Bottom bracket spindle length question

ricktabor1

I've got a problem with a Trek Pilot 1.2 (2006).

The BB needs replacing and i'm not sure what spindle length I need. I've ordered a new BB removal tool which hasn't arrived yet so I can just look at the one that needs replacing.

The bike has a 68mm shell and a Bontrager Select triple chainset.

Does anyone know what size i need? Also how do I find this kind of info? Shimano is good for the tech docs but I can't find info on other makes.

Thanks

alfablue

You can measure the length of the existing spindle (D) (assuming the cranks are off)



It is possible that the ends are not symetrical, but if they are equal length then its simply 68 x D for your BB size (such as 68 x 113 for example).

See http://www.sheldonbrown.com/bbsize.html

anyuser

Have a look here:
http://www.sheldonbrown.com/bbsize.html
Sheldon lists 113mm for all Bontrager square taper versions and 118 for the ISIS triple.
Personally I would wait and get the old one out and measure just to be sure.

alfablue

Shimano UN54 for £15 here: http://www.ukbikestore.co.uk/product/16 ... taper.html

Pretty good price, this BB should last for years.

keef66

Some sizes of UN54 are even cheaper at CRC. (Unfortunately not the size I needed though!) and they have the UN26 in 3 sizes for £9.99.

maddog 2

ebay has loads of UN54 sizes too

and a few of the much lighter UN71/72/73

ricktabor1

Thanks for the advice guys.

I forgot to say, the BB is splined (ISIS).

I'll have a go at measuring it whilst in the shell. See if it agrees with old Sheldon Brown's listing.

nicklouse

ricktabor1 wrote:

Thanks for the advice guys.

I forgot to say, the BB is splined (ISIS).

I'll have a go at measuring it whilst in the shell. See if it agrees with old Sheldon Brown's listing.

it will be one of 3 length and most likely be 118mm for a tripple
see
http://www.bikeradar.com/forum/viewtopic.php?t=12737715