bottom bracket width (cottered cranks)

[Black Sheep]

Hi, I know this is workshop, but it applies to traditional tech so thought it better suited here.

I need to replace the bottom bracket on my road bike, it's been on there 10 years, done goodness knows how much millage and it rocks and knocks.

What's on is what I could get hold of at the time and the chain line is not great, I've got the bearings and cups to replace, just need an axle.

How do I work out what width I need?

Is there a set way round they're meant to go? - how is this dictated?

ta

 

[mjr]

https://www.sheldonbrown.com/bbsize.html shows you what measurements to take and converts some of the Japanese/Indian codes to measurements. As far as I know, there's no set way round to use them and it's dictated by the chainline you want to achieve. I won't offer more advice because I've got a small collection of wrong spindles and never tried cottered cranks

 

[midlife]

Try and compare measurements with SJS website as a starter.

https://www.sjscycles.co.uk/cottered-traditional-axle/

The longer side goes on the drive side