Seem to be a few manufacturers heading towards this sort of design.
Anybody have any experiences or opinions to share on them?

a mate has one, a race face one. He also has a fancy clutch mech. His chain still comes off. But he says much rarer than it used to. (it is a 150mm suspension bike)

Thats all I know

What is one?

A chainring with alternate thick/thin teeth that fill the gaps on your chain to stop it falling off as often/ever. Used with a clutch mech you might not need a front chain device. Only used on 1 by X set ups. SRAM do them as a full drivetrain set and Raceface/Works components, etc do the rings for DIY types.

johnnystorm wrote:A chainring with alternate thick/thin teeth that fill the gaps on your chain to stop it falling off as often/ever. Used with a clutch mech you might not need a front chain device. Only used on 1 by X set ups. SRAM do them as a full drivetrain set and Raceface/Works components, etc do the rings for DIY types.

That makes sense :D Nice idea, assuming it works

Fair few people on pinkbike who swear by them, When they tested some apparently never dropped the chain once.

I've had a prototype one on a rigid 26er with 1x9 gears and a non clutch mech. I've not dropped the chain despite riding on various rough surfaces. Rocks roots etc.

Ian if you want to try one I have it spare currently as the bike has been decomissioned.

Are you thinking of going gears Ian!?

Ian, they need to be combined with a clutch mech to be fully effective off road.
I have one of the race face ones on my CX frame for about 2 months running 1 by 9 with a normal mech and it's not dropped, but it doesn't see full knarly action, a normal ring was dropping often, usually when back pedalling.

The XX1 crank and rings are another story. I've raced with the XX rings all year on a full bouncer, with a SRAM 10 speed clutch mech and have never dropped the chain once. Quite often swap from 34T to 28T using the same chain length and even with the "looser" chain, still no problems on some fast very bumpy courses. Love it and the clean lines of having no crap around the front ring, no mud build up is a bonus too.

I've had one on my chromag for 2 months with a clutch mech ,not dropped chain once in all kinds of terrain

OK, thanks for the all the replies folks. Very helpful. I've also read around a bit too and it seems you have to run these with a 10sp chain? The upside, is 10sp chains apparently work with 9sp cassettes?
Problem I have is in my box of gear gubbins (its not a very big box...), I only have 8sp cassette and thumbshifters. So, it seems without spending some extra reddies beyond the chainring, I don't think I'm going to get it work.

In which case, I'm on the look out for a chain device that will span the gap on a 100mm BB shell :?

In which case, I'm on the look out for a chain device that will span the gap on a 100mm BB shell

'Pauls' might work as is ... it could certainly be made to work

My OO Fatty was built up from a frame kit. I'm using a superstar BB mounted front chain device in place of a spacer. I've fitted a washer in the bolt that holds on the plastic bit to improve the fit. Might not need that depending on the cranks, etc you've got.

You could get a problem solver direct mount adaptor for 100mm bb shell and then get a direct mount chain guide.
http://problemsolversbike.com/products/ ... ur_adapter