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Rear derailleur pulls forward when backpedaling

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Rear derailleur pulls forward when backpedaling

Old 08-06-09, 04:06 PM
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dave manner
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Rear derailleur pulls forward when backpedaling

What could cause the rear derailleur to pull forward when backpedaling? Thanks!
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Old 08-06-09, 04:49 PM
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Don't backpedal.
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Old 08-06-09, 07:22 PM
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kycycler
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free hub or freewheel locked up.
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Old 08-06-09, 07:27 PM
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could be sticky pulleys. when you are pedaling forward the derailer is already pulled back tight. when you backpedal it will pull forward if the force needed to pull the derailer is less than the force needed to spin the pulleys backwards and let the chain through.
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Old 08-06-09, 07:31 PM
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If it is intermittent it could be a stiff chain link. It might also mean your shifter is slightly out of alignment.
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Old 08-06-09, 07:44 PM
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Originally Posted by cooker View Post
If it is intermittent it could be a stiff chain link. It might also mean your shifter is slightly out of alignment.
+1 This is what I was thinking. Or an old chain with a dried-up RD in need of cleaning and oiling.
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Old 08-06-09, 10:43 PM
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Originally Posted by cooker View Post
If it is intermittent it could be a stiff chain link. It might also mean your shifter is slightly out of alignment.
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Old 08-07-09, 02:51 AM
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It will also be yanked forward due to chain-line angles. If you're 2-3 gears sideways of a perfect chainline, the front-chainrings will bend the chain sideways and it'll rub the RD cage-plates when you pedal backwards. This will drag the RD forward with the chain.

Don't backpedal, what good does it do for you? It's a waste of energy and doesn't do anything to move you down the road any faster.
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Old 08-07-09, 06:32 AM
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Originally Posted by kycycler View Post
free hub or freewheel locked up.
No. A sticky freewheel will cause the top of the chain to go slack, and make it impossible to coast.

Originally Posted by cooker View Post
If it is intermittent it could be a stiff chain link. It might also mean your shifter is slightly out of alignment.
Not likely. A stiff link will be noticeable pedaling forward as well as backpedaling.

Originally Posted by DannoXYZ View Post
It will also be yanked forward due to chain-line angles. If you're 2-3 gears sideways of a perfect chainline, the front-chainrings will bend the chain sideways and it'll rub the RD cage-plates when you pedal backwards. This will drag the RD forward with the chain.

Don't backpedal, what good does it do for you? It's a waste of energy and doesn't do anything to move you down the road any faster.
Maybe, but the OP never said anything about intermittent, so probably not.

Originally Posted by wearyourtruth View Post
could be sticky pulleys. when you are pedaling forward the derailer is already pulled back tight. when you backpedal it will pull forward if the force needed to pull the derailer is less than the force needed to spin the pulleys backwards and let the chain through.
That's the right answer.

em
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Old 08-07-09, 06:53 AM
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Originally Posted by DannoXYZ View Post
It will also be yanked forward due to chain-line angles. If you're 2-3 gears sideways of a perfect chainline, the front-chainrings will bend the chain sideways and it'll rub the RD cage-plates when you pedal backwards. This will drag the RD forward with the chain.

Don't backpedal, what good does it do for you? It's a waste of energy and doesn't do anything to move you down the road any faster.
I doubt the OP is coasting along backpedaling continuously. The occasional backpedal can be used to relieve your muscles by changing their movement, or you may want to backpedal a little at a stop to get your pedals in the right position to start up.
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Old 08-07-09, 09:44 AM
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Or maybe people do it because they are bored, mindless, have nothing better to do, or it's the last brake they have because they didn't maintain their brakes, the soles of their shoes, and their significant other who would wack them in the side of the head to instill some some common sense.

Just bringing up other possibilities ya know...

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Old 08-07-09, 11:23 AM
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dave manner
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Thanks all!

Thanks everybody! It turns out the chain was just too gunked up!! I was looking at a used bike for sale, spun the crank backwards with my hand and noticed the derailleur pulled forward...I ended up buying the bike today, nothing a cleaning and adjustment didn't take care of. Thanks again everybody!
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Old 08-07-09, 12:15 PM
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