A
Andrew Cooke
Guest
Hi,
Has anyone else experienced the following (and knows how to fix it)?
Three times now (the last two while riding on a fairly rough surface at speed, so with a fair amount
of vibration) the chain has jumped off the outer wheel of the derailleur and jammed between that
wheel and the cage frame. By outer wheel, I mean the toothed wheel nearer the ground (and not the
other one nearer the rear wheel hub; together these two wheels form the chain into an S shape) -
what Shimano calls the "Tension Pulley Unit" at
http://bike.shimano.com/product_images/RD/ev_images/RD_M330-8_EV.pdf
It sounds impossible, but if you look at an Acera derailleur, the frame is actually quite wide where
the chain leaves (apparently on purpose, the sides of the cage are pressed with a step shape to
increase the width).
First time I stripped and cleaned the derailleur. This evening I've done the same, but also bent the
cage sides a little to reduce the gap.
I can't believe this is normal - I know this is a fairly cheap component by some people's standards,
but in my experience Shimano's moderately priced stuff works well when correctly adjusted (as far as
I can tell, this is correctly adjusted - which is why I'm asking for help!).
Probably unrelated, but the whole derailleur feels a bit stiff when shifting to larger sprockets.
Thanks, Andrew
--
http://www.acooke.org/andrew
Has anyone else experienced the following (and knows how to fix it)?
Three times now (the last two while riding on a fairly rough surface at speed, so with a fair amount
of vibration) the chain has jumped off the outer wheel of the derailleur and jammed between that
wheel and the cage frame. By outer wheel, I mean the toothed wheel nearer the ground (and not the
other one nearer the rear wheel hub; together these two wheels form the chain into an S shape) -
what Shimano calls the "Tension Pulley Unit" at
http://bike.shimano.com/product_images/RD/ev_images/RD_M330-8_EV.pdf
It sounds impossible, but if you look at an Acera derailleur, the frame is actually quite wide where
the chain leaves (apparently on purpose, the sides of the cage are pressed with a step shape to
increase the width).
First time I stripped and cleaned the derailleur. This evening I've done the same, but also bent the
cage sides a little to reduce the gap.
I can't believe this is normal - I know this is a fairly cheap component by some people's standards,
but in my experience Shimano's moderately priced stuff works well when correctly adjusted (as far as
I can tell, this is correctly adjusted - which is why I'm asking for help!).
Probably unrelated, but the whole derailleur feels a bit stiff when shifting to larger sprockets.
Thanks, Andrew
--
http://www.acooke.org/andrew