Gear problem!

[anonymous]

When I put my bike in low gears, the chain constantly jumps from its intended gear to a lower gear and possibly tries to correct itself. Almost in a jagged motion where my leg will loose any tension and then tighten again, and then continue in that process.

What could this be and how could I fix this?

Thanks

[cny-man]

Too many possibilities for the info given.

Need 1st to say which combos of front rear are a problem and which are OK. Also please use largest/2nd largest rear cog, middle chainwheel, 24 tooth cog on 11-28 set, etc, rather than low/high gear. People are not consistent on what they call low and high gears.

Next need to know when the problem started and if any maintenance or incident immediately preceded the problem beginning.

Also need some info about age of the bike, number of gears.

Until more info is available it's just a guessing game, rather that logical troubleshooting.

Thanks.

[DaveM]

If it's actually jumping BETWEEN gears, could be just a shifter adjustment, problem with derailleurs, etc.

If it just suddenly let's go when you're are putting a lot or pressure on the pedals and then re-catches while staying in the same gear, this is more often a sign of worn chain and gear cluster.