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Mis-shifting issues after a muddy trail ride.

715 Views 11 Replies 7 Participants Last post by  Cleared2land
My drivetrain has been good to me for about 1000kms. No mis-shifts up/down. Very flawless.

Went on a very muddy trail. My chain and derailleur really ate a lot of dirt. At one point, my chain was stuck on the biggest cog because the rear derailleur doesn't want to move anymore.

Went home, cleaned it really well, then when I tried it, it started mis-shifting.

I've already cleaned the cable and have replaced the housing. I have managed to tune it to the point that it doesn't mis-shift on almost all gears.

Currently, it shifts "ok" from smallest cog to # 3. Chain keeps on skipping from #3 to # 2. #2 to #1 is fine. Then shifts fine from biggest cog all the way to the smallest. If I turn the index knob 1-click either way, it would ruin everything.
Already tried the B screw.. didn't help a lot.

Here's my setup:

Deore 5100 - 11s
Sunrace 11-50T
Deore 5100 crankset w/ 36 narrow-wide chainring
Shimano 11s chain (forgot the exact model)

Cable has been lubed. There is no kinks.

I don't know what else to check. Last thing i want to do is replace the derailleur or the cassette.

Need help.
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Check the chain stretch with a gauge. Muddy rides grind TF outta drivetrains.


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Check the chain stretch with a gauge. Muddy rides grind TF outta drivetrains.


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Will check it. Thanks. I also suspect #2 cog has worn out since the chain shifts fine on all gears except going from #3 to #2. The teeth where it suppose to pick-up the chain are a bit worn.

Also, the problem worsen when i engage the clutch.
Also check the derailleur hanger alignment
Will check it. Thanks. I also suspect #2 cog has worn out since the chain shifts fine on all gears except going from #3 to #2. The teeth where it suppose to pick-up the chain are a bit worn.

Also, the problem worsen when i engage the clutch.
Bad chains ruin cassettes and chainrings. Treat them as maintenance items and replace when stretched or very very close to stretched (if big ride/event coming up etc.) and your life will be much more pleasant out on the trails... 😅
Muddy rides grind TF outta drivetrains.
and bearings.

the cost of dealing with the extra wear and tear alone is a good reason to avoid muddy rides as much as possible.
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Perhaps much better to not ride muddy trails.
I bet the OP is not one who maintains the trail.
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Perhaps much better to not ride muddy trails.
I bet the OP is not one who maintains the trail.
so helpful and non judgmental in a few short lines, nice work :rolleyes:

I've found the latest generation of shimano derailleurs sometimes need the pivots in the derailleurs lubed after getting particularly wet/dirty, being stuck in the biggest cog in poor conditions tends to be the hint for that (or that the clutch needs to be serviced). I use a dry teflon lube (not a wax) with good success on the pivots, ride a lot in the wet here where I am in the PNW. If you can't rotate the lower cage smoothly with the clutch on that's a good hint the clutch needs servicing.
It sounds like you have dirt stuffed in the housing at the derailleur (this assumes the bike was shifting well before the ride, and you didn't smack the derailleur during the ride).
Checked the chain, it is still good. The stretch looks like fairly new. I really suspect it's the #2 cog as it shifts fine on the rest.

Those teeth, (the ones beside the hyperglide groove), just can't catch the chain. I only left with 1 tooth that catches it perfectly. I also adjusted the barrel just for this one cog. Still can't catch it no matter how tight i turn the index knob.

Anyhow, has anybody tried modifying the profile of these catch teeth for it to shift smoothly? I'm willing to be the first. :D
update: I dremel the catching teeth (6 of them) on the #2 cog. Now it shifts perfectly. I changed the profile a bit to increase the contact surface of the cog to the chain.

I now understand how those hyperglide groove works.

Let me know if you're curious, I'll post pics.
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