Explanation for the simple minded needed

THanks

In a nutshell they stiffen the mech cage so that they don’t spring back when chain tension is slack and as a result the chain is less likely to jump off the chainring.

Increase cage tension, so the chain doesn’t bounce.

The clutch generally stops the cage moving forward, almost eliminating chain slap and helping your chain stay where it should.

Edit: and what they said ^^

OK, thanks

How long have they been around?

http://www.pinkbike.com/news/Tech-Tuesday-Inside-Shimanos-Shadow-Plus-Mech-and-How-To-Adjust-.html

Great stuff

Mine’s a SRAM, but gotta be similar eh?

Are they generally considered any good?

They’re good but seem to be wearing out quicker for some riders (the clutch part, the mech part is the same as a non-clutched mech essentially.).

Some would argue a clutch introduces unwanted dampening in the rear suspension if you have a full sus, that adversely effects the feel of the suspension.

Generally, most people like them. My next bike will have one as stock spec.

My drivetrain is noticeably quieter having fitted an XT clutch, I’d agree with the sentiment that they would inhibit the suspension performance for some bikes, but then so would a chainguide.

The SRAM solution is very elegant with a sprung loaded pin doing the work of lots of gubbins that occasionally break in a Shimano mech

What do they do?

Break mostly, IME.

So the SRAM is the better design?

What happens when they break?

My new bike has one, Sram X01, but haven’t really noticed it. But then no chain slap either so it clearly works.

At a guess, clutches on hardtails would last significantly longer than those on FS bikes? Especially those with large amounts of chain growth.

This is based on the logic that each shift and each movement of the suspension causes the mech cage to rotate against the friction of the clutch.

bonesetter – Member

What happens when they break?

There’s a wee bit of folded metal in the mechanism that snaps- no fuss to get it replaced on warranty though (I got a whole new mech, which was kind of overkill for a single wee part). But it just turns them into a normal mech so it’s no big deal really.

Oh aye, they do also break like other mechs break naturally- some folks think they break more, not convinced, my XTs have been battered but have held up really well

OK, thanks.

So carry on