Chain and Cogs: Don’t wait too long!

[Dirt]

This is one of those “Let my life serve as an example” sort of posts.

I’m usually pretty good about keeping an eye on chain wear so that I don’t have to do a wholesale drivetrain “upgrade” but failed miserably this time. I hadn’t messed with the chain on the fat fixie for wayyyyyy tooo long. I went to put a new chain on last night and when I went for a shakedown ride, all I heard was crunching and grinding out of a perfectly clean and partially new drivetrain. What should have been a $20 fix ended up costing me $150.

Background: As your ride, your chain stretches and wears. If you don’t clean your chain often, that process happens quicker. If you ride with a chain that is stretched and worn, the cogs (gears in the back) and the chainrings (gears in the front) wear to match the longer, worn out chain. When you finally do get around to replacing your chain, the bike will no longer pedal or shift correctly. Any time you put pressure on the pedals, the gears will pop and grind.

The “solution”: If you’ve waited too long the only solution is to change the chain, chainrings and cogs all at once. That gets expensive. One reason you see seemingly nice, lower-end bikes on Craigslist at a good deal is that someone paid $500 for a new bike two years ago, ignored the chain and just heard from their mechanic that is going to cost $300 to replace chain, cogs and chainrings. Buyer beware!

How do I avoid this?: There are many companies that make tools that measure how much your chain has worn. They’re simple to use and quite reliable. Use them frequently… especially if you ride when it is wet or don’t clean your chain often. When the gauge says that your chain should be replaced… or is getting close to needing to be replaced, buy a new chain and do it!!! The fix is easy to do. It is a great job for someone wanting to start doing their own repairs.

Links:

Chain wear gauge: http://www.parktool.com/product/chain-wear-indicator-CC-3-2

Chain wear video: http://www.youtube.com/watch?v=6pUgHM8HU2Q

Everything you ever wanted to know about chains and much, much more from Sheldon Brown (MHRIP): http://sheldonbrown.com/chains.html

Hope that is somewhat helpful.

Hugs and Kisses,

Pete

Topic

[hozn]

@jrenaut 90018 wrote:

I’m assuming the chain broke and got caught in the cranks? I don’t see how else it could have flipped him over the bars. Anyway, if you haven’t done it recently, go lube your chain and make sure it’s still in good working order.

I think it probably was just the momentum of pedaling; if you suddenly surge forward with no resistance from a chain the chances of going forward over the bars are great. Especially if you are working out of the saddle, etc.

Most (actually, I think all) chain failures I’ve had have been on mountain bike and there was nothing wrong-looking with the chain beforehand. But it was newby riding errors like shifting under load coupled with the more significant torque of mtb that caused those failures, I assume.

[jrenaut]

His bike is a very old steel road bike. When we did the century in May he had to get some emergency parts because the axle that goes through his pedal sheared off a mile into the ride.

[n18]

@jrenaut 90018 wrote:

Related to this thread – make sure your chain is in good shape. I don’t have good details on what happened, but my brother-in-law was in a bike accident out in San Fransisco. He’s okay, but according to the woman who used his cell phone to call his wife, his chain broke and he went over the handlebars. He lost a few teeth, some of which had to be cut out of his lip, and he broke his elbow, which is going to require surgery.

I’m assuming the chain broke and got caught in the cranks? I don’t see how else it could have flipped him over the bars. Anyway, if you haven’t done it recently, go lube your chain and make sure it’s still in good working order.

The chain probably got stiff links, combined with missing “missing links” or bad links that broke. When my chain got rusty, and I switch to the fastest speed, stiff links sometimes roll at the bottom around the largest gear in the front then going upward and under the chain on the top part of the front gear, resulting in the front gears locking up, and you can’t peddle forward, not even an inch. The only way to move the cranks at this stage is to peddle backward. It’s unnerving when it first happened to me as I didn’t know what’s wrong. I peddled backward by small amount, then forward, but nothing happened until I peddled backward quarter to half turn and seen the chain dropping. Going home and lubing the chain fixed the problem for a while.

I am sorry that this has happened to him, I wouldn’t think that something like this could happen. Cyclists need to be educated on the seriousness of this issue. Many are concerned with frame strength, but these days they are building them better than they used to.

[AFHokie]

While my bike was at REI they replaced a chain that showed just under .75 wear with the 3.2 park tool wear indicator. With the new chain/old cassette it shifts fine until under a load, (up hills, hard acceleration from a stop, etc) then it jumps or skips. It doesn’t appear to skip with infrequently used cogs, but I’ve only ridden once with the new chain…tonight’s commute home sould be fun.

Did I run the old chain too long and kill the frequently used cogs, or is this something common that needs a few more rides to settle, or an additional cable/derailleur adjustment?

If it helps its a SRAM PG-950 9spd cassette the bike came with & has ~3200 miles.

[huskerdont]

@AFHokie 130838 wrote:

While my bike was at REI they replaced a chain that showed just under .75 wear with the 3.2 park tool wear indicator. With the new chain/old cassette it shifts fine until under a load, (up hills, hard acceleration from a stop, etc) then it jumps or skips. It doesn’t appear to skip with infrequently used cogs, but I’ve only ridden once with the new chain…tonight’s commute home sould be fun.

Did I run the old chain too long and kill the frequently used cogs, or is this something common that needs a few more rides to settle, or an additional cable/derailleur adjustment?

If it helps its a SRAM PG-950 9spd cassette the bike came with & has ~3200 miles.

It’s quite common to have a new chain slip on an old cassette. I pretty much always replace the cassette when I replace the chain after once or twice trying to see if I could get by and finding I couldn’t. Your symptoms are exactly what happened. If possible, leave it in a cog that works and use the front derailleur to compensate until you can get a new cassette.

[TwoWheelsDC]

@AFHokie 130838 wrote:

While my bike was at REI they replaced a chain that showed just under .75 wear with the 3.2 park tool wear indicator. With the new chain/old cassette it shifts fine until under a load, (up hills, hard acceleration from a stop, etc) then it jumps or skips. It doesn’t appear to skip with infrequently used cogs, but I’ve only ridden once with the new chain…tonight’s commute home sould be fun.

Did I run the old chain too long and kill the frequently used cogs, or is this something common that needs a few more rides to settle, or an additional cable/derailleur adjustment?

If it helps its a SRAM PG-950 9spd cassette the bike came with & has ~3200 miles.

Before buying a new cassette, try adjusting the RD…shift into one of the skip-y gears, lift the rear wheel off the ground and crank the pedals while twisting the barrel adjuster until the skipping stops (if the RD shifts a cog, you’ve twisted too far). Then run through the gears and re-adjust as needed. If you can’t get the skipping to stop, then it may indeed be time for a new cassette.

If you don’t have a stand readily available, just hang your bike on a tree branch from the nose of the saddle.

[Vicegrip]

I now go through 4 or more chains per cassette. The first chain on my modern bike I ran too long and I ate the cassette up along with the chain. Learned my le$$on about $aving money the hard way and I now check and replace the chain just a bit before it hits .75.
Keeping the chain well oiled goes a long way. I no longer go to great lengths to clean the chain other than wiping the globby chunks off when I re-oil. For me it seems chains last the same amount of time and miles cleaned and oiled often as when they are simply just oiled often. I re oil often as needed or more and always after it gets wet. While slowly turning a crank backward I drip in chain oil until the chain is fully wet then turn for 15 seconds or so to work the oil around and in. I then wrap a bit of end of service life shop rag around the chain and spin the crank some more to wipe off the excess oil and most of the black gunk. Takes 60 seconds or so to re oil this way and no mess to clean up.

[dkel]

@TwoWheelsDC 130843 wrote:

Before buying a new cassette, try adjusting the RD…shift into one of the skip-y gears, lift the rear wheel off the ground and crank the pedals while twisting the barrel adjuster until the skipping stops (if the RD shifts a cog, you’ve twisted too far). Then run through the gears and re-adjust as needed. If you can’t get the skipping to stop, then it may indeed be time for a new cassette.

If you don’t have a stand readily available, just hang your bike on a tree branch from the nose of the saddle.

This would depend on what type of skipping we’re talking about. If the chain is jumping teeth, it’s probably not a derailleur trim issue, but a worn cog. If the chain just doesn’t want to settle into gear, that’s a derailleur issue.

[vvill]

I have so many bikes, cassettes and wheels that I have no idea how much wear is on each anymore.

[hozn]

@Vicegrip 130848 wrote:

I now go through 4 or more chains per cassette. The first chain on my modern bike I ran too long and I ate the cassette up along with the chain. Learned my le$$on about $aving money the hard way and I now check and replace the chain just a bit before it hits .75.
Keeping the chain well oiled goes a long way. I no longer go to great lengths to clean the chain other than wiping the globby chunks off when I re-oil. For me it seems chains last the same amount of time and miles cleaned and oiled often as when they are simply just oiled often. I re oil often as needed or more and always after it gets wet. While slowly turning a crank backward I drip in chain oil until the chain is fully wet then turn for 15 seconds or so to work the oil around and in. I then wrap a bit of end of service life shop rag around the chain and spin the crank some more to wipe off the excess oil and most of the black gunk. Takes 60 seconds or so to re oil this way and no mess to clean up.

So replacing chains between 0.50 and 0.75 for me gets me roughly 4 chains per cassette — or about 6k miles at 1.5k miles per chain. (On my commuter.) Last cassette I decided to just run the chain and cassette to the ground together and I got ~4500 miles on the chain and cassette before it started skipping (ever) and ran it up to about 5k before I felt like the performance really was suffering. So I don’t think I’ll change chains out anymore — at least not to save money.

[sethpo]

I recently had a chain skipping issue that turned out to be a stuck link. The chain was pretty clean and only about 1/2 through it’s normal life span. I lubed the heck out of the link but that didn’t really work. I ended up using this method to fix it.

https://www.youtube.com/watch?v=QU79CQsz-Ps

I guess it got just a tad bent somehow. Anyway, if you have skipping be sure to check that the chain links are functioning properly as well.

Oh, since we’re talking about chains: I go w/ the cheapest available. I’ve not found any difference in performance or durability with more expensive chains. KMC4me! YMMV of course.

[Crickey7]

@hozn 130860 wrote:

Last cassette I decided to just run the chain and cassette to the ground together and I got ~4500 miles on the chain and cassette before it started skipping (ever) and ran it up to about 5k before I felt like the performance really was suffering. So I don’t think I’ll change chains out anymore — at least not to save money.

That’s my experience as well. I wear them out together and get around 5k per, less if I fail to clean them religiously. The one warning is that I think this method wears out your chainrings somewhat quicker than the alternative, but, again, not sure it’s worth changing that. I’ll get around 10K out of my chainrings, and I suspect I would not get than much more if I changed chains more frequently.

[Steve O]

I have never kept track before, just waiting til problems develop. But now that we are having this discussion, I’m in a good position to do so. I switched out my entire drive train last spring after FS ended, going to 1×9, so everything was new. I can check Strava for my miles and see how far I go before it all goes to crap. I’m probably at close to 4000 miles right now without any noticeable issues. I wonder if having a single on the front will make it last longer, since the chain isn’t ever being dragged across it.

How do I add up all the miles for one particular bike within a date range? I can add up my total miles, but that includes miles on other bikes and CaBi, etc. than just the one in question.

[dkel]

I’m not sure what I’m doing differently from everyone else, but by way of comparison, I am at 6000 miles, and have only swapped out my chain once—not that long ago. I’m nowhere near .75 on the new chain, and things are running great. I do a lube and serious wipe down about every 75 miles or so, but that’s it. I expect my current chain will run another couple thousand miles at least, and then I’ll change the cassette. My theory is that it’s because of the extremely long front fender—with mudflap—that runs only a couple inches off the ground. Or maybe I’m just lucky. Either way, I’m pretty happy about it!

[hozn]

Maybe you ride gently? Half kidding I definitely know there are folks that get 10k on chains without fenders, so I don’t think the fenders are a significant factor. But I could be wrong. I do definitely get longer chain life on the bike that doesn’t get ridden in the rain as much. But I noticed no difference in chain life moving from almost-touching-ground mudflap to no mudflap. (Also no significant difference in how dry/wet my feed ended up, though I suspect there was *some* difference if someone were to apply science there.)

[Author]

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