Jbr Posted September 28, 2020 Share Your shifting issue is related to the clutch being dry and too tight out of the factory. Back off the clutch pressure and see if this improves things. We solved the exact problem you describe this way at Tankwa Trek. The shifting was so bad at one stage we replaced sifters thinking it was the problem, mean time, a 2min clutch lube and tension adjustment and the shifting was pristine as XTR should be. Bleeding wise, Going slow is the key here. These breaks are ultra simple.I presume you are using the supplied Shimano bleed blocks? Bleeding is an artwork and should not be rushed (after all it is a safety mechanism on your bike). What I do to finish a bleed, I remove the bleed block and pump the lever once to push the pistons out. I only do a slight sliver of piston on each side. Then I take bleed block that is about the size and then put that between the pistons (so the pistons are sticking out more and the bleed block is narrower) the I bleed some more. I also stress you just have the lever reach out quite far for a large hand to get a better bleed. Once I get a firm feel with this, I remove the thin block, use a plastic tyre lever and gentled push the pistons back, quite slowly and gingerly. I bleed with the normal bleed block and the brake feels hard usually.Thanks man I'll try all this. Have to admit with the clutch off it does shift much better, so you're probably onto something Link to comment Share on other sites More sharing options...
DieselnDust Posted September 28, 2020 Share Building on what Lance is saying the XTR for some reason is a bit tricky. I have the Level TLM on my 2018 Scalpel and i order to bleed properly I have to ensure that the rear brake caliper is at the lowest point in the system and that means tilting the bike upward in the workstand. After checking the clutch on the rear mech, also ensure that the zip ties holding the derailleur cable to the rear chainstays are not pulled so tight that they compress the cable housing. The zip ties are just a guide to prevent the cable housing flopping into your rear wheel or getting caught on the crank. A worn chain will also deliver erratic shifting. Link to comment Share on other sites More sharing options...
Jbr Posted September 28, 2020 Share MMhhh I made a mistake pumping having forgotten to put anything between the pistons (I don't have any bleed blocks left), seems one of the piston was a bit stuck there as I had a hard time pushing it back in, and doing so cleaned up multiple times until it sled nicely...Probably was explaining why the brakes were both spongy and had no bite if all the oil was doing was pushing one of the two pistons. Much better now that both pistons move. I'll check the manual later for the clutch ajustment, thanks all Edited September 28, 2020 by Jbr DieselnDust 1 Link to comment Share on other sites More sharing options...
Jbr Posted September 28, 2020 Share clutch doesn't seem to make a difference, up to mid cassette my derailer is aligned, higher than that on the cassette it seems to go closer to the bigger one... bit annoying... it's like the more you pull the cable the more it pulls at each click... I'm also now questionning the shifters... Edited September 28, 2020 by Jbr Link to comment Share on other sites More sharing options...
porqui Posted September 28, 2020 Share clutch doesn't seem to make a difference, up to mid cassette my derailer is aligned, higher than that on the cassette it seems to go closer to the bigger one... bit annoying... it's like the more you pull the cable the more it pulls at each click... I'm also now questionning the shifters... Did you replace the outer housing when you replaced the cable ? Link to comment Share on other sites More sharing options...
dewaldsss Posted September 29, 2020 Share Hi thereQuick questions:-what cassette ratio are you running? -are you running the longer cage derailleur? (To be used with 51t cassette)If you have a GS instead of a SGS it might be the issue. *Also, check that your shifter is set to 12speed, the shifter can be set to work on 11spd systems.(Bottom of the shifter there is a tiny screw)See pic attached From the web:Shimano has three new rear derailleurs to accompany these four drivetrain configurations. The long-cage RD-M9100-SGS is compatible with both 10-51t and 10-45t 12-speed cassettes. The short-cage RD-M9100-GS is the go-to gear changer for riders dedicated to running 1x drivetrains with either 11- or 12-speed 10-45t cassettes. Edited September 29, 2020 by dewaldsss Link to comment Share on other sites More sharing options...
Jbr Posted September 29, 2020 Share nop didn't replace de housing. I checked this morning I'm on 12spd, if I change the setting it just doesn't go up to the granny gear. Next step I'll try and clean the shifters and if it doesn't solve it next service I'll ask to control the hanger see if it's bent... Link to comment Share on other sites More sharing options...
RobertWhitehead Posted September 30, 2020 Share Shifting: new cable (needs to be stretched) and clutch as mentioned before.Spongy feel on the levers: you still have air pockets in the system, remember that the lever needs to be the highest point and to tap the caliper to release the bubbles which are stuck. I would also consider pushing some more mineral oil through it to see if it helps Link to comment Share on other sites More sharing options...
King_Crispy Posted September 30, 2020 Share After this amount of time I struggle to comprehend why you would still be stuffing around with this? If it were an attempt at cost saving, well then, failed exercise. So too if you were trying to bond with your bike.Just send the bloody bike into an accredited Shimano agent and tell them what's wrong.You've probably voided any warranty on the new equipment and haven't achieved anything.Time is precious, stop wasting it RobertWhitehead 1 Link to comment Share on other sites More sharing options...
Jbr Posted September 30, 2020 Share the bike has been 3 times to 2 different shops for the brakes and everytime I can't sort something out myself the shop usually makes it worse or/and advises a replacement.Only shop I trust is Giant Durbanville but it takes me an hour to go there and back.The brakes are now almost perfect, when I get a chance I'll get bleed blocs and pull that adjuster all the way out and see if I can get a few more bubbles out.The gears are decent, I just want it perfect, but not at the cost of a new derailleur. That will do for now. I'll have to send the bike in as I'm waiting for parts from omnico, I'll ask the shop to have a look then.If they advise a replacement then it will be for a 45 / Short cage Edited September 30, 2020 by Jbr Link to comment Share on other sites More sharing options...
Paulst12 Posted September 30, 2020 Share Scalpel 2019, and both cables come out the main frame below the BB and run along the rear triangle with plenty of length available. No I just fitted the new lever and bled the system.I had exactly the same problem with my XTR brakes on my Scalpel Black Inc 2019. Sollution in the end was to change down to XT brakes and i never had another issue thereafter. For some reason the XTR braking system didnt do well on the back brake. And yes, i did swap the rear brake several times to see if it was an internal problem with the lever. I believe they use lighter, less hardy internals on the XTRs for weight purposes vs the XT brakes. Link to comment Share on other sites More sharing options...
lechatnoir Posted September 30, 2020 Share After this amount of time I struggle to comprehend why you would still be stuffing around with this? If it were an attempt at cost saving, well then, failed exercise. So too if you were trying to bond with your bike.Just send the bloody bike into an accredited Shimano agent and tell them what's wrong.You've probably voided any warranty on the new equipment and haven't achieved anything.Time is precious, stop wasting it that failed at XTR Link to comment Share on other sites More sharing options...
Jbr Posted September 30, 2020 Share that failed at XTR Link to comment Share on other sites More sharing options...
DR ◣◢ Posted September 30, 2020 Share Had XTR brakes before with the same problem. Could not get them to stop going soft on me. Front brake was the issue. Also didn’t impress me with stopping power. Went with Hope Race X2 and never looked back. Now on Tech 3 V4 and I’m still super impressed. Time for a bleed I think after about 7 years. They still feel the same as the day I got them. Might leave it for my 6 month tear down service. Link to comment Share on other sites More sharing options...
s14phoenix Posted September 30, 2020 Share nop didn't replace de housing. I checked this morning I'm on 12spd, if I change the setting it just doesn't go up to the granny gear. Next step I'll try and clean the shifters and if it doesn't solve it next service I'll ask to control the hanger see if it's bent... First mistake - you could have a pinch or funny kink or something in the housing. Replace it. You should have done this as step 1 or 2 when you have issues with any shifting on any brand. replacing just an inner is probably pretty pointless if not done with the outer if you are having shifting issues - crap gets down into the outer and could cause mayor havoc. Link to comment Share on other sites More sharing options...
Maaknplan Posted September 30, 2020 Share Have they tried replacing the olive and insert on the hose at the brake lever? Link to comment Share on other sites More sharing options...
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