I’ve had my XTR clutch mech a few months now and I’m probably nearing 15 rides on the bike that has the mech fitted.

I’m running 2×10 (38/26) with a 11-36 cassette and an SG rear mech. The XTR Shadow+ mech was a replacement for a standard XT mech of the same length (SG). So no difference in chain length. Although the LBS fitted the mech as the bike was in for something else at the time so I presume they just swapped them over.

First few rides, fine, but now when things get fast and rocky it normally bounces the chain off the big ring and onto the smaller inner. On one occassion it dropped onto the bb shell. The reason I bought this mech was to stop this from happening.

I was hoping to avoid a chain device, like an E13 TRS+, so is there anything I can do to improve this? Does everyones clutch mech do this?

I’m only really getting a slight improvement over a standard mech.

Is that not a badly set up front mech rather than rear mech?

Is it switched on? (Stupid question but there is a lever)

Sounds like poorly set up front mech.

Yep, it’s switched on 🙂

So what do I need to look at from a front mech perspective? The shifting up and down the front two rings is faultless.

look at the limits when it’s in position and see if it’s right across the cassette. Then look at chain length, what is spare when running big to big (on the bike as is). Clutch mechs can help but you may need a chain guide. Other thoughts is what gears are you in?

I’m running 1×10 with a top guide (e13 something or other), no bottom guide. The chain never comes off during normal riding (Occasionally it falls off if I pedal backwards, E.g. doing stupid fakie car park stunts). So it sounds like something is wrong.

Check front mech setup. This would be my guess.
Check the clutch is engaged (you should be able to hear it anyway) – lever up
There is an adjustment on the clutch – some people say it needs tightening a bit after a few rides. I haven’t felt the need for this but it’s worth thinking about. http://www.pinkbike.com/news/Tech-Tuesday-Inside-Shimanos-Shadow-Plus-Mech-and-How-To-Adjust-.html

but now when things get fast and rocky it normally bounces the chain off the big ring and onto the smaller inner. On one occassion it dropped onto the bb shell.

Do you mean it does this even when not peddling? if so then its not the front mech.

Sounds like you need to adjust the ‘clutch’ on your rear mech, no idea how to do it but other threads on this subject seem to suggest they need maintenance over time.