Chain Skipping in Low Gears

[Lovetoclimb]

Installed a new KMC X11SL (Campy 11 specific) chain in place of a worn Chorus 11 chain last night. Everything checked out in the workstand, ran through all gears with no issue, noise is reduced thanks to new chain, etc. No missed shifts or anything to note, and I measured the new chain against the old one, both use the KMC missing link.

My problem, is when I get out of the saddle to put any sort of power down in the climbing gears (39x27/25/23/19) horrible skipping ensues. Does not seem to behave the same in the 53 front ring, but I can not replicate the problem in the workstand despite maximum forearm and shoulder watts.

Anyone have a thought on what I did wrong on my new chain install?

[Louis]

How old / worn are the cassette cogs?

[mktng]

My money is on the cassette being worn. :(

[Lovetoclimb]

It is definitely north of 5000 miles. I honestly do not keep good record of miles so it could be closer to 10k. Do you think the chain wear will catch up to the cassette in a few hundred miles?

[gavingould]

i'd go with worn cassette. replace or it will quickly ruin your new chain.

[David Kirk]

It is definitely north of 5000 miles. I honestly do not keep good record of miles so it could be closer to 10k. Do you think the chain wear will catch up to the cassette in a few hundred miles?

Unfortunately the answer is 'no'. I suppose if you could ride easily for a few thousand miles the chain might stretch enough to work with the worn out cassette but then you are back to where you were.........your bike would have a worn out cassette and chain yet again.

At the risk of sounding like a rich elitist snob who can throw many around I would say that one really needs to consider chains and cassettes as wear items that are little different than tires. Most chains/cassettes will last a few thousand miles before they start going south. They can last longer if kept clean and properly lubed but any way you cut it they are not 10,000 items.

There is one thing that has proven to make both the chain and cassette last longer and it just requires a little planning and a small upfront expenditure........when your system wears out (which yours has most certainly done) buy a new cassette and two chains. Set the bike up and run one of the chains for 200 - 500 miles and then swap it for the other chain and repeat. Cassettes mostly wear from the chain being stretched so if you keep a fresher chain on it longer it will wear less and last longer. So then every 200-500 miles switch to the other chain and everything will wear more slowly and you'll get more miles out of the whole deal ........ and ......... it will work better that whole time too and the shifting will be better and the noise will be lower.

At some point even the stuff in the '2 chain, one cassette' deal will wear out and when they do (as evidenced by poor shifting and noise) you should replace them yet again with the '2 and 1' deal.

Hope that helps.

dave

[ultraman6970]

I would check the b-screw in the rd, and the rd hanger because might be lose.

[2LeftCleats]

The above info is very helpful. Along the same lines: How long can one expect a set of chainrings--especially the more often used inner ring-- to last? I realize it will vary relative to wear on the chain but does anyone have a rule of thumb? For example is there a mileage at which point one would expect the teeth to deform? Or after x number of cassette replacements, the chainrings should be expected to wear out? How about the RD upper and lower cogs?

Thanks.

[AngryScientist]

cassette is shot. replace post haste before you kill your new chain too.

[djg21]

Installed a new KMC X11SL (Campy 11 specific) chain in place of a worn Chorus 11 chain last night. Everything checked out in the workstand, ran through all gears with no issue, noise is reduced thanks to new chain, etc. No missed shifts or anything to note, and I measured the new chain against the old one, both use the KMC missing link.

My problem, is when I get out of the saddle to put any sort of power down in the climbing gears (39x27/25/23/19) horrible skipping ensues. Does not seem to behave the same in the 53 front ring, but I can not replicate the problem in the workstand despite maximum forearm and shoulder watts.

Anyone have a thought on what I did wrong on my new chain install?

Sounds like you waited too long to change the chain, and now also need a new cassette. This is why its a good idea to change chains at 1,500 miles or so, before they stretch appreciably and wear the cogset.

[Ken Robb]

does the fact that the skipping only occurs in the small ring tell us anything else? Is that ring also used up? Could it be only the small ring that's bad?

[biker72]

cassette is shot. Replace post haste before you kill your new chain too.

+1

[tiretrax]

cassette is shot. replace post haste before you kill your new chain too.

+2. Don't take my word for it; I'm a lawyer, he's a scientist!

[Mark McM]

does the fact that the skipping only occurs in the small ring tell us anything else? Is that ring also used up? Could it be only the small ring that's bad?

Possibly. All else being equal, small rings wear faster than big rings, plus the smaller radius of curvature is more sensitive to wear in regard to proper chain engagement/disengagement.

However, There is another phenomena that may be responsible for only skipping in the small chainring - for a give crank torque, the tension in the chain is inversely proportional to the chainring size. Since a 39 tooth chainring is 3/4 of the size of a 52 tooth chainring, there will be 4/3rds the tension when in the small chainring (i.e. 1/3 more chain tension). A chain is more likely to skip under higher tension, so this may be the cause for skipping in the small ring.

Even still, the small chainring should be examined for wear. This usually shows up as a distinct "shark fin" shape to the teeth - unworn teeth should be symmetrical, instead of the more triangular "shark fin" shape. If the chainring has been mounted in the same orientation through out its life, the "shark fin" shape should be more prominent at right angles from the crank arms.

[Richard]

Did you remove the appropriate number of links before you installed? While the most likely culprit is a worn cassette, a too long chain could contribute.

[bikinchris]

The above info is very helpful. Along the same lines: How long can one expect a set of chainrings--especially the more often used inner ring-- to last? I realize it will vary relative to wear on the chain but does anyone have a rule of thumb? For example is there a mileage at which point one would expect the teeth to deform? Or after x number of cassette replacements, the chainrings should be expected to wear out? How about the RD upper and lower cogs?

Thanks.

If you replace your chain BEFORE it is worn out, your chain, cassette chain rings and jockey wheels will last hundreds of chains. Wear it too far ONCE and the wear will not go away. Measure your chain with the tool from either Rohloff, Park or others and replace it before it is worn.
The speed at which a chain wears out depends on how much power you have and the terrain you ride. Strong riders who ride very fast up steep hills will wear out the chain much faster than grandma riding the flats at slow speeds.

For the OP:
You might even look for a tight link in the chain.

[Dave]

Actually, it may only take a few hundred miles for use for the chain to wear enough to quit skipping with the worn cogs.

I'd still get a new cassette and after a few hundred miles, try swapping back, if you want to get some more use from the cassette.

If you really want the most life from a cassette, alternate the use of 3-4 chains and never leave one in use for more than 2,000 miles, before changing to a new one. With continued rotation, you can get more miles from each chain.

[Dave]

If you replace your chain BEFORE it is worn out, your chain, cassette chain rings and jockey wheels will last hundreds of chains. Wear it too far ONCE and the wear will not go away. Measure your chain with the tool from either Rohloff, Park or others and replace it before it is worn.
The speed at which a chain wears out depends on how much power you have and the terrain you ride. Strong riders who ride very fast up steep hills will wear out the chain much faster than grandma riding the flats at slow speeds.

For the OP:
You might even look for a tight link in the chain.

Not true. Cogs will still wear out after less than 10 chains, even if you changed them at 1500 miles, or less. There's a point where changing chains too often is a big waste of money - exceeding the cost of a new cassette. Ti cogs will wear out about twice as fast as steel cogs, regardless of how often the chain is changed.

With 11 speed Campy, I recommend using 3-4 chains and alternating their use. Change to a new chain when the space between the rollers increases from it's original .200-.205 to .215-.220 inch. If you do that, you'll get all of the chains in use and not encounter new-chain skip. After that, alternate chains at least every 1000 miles. I trash chains when the space between the rollers increases to .235-.240. I expect about 4,000 miles from each chain.

I've found that it takes me 6,000 miles to get that much roller wear from a Campy 10 chain. At that point, the elongation is still only .15%.

The key to avoid new chain skip is keep all the chains in a rotation at a similar amount of wear.

Power output is not the only culprit when it comes to cog wear. Using small chain ring for climbing, greatly increases the chain tension. Using a 53/39/28 triple, I wore out the 19 and 21T cogs on a Record 10 Ti cassette in only 4,000 miles, even though the chain had less than .15% elongation.

[Lovetoclimb]

Lots of great input and I will bite the bullet on a new cassette. Fortunately I purchased two new chains so I can start a small rotation as some have suggested once the new cassette is on.

Funny someone mentioned terrain and riding style have influence on drivetrain wear. Since moving to the mountains I have obviously been riding uphill MUCH MORE, and my climbing style involves lots of speedwork, out of the saddle efforts, and generally Froomeish grotesqueness (super high cadence spinning aside).

[Louis]

Fortunately I purchased two new chains so I can start a small rotation as some have suggested once the new cassette is on.

I wonder how many "semi-serious" cyclists actually do rotate chains?

I suppose that ideally the number of chains in a rotation would be the same as the number that would match the life of the cogs.

[oldpotatoe]

Installed a new KMC X11SL (Campy 11 specific) chain in place of a worn Chorus 11 chain last night. Everything checked out in the workstand, ran through all gears with no issue, noise is reduced thanks to new chain, etc. No missed shifts or anything to note, and I measured the new chain against the old one, both use the KMC missing link.

My problem, is when I get out of the saddle to put any sort of power down in the climbing gears (39x27/25/23/19) horrible skipping ensues. Does not seem to behave the same in the 53 front ring, but I can not replicate the problem in the workstand despite maximum forearm and shoulder watts.

Anyone have a thought on what I did wrong on my new chain install?

Probably nothing..cogset worn out?

"Do you think the chain wear will catch up to the cassette in a few hundred miles?"

Nope

[bikinchris]

Not true. Cogs will still wear out after less than 10 chains, even if you changed them at 1500 miles, or less.

That's called hyperbole. It is used to make a point. I know a guy who never cleans his chain. He bought a spool of the cheap chains bike companies use. When his chain looks dirty, he throws it away and puts a new chain that he keeps in a ziplock bag. This is on a tandem no less.

[Lionel]

All this recommendations of alternating chains for a given cassette must be coming from guys using one bike and one wheelset. Do you guys realize the nightmare it becomes if you have a few bikes and a few extra wheelsets ? Good luck with that.

Me I change my campy chains after 5000km or so, which when you have a few bikes like me and ride about 10000km per year is not often!

[djg21]

Not true. Cogs will still wear out after less than 10 chains, even if you changed them at 1500 miles, or less. There's a point where changing chains too often is a big waste of money - exceeding the cost of a new cassette. Ti cogs will wear out about twice as fast as steel cogs, regardless of how often the chain is changed.

With 11 speed Campy, I recommend using 3-4 chains and alternating their use. Change to a new chain when the space between the rollers increases from it's original .200-.205 to .215-.220 inch. If you do that, you'll get all of the chains in use and not encounter new-chain skip. After that, alternate chains at least every 1000 miles. I trash chains when the space between the rollers increases to .235-.240. I expect about 4,000 miles from each chain.

I've found that it takes me 6,000 miles to get that much roller wear from a Campy 10 chain. At that point, the elongation is still only .15%.

The key to avoid new chain skip is keep all the chains in a rotation at a similar amount of wear.

Power output is not the only culprit when it comes to cog wear. Using small chain ring for climbing, greatly increases the chain tension. Using a 53/39/28 triple, I wore out the 19 and 21T cogs on a Record 10 Ti cassette in only 4,000 miles, even though the chain had less than .15% elongation.

Frankly, rotating chains sound like a pain in the ass.

I replace my chains at 1,500 miles, and I've only rarely worn a cassette out.
That being said, I do not spend money on overly expensive, top-of-the line chains. Chains are wear items that are designed to be frequently replaced. I tend to clean the chain on the bike, but do use a connex link and will remove the chain and thoroughly clean it from time to time when necessary.

[Dave]

does the fact that the skipping only occurs in the small ring tell us anything else? Is that ring also used up? Could it be only the small ring that's bad?

The chain tension is higher when using the little ring. That's why it's more prone to skipping when the worn cogs are used.

[Dave]

Chain rotation isn't for everyone, but the way I use my bikes, each one only has one wheel set. Having several clean chains ready to install is really convenient. If I take a chain off for cleaning, I can put a different one on the bike and do the chain cleaning some other time, if desired.

If you run 11 speed, there is no such thing as a cheap chain and even steel cog cassettes aren't cheap, so the idea is to get the most use from each chain and cassette.

With Chorus 11 for example, a cassette costs about the same as 3 chains. I can alternate chains and get up to twice the use from each one, compared to premature trashing of the chains, to protect the cassette. That saves enough to buy a new cassette, when the times comes. I also never have to worry about unexpected new-chain skip.

[Ken Robb]

Strong riders who ride very fast up steep hills will wear out the chain much faster than grandma riding the flats at slow speeds.



I routinely get 50,000-60,000 miles on my chains. :)

[Louis]

I routinely get 50,000-60,000 miles on my chains. :)

Ken, in that case, you must be a great-grandma. ;)

[gearmeister]

Installed a new KMC X11SL (Campy 11 specific) chain in place of a worn Chorus 11 chain last night. Everything checked out in the workstand, ran through all gears with no issue, noise is reduced thanks to new chain, etc. No missed shifts or anything to note, and I measured the new chain against the old one, both use the KMC missing link.

My problem, is when I get out of the saddle to put any sort of power down in the climbing gears (39x27/25/23/19) horrible skipping ensues. Does not seem to behave the same in the 53 front ring, but I can not replicate the problem in the workstand despite maximum forearm and shoulder watts.

Anyone have a thought on what I did wrong on my new chain install?

I had the same issue with a KMC 10SL (shimano specific)... Skipping occured only in the small chain ring (39) ... This was the first KMC chain I ever purchased or used and while I liked the missing link aspect I was not impressed with how dirty the chain always seemed to be even after very thorough cleaning... The skipping gears put me over the edge.. I replaced with a shimano dura ace chain and the problem was resolved... I also noticed that the KMC chain was more worn on one side (inner) than the outer side... Possibly despite claiming to be compatible they are not... I definitely will not be purchasing another KMC chain after this experience... Having said this, does anyone know whether the KMC missing link is compatible with a shimano dura ace chain??

[oldpotatoe]

I had the same issue with a KMC 10SL (shimano specific)... Skipping occured only in the small chain ring (39) ... This was the first KMC chain I ever purchased or used and while I liked the missing link aspect I was not impressed with how dirty the chain always seemed to be even after very thorough cleaning... The skipping gears put me over the edge.. I replaced with a shimano dura ace chain and the problem was resolved... I also noticed that the KMC chain was more worn on one side (inner) than the outer side... Possibly despite claiming to be compatible they are not... I definitely will not be purchasing another KMC chain after this experience... Having said this, does anyone know whether the KMC missing link is compatible with a shimano dura ace chain??

yes, as are the Wipperman links or IRD links. 10s chains, all of them, are of the same dimensions.

[Ken Robb]

I had the same issue with a KMC 10SL (shimano specific)... Skipping occured only in the small chain ring (39) ... This was the first KMC chain I ever purchased or used and while I liked the missing link aspect I was not impressed with how dirty the chain always seemed to be even after very thorough cleaning... The skipping gears put me over the edge.. I replaced with a shimano dura ace chain and the problem was resolved... I also noticed that the KMC chain was more worn on one side (inner) than the outer side... Possibly despite claiming to be compatible they are not... I definitely will not be purchasing another KMC chain after this experience... Having said this, does anyone know whether the KMC missing link is compatible with a shimano dura ace chain??


Do you think there was something like a dirt magnet in your KMC chain?

[gearmeister]

Do you think there was something like a dirt magnet in your KMC chain?

Absolutely.. whatever pre-lube was used during manufacturing was definitely a dirt collector... the chain was cleaned with degreaser every two rides... I finally submerged it in paint thinner as a last resort.... Still seemed dirty but definitely not as bad... I use a dry lube as a rule...

[shovelhd]

yes, as are the Wipperman links or IRD links. 10s chains, all of them, are of the same dimensions.

True, but the DA7900 chains are asymmetrical. I did not have good luck using it with a missing link.

Regarding worn chainrings. Chainring teeth are roughly symmetrical where the chain roller hits the chain wheel tooth. Teeth may vary in size and shape throughout the chain wheel but the contact point should be round and smooth. When a chainring wears is loses this symmetry. When it's really worn, the chainring ramp develops a hook, a break in the symmetry that you can feel with your fingernail. At that point it should be replaced.

[oldpotatoe]

True, but the DA7900 chains are asymmetrical. I did not have good luck using it with a missing link.

Regarding worn chainrings. Chainring teeth are roughly symmetrical where the chain roller hits the chain wheel tooth. Teeth may vary in size and shape throughout the chain wheel but the contact point should be round and smooth. When a chainring wears is loses this symmetry. When it's really worn, the chainring ramp develops a hook, a break in the symmetry that you can feel with your fingernail. At that point it should be replaced.

Ok..I have used a bunch of Wipperman links on the asymmetrical 6700 and 5700 chains w/o issue..maybe it's the KMC or sram link design? I only sell the Wipperman links.

[shovelhd]

Good point. I only tried the KMC Missing Link, on both a 7900 and 6700 chain. I have not tried a Wipperman. These days I use KMC DX-10 exclusively with no issues.

[oldpotatoe]

Good point. I only tried the KMC Missing Link, on both a 7900 and 6700 chain. I have not tried a Wipperman. These days I use KMC DX-10 exclusively with no issues.

I like that one too..interesting to me that KMC has been able to design a reliable 'link', but shimano and Campagnolo feel like it's not worth their time.

[shovelhd]

I like that one too..interesting to me that KMC has been able to design a reliable 'link', but shimano and Campagnolo feel like it's not worth their time.

Yeah, I don't understand this. Maybe it's just me but I like to keep the drivetrain very clean. This means a complete cleaning off the bike every 3 weeks or so. That's not practical without a removable link. One thing I found after installing Di2 is that the direction of the link and the fit of the link are important. The FD will tear up a loose or improperly fitting link in short order. I have spares and carry one in my seat bag.

[Thiel]

Front chainring.