Commuting - Do I need special chainrings and cogs for SS?

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rykoala
07-08-04, 02:10 PM
Tonight I get my old 1990 Trek 820 back. Its a good bike with a bent derailer hanger. Gonna convert it to SS, if the dropouts are OK, can't remember if they are or not.

Can I just use the chainring that's on it (probably a 48) and one of the rear cogs spaced for a good chainline? Will those have problems with derailing? Will I need a BMX cog in the back to make it work?

Thanks.

EDIT: Its a moot point. Vertical dropouts!
Another EDIT: D'oh!!! Wrong forum at that. Must get more sleep.

Is there a mod that can delete this for me?!

svwagner
07-08-04, 03:25 PM
Even though it's sort moot...

1. You can use biopace.
2. BMX cog with spacers in the back
3. Chain tensioner, ENO hub, or a lucky cog/chainring/chainstay length combo.

no.
RainmanP
07-09-04, 06:44 AM
It's still possible. In fact you could just use whatever freewheel or cassette you have. It would cost you nothing, but you may have to compromise on your gearing. Take off the der wrap the chain around the chainring and a suitable cog. See if it looks like you can get a snug chain. If you can get a snug chain your chainline can be off a bit and still work. Assuming you have a double crank, you can move the chainring to the inner or outer position to try different cog and chainline setups. You will still have a multi cog rear, but you will be riding single speed at no cost. If you find a gear combination that gives you a reliably snug chain, you could spring for a ss freewheel of the same size. I like Shimano because they are only about $20 and quieter than others I have tried. If something like 48/18 works that is not a bad combination if you don't have many steep hills. The thing is, play around with what you have to see if you can get something to work.