there's two diameters of BB/spanner and perhaps some shims/adapters involved but a brief foray with the calipers didn't produce a match for any of them.
Before i have to order 3 different spanners, anyone know what i need or how i work it out?!
cheers
Firstly...
IF it's Hollowtech II then it's a Shimano BB not SRAM.
Shimano have two external cup sizes on their Hollowtech II BB's - I know because my new Shimano 105 BB was smaller than the Sora BB it replaced.
I had to buy an adaptor; it fits the smaller BB and enlarges it to enable the existing BB spanner to turn it.
Pic? You've tried Sheldon Brown?
Had a similar issue recently when changing from Isis/Truvativ to Shimano Local bike shop charged me about £16 to remove it. I have the shimano tool, didn't want to buy the Isis tool just for a one-off if I could give business to my LBS. Now I have a stubborn square-tapered BB that needs removing and both the LBS and Halfords quote £25. That's inflation! I'm so skint ATM I just ignore the 5mm play in the BB and wear headphones. Seems to work so far 😂
Sorry that doesnt help, except maybe just bite the bullet and get the LBS to remove it? Unless the bike is a stock-build and you can trace the specs?

£16 justnto remove a B.B.
time to put our prices up
is the £25 quoted above supply and fit a new taper B.B. or just remove a tight one ?
Shimano have two external cup sizes on their Hollowtech II BB’s
There's actually three different sizes.
The original size that your spanner fits then the XT and XTR are both different sizes again.
As it happens, I was swapping an XTR BB-93 tonight. It actually comes with the adapter insert (adapts to fit TL-FC32 - full size tool) which makes life much easier:

(For reference: top left is a regular, full size BB socket, top right is an old, full size BB, bottom left is the tool supplied with the BB-93 and bottom right is an XTR BB-93)
FWIW, the supplied tool was surprisingly robust when used with this particular socket and would, I think, take a moderate amount of abuse before failing. I think it would be a different story if used with a spanner-type tool, which is one reason why I've stopped using mine and moved to a socket instead which seems to make the whole job easier.
For OP: the last SRAM BB I did was a GXP on a Whyte and it used the full-sized tool without adapter.
thanks all!
IF it’s Hollowtech II then it’s a Shimano BB not SRAM.
erm deliberate mistake, i was err just testing you 😉 erm yes oops.
Sorry that doesnt help, except maybe just bite the bullet and get the LBS to remove it? Unless the bike is a stock-build and you can trace the specs?
if its £25 quid i could get all 3 spanner sizes together for less money. Not adverse to funding my LBS (heck most of my spare cash ends up there!) but this in theory should be a simple repeatable job once i have the right tool.
Going to buy a standard diameter socket like above and one of those adapters and take it from there.
thanks for all the help
As above, you might not need to buy the adaptors. The last xt bb I bought came with the adaptor.
is the £25 quoted above supply and fit a new taper B.B. or just remove a tight one
Just to remove. Quoted £55 max to supply and fit new one.
Quoted £55 max to supply and fit new one.
Ouch!
Malvern Rider, I suspect what you need to remove your square taper BB is a tool like this VAR one

The bolt screws into the square taper and the spring keeps the tool in place. You then use a big adjustable spanner on the (32mm) flats. If elbow grease alone won't work and the BB won't move, then you can use a small hammer on the spanner to break the seal.
If elbow grease alone won’t work and the BB won’t move, then you can use a small hammer on the spanner to break the seal
And only when you've tried all these things should you then attempt the last resort technique of actually turning it in the correct direction...
(Don't deny it - we've all done it at least once! 🙂 )
This is the device I bought and it works fine….
I wondered what that was for; it was in the box of SLX bits I got back from the bike shop after a drivetrain change.
Don’t deny it – we’ve all done it at least once! 🙂
I have no idea what you mean...
£55 to supply and fit a tapper B.B. I hopes that’s a speacil B.B. and not just a normal Shimano un26
defiantly time for a price rise at work
