What bottom bracket do I need?

[Runes]

Hi,

I've got an old, worn out one of these Marin bikes, and I'm going to have a go at refurbishing it:

https://www.bikepedia.com/QuickBike/BikeSpecs.aspx...

It's currently got a square taper bottom bracket:



I want to fit this Shimano SLX crankset:

http://www.chainreactioncycles.com/shimano-slx-m55...

I've read up about it, but can't figure out what bottom bracket I will need to make it fit. Can anyone help, please?

[CoolC]

something like this: http://www.wiggle.co.uk/shimano-bb-r60-ultegra-680...

[Runes]

CoolC said:

something like this: http://www.wiggle.co.uk/shimano-bb-r60-ultegra-680...

OK great, thanks. That's what I thought, but the choice seems bewildering. I'm guessing I need the English threaded option, not the Italian threaded?

[Magic919]

If one side is left hand thread and the other is right hand, you need English.

[CoolC]

A Marin will be English thread.

[Bobley]

Some folks will say that you need to get the ends of the frame re-faced to ensure a smooth flat contact from the Hollowtech cups into the frame and it's a good idea if you can find a friendly bike shop to do it for you (not all bike shops bother) but I fitted a Hollowtech to an old Marin about 5 years ago and it worked fine.

[Runes]

Many thanks for all the information guys.

[Barchettaman]

Bobley said:

Some folks will say that you need to get the ends of the frame re-faced to ensure a smooth flat contact from the Hollowtech cups into the frame and it's a good idea if you can find a friendly bike shop to do it for you (not all bike shops bother) but I fitted a Hollowtech to an old Marin about 5 years ago and it worked fine.

Yep, this is a good idea - they will clean up the BB threads too, so it will most likely prolong the life of the external BB as well as improving its performance with refaced surfaces.

[mikey P 500]

The slx crankset will include the external bottom bracket as part of it. Worth measuring the bike to check but assuming you have a 73mm bottom bracket, fit just one spacer to drive chain side when installing, if you have a 68mm bottom bracket then use all 3 supplied spacers (2 drive chainside and 1 on other. Other than needing the correct tool (only a couple of pounds) its very easy to fit.