BIKEPGH MESSAGE BOARD ARCHIVE

I don't see the point. So what if you wear out cassettes less often? They cost a small multiple of the price of a good chain. Just replace chain, cassette, and chainrings as needed.

I asked a bike mechanic i really respect about this on my last rehab. I asked, instead of changing out the chain, the chainrings, and the cassette every 4000 miles, would i be better to replace the chain every 2000 miles to stretch the life of the other components? (I use Wipperman chains) The answer was: hard to tell. Could go either way. There's an incremental extension of the chainring/cassette service life but not a huge one. FWIW

My approach is run it until it breaks. I got a complete overhaul on my Redline after about 4,000 miles. I wasn't paying that close attention to miles on any of the previous bikes, but that sounds about right. More commonly I was wearing out chains because of rust and poor storage but the cassette and rings were still OK. Short version, I don't think you're saving much by replacing them more frequently. Maybe before a long trip (CtC or some other cross country thing), but not for local riding.

Considering an Ultegra 10 or 11 chain is 45 dollars and a cassette is 100 or so, I don't see where spending 135 dollars over 3 chains and not having to replace a cassette or rings is cheaper than doing both at the same time (and most likely one ring) at only double the service interval. A chain is well past its lifespan if it skips on its original cassette. I can only imagine how terribly it shifts before that point. Also, 's chains and/or cassettes are not just as good as Campagnolo's or Shimano's.

Also, when changing a chain more frequently, the drivetrain stays cleaner and thus wears less rapidly. A chain that's rollers are filled with grit will wear and stretch more rapidly (and cause cassette/chainring wear) since whatever grit - be it sand from the trail or whatever acts as an abrasive and wears the interface between the roller and bushing- than a cleaner/replaced chain.

- I've only changed a cassette once. I think it maybe lasted ~5k miles. I felt bad. (Then that bike got stolen.) - Changing a chain is not a big deal (other than the ~$20). - Oil. Keep oiling; it will actually extend gear life (duh). I feel it should be every 2 weeks or 100 mi, which ever comes first. But that's aspirational. (And I continue to struggle with aspiration.) - Clean your chain. Those fancy chain cleaner thingies (eg Park) are nice. I have one. But it's hard to beat a jug of kerosene. Shaken not stirred. - And get one of those (cheap) chain-stretch gauge tools. It will tell you when your chain is too stretched out (and trashing your cassette).

Steve K is spot on. Why not spend a little bit on a chain and greatly increase the life of your cassette and rings? Furthermore, depending on the age and quality of your chainrings you may be looking at a new crank rather than new rings. There's also almost no difference in a top of the line chain vs bottom. Get the cheapest chain you can (be it whatever brand) and just buy them often. In practical terms I can get 3 chains to one cassette. I buy 4-5 chains a year and maybe two cassettes a year. Chainrings every other year or so?

Just bought and installed an el-cheapo (10$) kmc chain to replace my rusty one from winter. It's a meaningful improvement to how the bike shifts even with a lot else looking similarly rusted and horrible. I know I'll be doing it more often in the future.

I change chains. I use a cassette with a very low low gear (which is easy to find) and a second gear that is not a huge jump from th first gear (and THAT is hard to come by). My 2nd gear is the one I use most.

This has been interesting, but one thing I've never understood is this: why change your chain, other than to protect your cassette and chainrings? What are the negative consequences of having a worn chain?

Your chain is what grinds away your cassette and chainrings. On anything past/above/over 9spd chains tend to get lateral slop before they wear out longitudinally, meaning shifting degrades pretty quickly. In a more general sense, new chains save you money in the long run. I suppose if you want to replace your entire drivetrain (including perhaps cranks) periodically and incur the costs and lost time of that it's your business. But replacing a chain on a regular basis is preventative maintenance.

@jonawebb In my own experience, the interface between the gears and the chain becomes so degraded that the drive chain can't handle any significant torque before it starts slipping, so you literally can't apply power to the wheel. First time it's happened to me in a while, but I guess I was negligent enough this time for it to happen again. So on the way home, about a block away from my house, there's one part that's especially steep, which I couldn't get up without the chain slipping, so I had to walk the bike home. Luckily, I happened to have a spare drive chain lying around so I just switched everything out. I guess my next level of improvement would be to go from my use of 8spd to 10spd

@CM, thanks for explaining that again. I have heard the claim about shifting before, but I doubt it, just because I don't think there's that much stress put on the chain side-to-side. They're made of steel, after all. And how much slack would it take to really cause a difference in shifting -- the gap between the derailleur and the cog or chainring is just a few cm. Danny Chew told me I think last year that he was experimenting with not replacing his chain for a long time; I wonder how that worked out? Did he notice a difference in shifting? I'll try to observe when I change things myself in a week or so, once the weather's sorted out. @gg, yeah, if your gears start skipping I agree it's time to replace stuff. But I haven't heard a credible reason to measure chain stretch, etc., and replace it when it's worn otherwise. Is there any significant loss in efficiency, I wonder. Otherwise, I suspect this is just a case of conspicuous consumption. You have enough time, money, and expertise to keep your bike in tip-top shape all the time. So you do. Nothing wrong with that; buying stuff is what made this country great. But bikes don't really require it; they are durable, practical vehicles, which do just fine with moderate maintenance.

My guess is the shifting problem is related to the slipping problem. If somebody is shifting under load and they've already lost a lot of torque potential (torque that can be applied before the chain slips,) when they're changing gear the amount of teeth they're working with is less during the change, which results in slipping with even less torque applied. Thus, when you're trying to change gears, it's just a lot of slipping and you have to try and get to some gear you don't regularly use that isn't as worn. Without measuring the chain or checking visually to make sure the chain is seating properly on the chain ring, I don't think you'd be able to tell until slipping starts, at which point, I think the whole system deteriorates rapidly. I think it'd be less stressful to just spend a certain amount of money on parts ahead of time and periodically replace stuff before it ges to that point. It's like preventative maintenance versus fixing stuff once it breaks. I think Sheldon Brown says replace it when it's either a 1/16 or an 1/8 of an inch off, but the former is pretty hard to measure visually I think with a ruler For people who don't have a bunch of bikes laying around, I think it'd be far less stressful to do preventative maintenance when you can control the circumstances and time of the repair. When I was younger, I had a lot of nights being up until 12, 2, 3 in the morning screwing around with my bike when I needed to use it to get to work the next day. (or much less often, a date was waiting for me longingly :) Having another bike in working order is also a good strategy :) I've been slowly moving away from the practice running everything on a bike into the ground and then fixing it all, versus gradually fixing stuff over a spread out period of time. I think it makes the overall riding experience better as well, and probably less dangerous

"This has been interesting, but one thing I’ve never understood is this: why change your chain, other than to protect your cassette and chainrings? What are the negative consequences of having a worn chain?" I typically change chains when the Park stretch tool says they hit .75% of wear, although I sometimes let them go a little longer. It does seem to extend cassette and chain ring life. I can't quantify the savings or increased life span, other than to say that like Chris, I go through 3 chains per cassette on road bikes. Frankly I don't care about the economics; it's about having bikes that are as safe and reliable as possible. Perhaps that is gratuitous consumption, but I don't want to be the asshole whose chain breaks or derails at a race and causes 5 people (all of whom have to work the next day) to hit the pavement at 30 MPH. Nor do I wish to spend 3-5 hours driving down to Shenandoah or Canaan for a weekend of riding or racing, only to piss around with and be aggravated by a malfunctioning drivetrain. Nor do I wish to have an old chain pick up a bunch of grit in the rollers, get hung up on worn out rings, and ultimately get sucked into the chain stays and destroy an $800 mountain bike frame. Nor do I want to see any of the above happen to my wife and/or her bikes. So, from my perspective there are good reasons to spend what is frankly chickenshit money to keep everything in very good operating condition. If I were only commuting and always had a Port Authority bus to ride me home when my equipment fails, then I could see trying to get every last mile out of a drivetrain.

The only time I've had chains break was when I'd changed them recently, and was still using those narrow Shimano chains that are very picky about how far you're supposed to insert the rivet (but then, the guy who works on my bike is just barely competent). Before that, when I was using wider chains, and since I've switched to SRAM with a master link, no problem. I don't think chain breakage is really an issue with worn chains, at least until they get ridiculously old. Gear slippage and grabby chainring teeth are definitely signs it's time for new drivetrain parts. No question there. Though you can file off the hook of the grabby teeth and get by for a while. I read Sheldon's detailed description of how chains wear, and the consequences for gear teeth, but even he doesn't exactly explain what other problems there are for riding with a worn chain, other than wear on other drivetrain parts. It's enough, for him, to post pictures of worn teeth and say, "see"? I guess that's more of an issue if the gears aren't readily replaceable the way they are on modern bikes. I totally agree that if I was racing I would replace chains frequently, for the reasons my friend Jake McCrea states.

I wore a chain out a few years ago without knowing it and the first time it "skipped" was at an uphill intersection with lots of turning traffic as I climbed out of the saddle (and almost onto the pavement). It was scary enough that I still remember it. So it's not just the racers that should consider chain wear issues sooner rather than later.

+1 Marko Happened to me too. Slipping when the light turns green is a PITA. I've also had a chain brake, and if memory serves me right, it was before the point of slipping. This was a few years ago... While trying to fix it, my chain tool broke, late at night around 11pm. My cell phone was dead too. So I had to lock my bike up, jog from the waterfront side of the Rankin bridge to by the School for the Deaf by Wilkinsburg where my girlfriend's place was, then in the morning take a bus to East Liberty, then jog from Target to my house at the very most northern part of Morningside, then ride another bike back to Homestead, get my panniers, go to work and then I think I picked the bike up the next day or something with a car

We can measure chain stretch. However, Is there a good way to measure, not eyeball, whether a cassette or chainring is worn to the point where it should be replaced?

there's a tool for that, although I've never used one https://www.youtube.com/watch?v=DGMgIyNYGiU

Interesting tool. I wonder if I couldn't just use my chain whip the same way?

Here is what the GCN guys have to say about it. At 3.32 there is a pretty simple test.

The English voice of authority: strangely convincing.