Pls help - chain catching in RD cage...
 

the chain seems to be catching in the rear mech cage.

It happens much more in the smaller cogs and when I ride it feels like the chain is jumping - but it isn't changing cogs..

When I pedal with bike off ground to watch it - what happens is the chain seems to get caught for a second and the cage gets pulled forward a little - then it releases and hence it feels like the chain has jumped...

Anyone had this ? know what it is ?

I took the mech off my old bike & it worked fine on that -

the cable tension is set fine and the chain shifts fine - so it's not cable tension

Thanks..

The RD wheels may be too close to the cogs.
There is a "B" screw that can be adjusted to prevent this.
You could have a stiff chain link.
Chain may be too long allowing RD wheels to fold back too far.

Enjoy

Ultegra RD and Shimano chain?

No, it's an MTB shimano XT RD with Sram chain...

sounds like it's one of the 3 possibilities mentioned by powers... will give that a go.

thks !

I had the same problem on a highbred, turning the chain real slow while watching every link pass over the rollers, I identified a stiff link.

Yup - stiff link it was... brand new chain as well...! thanks for the good advice.

Can I change the faulty link ? it's a Sram chain and I must admit I am having trouble using the chain tool to add links back in.

The tool is easy to use to take a link out, but when I try to add a link the pin doesn't click back like it does when it clicks out, so you have to see by eye when to stop pushing it through and always where I joined the link it is very stiff.

am I doing something wrong ?

You should be able to losen the link with your hands by flexing the chain in the link area side-to-side. It is not a big deal. Just repeat it until the link gets reasonably loose.