Bottom bracket help

[jack smith]

My clunker mtb' cranks kept coming loose due to the bb it also creaks like hell, I've taken it out but this ring is stuck in, how do I remove it? And is it reverse threads cause I'm unsure, also can someone link me to a replacement unit? Preferably one of those sealed things the axle says. 13-10 nlco3s if that helps

 

[jack smith]

 

[simon.r]

I'm about to resort to a junior hacksaw to remove the one on a 35 year old Raleigh in my garage!

You need to measure the BB shell width (probably 68 or 73mm) and the axle length to order a replacement. I picked up a cheap Shimano sealed unit from CRC for a fiver.

Edit - link to cheap BB http://www.chainreactioncycles.com/shimano-un26-square-taper-bottom-bracket/rp-prod34652

 

[jack smith]

Thankyou! Wasnt sure what parts to measure thanks alot, i can vouch for the bolt method though it worked right away, id been at it with a cutting disk an allsorts

 

[jack smith]

125 68 sorted!

 

[jack smith]

Well I've measured 125 a few times but I'm guessing 122.5 will fit?

 

[simon.r]

Well I've measured 125 a few times but I'm guessing 122.5 will fit?

2.5mm difference equals 1.25mm either side - I'd be surprised if the tolerances on an old bike are that critical.

 

[simon.r]

FWIW, the bits that screw into the frame on the BB I linked are plastic. IME not an issue if you're careful and use plenty of copper grease when installing, but be aware.

 

[jack smith]

Cheers! Ive found the correct front mech i need really cheap on halfords too but it says not availible for delivery or store collecton, seems to say that about alot of things.. Think this service might get abit pricey

 

[jack smith]

Ordered the lot from chain reaction, thanks alot, 18 quid to fully to get a bike up and running so not too bad, bottom bracket. Front mech and cable

 

[RecordAceFromNew]

My clunker mtb' cranks kept coming loose due to the bb it also creaks like hell, I've taken it out but this ring is stuck in, how do I remove it? And is it reverse threads cause I'm unsure, also can someone link me to a replacement unit? Preferably one of those sealed things the axle says. 13-10 nlco3s if that helps

You might want to measure the BB axle. If it is a 3S (see the table here) then a conventional Shimano cartridge BB of 122.5mm is not going to give you the same chainline with the same chainset as before, because the 122.5mm UNxx is less asymmetric.

Do you know what the chainline was before you took it all apart? Do you know what chainline the new front mech is designed to work with?

I agree the nut and bolt method is the way to go to remove the fixed cup. A BB cup will likely destroy a saw if the quality of its steel is any good.

 

[jack smith]

Ive no idea about the chainline, if i get some rub im Not too bothered as its just for trails and popping to the shops ect, its due tommorrow so ill post and let you know how i get on