Bit confused by 1998(?) Rockhopper A1 FS bottom bracket

[rmwesley]

I'm sprucing up a Rockhopper A1 FS which I think is 1998ish. Just taken the bottom bracket out and was a bit surprised by the sizing. It is a 73mm shell but only 107mm across the axle ends. I can't see any marking on the BB although a forum Specialized catalogue from 1997 suggests it might be a SBC sealed cartridge. I was expecting to put in the bog-standard Shimano BB-UN300, but the smallest axle width on a 73mm shell is 113mm.

Does anyone know if 73mm x 107mm is indeed the correct size, in which case I'm going to have to cast the net wider than Shimano. A quick Google doesn't bring back too many (any?) options. Or would a 113mm Shimano be an acceptable option?

Many thanks in advance for any advice, Richard.

 

[ishaw]

It all depends mostly on the cranks as to the correct axle length. What cranks are you running? The Sheldon brown site has lots of info on cranks and BBS.

 

[rmwesley]

It all depends mostly on the cranks as to the correct axle length. What cranks are you running? The Sheldon brown site has lots of info on cranks and BBS.

Nothing fancy. I was planning to just put the stock cranks back on, which are SBC "Son of Strongarm" triple 42T-32T-22T 175mm. Think they were manufactured by Sugino for Specialized, but can't find out much about them, even on Sheldon.

I've found used BB on eBay with the correct dimensions (e.g. Shimano Deore XT BB-UN72), but it might be a bit of a lottery how long they will last, so was hoping to put a new one on. I doubt this size is manufactured any more. Will probably just bid on an eBay jobby.

Thanks again.

 

[legrandefromage]

The original looks like a ahimano

Here is a reasonable replacement

Tange LN-3922 Sealed Square Taper Bottom Bracket 73mm All Sizes | eBay

No matter where Tange Seiki products are manufactured, they are all made to the precise Japanese standard. Tange Seiki has a long and storied history in the bicycle industry. Yosujirou Tange founded Tange Tekkousho (Tange Iron Works) in 1920 to produce high end front forks.

www.ebay.co.uk

 

[rmwesley]

The original looks like a ahimano

Here is a reasonable replacement

Tange LN-3922 Sealed Square Taper Bottom Bracket 73mm All Sizes | eBay

No matter where Tange Seiki products are manufactured, they are all made to the precise Japanese standard. Tange Seiki has a long and storied history in the bicycle industry. Yosujirou Tange founded Tange Tekkousho (Tange Iron Works) in 1920 to produce high end front forks.

www.ebay.co.uk

I've officially downgraded my Google skills from "barely adequate" to "pitiful".

Thank you very much. This is exactly what I was trying to find, so much appreciated

 

[ishaw]

The 107mm size was iirc the size for m900 cranks. I might have a decent BB in my stash. I do have a spesh ti BB but can't recall the axle length. I can have a rummage and see what I have if interested?

 

[rmwesley]

The 107mm size was iirc the size for m900 cranks. I might have a decent BB in my stash. I do have a spesh ti BB but can't recall the axle length. I can have a rummage and see what I have if interested?

That is a very kind offer, thank you, however the order has already gone in for the Tange one linked above. The remit for this one is just to get it working again after being left out in the rain for 15 years It never fails to impress me how helpful people are on here.