you can count the cogs on the rear wheel..
and you can measure how wide the inside space between
the rear dropouts..
If there is 126mm (Like 5") between the dropouts .. that's all you got ..6 ...
or 7, which is just making space between the cogs narrower to get another one in the same frame.
Given : cannot spread an aluminum frame , so thats what you have to work with.
But it will still get you down the road just fine..
Last edited by fietsbob; 03-24-11 at 06:27 PM.