Ultegra & Dura Ace chains barely elongated after ~3500 miles (5600 km)
Moderator: robbosmans
How much do you weigh? How much do you climb? and how hard do you ride?
I weigh 170 and my wife weighs 110. I wear out chains. She has never worn out anything. Not even tires (exageration).
I weigh 170 and my wife weighs 110. I wear out chains. She has never worn out anything. Not even tires (exageration).
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.
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It makes perfect sense. The roller wear cancels out. In effect, the entire chain displaces by the amount of individual roller wear, preserving the chain pitch. Each tooth still engages each roller.
I'm under 165, climb decent amount (~1000 ft. for every ~10 miles riden) and ride relatively hard. At given elongation rate, over 6000 miles is a given. I'm puzzled how people destroy chains at 2000 miles. It must be due to contamination. Don't start your ride with a filthy chain
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.
CBA = Chronic Bike Addiction
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Yep, I fluctuate between 132-145lbs and ride decently hard. I expect 6000mi out of a chain and sometimes eked out 8000mi while using dry drip lubes like RnR Gold. It's harder for me to track chain-life now that I use hot-melt wax and rotate between 5 chains.mpulsiv wrote: ↑Thu Jun 11, 2020 6:47 am
I'm under 165, climb decent amount (~1000 ft. for every ~10 miles riden) and ride relatively hard. At given elongation rate, over 6000 miles is a given. I'm puzzled how people destroy chains at 2000 miles. It must be due to contamination. Don't start your ride with a filthy chain
Contamination plays a huge role. I use the smart trainer a lot and I have a spare bike that hasn't seen an outdoor ride in 3.5 years. That's also how old the chain is and it's got the equivalent of 16000mi or more on it at ~220W average. It still hasn't elongated past .4% let alone .5%. In fact the link plates themselves are becoming visibly scalloped and that may be what finally drives me to replace the chain.
Nope. Roller wear has no impact on pin-to-pin spacing which is what controls the load transfer between chain and chainring. I was going to make a sketch to illustrate this, but because I'm lazy, suggest reading the following instead.
http://pardo.net/bike/pic/fail-004/000.html
"Measuring Wear
The important issue of chain wear is that the spacing changes, causing the chain to ride up on the sprocket teeth. Thus, it is important to measure pin/bushing wear. However, bushing/roller wear does not affect chain performance unless it becomes so severe that it affects structural integrity — the bearing is worn away, the roller fractures, or the like. Thus, bushing/roller wear should not be included in overall wear measurements."
http://pardo.net/bike/pic/fail-004/000.html
"Measuring Wear
The important issue of chain wear is that the spacing changes, causing the chain to ride up on the sprocket teeth. Thus, it is important to measure pin/bushing wear. However, bushing/roller wear does not affect chain performance unless it becomes so severe that it affects structural integrity — the bearing is worn away, the roller fractures, or the like. Thus, bushing/roller wear should not be included in overall wear measurements."
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This isn't true... to put more strain on a cassette/chainring you need to reduce the points of engagement. An elongated chain puts more wear on those components because the chain/pin pitch doesn't match the gear pitch. This means that when one roller is engaged with one tooth, the next roller is only partially engaged or not at all, and it gets worse and worse farther away. When chain pitch is conserved, as with consistent roller wear, the gears still mesh with the chain correctly.
It is not only the spacing counts. The new or little weared rollers match well with the gear shape while the weared ones not. The less contacting area, though all the rollers seem to engage, puts more strain under the same power.TobinHatesYou wrote: ↑Thu Jun 11, 2020 9:12 am
This isn't true... to put more strain on a cassette/chainring you need to reduce the points of engagement. An elongated chain puts more wear on those components because the chain/pin pitch doesn't match the gear pitch. This means that when one roller is engaged with one tooth, the next roller is only partially engaged or not at all, and it gets worse and worse farther away. When chain pitch is conserved, as with consistent roller wear, the gears still mesh with the chain correctly.
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There are roughly 108 hardened rollers per chain vs 15/16/17 teeth on your most used cogs. In addition the entire circumference of the roller will wear evenly whereas teeth don't have as much surface area. I can assure you the wear on the cog teeth will be far more problematic than roller wear.
^ that's not correct. All the rollers shift so that only the front inner diameter is loaded by the pin because the chain is under tension. The roller is compressed between the pin and sprocket. What you are describing is one roller loaded on the front by one sprocket, and one roller loaded in the back by a another sprocket. Which would cause the chain to kink or ride up.
That's not to say the a chain that is unstretched but suffering from roller wear will shift well or be efficient. Allowing the roller to wear that much will open up the interface between roller and pin, making it much harder to maintain lubricant in that space.
That's not to say the a chain that is unstretched but suffering from roller wear will shift well or be efficient. Allowing the roller to wear that much will open up the interface between roller and pin, making it much harder to maintain lubricant in that space.
I have an Ultegra R8000 bike I bought last year with just over 6000km on it and I'm not even close to 0.5mm of wear on it yet. About half of that has been on a trainer and I'm not sure if that matters, but I'm still quite impressed by the fact that I'm probably going to get a few thousand more kms on it. Previously I'd found about 5000k was my max.
That's what I've posted and what you've quoted: A chain with little elongation but significiant roller wear has more strain on the cassette and chainring, shortening the period of switching the cassette and chainringTobinHatesYou wrote: ↑Thu Jun 11, 2020 9:45 am
There are roughly 108 hardened rollers per chain vs 15/16/17 teeth on your most used cogs. In addition the entire circumference of the roller will wear evenly whereas teeth don't have as much surface area. I can assure you the wear on the cog teeth will be far more problematic than roller wear.
Switching the chain is not only about chain itself but to ensure the whole drivetrain healthy. That's why roller wear should count.
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alanyu wrote: ↑Thu Jun 11, 2020 4:46 pmThat's what I've posted and what you've quoted: A chain with little elongation but significiant roller wear has more strain on the cassette and chainring, shortening the period of switching the cassette and chainringTobinHatesYou wrote: ↑Thu Jun 11, 2020 9:45 am
There are roughly 108 hardened rollers per chain vs 15/16/17 teeth on your most used cogs. In addition the entire circumference of the roller will wear evenly whereas teeth don't have as much surface area. I can assure you the wear on the cog teeth will be far more problematic than roller wear.
Switching the chain is not only about chain itself but to ensure the whole drivetrain healthy. That's why roller wear should count.
No, my point is your cogs will always wear meaningfully faster than rollers on a chain. However elongation will happen will happen at the pin/plate interface so the issue of roller wear is moot either way.
That doesn't mean roller wear doesn't count anyway and you can find a lot of web, papers, etc on roller wear such as https://www.diamondchain.com/understanding-wear-life/TobinHatesYou wrote: ↑Thu Jun 11, 2020 9:14 pmalanyu wrote: ↑Thu Jun 11, 2020 4:46 pmThat's what I've posted and what you've quoted: A chain with little elongation but significiant roller wear has more strain on the cassette and chainring, shortening the period of switching the cassette and chainringTobinHatesYou wrote: ↑Thu Jun 11, 2020 9:45 am
There are roughly 108 hardened rollers per chain vs 15/16/17 teeth on your most used cogs. In addition the entire circumference of the roller will wear evenly whereas teeth don't have as much surface area. I can assure you the wear on the cog teeth will be far more problematic than roller wear.
Switching the chain is not only about chain itself but to ensure the whole drivetrain healthy. That's why roller wear should count.
No, my point is your cogs will always wear meaningfully faster than rollers on a chain. However elongation will happen will happen at the pin/plate interface so the issue of roller wear is moot either way.
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alanyu wrote: ↑Thu Jun 11, 2020 9:59 pm
That doesn't mean roller wear doesn't count anyway and you can find a lot of web, papers, etc on roller wear such as https://www.diamondchain.com/understanding-wear-life/
That page just says roller wear occurs. That's a given. The point you continually ignore is that the wear does. not. matter. in the context of functionality, only structural integrity.
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