BB question

[m@]

Apologies in advance if this is a particularly stupid question, but is it possible to swap out an old cup'n'cone BB for a cassette one, or are the threads/sizes different?

[LuckyPierre]

As far as I know it is.

[Mulger bill]

Different tools but same job M@.

Just bear in mind there is multiple "standards" in thread pitch and handedness make sure the cartridge unit you buy matches the old one.

Shaun

[il padrone]

BB threads are two main types - English with rh thread on left cup, lh thread on right cup; and Italian with rh thread on both cups. There is also French threaded BBs which may be found on some old bikes.

See Sheldon Brown for more details.

[RoryW]

Apologies in advance if this is a particularly stupid question, but is it possible to swap out an old cup'n'cone BB for a cassette one, or are the threads/sizes different?

As well as the thread types there is also the BB shell width - usually 68mm but could be anything from 68-76, and the overall length of the axle - 113, 115, 121 are typical but all sorts of lengths are possible

Fiddling Last week with an old Carlton/Raleigh which has a 72mm shell. Ended up using an old Nervar branded axle from my old parts tin.

Also depends on the crank and the taper and the overall geometry. I have shimmed cartridge BBs to imrove the chainline also

As advised elsewhere its all in the capt'n's (Sheldon's) database, Bless him.

Rory W

[m@]

Might just give this thread a bump

Thanks for the replies, does anyone just happen to know the shell width, thread and axle length for a Repco Traveller, circa 1990ish, off the top of their head?

If not I guess I'll have to break out the tape measure

[LuckyPierre]

If I get annoyed by posts that ask questions that are readily answered by the most obvious of searches, how annoyed should I get by that one m@?
But, to be honest, I was out of my chair and halfway to the door with my tape measure in hand before the 'indignation' set in.

[vx255]

Might just give this thread a bump

Thanks for the replies, does anyone just happen to know the shell width, thread and axle length for a Repco Traveller, circa 1990ish, off the top of their head?

If not I guess I'll have to break out the tape measure

I fitted a standard 68mm cartridge BB to both my 92 Repco and my 88 Ricardo (Shimano UN54 or something similar they were).

Eddie

[m@]

If I get annoyed by posts that ask questions that are readily answered by the most obvious of searches, how annoyed should I get by that one m@?

Well, I was just hoping someone knew offhand... not entirely sure how to measure the diameter and axle lenghth, and don't have the tools to remove the old bb and inspect the threads... Couldn't fing anything with google either so thought I'd try my luck here.

I fitted a standard 68mm cartridge BB to both my 92 Repco and my 88 Ricardo (Shimano UN54 or something similar they were).

Eddie

Thanks for the helpful answer

[VIC Mech]

try not to over complicate your life!

The diameter of your BB will be the same regardless of its origins. The important things are width, axle length and whether its english italian or french forthe reasons stated above.

Measure the width of the frame and you'll find its most likely 68mm.

measure the axle from end to end and thats the length of cassette type BB you need.

If you dont have the tools to remove the old one take it to someone who does or you stand the chance of ballsing it up badly enough that it could take hours to get out rather than the minutes it should take. Believe me ive done it! It took me 3 hours to cut a BB out of a customers bike the other week.

A quick trip to your local bikeshop and they'll have the old one out and replaced in under half an hour.

Cheers m'dear, JJ