I like bodging (though sadly I don’t have much time for it these days), often for the sake of it alone, and looking at the new clutch rear mechs, unless I’ve missed something, they’re simply normal mechs with the tensioner pivot having added drag to prevent chainslap.

Given that, I reckon you could make a normal mech into a ‘clutch’ one just by adding friction to the movement of the cage. Obviously you could do that in many ways but I reckon that you could relatively easily do it with some shims and then by adjusting the tension on the pivot bolt.

Don’t suppose anyone’s tried it yet, have they (Well, I guess that I did years ago when an XT mech corroded and wouldn’t pivot smoothly 🙂 )

Doesn’t it need to only resist in one direction though?

Yeah, it’s not just draggy, it needs to be able to return normally but resist “stretching”

Think car seat belt – allows a slow year changing pull but a quick chainslaping jerk will lock it out.

OK, maybe more thought needed 🙂 I should add that I haven’t actually seen one in the flesh yet..

Wasn’t there an external spring you could attach to an aluminium bar that pulled the rear mech back?

Similar era to the Dave’s Chain Device, and yet again proof that everything comes full circle.

Bullet Bros Chain Tensioner
Bit of metal and a spring for the home bodge.

I had one of those in the 90s 🙂

Buy one and strip it to work out how it works

Something like this?

Ive just done the ‘shimano clutch with sram 9spd shifter’ and have to say im chuffed i found out about it before i wasted time trying to work out how to bodge an existing mech.

9 speed? Tell me more.

You take a shimano 10spd mech, fit a 6mm spacer to the cable clamp, mate up to sram 9spd shifter. Sorted, 9spd clutch. There are many threads about it on here and mtbr, check the wolf rings thread for a bit more info.

The clutch is just a sprag bearing with a band brake wrapped around it. The switch tightens/loosens the band, tension on which can be tweeked by adjusting a small nut. Pay the extra £20 – they work well IMO.