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After years of a completely worn out SRAM GX 1x11 drivetrain i've spent some money replacing everything for 1x11 Shimano XT M8000 kit, including the shifter, medium cage mech, 11-46t cassette, inner and out cable and replaced the chainring and chain for new.
I'm having real trouble getting it to shift smoothly and stay that way through a ride, ive tried changing the mech hanger for a new one, lubricating the inner cables with ptfe, adjusting the clutch tension, following the Park Tool indexing guide to the letter and playing around with the B screw. It seems to be very clunky shifting while riding, but not on the stand when indexing it, and it's constantly catching the chain on the next largest cog whatever i seem to adjust.
Is it time to give up and give it to the LBS to sort, or should i start from scratch, or have i bought something incompatible without realising? Really at a loss as i've never had this much trouble before and it really should be a lot nicer than the old parts that came off.
Outer cable length if its a full sus, maybe too short?
What parts are you using?
Outer cable length if its a full sus, maybe too short?
Should be long enough but I guess it's cheap enough to buy some more and start again erring on the side of leaving them long at first. You've made me think though, the cable is routed along the underside of the chainstay and cable tied onto little eyelets, maybe I need to get a bigger cable tie and make it super tight.
What parts are you using?
All M8000 11spd XT and the chainring is a 26t Raceface direct mount narrow wide. KMC 11 speed chain.
Doesn’t mean its straight.
The catching on the next largest cog would have me checking the hanger alignment first.
Is there any way I can do that at home?
Did you shorten the chain and have you double checked the pin / quick link is fitted properly?
I had a similar issue and it turned out to be a damaged link that snapped out on the trail, new quick link and everything was smooth
You'd need to buy or borrow a hanger alignment tool. The lifeline one is fine and you'll probably end up using it more than you think.
Anther thing to double or triple check is cable clamping at the mech - if thats not correct you can get all sorts of shifting horrors.
My first goto with indexing problems are the hanger, then the gear cable.
Is the chain on the correct way?
Hope I’m not teaching you to suck eggs here, but it is surprisingly easy to miss something basic when you have the excitement of new bits eh
Thanks, will check all the above items, chain shortened but perhaps could do with another link coming out.
Hope I’m not teaching you to suck eggs here, but it is surprisingly easy to miss something basic when you have the excitement of new bits eh
No not at all, it's been over half a decade since I last fitted a new drivetrain from scratch so I've got some items to look at now.
All M8000 11spd XT and the chainring is a 26t Raceface direct mount narrow wide.
Is the 26T chainring running a narrower chainline than a standard Shimano ring?
That could be adding to the catching on the next cog up problem but I'd still start by making sure the gear hanger is straight in all directions.
Yes good point, try and measure the chain line both front and rear.
Silly point but is the mech nice and tight with no movement?
I had similar problems with an XT M8000 set up. After much frustration I downloaded the shimano instructions and it turned out that the B screw adjustment was much larger than on other models.
It was 11mm between jockey wheel and large cog on the cassette.
Might be worth a look.
Re the hanger alignment tool - if you can’t get hold of one, but have a spare rear wheel with a threaded axle like a Shimano cup and cone 135mm QR axle, you can thread that onto your hanger and eyeball whether that wheel is parallel to your wheel. If not, your hanger is out of whack.
It's always worth checking the Shimano workshop instructions, I was having issues with my 11speed Deore setup and it turns out my chain was too short by a few links. The method of measuring a chain has changed from how it used to be and I hadn't realised!
Try following the Shimano set up guide in the dealer manual: https://bike.shimano.com/en-EU/product/component/deorext-m8000/RD-M8000-GS.html
Thanks both, I've downloaded that and will give it a try shortly.
For anyone curious the problem was solved by replacing the KMC chain for a Shimano one. No idea why that made such a difference but it has.
@airvent Interested where you found a complete M8000 11 speed groupset! I've been looking for ages.
the problem was solved by replacing the KMC chain for a Shimano one.
That is really quite surprising. If anyone has any idea why I would love to know
@Davesport I bought the parts seperately on a good deal from CRC, didn't need cranks.
@Davesport I bought the parts seperately on a good deal from CRC, didn’t need cranks.
@airvent Thank you:o)
I've had a similar issue with a chain that was slightly short. Adding back just one link made the difference.