You are hereForums / By Discipline / Mountain (off road) / MTB Gear / Chain drop from top derailler
Chain drop from top derailler
G'Day !
Long time reader, first time blogger !
Can anyone suggest why the chain "drops" from the middle front chain ring when I go down "steps" etc.. Depending on the "drop" the chain "falls" to the smaller cog.
Any ideas ?
Cheers, Toddy
- Login to post comments
- Bookmark & share
Tags
The rear deraileur flaps around when going down stairs. This may slacken the chain for a bit allowing it to fall off the chainring.
To increase your tension, remove unnecessary chain links. Put the chain on the largest cog front and back, the rear derailleur should be at least perpendicular to the ground, i prefer my pulled forward a bit. NB, if you have a dually, you have to allow for chain stretch as your suspension compresses (depending on your suspension design).
Also, ensure your derailleurs are correctly setup.
lastly, when riding down stairs, put the chain in the larger sprcokets to provide a higher chain tension.
Cheers for the suggestions. The "steps" I'm referring to are "rocky" as oppose to the "walking" type! And the chain always comes off the front, that is, from 2nd (middle gear) to 1st (bottom gear.
I've wondered if the chain maybe slack, but gear changes are tight, there's no slippage under strain, only when "bouncing" over rough terrain.
Any other suggestions ?
Cheers
jpack covered it all there. All bikes do it if you don't have the chain at the right tension, unless you have a chain guide as many down hillers do. You might want to check your rear mech is set at the correct distance from the large ring too.
I would try shifting to the bigger ring when hitting the rough stuff.
Hi Toddy,
Check your chainwheel offset. I had the same problem with my old deore crankset. I switched to an SLX crankset that sat closer to the frame and haven't had an issue since.
Thanks to all. I will check the distant on the rear mech and change to the larger cog when hitting the rough stuff.
Thanks again, appreciate your help and comments
Toddy