Chain, Cassette, and Chain Ring life expectancy

Triathlon Forum
1

Ok ST crew I am in need of advice.

I took my bike into a new to me LBS. Recommended by a friend who is a great coach. I brought the bike in to be re cabled, mostly because when I built the bike up I left the cables too long and as I dropped the stem the cables just looked sloppy.

I show up to pick the bike up and I get a stern look and essentially a bit of a lecture about my drive train.

I am told I need a new chain and cassette and I really should replace the chain rings. Explanation was that the chain 2,200 miles on it was pooched. That part I buy. Next was that since the cassette too had that mileage and also the chain rings they were likely toast too. He said they wear together, which I do understand. I have worked on motorcycles for years and know that when you replace chains you usually want to replace sprockets too.

He said had I checked my chain length more frequently and replaced the chain earlier I would have been ok to just replace that.

What I cannot figure out is… if my drive train is so pooched, why does it still shift like the day I bought it? I would think there would be some kind of poor shifting if everything were a total loss.

As stated 2,200 miles on the drive train. Chain cleaned and lubed every 150-250 miles or so. Shifting is fine.

Should note the components are Ultegra 6700.

What would you do in my situation? He is telling me if I put a new chain on now (which I already have mind you) that it will wear out in a month.

I see no visible wear on the cassette teeth or chain ring teeth.

Thanks in advance, Cheers

2

I usually get 3000 to 3300 out of Shimano and SRAM chains. I clean them with Pro Gold about every 200 miles. I get 4000+ out of Campy chains. Cassettes usually last for 2, sometimes 3 chains. I have never worn out a set of chainrings. Most I’ve ever put on a set is over 20,000 miles.

Not cleaning your drivetrain regularly will reduce mileage.

While it’s possible the guy at the LBS has a good enough eye to know that your cassette needs replacement, most of the mechanics I know usually say “might”. I always try the new chain without replacing the cassette. If the new chain skips, then I replace the cassette.

Others will likely know more, but this has worked for me.

hth

3

Ok ST crew I am in need of advice.

I took my bike into a new to me LBS. Recommended by a friend who is a great coach. I brought the bike in to be re cabled, mostly because when I built the bike up I left the cables too long and as I dropped the stem the cables just looked sloppy.

I show up to pick the bike up and I get a stern look and essentially a bit of a lecture about my drive train.

I am told I need a new chain and cassette and I really should replace the chain rings. Explanation was that the chain 2,200 miles on it was pooched. That part I buy. Next was that since the cassette too had that mileage and also the chain rings they were likely toast too. He said they wear together, which I do understand. I have worked on motorcycles for years and know that when you replace chains you usually want to replace sprockets too.

He said had I checked my chain length more frequently and replaced the chain earlier I would have been ok to just replace that.

What I cannot figure out is… if my drive train is so pooched, why does it still shift like the day I bought it? I would think there would be some kind of poor shifting if everything were a total loss.

As stated 2,200 miles on the drive train. Chain cleaned and lubed every 150-250 miles or so. Shifting is fine.

Should note the components are Ultegra 6700.

What would you do in my situation? He is telling me if I put a new chain on now (which I already have mind you) that it will wear out in a month.

I see no visible wear on the cassette teeth or chain ring teeth.

Thanks in advance, Cheers

I have chainrings with 50,000 on them, chains with 20,000 - you will hear other stories as well. Bottom line, could the chainrings with 50k shift a little smoother? Maybe, but they work fine and I can’t remember ever missing a shift.

4

I have chainrings with 50,000 on them, chains with 20,000 - you will hear other stories as well. Bottom line, could the chainrings with 50k shift a little smoother? Maybe, but they work fine and I can’t remember ever missing a shift.

Exactly this. I wouldn’t change a thing.

5

I have chainrings with 50,000 on them, chains with 20,000 - you will hear other stories as well. Bottom line, could the chainrings with 50k shift a little smoother? Maybe, but they work fine and I can’t remember ever missing a shift.

Power loss?

6

I have chainrings with 50,000 on them, chains with 20,000 - you will hear other stories as well. Bottom line, could the chainrings with 50k shift a little smoother? Maybe, but they work fine and I can’t remember ever missing a shift.

Power loss?

Power loss, you obviously have not seen the 60 lb cross bike I have with 42mm tires that weigh over 2lbs a piece and baskets and rear rack that I take on group rides. If you are trying to eek out every bit of performance for a race then yes, you swap out the chain rings, chain, cassette, and derailleur pulleys for your race day stuff. Otherwise any power loss experience thru the drivetrain in training usually results in inadvertent human power gains thru increased volume, intensity or both.

7

I generally replace chains around 2,500 to 3,000 miles and replace cassettes every other chain. That’s generally less than $150 a year for two chains and a cassette.

I’ve never replaced a chainring using the above maintenance schedule.

8

Chain could certainly need replacing, easy to check with wear gauge. Cassette, almost certainly not as it has 10 gears which get distributed wear. Chainrings, no way.

9

Don’t fix what isn’t broken…

If it shifts like new then why would you replace anything? I don’t believe in throwing away money or perfectly good parts. My current chain has at least 5k on it, the cassette probably a couple thousand more than that… it shifts great… quick accurate shifts every time. Chainrings… give me a break… those last forever. If it was me I wouldn’t replace any of it right now. That said… drivetrain parts wear so slowly that you might not notice that the shifting has been degrading until you replace them.

I also don’t recable my bike yearly… oh the horror…

10

Thanks for confirming what I was feeling. When I showed up to the shop to drop the bike off the guy came in with a 6 pack at 2pm… and when I got there to pick up the bike his friend had brought him 4 more. It wss pretty offputting. And i love beer but i can wait until im done with work. Last time going there. I will continue to work on my own bike like I have been. I’m having a hard time finding a trustworthy shop that isn’t backed up a month.

11

www.friction-facts.com will sort this out for you. Read all you can from them. My take away was that there is power loss due to chain wear, but not so much cassette and rings. Really insightful.

12

If your chain is ‘stretched’, it could damage the teeth on your cassette and / or chainring.

The cheapest way to check chain stretch is to follow the logic of Sheldon Brown (as listed below). I’m interested to hear your measurement of 10 chain links. If you keep an eye on your chain and don’t let it wear too much, you’ll get tons of mileage out of your cassette and chainrings.

…if your chainrings cassette are worn down, a new chain will actually mesh worse than the old one.

http://sheldonbrown.com/chains.html
In metric measurement, 10 links of a new chain are 25.4 cm, or 15 links, 38.1 cm.
If the link pin is up to 25.5 cm or halfway between 38.2 cm and 38.3 cm, all is well.If the link pin is a little bit past 25.5 cm, or approaching 38.3 cm, you should replace the chain, but the sprockets are probably undamaged.If the link pin is approaching 25.7 cm or 38.5 cm, you have left it too long, and the sprockets (at least the favorite ones) will be too badly worn. If you replace a chain at this point, without replacing the sprockets, it may run OK and not skip, but the worn sprockets will cause the new chain to wear much faster than it should, until it catches up with the wear state of the sprockets.More than that, and a new chain will almost certainly skip on the worn sprockets, especially the smaller ones.
There are also special tools made to measure chain wear; these are a bit more convenient, though by no means necessary, and most – except for the Shimano TL-CN40 and TL-CN41 – are inaccurate because they allow roller play to confound the measurement of link-pin wear.

13

I just replace my chain on Friday, I do about 12,000K a year, and have been doing lots of climbing this year which I assume might put more stress on the chain. I did not replace the cassette.

Today on my ride, when I would put pressure on the pedals, standing for instance, the chain would skip off the teeth they were on. It wasn’t a skip when changing gears. I asked at a bike shop what this might be, and they said that a new chain with an old cassette could be an issue. I do think I left the chain replacement too long, so it might have denigrated the cassette as well. Changed the cassette today as I plan to do approx. 100 miles tomorrow with lots of climbing and did not want to deal with skipping issues.

14

I replaced my chain today. Weather permitting I have a ride planned tomorrow. We’ll see how it goes. It was great for 3 to 4 miles around the block this afternoon. I figure it can’t hurt to try first.

15

I agree with the general sentiment here - change it if you feel a drop in performance, otherwise, leave it.

However, I was shocked by some of the mileages people reported getting from their drivetrains. I just replaced my chain on my commuter bike after ~7 months of use. I’m not sure what the mileage is exactly but it is maaaybe 3000 km at most. I noticed decreased shifting performance, the chain is definitely lengthened (not sure by how much), but given its relatively low mileage I left the cogs and chainrings. Shifting is improved. (I keep my chain clean via wiping down after every ride and lubing with Tri-Flo once per week.)

I replaced the drivetrains on my and my wife’s mountain bikes, which are now 10 years old. Hers was so bad the chain kept skipping no matter how I adjusted the barrel adjuster on the rear derailleur. The point is that it will become very obvious when the drivetrain needs replacement vs. “should be” replaced according to your LBS’ recommendation.

16

i feel like you have to trust your lbs mechanic. if you dont, find another. there are many great ones out there.

17

I would check the chain length but I would bet you are fine.

I have had an Ultegra drivetrain go completely to crap in 4000 miles. I would guess chain rings were not properly hardened or Tthe alloy was mixed improperly. That kind of crappy quality control is why I only ride Campy. It costs a bit more for Chorus or Athena, but it lasts forever

18

chain wear you can mostly check with a simple chain tool, pick one up. If you are big and/or do a lot of hard sprinting you will want to replace the chain before a chain tool indicates wear though.

Life will depend a lot on conditions you ride in and how often you clean/lube your chain.

If you have a 50/34 crankset you may wear through front chain rings pretty quick, since you will almost always be in the big ring and there aren’t as many teeth sharing the load.

19

The chain was done. I replaced it. So far it rides really nicely. If it goes prematurely, I’ll consider it a lesson learned and swap the cassette to. But I’m not doing chain rings just for the hell of it.

The reason I am gun shy with this shop is… the last time I went in which was the first time I went in… i asked about picking up a used speed concept 7. He told me that they kind of suck and with 800 supposed miles on it he would do a total overhaul. New shifters cables and drivetrain. Seems like the guy just likes making more work.

I am a auto tech and we get a bad rap for doing the same thing. I am a realist and I never oversell a customer. I may explain the pros and cons of doing things a certain way but ultimately I don’t disrespect a customer and call him “reckless” in a yoda voice … no I’m not kidding… He did do that.

20

800 miles between total overhauls, LOL, that’s a good month of training.