Ultegra Rings Worn Down? (Video)

cgfw201

Hi,
Have a 1 year old Canyon with Ultegra 6800. Bike's done around 3800 miles and gets looked after well.

On a ride at the weekend the chain started coming off under pressure, usually when getting out of the saddle accelerating out of a corner or up a hill, only when in the big ring.

Have given the cassette a proper clean out and put a new chain on but still having the same issues.

Only thing I assume it could be is the big ring has worn down too much, but surely I should be getting more than 3900miles out of it?!

Just taken a slowmo video of the chain coming off and put on youtube which may help understand the problem. (Skip to 40s for best example of problem)

https://www.youtube.com/watch?v=cnwbvGK ... e=youtu.be

Also some rubbish photos of the big ring here. Does it look dodgy to anyone? Can't see any of the 'shark tooth' shape which indicates wear?

https://plus.google.com/photos/10214313 ... yK3Xu9Cpag

Any advice appreciated, otherwise will go shopping for a big ring at the weekend.

nicklouse

Looks nice and worn to me.

nigelgos

At what point did you put a new chain on? If you let it get too warn then the cassette will have worn too and will need replacing at the same point as the chain.

dj58

Looks like you let the O.E. chain wear past the 0.75% point.

ElectronShepherd

The chain ring certainly looks worn. See http://roadcyclinguk.com/how-to/maintenance/how-to-identify-the-signs-of-a-worn-drivetrain.html/2 for a comparison of "new" to "knackered" - yours is very much closer to the "knackered" image.

The other thing I'd look at is the chain tension - how much is the rear derailleur "pulling back"? A weak/broken spring in the RD won't be helping (a bit like the reverse of the clutch derailleurs from the MTB side, which have a stronger spring specifically to help prevent chain drop).

If it was entirely due to chain wear, I wouldn't have expected it to have suddenly started (which is sort of implied by your post, but maybe I've misread that part). Having said that, the worn chainring won't be helping.

cgfw201

One thing did just occur to me...lbs took a few links out of the chain a few months ago which I questioned as I didn't think Canyon would supply a chain of the wrong length...could riding on a chain that's too short have accelerated the wear on the big ring?

The spiky profile of The buggered ones in the picture looks a bit like mine, so all things are pointing towards an expensive new ring.

Ben6899

cgfw201 wrote:

One thing did just occur to me...lbs took a few links out of the chain a few months ago which I questioned as I didn't think Canyon would supply a chain of the wrong length...could riding on a chain that's too short have accelerated the wear on the big ring?

The spiky profile of The buggered ones in the picture looks a bit like mine, so all things are pointing towards an expensive new ring.

Your chainring does look a bit worn, but it should be noted that a Shimano big ring out the box doesn't look like the "new" example in the link above. Shimano big ring teeth are varying profile.

cgfw201

Couple more points...

- this did come on very suddenly, from no issues at all to every single time i put the power down the chain comes off, and this started in the middle of an 80 mile ride at the weekend. No crashes/interference to the mech.

- does my big ring really look worn down? pic below puts it next to a brand new one, it's not the same but there's pictures of ones a lot worse online which still work.

Any thoughts if there could be another issue at play here?

JC78DSL99

I'd say the chain is the issue or maybe a bent derailleur hanger. Those chain rings look ok.

cgfw201

JC78DSL99 wrote:

I'd say the chain is the issue or maybe a bent derailleur hanger. Those chain rings look ok.

There's a new chain and cassette on the bike so that shouldn't be it (both Ultegra components too).

Wondering if a spring or something may have gone in the Rear Derailleur?

DeVlaeminck

Have you checked the obvious such as front mech poorly adjusted?

cgfw201

DeVlaeminck wrote:

Have you checked the obvious such as front mech poorly adjusted?

Yeah the shifting is still smooth and the derailleur is spot on in terms of alignment.

cgfw201

Have emailed Canyon to see if they've got any pearls of wisdom. Hoping it's something nice and simple rather than a £100 new ring which I'm not convinced is the issue.

Ben6899

cgfw201 wrote:

Have emailed Canyon to see if they've got any pearls of wisdom. Hoping it's something nice and simple rather than a £100 new ring which I'm not convinced is the issue.

In your video, you're in 50x11, 50x12 whatever. Does this skipping happen further up the block towards the spokes?

I only ask because if not, then it might be related to lack of tension in the derailleur - on the smaller sprockets, you really need the derailleur to be doing its job of keeping the chain tensioned.

cgfw201

Ben6899 wrote:

cgfw201 wrote:

Have emailed Canyon to see if they've got any pearls of wisdom. Hoping it's something nice and simple rather than a £100 new ring which I'm not convinced is the issue.

In your video, you're in 50x11, 50x12 whatever. Does this skipping happen further up the block towards the spokes?

I only ask because if not, then it might be related to lack of tension in the derailleur - on the smaller sprockets, you really need the derailleur to be doing its job of keeping the chain tensioned.

It's definitely more noticeable in the smaller ones. Reckon the chain could be too long?

Ben6899

Chain length looks okay, to be honest.

curium

I have a bent tooth on my 105 crank which I'll be replacing in April, when the weather improves. It doesn't cause many issues. Check all the teeth on your crank, it may be a few rogues ones causing your issues.

Although I have to say on that last image you posted the front of the teeth look rounded when they should be more straight so it is definitely worn but I couldn't say whether it was replacement time worn.

eddiefiola

My ultegra chainrings are much worse than that, just replacing it this week after 15000 kms and never had any skipping like youre describing, the times I've had skipping or slipping, was only under load and a cassette change fixed it. One time it just stopped by itself before i had a chance to change.

Not much help but just to say i think the chainrings are ok.

cgfw201

eddiefiola wrote:

My ultegra chainrings are much worse than that, just replacing it this week after 15000 kms and never had any skipping like youre describing, the times I've had skipping or slipping, was only under load and a cassette change fixed it. One time it just stopped by itself before i had a chance to change.

Not much help but just to say i think the chainrings are ok.

Thanks. This is what's confusing me. I think there must be some kind of minor issue causing this because there's no way my chainring is worn enough for 100% of the time to have the chain falling off.

Ben6899

Can you borrow a rear mech, to rule out possible lack of spring tension? Because - yes - it's obvious your chainring is worn (because you've used it), but it's not *that* worn.

apreading

Its weird the way the chain detaches from the chainring, starting at the bottom and working anti-clockwise. I dont know this but my layman's science suggests that a chain coming off because of worn/bent teeth would more likely detach at the top first?

Detaching at the bottom could be because the rear derailleur and/or jockey wheels have a problem and stop taking up the slack in the lower run of the chain, thus making it 'fall' off the bottom of the chain ring?

Probably I have the science all wrong, but seems worth considering?

cgfw201

Ben6899 wrote:

Can you borrow a rear mech, to rule out possible lack of spring tension? Because - yes - it's obvious your chainring is worn (because you've used it), but it's not *that* worn.

Not easily, housemates with a variety of 105/Campag groupsets, none of which 11 speed. Will take into Velosport in Putney in the morning to have a look at it I think.

keef66

I've watched the video now. I'd say it's the combination of worn chainring and new chain. Do you have the the old chain still to try? It can start quite suddenly, but once it starts jumping off like that under power it really accelerates the wear.

I'm guessing the bike shop will want to sell you a new chainring.

Modern drivetrains are optimised for smooth shifting at the expense of longevity. Compared to the old-school kit I grew up with the teeth are shallower, often with extensive machining / profiling, and the rings themselves are narrower so there's less metal to resist wear.

Oddly enough I've just had a Wiggle parcel containing among other things a middle chainring for my 105 triple I spend 95% of the time in the 39 ring, so it's now quite worn unlike the other two. Since I'm fitting a new chain and cassette I thought it would extend their life and avoid the kind of problem you seem to have.

cgfw201

keef66 wrote:

I've watched the video now. I'd say it's the combination of worn chainring and new chain. Do you have the the old chain still to try? It can start quite suddenly, but once it starts jumping off like that under power it really accelerates the wear.

I'm guessing the bike shop will want to sell you a new chainring.

Modern drivetrains are optimised for smooth shifting at the expense of longevity. Compared to the old-school kit I grew up with the teeth are shallower, often with extensive machining / profiling, and the rings themselves are narrower so there's less metal to resist wear.

Oddly enough I've just had a Wiggle parcel containing among other things a middle chainring for my 105 triple I spend 95% of the time in the 39 ring, so it's now quite worn unlike the other two. Since I'm fitting a new chain and cassette I thought it would extend their life and avoid the kind of problem you seem to have.

I bought the new chain because I thought the old one was causing the problem. The issue is identical on the new chain that's done 30 miles as it was for the final 30 miles of the old chain. Chain ain't the issue.

keef66

Worn chainring then. Out of curiosity I've just been checking prices online :shock:

Cheapest from Germany at the moment

cgfw201

keef66 wrote:

Worn chainring then. Out of curiosity I've just been checking prices online :shock:

Cheapest from Germany at the moment

What they looking like there £? LBS quoted me £70 + £10 labour yesterday.

keef66

Looked like £45 on bike discount DE

Edited to say that's for the 5 arm 10 speed stuff; they don't have the newer 4 arm ones.

cgfw201

Think I'll pay £25 to get out and ride in the 'heatwave' this weekend!

keef66

The 6800 ones are £90 on CRC so you may well be taking the best course of action

And £76 from Rose, so big thumbs up to your bike shop!

cgfw201

New ring fitted on Sat, 60 mile ride yesterday without issues, new big ring was the solution.

Thanks for various bits of advice, correct or otherwise, all useful and interesting.

keef66

Thanks for taking the time to update the thread. Always good to hear how things worked out.