i’m looking to put a cassette and rear mech on my inbred 29er swap out. ideally a single chainring with a 9 speed cassette. currently running 32/14 singlespeed. i read something about new shimano rear mechs with some kind of clutch mechanism – if i put one of these on, could i get away without a chain device to stop the chain dropping off the front? or would i still need something like the bionicon chain guide?

thanks.
L.

I still use a top guide but it removes the need for a bottom one (or, so far anyway, still testing).

But, 10-speed only.

As northwind says, they’re only suitable for a 10 spd drivetrain as the cable pull ratio is slightly different.

Ah – that’s stuffed it then. i have an older xtr shifter pod that i want to use. 9 speed only.

what would people recommend to keep chain on with a single chainring set up on an XC bike?

ta,
L.

That’s what I use, weighs next to nothing, easy to setup and comes in black too.

EDIT: That’s the M:Part Single Ring XC chain device, RRP £29.99

I’m using the same device (only branded up Superstar) on a 1×9 XC bike. It’s not quite enough but combined with a proper single ring the chain drops rarely. FWIW my MRP 1x works a little better, but it’ll still let the chain drop on this setup as it can flap off the bottom.

So, good enough for me, or at least, good enough to prevent me from wanting to fit a bottom guide or change another bike to 1×10!