seanb

I have an 80's or late 70's Univega "Viva Sport". I know the largest gear in the front is 51 teeth and the smallest in the back is 13. My goal is to get more speed. Ok - I could increase my RPM on the peddle - but if I change the 13 tooth to a 7 tooth - will I get more speed or just tire myself out? Has anyone on this forum ever changed their gear ratio?

I did find this site to help with the calculations - but what about the weight of the person or the bike?

https://www.arachnoid.com/bike/index.html

Moose

Take your bike to a mechanic and he'll tell you what your options are.

KevinF

You're going to have a very hard time finding anything smaller then a 12-tooth cog. The diameter of the freewheel coupled with the size of each chain link makes anything smaller then an 11-tooth cog physically impossible. You can change the chainrings up front if you want; you should be able to easily find something larger there. I don't think you're suddenly going to find yourself going any faster though (except on downhills).