heya
running an Ibis mojo with 2*9
Bash/32/granny up front and 32-11 out back, running 9spd xtr shifters which is why I haven't moved on so far (and prefer shimano shifting)
I keep dropping the chain to the inside through rough terrain and particularly when trying to 'swap my feet' by back pedalling half a stroke between corners.
I go to the alps on Saturday, any quick fixes? what is the 'best' long run option?
are you usuing a 2x front mech. I had this problem when I first converted and just re-adjusted the 3x front mech.
Correct it is just a 3* front mech with the limit screw wound in (and it therefore sitting well above the bash when viewed from the side)
didn't even know there were 2* front mechs...
There's a 2x-specific MRP chainjuide for the Mojo, although 2x chainguides are generaly not great.
1x10(11) is the answer, really.
Probably your limit screws not set up correctly on front derailleur or a worn chain, or too long a chain
could also be stiff cogs in rear derailleur if dropping chain when back pedalling.
agree with a 2x front mech with a short cage.
Look at a Bionicon type chain guide too.
Quick fix might be a Blackspire stinger or something like that to keep some tension in the chain. If you're not spending - is chain too long, front mech adjusted properly etc etc
ooh, yes - you did shorten the chain when you took the big ring off?
Pedal forwards not back. 😉
The dropping chain whilst back pedalling sounds like a symptom of a worn drive train. Check for hooking on the chainrings and the chain wear.
Also 2x front mechs have a different radius on the cage, designed for smaller chainrings compared to 3x mechs.
1 chain tension, 2 recheck everything as it really shouldn't be happening, 3 stick a plaster on it with a stinger or similar which should pretty much fix your backpedalling issue.
Double mech doesn't make a lot of difference ime- easier to set up and a little bit less noisy but I don't think it'll sort you. I've got an SLX double going spare (lighter than XTR triple I think) if you want to try it for not much money but I couldn't guarantee delivery before you go...
chain was shortened, its pretty much right at the limit of how short. Drivechain might be too worn though... mmmmmm
What about hub compatibility these days? im pretty commited to my old skool 9 speed chris king ISO's will that take 10 or 11 speed?
10 speed and Shimano 11 speed no bother, SRAM 11 speed needs a specific freehub though maybe King make one?
Nothing intrinsically wrong with 2x9.
As above, pedal forward not back. If chain is jumping off you may have a stiff link in your chain?
To increase chain tension you could fit a clutch mech but I think they need some twiddling to work with 9 speed. Else get a front chain device as discussed here -
[url] http://singletrackmag.com/forum/topic/chain-devices-for-double-ring [/url]
Else get hold of a bullet bros chain tensioner but you're unlikely to get any of these before Saturday...
9-speed clutch mech isn't realistic here, it's simple enough to do with SRAM 9-speed but not with Shimano so it'd mean replacing so many parts, you might as well just go the whole hog
