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Got a Canyon Spectral 3 weeks ago, have done around 2 hours riding on it and have noticed an issue with shifting from the largest cog to second largest. The drivetrain is SRAM NX 1x12.

There are two different scenarios -

1) When the bike is upside down

The chain will stay on the largest cog no matter how much I shift down, the derailleur does not move when these shifts are done (hence why it stays on the largest cog). If I give the derailleur a gentle push it will then move into gear as the slack is there for it. When it's in a different gear I can go all the way down to the smallest cog fine and back up to the largest. After reaching the largest it repeats the issue.

2) When riding

When in the largest cog and riding it will shift after around 5 seconds of pedaling on some occasions and almost immediately when cornering like the motion helps it out of the gear. When on the largest cog and clicking shift twice it will skip down into the third largest no problem.

Video of scenario 1) https://www.dropbox.com/s/qs2k2ma9rgvlth4/VID_20181212_184618.mp4?dl=0

I'm already contacting bike shops and canyon have suggested taking it to a bike shop but putting this up to see if anyone has any ideas or has had a similar experience.

  • Shifting behaviour may alter if you put a bicycle upside down. One reason why you should never do it. The other being to avoid damage and scratches. – Carel Dec 13 '18 at 12:15
  • @Carel I always put a wood sheet and a blanket on the floor before doing it so no worry of the bike getting damaged, its simply for convenience until my bike stand arrives. But noted the shift behavior point. – bSky Dec 13 '18 at 12:25
  • The bike probably needs a tuneup. If you bought the bike through a reputable shop they should provide one free tuneup after a few weeks riding. – Daniel R Hicks Dec 13 '18 at 12:52
  • @DanielRHicks its a Canyon so bought direct through them, so far they have offered to pay for it to be looked at (a measly amount to be honest, wont cover much) Issue for me is having the time to get it to a shop to be looked at so thought it was best to post here first. – bSky Dec 13 '18 at 12:59
  • There is a "break-in" period for any multi-speed bike, as the cables stretch and the bits of the derailer get comfortable with each other. So a tuneup after a few hundred miles is to be expected. – Daniel R Hicks Dec 13 '18 at 13:03
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Either the derailleur is sticking when at it's most inboard position, i.e. on the largest sprocket, or the shift cable is sticking in the housing somewhere.

It's not surprising that the derailleur will eventually shift up when on the trail, it's being shaken and vibrated by trail irregularities which overcomes the stickiness.

Fiddling with the barrel adjuster will not do anything. The cable is payed out from the shifter when changing to higher gears so it can't pull the derailleur outward. The barrel only adjusts the length of cable and hence position of the derailleur not the cable tension in any case.

You want to figure where the stickiness is. Detach the shift cable from the derailleur. With the bike on a work stand or inverted, push the derailleur manually while pedaling to change gear (it really helps to have a friend pedal for you, and be really careful to keep your fingers out of the chain). If the derailleur sticks in the lowest gear there's the problem.

You can also hold the shift cable with a pair of pliers, put some tension on it and work the shifter, you may be able to feel some resistance.

I've never encountered a malfunctioning new derailleur. If the derailleur is sticking perhaps working it through it's range of motion a few times will free it up. Look for dirt, dried lube or anything in the parallelogram that might be binding it up.

Old, dirty cable can develop excess resistance and stickiness, The solution is to replace them, but your's are obviously new. Perhaps pull the cable out of the housing, give it a wipe down and add a little lube.

  • Okay i will give up on the barrel adjuster, I will detach the cable tonight and see what happens. – bSky Dec 13 '18 at 13:29
  • @bSky All the tension is coming from the derailleur spring anyway. The cable pulls the derailleur inwards and slackens to let it outwards. – Argenti Apparatus Dec 13 '18 at 14:07
  • "Fiddling with the barrel adjuster will not do anything, it only adjusts the position of the derailleur not the cable tension." Where did you get this information? The entire purpose of an inline barrel adjuster is to make small changes to cable tension in order to tune the gears without unclamping the cable each time. – Carbon side up Dec 13 '18 at 20:46
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    @Carbonsideup, OK so I suppose it depends what you mean by 'tension'. The barrel adjuster effectively lengthens or shortens the cable relative to the housing, thereby moving the position (indexing) of the derailleur. Lots of people call this 'tension', but it really isn't. The actual tensile force on the cable comes from the derailleur return spring. – Argenti Apparatus Dec 13 '18 at 20:52
  • While it might not be technically correct to call it tension, I'm yet to meet a bike mechanic who calls it anything else. – Carbon side up Dec 13 '18 at 21:17
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Can you put your bike in a stand and shift while turning the crankset forwards? While not the main issue that you're having, shifting while not pedalling will always make it worse. Eagle drivetrains never shift particularly well into or out of the biggest cog at the best of times.

Did you tune your shifting with the bike upside down on the floor like in the video? Did you tune it to shift into the big cog by clicking the shifter while the pedals weren't turning, then turning them? If so, you probably just need to reduce the cable tension a little.

  • Point taken, when you say make the issue worse, do you mean damage or just not help with diagnosing the issue? Im actually waiting for a bike stand to arrive so until that comes having bike upside down is the easiest way for me to work on the bike. When the bike was upside down i did play with the tuning yes, but then i tried scenario 2 and cycling around I moved the barrel adjuster so it shifts through all the other gears smoothly, but as mentioned in scenario 2 largest cog to second largest does shift but not always first time / takes a while. – bSky Dec 13 '18 at 11:07
  • Note that even on a bike stand you will not get the same behavior as you get when actually riding. I generally take the bike out for a ride after tuning on a stand, then come back and tweak it. – Daniel R Hicks Dec 13 '18 at 12:54
  • It's not doing any damage to the drivetrain, but simply making the issue more noticeable. When tuning it this time, you want the absolute bare minimum of cable tension that will still allow you to shift into the big cog. If it doesn't shift as smoothly as on the rest of the cassette, that's fine. You just want it to get there if you push right though on the lever. – Carbon side up Dec 13 '18 at 20:38
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Have seen this only once before. It was the upper limit screw "marked L on the derailleur body" was too tight. When you shift into the large ring the chain wedges into the ring and is held by the limit screw. That is why shifting twice to a higher gear pops it loose. It increases the derailleur spring tension and overcomes the "jam", Loosen the limit screw 1/2 turn. Be sure you are not crosschaining (big ring front to big ring rear). It compounds the "sticky shifting" issue.

  • OP says they have a 1x12 SRAM NX setup so cross-chaining not an issue. Shifting to a higher gear, which loosens the cable can't increase the derailleur spring tension. – Argenti Apparatus Dec 13 '18 at 19:17
  • oops - would be hard to cross-chain a 1 x 12. I will slow down and read more carefully/completely. – Cliff Dec 13 '18 at 21:40
  • BTW what do you mean by 'the chain wedges into the ring and is held by the limit screw'? – Argenti Apparatus Dec 13 '18 at 21:46
  • My comment on the root cause may have been too much of a leap. By loosening the low speed limit screw, my grandson's 10 speed bike began to shift smoothly up and down from large cassette gear to next largest. It may be possible the root cause was jamming the derailleur against the limit screw with heavy thumb pressure?? I did concurrently slightly straighten the derailleur hanger with my Park derailleur tool,. Sometimes an out of true hanger causes a person to incorrectly adjust the cable and cause reluctant or lagging shifts. My two corrective actions may have obscured the root cause. – Cliff Dec 14 '18 at 19:30

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