Originally Posted by
Randybb
I have an old 7spd 12-21t uniglide casette that I'd like to upgrade to a modern 8 speed cassette to get some lower gear ratios, at least 28t or 32t.
I'm not sure exactly what I need to do though. Do I need to replace the entire rear hub (it's currently in very good condition)? Do I just need to replace the freehub body? Can I use the same freehub somehow?
Can I use practically any shimano 8spd cassette? How much could I save by doing this myself rather than letting my LBS work their magic?
The number of cogs and lower gearing are 2 separate issues. I have many bikes, most of which have 7-speed cogsets. This is more than enough.
The most practical solution will cost you about $5. Go to your local bike co-op and get a trashed cassette with the bigger cogs that you want. 6,7,8 or 9 speed. Check the 3 largest cogs - make sure these are still good. Unbolt or drill out the 3 pins connecting the cogs. Spend a few minutes grinding the single wide Hyperglide spline on each of the cogs until they slide onto your Uniglide freehub body. Remember to use your old spacers.
This is not rocket science.
Bike shop? Ha. 50% won't have a clue what you're yammering on about. The other 50% will identify that at shop rates, it makes no sense for you
not to just buy a new wheel. BTW: the wheel that they will carelessly shove you out the door with will be for 130 or more likely 135mm stay spacing. It will take 2 strong guys and a whole bunch of frame creaking and flex to fit it in your stays.