chain jumping; quite frustrating, help?

eric- and even now, just riding along on the flat
at 15-20 mph without any unusual pressure applied, it will jump. the
especially disconcerting part is all of a sudden, it feels like i just
shifted into neutral of a car, with almost no resistance at all. i just
start spinning like crazy. BRBR

The chain is dancing or skating on top of the cogs rather than having the chain
engage the cog teeth. I think a rear der problem, with the top pully or the
rear der alignment..Something is not keeping the chain on the cog selected.



Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"