After a pretty bad accident at the weekend when the chain dropped off the middle ring and jammed solid between the deraileur and the chain ring just in front of a tree stump on the marin trail, I feel I need a chain guide.

or at least thats what I think I need. But from googling around they appear a bit of a mystery, can anyone tell me what exactly I need in order to fit one, there seem to be a myriad of different types (and costs) and I've read some things that imply I will need a new bottom bracket too.

Also, Do they have any bad side effects?

This is for a 2005 specialized Enduro Expert, if anyone has fitted one to this bike I'd appreciate your comments.

Hey there, I'm also on the look out for a chain device and have been reading up on them. The first thing to note is that you will probably have to loose a chain ring and go to only the middle and inner up front. As far as I'm aware the only 3 ring guide on the market is called the Heim 3guide, check out the reviews at mtbr.com. I'm also taking it for granted here that you wouldn't like to go to a single ring setup, which would probably suck for riding stuff like the Marin trail.
If dropping to two rings isn't a problem, (remembering you can always fit a 36t middle,) then have a look at the e13 site and the Blackspire site.
As far as compatibility goes, check that the guide is suited to a full suspension bike of your type and the type of bb you have got.
Bad side effects, hmm. some say that they add weight and a slight amount of rolling resistance but that depends on the model.
Speaking of which, does anybody know of a guide that fits hollowtech 11 type cranks i.e. saint, hone, xt

I think Truvativ make one called the shiftguide for two rings as well might be worth taking a look at.

i can't help on the chainguide, but this may be of help to you

http://www.blackspire.com/prod_cguard.html

cheers for the replies.

Didnt really want to lose the 3rd ring, but maybe thats the sacrifice I have to make for a more reliable (ie one that doesent jam in a dangerous spot) bike.

Will investigate some more.

Just about managing to walk without a limp today.

This is what you need. it stops the chain rising under neath the frame between the BB shell and the Chain rings

They sit in the wheel stays behind the seat post tube.

I'm not sure you can use a chain guide if you're using 3 rings,I can't see how that would work


Tell me I'm wrong

Can't see how it works with 2, but never mind, lose the 3rd ring increase your clearance fit a bash guard.

I rarely use the big ring, and I barely notice a difference from the middle to be honest.

Why not save yer money and adjust your front mech properly. A properly adjusted I like the idea of a bash guard in place of the big ring. I only use it to mash on the roads and thats once in a blue moon. Looked at the raceface one today and liked the look of it.

What could be mal-adjusted in terms of the front mech? It shifts to all 3 rings correctly.

I was pedalling hard in the middle ring on the usual sort of bumpy downhill singletrack, and the chain tried to jump to the small ring, but got wedged between the small ring and the front mech and locked the cranks up, sending me down a ditch into a tree stump.

BTW tempted to go to a 2 ring setup, will see how it goes.

Is the chain too slack?

I guess it could be, I havent looked at it to check, its just as it came from specialized, so I assumed it would be set correctly.

You'd have thought so but worth a look

How many miles has it done?

maybe 50 miles, not much less.

Sort out the adustment's first as that should be enough,but if you want a little more security go for one of these
you can then get a 36 or 38 tooth middle ring and then fit one of these
there is a UK importer or go direct to Darkcycles they look even better in the flesh.