Rockhopper BB Help!

[lebowski]

Newbie here, so please treat me gently.... Just getting into refurbing having inherited a 2000 Rockhopper. Having checked it over I need a new BB but despite searching here and elsewhere I can't seem to find a definitive answer as to which BB to buy.

 

[kyle888]

Welcome

A quick google shows a Shimano UN-40 bottom bracket but shell width and spindle length are not listed.
Best bet would be to remove it and measure.
Or measure the width of the frame where the bb goes through it will be either 68mm or 73mm and remove the crank arms to measure the length of the spindle.

Kyle

 

[ishaw]

It will depend on the cranks. What do you have?

 

[lebowski]

Welcome

A quick google shows a Shimano UN-40 bottom bracket but shell width and spindle length are not listed.
Best bet would be to remove it and measure.
Or measure the width of the frame where the bb goes through it will be either 68mm or 73mm and remove the crank arms to measure the length of the spindle.

Kyle

Thanks very much for the welcome and the reply and apologies for the late reply.
The existing BB has got a fair bit of corrosion on it but I can make out PowerPro BB-7?20. Then I can make out B?1.37x?4T, finally there's L-68-R

Investigating I've found this.... https://www.tradeinn.com/bikeinn/en/fsa-power-pro-bb-7420ai-jis-bottom-bracket/138387894/p which looks right, do you think?

 

[lebowski]

It will depend on the cranks. What do you have?

Thanks very much for your reply.

It has what I assume is the standard 3 speed Deore cranks. For the time being I'm happy to run with this set up.

 

[lebowski]

Thanks very much for the welcome and the reply and apologies for the late reply.
The existing BB has got a fair bit of corrosion on it but I can make out PowerPro BB-7?20. Then I can make out B?1.37x?4T, finally there's L-68-R

Investigating I've found this.... https://www.tradeinn.com/bikeinn/en/fsa-power-pro-bb-7420ai-jis-bottom-bracket/138387894/p which looks right, do you think?

Sorry forgot.... The spindle measures 111mm which I'm assuming works out to be the 110.5 on the bikeinn site.

 

[kyle888]

Looks to be the same one. But there is no issue with looking for a Shimano 68mm 110.5mm square taper bottom bracket so you don’t have to buy the same brand you have now.

Kyle

 

[ishaw]

True, any 68 x 110 ISH square taper BB should work.

 

[DirtWizard]

I have a 1998 and measured it as 73x110 square taper

I ordered a Tange from eBay: https://www.ebay.com/itm/291078246208

A digital caliper is your friend

 

[lebowski]

Looks to be the same one. But there is no issue with looking for a Shimano 68mm 110.5mm square taper bottom bracket so you don’t have to buy the same brand you have now.

Kyle

Thanks Kyle, much appreciated