Transmission database - for all your crank / bb / bottom bracket questions

Took apart a UN55 non-drive side for the heck of it (currently job hunting...), pretty easy to do if you have 2 or 3 spoke width picks, or finer.

First pic is a black plastic retainer cap that fits tight over the axle and holds down a rubber dust cap. Note the pick marks from where I pried it off; would recommend using multiple picks and a flat tool like a c Hh sim checker to gently lift it around the circumference of the axle like a tyre off a rim. Note which side goes down because if you reinstall it wrong it’ll create loads of drag.

Second and third pics are inside of the cartridge: the grey/white plastic you see is the bearing retainer, which lifts off easily exposing the bearings. You can clean them out and regrease, but they don’t come out of the BB from non drive side.

Drive side axle has a tough retaining ring, possibly steel, pressed tight onto the axle. Couldn’t pry it out but didn’t force it.

Putting it back together is easier than taking it apart, just be careful with that black cap.

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Praxis 22/24 mm bb question. i have installed one last night with the plastic protective sleve backwards i.e.flange side of the sleve into nds cup, everythings seems smooth, is it ok, or do i need to take it apart ? It was a loose fit either way and didn't bother reading the instructions...

Is there alternatives for SRAM DUB bottom bracket (SRAM NX Eagle 12 Speed Mountain Bike Groupset)?

Rotor track cranks. Are the ROTOR track BB cups slightly narrower than normal (i.e Hollowtech) 24mm road BB's?

Would i need to use the Rotor specific BB to get the right chainline or can i use other cheaper options?

Specialized Langster frame

It just says

Cr-Mo axle, 68mm

Cranks to be used are Miche Primato 49x170

I'm not sure which Bottom Bracket would work? Please help!

what hub you got?

Just some stock Quando hubs on the wheels - is that what you mean? Didn't realise the BB depended on the wheel hubs!

check the first post of this thread for combinations that work.

looks like a 107mm BB might work. so one of these.. https://brixtoncycles.co.uk/product/9025­2/shimano-bb-un55-bottom-bracket-british­-thread-68-107-mm/

Thanks a lot! Think I'll pick up one of these

Anyone in here ever used barelli track cranks and know what size bottom bracket I’d need with them?

What sort of tension should my chain be running Alfine 8 with horizontal dropouts?
I'm struggling to get it anything but pretty loose at the moment.

Didn't see it on the first page:

Anyone know what spindle length is needed to get a 47.5mm chainline on the old Sugino-made 94/58BCD White Ind. cranks?

Thanks.

I've got a 2018 Chisel with a FSA BSA Threaded BB. Went on wiggle chat for advice and they said as it's SRAM, the only compatible one was a prime bb, which had bad reviews. Any advice for a replacement? Cheers :)

https://www.specializedconceptstore.co.u­k/product/11396/2018-men-s-chisel-expert­--1x/

Any decent fixed crankset for at most ~150€ needing a 107mm ISO BB that isn't Miche? I have a frame with a Miche BB stuck in it (teeth are completely gone on both sides)

EDIT: Must be available in silver!

Is there any particular reason why I shouldn't use a headset removal tool to remove a press fit BB?

I have a caad12 frame with a BB30 bottom bracket.
I have an existing GXP crankset I’d like to fit.

I’ve seen you can buy an English adaptor, which apparently has the added benefit of reducing creaking. Would the additional width of the external BB pose issues with Q factor? Am I making this needlessly complicated? Cheers :)

So; new project for the GF. Has a stuck Shimano 107mm BB in the frame, will I need a track crank to clear the chainstay? Haven't given the BB the full beans yet but likely stuck as its alu, luckily its buttery smooth. Ideally would like to run a double on the front but want to see what cranks we need first.

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I'm measuring a triple inside ring which is why these numbers are a bit weird
If a 113mm BB in a 73mm shell gives me a 40mm chainline
What BB do I need for a 45mm chainline?
Thanks

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