hi guys.chain keeps dropping when changing down to granny ring.
running 22/36.
xt 22
deore 36
xt HT11 cranks.
slx twin front mech.
blackspire stinger
iv,e adjusted the mech position and stop screws until i can adjust no more.
this ones got me beat.
i need help before i top myself...
cheers...
wrong bb?
So how can it drop the chain off the granny if the lower mech stops are adjusted up so the chain can't go through the gap. Is the mech at the right height on the seat tube. Chain line / bb spacers correct. Try removing a spacer if you've got two on the drive side ie 68mm shell.
,
thesweed.as i change down the chain just flies through.i,ll try removing a spacer and see what happens.
the adjusters seem to be spot on..
as i said it,s got me beat...damm mountain biking... 😉
Or go ss 😉
hahaha.yer there,s always that option.
right...just done it in slow motion..
the chain seems to be sticking to the front of the 36 as i change down to the granny so as it comes to the bottom it kind of flicks over the granny.
both the chain and the 36 have only done about 100 miles.
Start from the beginning.
Cable/outers properly seated?
Mech properly positioned? Should be 1-3mm clearance between outer plate and big chainring in the outboard position. Mech parallel with chainrings?
Correct arrangement of spacers for external BB for 68/73mm?
"Low" limit screw correctly set? Are you adjusting the correct screw? The "L" screw is not always inboard of the two - varies from mech to mech. If the mech is too far inboard to prevent chain dropping even with the "L" screw wound all the way in then you may need some more tension in the cable first.
Good luck
namastebuzz.
thanks bud. i,ll go and have a mess about with it AGAIN...
but i think i can already tick all your boxes..
OK just read your last post.
Make sure the REAR mech "L" limit screw is properly adjusted so there's no sideways pressure on the chain.
Take it you have a long cage rear mech that'll handle the no of teeth and that the "B" screw is adjusted for enough clearance between the guide pulley and the teeth of the 36?
yep.long cage xt.
yep all adjusted spot on.
just put my old xt front mech on and adjusted the stops to suit and all is well.?
slx twin specific is now in the tool box.
namastebuzz...what do you reckon?
Dunno TBH 😕
You've isolated the SLX mech as the problem at least. Does the curvature of the SLX mech match the chainrings?
I'd run with the XT front mech if it works well enough I guess?
Look at the Shimano tech docs for the SLX mech - maybe you're overlooking something in the set-up?
Or, more precisely, [url= http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SLX/SI_6PZFA_002/SI-6PZFA-002-En_v1_m56577569830647029.pdf ]HERE[/url]
Make sure the cable routing is corect for the SLX mech - it may differ from the XT and may not be readily apparent.
I once had a similar problem with the same setup. In the end I solved it by getting a medium cage rear mech and running a MUCH shorter chain. Cant really tell you how or why that helped, it just did.
Oh one more point not yet mentioned so far. Are you sure your inner ring is mounted correctly relative to the middle one? (If you are not sure, take off the inner one, rotate it one quarter, and put it back on again, see if it shifts better.
Oh one more point not yet mentioned so far. Are you sure your inner ring is mounted correctly relative to the middle one? (If you are not sure, take off the inner one, rotate it one quarter, and put it back on again, see if it shifts better.
Good point too...........
think iv,e sussed out one problem.
in tech doc,s it says that the outer plate should sit basically on the edge of the bash.1mm in ,1mm up.if you do this with a blackspire bash the chain rubs like f..k on the outer plate.so mine was set out by about 5mm(not up).
don,t know how to get out of that one.
both rings are set right.small tab behind arm.
this is the mech in question
namastebuzz.this is the mech in question
Not too well versed in bash plates.
Can you shim it out with spacers to avoid the rub?
yer you could shim it out but unfortunately that would not effect the chain jumping.
OK - so what's different between the XT mech that works and the SLX which won't?
plates seem to be different.