Rear derailleur pulley sticking when pedaling in reverse

[bake0408]

Just bought a bike a few weeks ago. Nothing fancy, but one with 7 speeds. I recently adjusted the derailleur as it was not shifting to all the gears. It took some doing as I am not experienced with this kind of thing. I got through it, but now after going out for a short ride my chain fell off after I pedaled in reverse (I think). After putting the chain back on I pedaled in reverse on a stand and found that the pulley was sticking and pulling forward toward the front of the bike, thus making the chain longer than necessary. Normally nothing should happen with the derailleur when you pedal in reverse right?? I only go in reverse when going down a hill to readjust my feet positions. Any ideas?? Do I just need to lubricate the pulley?

[RobAR]

... nothing should happen with the derailleur when you pedal in reverse right?? I only go in reverse when going down a hill to readjust my feet positions. Any ideas?? Do I just need to lubricate the pulley?

You are correct in that nothing should derail by pedaling backward. But (and there is always a big but) it is probably more a matter of 'fine tuned' adjustments. Your chainring and cassette teeth are designed to rotate in one direction for shifting. Perhaps I am not understanding why you need to back-pedal to adjust foot position.

[bake0408]

(10-06-2010, 10:19 PM)RobAR Wrote:  ... nothing should happen with the derailleur when you pedal in reverse right?? I only go in reverse when going down a hill to readjust my feet positions. Any ideas?? Do I just need to lubricate the pulley?

You are correct in that nothing should derail by pedaling backward. But (and there is always a big but) it is probably more a matter of 'fine tuned' adjustments. Your chainring and cassette teeth are designed to rotate in one direction for shifting. Perhaps I am not understanding why you need to back-pedal to adjust foot position.

The lowest pulley is coming forward when the pedals are going in reverse, which does not normally happen. Just want to know how to stop that. : )

[DaveM]

You are right that this shouldn't happen. It could be the pulley, but it could also be something binding up in the freewheel/freehub, the chain binding somewhere on the rear cogs' teeth or in the derailleur, or either of the two pulleys. Any of these would lock the chain and make the bottom of the derailleur cage pull forward. Probably have to start eliminating things.

If you lift the chain off and test the pulleys you should be able to feel if they are binding at all.
If you can make this happen again, hold the position and look at the chain as it passes through the whole rear area. Is binding on anything.
Take your wheel off and try spinning the cogs, is it smooth & quiet?

When you're coasting, does the top section of the chain ever suddenly pull forward and the chain goes slack? If so, your freewheel/freehub is probably binding up inside.

[bake0408]

(10-07-2010, 12:55 PM)DaveM Wrote:  You are right that this shouldn't happen. It could be the pulley, but it could also be something binding up in the freewheel/freehub, the chain binding somewhere on the rear cogs' teeth or in the derailleur, or either of the two pulleys. Any of these would lock the chain and make the bottom of the derailleur cage pull forward. Probably have to start eliminating things.

If you lift the chain off and test the pulleys you should be able to feel if they are binding at all.
If you can make this happen again, hold the position and look at the chain as it passes through the whole rear area. Is binding on anything.
Take your wheel off and try spinning the cogs, is it smooth & quiet?

When you're coasting, does the top section of the chain ever suddenly pull forward and the chain goes slack? If so, your freewheel/freehub is probably binding up inside.

I am not really sure where it is sticking. I just know that at some point it is sticking and causing the chain to lengthen and eventually fall off. Would the first place to start be to lubricate any particular area?? It is a brand new bike, I have only ridden it for maybe 10 hours or less. So I can't imagine it is anything too serious.

[Bill]

Just a thought to add possibly a stiff link? If so watch this video to correct it... http://bikeride.com/stiff-chain-link/ .

Also if you said it was a "new" bike you can take it back and have them correct it, unless it was a department store you got it from. I mean yea you could probably return it to get a different one or refund.