SLX rear derailleur/clutch

Tim

aka sptimmy43
I've got an SLX 11 speed rear derailleur. I seem to have to adjust/increase tension on the clutch about every 3 or 4 rides or so or I drop chains when doing big bunny hops or jumping. Today I dropped a chain at 6 Mile on the little jump section of red between blue and white on the very first jump (cleared it, not a case). Is this normal? It's getting a bit annoying. It sucks to have to stop and put the chain back on the ring.
 

Tim

aka sptimmy43
Loctite on the clutch screw?
I could try that but I don't think it is backing out. How fast does the clutch wear?
Why do you need to adjust? Clutches are set and forget. What is your chainring?
Chainring is a RaceFace 32T N/W. I am on my 3rd chain and second cassette but I am fairly certain this chainring still has some life left in it. Honestly, today may have been a fluke. I wasn't hearing a lot of chain slap. The bike was pretty quiet and then boom....dropped chain.

I could get a bashguard/chain device but I don't really want to go that route if I don't have to.
 

jShort

2018 Fantasy Football Toilet Bowl Lead Technician
Team MTBNJ Halter's
I could try that but I don't think it is backing out. How fast does the clutch wear?

Chainring is a RaceFace 32T N/W. I am on my 3rd chain and second cassette but I am fairly certain this chainring still has some life left in it. Honestly, today may have been a fluke. I wasn't hearing a lot of chain slap. The bike was pretty quiet and then boom....dropped chain.

I could get a bashguard/chain device but I don't really want to go that route if I don't have to.

Maybe your chain is too long?
 

Tim

aka sptimmy43
Maybe your chain is too long?
I am pretty sure it’s the correct length. Assuming the bike came with a properly sized chain then the replacement is identical in length. In 46t cog it doesn’t seem like there would be enough slack to remove 2 links.
I had a older XT clutch spring break. Remove the plastic cover and check if it's working when the lever is moved.
I am pretty sure it works as there is a noticeable difference in trying to move the derailleur when it’s on or off. I’ll check that out, anyway.
 

jShort

2018 Fantasy Football Toilet Bowl Lead Technician
Team MTBNJ Halter's
Interesting. It's not normal by the way. Maybe the chain stretching? Maybe worn front chainring. Or maybe you could try a chain keeper.
 

Karate Monkey

Well-Known Member
Purple loctite on screw threads. When active, the screw is tensioned, so it shouldn't be losing adjustment.

FYI, the clutch does need to be serviced periodically, or it can skip/stick. Shimano specs their Nexus grease...any shop that services IGHs will have it...or if you pass by Colts Neck, let me know and I'll squirt a little in a small baggie and leave it in the mailbox.

Grease only the outside of the clutch, where it touches the band, or the whole unit can slip on the roller bearings inside the clutch unit. You'll have to refresh it after a ride, but you can narrow it down to having to service by putting a couple of drops of ATF along the outside of the clutch...if the behavior returns to normal, well, it's time to pull it apart to grease it.
 

Tim

aka sptimmy43
I am starting to think maybe it was just way out of adjustment when it was new. I don't think it's losing adjustment. I think I have just added tension several times over the last month or so.

I am going to service the clutch at some point. The chainring could also be the culprit. It has 1,031 miles on it and I would expect more life but I know these things wear out. I rode Chimney Rock today so no shortage of rocks and roots to bounce over and no dropped chains.
 
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Karate Monkey

Well-Known Member
FYI, there is a T30/M5 broach in the inner chain plate. With the clutch on, you should read ~5NM on a torque wrench before it moves.
 
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qclabrat

Well-Known Member
I have an XX1 derailleur and it was also acting up on the downhills at Stephens today. Showed it to a few guys on the ride and it appeared to be skipping a at the upper pulley. @Mathers also had the same problem before on his Shimano rd. He engaged the cage and snapped back in place but later in the ride it started doing the same. So I'll likely need to service it this winter. Guessing it has about 600-700 miles
 

Tim

aka sptimmy43
Think this was the problem?...
20180928_205656699_iOS.jpg
 

Tim

aka sptimmy43
I've got slx everything and have never dropped

Yeah. My last post was rhetorical. It was most definitely the chainring. It was worn way past the point of when it should have been replaced. I replaced it with a steel one and all is good again. In fact, I actually reduced the amount of tension on the clutch quite a bit and no dropped chains.
 

goldsbar

Well-Known Member
So a clutch derailleur actually has a clutch? Two friction plates that join together? Learned something new today! Thought it was just a useless marketing term. For the record, l leave mine switched off and never lost the chain as it's still far stiffer than a normal derailleur.
 

Karate Monkey

Well-Known Member
So a clutch derailleur actually has a clutch? Two friction plates that join together? Learned something new today! Thought it was just a useless marketing term. For the record, l leave mine switched off and never lost the chain as it's still far stiffer than a normal derailleur.

Yes, they use a combination of roller clutch (bearings) and a band brake. The roller bearing prevents it [the pulley cage] from rotating forwards (loosing chain tension), unless the whole assembly exceeds the clamping force of the band brake. When the clutch is 'off', the band is still under tension, providing a measure of resistance. The roller clutch, obviously, allows the cage to move freely in the other direction, providing easy, reliable shifts down, where only the spring is pulling the parallelogram back.
 
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