chain coming off

jon1993

I'm gradually getting better and upgrading as I go I've got a boardman pro HT with an fsa comet chainset 2x10. everything is set up right and had it checked over numerous times yet my chain on the chainset keeps coming off either side i go every weekend to dalby and how shakey parts of that are in places my chain comes off when jumping or backing of the power a bit (chain tension reduced) I'm thinking maybe a roller bash guard and box and convert to single up front but rather not if i can help it any suggestions that will fit these odd chainsets (3 pins hold the rings on) thanks

jon1993

P.s. hope this makes sense I'm posting this from my phone and can't see what I've written

MikeMc

Assuming High and Low derailleur stops are set right. Maybe chain length or possibly the free hub is not as free as it should be.

jon1993

no they all seem to be fine i cant put my finger on whats causing it i am riding the bike really hard sometimes though might be something to do with it? thanks alot

captainfly

There are quite a few double ring guides out there like the blackspire singer, e13 helm, gamut P20, MPR LRP etc there are loads so no need to go single and sometimes there is no fathomable reason for a chain to misbehave.

Si1988

I created myself a similar problem a week or two back. It started happening after I over-adjusted the b screw on the rear mech, moving the derailleur too far forward.

Seemed odd to me that it would be the rear mech causing it, but when I was in small ring at the front and around the middle at the back (on a double ring/9 speed setup) it had quite a tight chainline and not much tension.

It's likeley your problem isnt the same as mine, but may be worth a go, try fettling the b screw to angle the mech to a more rearward position, just take note of where it was before so as not to mess things up.

MikeMc

Just another thought, are you able to move the spring in your rear derailleur to give more spring tension. My XO derailleur has 3 positions, as the spring looses tension with time you can move to the next position to increase tension. More tension on the chain may stop it coming off.

jon1993

It could be that I guess but the bike is brand new surely the spring wouldn't have stretched already the bikes done 100 miles just

jon1993

Also I know there's a lot of Double mounted guards bit its finding one that this chainset/frame. The chainset has 3 pins holding the ring and the guards only seem to come in 4/5 pin ones. Also this frame has no attachments for the rollers ect I know some have like 3 pins behind the chain rings on the frame to hold them but this doesn't, any ideas? Thanks again

gilesjuk

Is it shaking off or is it coming off when changing gear?

If the chain is too long it won't help.

jon1993

The chains shaking off generally when I come of the power for a fast decent (more shaking) then try and pedal out and comes off

77ric

jon1993 Is this the 2011 model HT Pro we're talking about?

If so then i'm afraid there is no roller/chain device that will mount with a BB30, there are upper chain devices that will mount on the seat tube but that will mean losing the front derailleur and granny gear, and will not solve your problem.

Check your chain length to start with, if it is too long then that would be a contributing factor to losing the chain. Failing that then I would then check the B screw on the rear derailleur as suggested to check the tension.

Beyond that then i'm not sure what else you can do.

It doesn't sound like a stop limit problem if it is happening while riding rather than changing gear but it might be worth checking the limit stop screws anyway.

jon1993

Yes 2011 model that sucks, ah well ill have to live with it. ill try playing about with it but I'm pretty sure there's nothing up I've gone over it time and time again think ill convert it eventually so I can ride it harder XD haha thanks fot your help!