[A] Oval chain ring possibly worn out clutch

[Martin PJ]

It's not made of glass. Surely riding a mtb in it's intended environment results in chain bounce and will induce constant movement in the rear derailleur? They're designed for pretty hard use on mtb's.

 

I know many, many riders who use oval rings and have never heard of a clutch wearing out. Pretty much all ride Shimano XT or XTR. 

 

I am sure the clutch would need servicing anyway after a while, no matter what you use. The mud and dirt from riding is probably a lot more damaging that an oval movement. I am not too worried about my clutch, just learnt from this thread that you can service it, which I will do.

[Barry]

I am sure the clutch would need servicing anyway after a while, no matter what you use. The mud and dirt from riding is probably a lot more damaging that an oval movement. I am not too worried about my clutch, just learnt from this thread that you can service it, which I will do.

Yes the clutch needs to be serviced just like any other moving parts

but it would seen that this is not offered as the derailleur is seen as a disposable part 

Just like STI on road bikes a bit of TLC and grease will make them work nice and last longer

[Reme Le Hane]

Schoolfees hey...

[DieselnDust]

It's not made of glass. Surely riding a mtb in it's intended environment results in chain bounce and will induce constant movement in the rear derailleur? They're designed for pretty hard use on mtb's.

 

I know many, many riders who use oval rings and have never heard of a clutch wearing out. Pretty much all ride Shimano XT or XTR. 

 

 

It is a friction based system. UNder normal use the clutch is preventing rapid movements of the cage whilst remaining free enough to allow the cage to articulate when changing gears.

With an oval you have 2 small rapid movements of the cage as it follows the rise and fall of the chainring. Its these little movements the clutch is designed to prevent. You're now adding increasing the number of cycles the unit is working through hence t wears faster. 

Yes it can be serviced.

But by then it already displays wear (its a friction based system so wear must happen)

More cycles more wear. Simple really

[PhilipV]

An inefficient pedal stroke with a smaller ring combined with those tractor tyres probably all combined to make you feel meh. Maybe them back one at a time to see how it affects the ride.

 

I'm not a fan of oval rings , so I won't downgrade from XT to NX to ride an affordable oval friendly option. Maar een man se lelik is 'n ander man se vrou. So ride whatever you enjoy riding most.

If you change to NX, please don't throw the ls parts away, shimano components are rebuildable if you have donor spares, you might just save a friend in a bind one day.

[DieselnDust]

An inefficient pedal stroke with a smaller ring combined with those tractor tyres probably all combined to make you feel meh. Maybe them back one at a time to see how it affects the ride.

 

I'm not a fan of oval rings , so I won't downgrade from XT to NX to ride an affordable oval friendly option. Maar een man se lelik is 'n ander man se vrou. So ride whatever you enjoy riding most.

If you change to NX, please don't throw the ls parts away, shimano components are rebuildable if you have donor spares, you might just save a friend in a bind one day.

 

 

can buy a lot of Shimano spares from SJSCycles.co.uk 

The CoolHeat won't carry as stock because its cheaper to sell you a new derailleur/shifter

[Martin PJ]

An inefficient pedal stroke with a smaller ring combined with those tractor tyres probably all combined to make you feel meh. Maybe them back one at a time to see how it affects the ride.

 

I'm not a fan of oval rings , so I won't downgrade from XT to NX to ride an affordable oval friendly option. Maar een man se lelik is 'n ander man se vrou. So ride whatever you enjoy riding most.

If you change to NX, please don't throw the ls parts away, shimano components are rebuildable if you have donor spares, you might just save a friend in a bind one day.

 

Agreed, would never take off XT to put SRAM, just plain wrong. Best surprise ever was when I found out my wife's 11 speed NX derailleur could be swopped for an SLX 11 speed derailleur while still using the SRAM shifter, I said to myself "which genius from Shimano designed this?" NX derailleur did not last a year with no oval chain ring. Spring was so loose it was rubbish.

[PhilipV]

can buy a lot of Shimano spares from SJSCycles.co.uk

The CoolHeat won't carry as stock because its cheaper to sell you a new derailleur/shifter

I'll remember that thanks. Fortunately I've always been able to help myself or a friend from my parts drawer or someone else's stash.

 

Coolheat is a classic case of why people buy from overseas to plug the gaps they leave.

[Reme Le Hane]

An inefficient pedal stroke with a smaller ring combined with those tractor tyres probably all combined to make you feel meh. Maybe them back one at a time to see how it affects the ride.

 

I'm not a fan of oval rings , so I won't downgrade from XT to NX to ride an affordable oval friendly option. Maar een man se lelik is 'n ander man se vrou. So ride whatever you enjoy riding most.

If you change to NX, please don't throw the ls parts away, shimano components are rebuildable if you have donor spares, you might just save a friend in a bind one day.

The Minions never came off, went on a week before hoogekraal which is what I put the 30t on for and they still on.

 

The ride on Saturday was the 100km wannabees monster. Eks mos befok ini kop.

 

So the ring was only difference so an easy point of blame.

[Quagga]

Then my thinking is, if I can at least keep the derail ure running much closer to my cassettes death date, which chain 2 has just hit 0.75 so should also die around years end, then grab a sram nx upgrade kit and live happily on with my oval. Long run that seems the most cost effive as a new cassette, derail ure and chain would run a little over 3k and the upgrade kits just over 4.

If you get an NX kit, do yourself a favour and replace the pulley on day one with the GX ones.

 

NX has a design problem where the top pulley undoes the screw and then the pulley falls out and your RD will wrap itself around the cassette.

[droo]

I have seen this issue with every Shimano derailleur fitted with a clutch and where an oval chainring is used. My sample size isn't as big as an lbs but I don't see the issue with drive trains using round rings.

 

By extension you shouldn't use a Shimano RD on a full sus bike either then? The chain growth will cause at least as much movement as an oval ring.

 

OP, if there's no tension on the 11T it's most likely that the RD cage pivot needs to be stripped and cleaned out, they quite often get gummed up. When you're reassembling, there are 2 holes on the cage for the spring - if the first isn't providing enough tension, use the second one.

 

Your clutch will get a service as part of the deal since you have to strip it to get the cage off.

[DieselnDust]

By extension you shouldn't use a Shimano RD on a full sus bike either then? The chain growth will cause at least as much movement as an oval ring.

 

OP, if there's no tension on the 11T it's most likely that the RD cage pivot needs to be stripped and cleaned out, they quite often get gummed up. When you're reassembling, there are 2 holes on the cage for the spring - if the first isn't providing enough tension, use the second one.

 

Your clutch will get a service as part of the deal since you have to strip it to get the cage off.

Thanks for missing the point. Besides the derailleur cage pivot gumming up, corroding actually (have seen this on all the Shimano derailleurs) the issues manifest more quickly on bikes fitted with oval rings. These issues occur regardless. Just manifest faster with ovals. Nowhere did anyone say “don’t use Shimano “. If that’s your position then own it. It’s certainly not my position.

I also seem to recall Shimano advising against the use of aftermarket chainrings and the fact that they don’t make any oval chainrings supporting the assertion that they prefer you didn’t.

It took SRAM two years of testing ovals before they released their own ovals due to market pressure. Two years to ensure there was no adverse effects on their drivetrains.

 

Sticky derailleur cages is a legacy Shimano issue. It goes back to the original Deore XT.

I’ve had to clean up the Pulley cage pivot on my Dura Ace derailleur several times whilst under warranty because they refused to warranty the unit. They called it a service related issue.

With clutch derailleur and oval rings that service point occurs much earlier in the life of the derailleur. When you inspect the clutch parts wear is much ore noticeable.

Surely earlier servicing plus more wear =shorter life

[Quagga]

Thanks for missing the point. Besides the derailleur cage pivot gumming up, corroding actually (have seen this on all the Shimano derailleurs) the issues manifest more quickly on bikes fitted with oval rings. These issues occur regardless. Just manifest faster with ovals. Nowhere did anyone say “don’t use Shimano “. If that’s your position then own it. It’s certainly not my position.

I also seem to recall Shimano advising against the use of aftermarket chainrings and the fact that they don’t make any oval chainrings supporting the assertion that they prefer you didn’t.

It took SRAM two years of testing ovals before they released their own ovals due to market pressure. Two years to ensure there was no adverse effects on their drivetrains.

 

Sticky derailleur cages is a legacy Shimano issue. It goes back to the original Deore XT.

I’ve had to clean up the Pulley cage pivot on my Dura Ace derailleur several times whilst under warranty because they refused to warranty the unit. They called it a service related issue.

With clutch derailleur and oval rings that service point occurs much earlier in the life of the derailleur. When you inspect the clutch parts wear is much ore noticeable.

Surely earlier servicing plus more wear =shorter life

So if you ride a lot of rocky stuff with a HT the clutch will go quicker also?

[DieselnDust]

So if you ride a lot of rocky stuff with a HT the clutch will go quicker also?

I don’t have enough data to answer your question. I would require the people whose bikes I troubleshoot to keep copious records. All I see is more wear in the clutches of bikes fitted with oval chainrings.

[SCD]

I think two entirely different effects are mixed up in this assessment.

Your interpretation suggests that the oval ring causes a change in chain wrap and thus free chain length, and thus would cause the derailleur to compensate. If that was true it should be impossible to use an oval ring with a single speed without a tensioner. But it is isn't. So I think the premise is wrong.

 

Now, even if the premise was right. If you ride trail your cadence would cause the suggested movement 70-90x per minute. Trail bounce will swing the chain around several times each second, and for much larger amplitudes. This has a much bigger wearing load on the clutch.

Bottomline, in my opinion, I think Shimano is using the oval ring as a scape goat.

 

PS: I rode XT Clutch 10x for about 3000km with no issues. XO1 11s for 7000km with no issues and X01 Eagle for 4000km with no issues. Half of that trail. All oval.

[DieselnDust]

I think two entirely different effects are mixed up in this assessment.

Your interpretation suggests that the oval ring causes a change in chain wrap and thus free chain length, and thus would cause the derailleur to compensate. If that was true it should be impossible to use an oval ring with a single speed without a tensioner. But it is isn't. So I think the premise is wrong.

 

Now, even if the premise was right. If you ride trail your cadence would cause the suggested movement 70-90x per minute. Trail bounce will swing the chain around several times each second, and for much larger amplitudes. This has a much bigger wearing load on the clutch.

Bottomline, in my opinion, I think Shimano is using the oval ring as a scape goat.

 

PS: I rode XT Clutch 10x for about 3000km with no issues. XO1 11s for 7000km with no issues and X01 Eagle for 4000km with no issues. Half of that trail. All oval.

 

 

i hear what you saying and I remember when i ran a oval on a single speed I needed the tensioner. There could be something to do with the ovality of some rings in conjunction with tolerances that perhaps some set ups don't need a tensioner. I've seen both but mine definitely needed a tensioner. (38X16 )