Forum menu
Bottom bracket
 

[Closed] Bottom bracket

Posts: 0
Free Member
Topic starter
 
[#1671169]

If I don't have a original bottom bracket how do I find out the axle length? if I know the BB shell length?


 
Posted : 03/06/2010 9:18 pm
Posts: 507
Free Member
 

It's dependant on the BB shell width and the chainset that you're using.


 
Posted : 03/06/2010 9:42 pm
Posts: 0
Free Member
 

And what chainline you need to achieve!


 
Posted : 03/06/2010 9:45 pm
Posts: 0
Free Member
Topic starter
 

Don't know the chain line because it's going to be single speed


 
Posted : 03/06/2010 9:52 pm
Posts: 0
Free Member
 

You'll need to match the chainline of the cranks/crankset with the rear hub to get your chain running straight.

What are planning to run?

Have a look at Sheldon Brown if you don't believe me!!


 
Posted : 03/06/2010 9:59 pm
Posts: 0
Free Member
Topic starter
 

Do believe you :P. It's going to be Deore canks with a single speed at the back on a carerra kraken frame. Surely I can get any size then adjust at the back with spacers?


 
Posted : 03/06/2010 10:01 pm
Posts: 0
Free Member
 

Well, my approach would be to find out what chainline Shimano specify for your crankset and they should, to answer your first question, give a BB spindle length to achieve this chainline. The chainline measurement varies dependant upon whether it's a triple or double and where you happen to place your single chainring. If struggling, Sheldon Brown's website does list this but often the specific page can be a bugger to find.

The BB shell width is the least critical reference.

Then you source a hub that gives you as close to this chainline as possible and hey presto, you'll have minimal need for the use of any spacers.

This is maybe complete crap and I'm talking out of my rear but it makes sense to me!

I'm guessing if Deore they're old style hollowtech octalink cranks?


 
Posted : 03/06/2010 10:29 pm
Posts: 0
Free Member
Topic starter
 

Yeah they are the old style cranks I'm going to buy later


 
Posted : 03/06/2010 10:41 pm
Posts: 25939
Full Member
 

are you using a ss wheel or a cassette wheel with a "kit" fitted ?

The latter is pretty easy to alter chainline by re-spacing at the back; former much more important to get the front bang on

(err, I think)


 
Posted : 03/06/2010 10:45 pm
Posts: 0
Free Member
 

Not that I came on here to try and sell you anything but I do happen to have some black Octalink crank arms, an alloy SG-X 32T chainring. All in pretty good shape but not perfect by any means.

Going for a song as they're absolutely no good to me whatsoever!!

If not that's fine and good luck with it all.

Cheers.


 
Posted : 03/06/2010 11:02 pm