new bike chain is constantly jumping off bottom jockey wheel and pissing me off!!!!Is there a simple solution? hanger is not bent and gears index well!
Never had a chain jump off a shimano jockey wheel!

I had a Dura Ace mech do this repeatedly. Replaced jockeys, still did it. Replaced the mech in the end, think it must have been bent.

Sorry, doesn’t really help!

mech is a month old and looks sound!!!

How is the lower limit set? Mine has done it a couple of times and a tweak of the lower limit sorts it

What do you mean by the lower limit Mike?

Stop screw I’m guessing?

The high low limit screw (3 or 4mm allen key bolts) that set the limits of travel for the mech. Should stop your mech running too low.

I had this on the dh bike.Swapped it for an identical one off a more worn mech….solved.Dunno how that works.

done some tweaking still having the same problems so much so there is a nice gouge in my cage,hard to spot when your riding in filth!!! On the stand when I,m spinning the cranks a slight push sideways of the chain and off it pops 🙁

[url=https://flic.kr/p/qyeRUM]10917273_10153071275801474_626330306961839551_n[/url] by Richard Munro, on Flickr

Any ideas apart from a new mech

Check that it has ‘lower pulley’ marked on it (I know its new but it could still have happened in the factory).Outwardly the upper and lower look the same (unlike shimano).

Is the jockey in the wrong way round? try swaping it around,and give a clean too 🙂

Checked for lower pulley and its correct !! tried pushing a chain off the lower jockey on my shimano equipped bikes and its impossible!

Mech has not had the jockey wheels out and I doubt you can put a jockey wheel on the wrong way 😉

Is the chain running through the jockey wheels correctly.

I’ve just bought a bike and the chain was routed wrongly and ran over a bar that stuck out between the mech plates instead of under it.