I just installed a new chain on my 2002 Trek 2200 Road Bike. The old chain was a Shimano 9 speed that I installed 18 months and about 5000 miles ago. It had stretched modestly and was full of winter cruft/grime. The new chain is a SRAM 9 speed, my first time using the gold snap ring system. I followed instructions and made sure I have the same link count as the chain that came off the bike. The cassette was new with the old chain, so it has about 5000 miles on it and doesn't appear to have significant wear. After installation and a clean/wipe/lube/wipe, I took it for a 15 mile easy ride at about 15-16 mph. It shifts perfectly and I didn't have to make any adjustments to either derailleur. Three times, however, when putting it under stain (once on a modest hill climb, once starting from a stop sign in a fairly big gear, and once on an acceleration coming out of a sharp turn) it skipped several teeth and caused my foot to slam down hard. On the hill, it actually hurt as I had my weight off the saddle (not really standing) and I came down hard on the inside of my thigh. I think all three were on the right side (power train side) pedal stroke, and I don't think they were all in the same gear. I'm pretty sure it was the rear cassette that skipped, not the front chainring, but it did happen really fast each time. I will also say that it's not like these were the only three times I put substantial pressure on the pedals in the ride - I wasn't going hard, but I wasn't being tentative or anything. Also, in case it's relevant, it was cold, about 40 degrees F or about 4 degrees Centigrade.

My question: Is this going to get me hurt, or will the new chain 'settle in' over a few rides? I searched here and pretty much got confirmation of what I had previously thought, that you always get a new chain when you get a new cassette, but you should be able to get a few chains out of each cassette. Thanks!

  • When was the last time you replaced the cassette. Perhaps it is too worn. Mixing old cassettes with new chains can sometimes cause problems.
    – Kibbee
    Commented Feb 26, 2013 at 20:12
  • I replaced both cassette and chain in the Summer of '11, about 5000 miles ago. I thought I would get more miles from the cassette, and think I have done in the past.
    – Dan Catlin
    Commented Feb 26, 2013 at 21:19
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    5000 miles is about what you can expect from a cassette -- maybe more, maybe less. (And 2000 miles is about what you should expect from a chain.) Commented Feb 26, 2013 at 23:32
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    I've heard people changing their chains at 2000 miles, but I use one of those chain measuring tools and it was within tolerance even at 5000 miles. I guess I thought 2000 was a bit like changing the oil on your car at 3000 - used to be the standard but most new car manuals say 5000 or even 7500 miles is fine with new tolerances, etc. Maybe the new rule for me is change them together once a season or every 5000 miles or so. Thanks.
    – Dan Catlin
    Commented Feb 27, 2013 at 13:35
  • 5000 miles out of a casette is what you can expect? Wow, that's like ... an oil change interval on a car. And I'm assuming that's a good quality casette, not something from a "bicycle shaped object?" Geez what an industry, this cycling.
    – Kaz
    Commented Mar 2, 2013 at 1:28

6 Answers 6


Over time an old chain and cassette wear together, so you don't notice the wear until it gets really bad. When you replace the chain while leaving the old cassette the tooth profile is no longer correct and the new chain will skip off of the teeth, especially under load.

Unfortunately it won't get better and the only recourse is to replace the cassette as well. In the future you can save money by changing the relatively inexpensive chain more often as the cassette wears faster with an elongated chain.

More info: http://sheldonbrown.com/chains.html

  • 1
    Thanks for the Sheldon Brown article - I hadn't thought to check his site. If it adds anything to the conversation, I hadn't really noticed any wear - just thought it was time - the chain measurement tool was still (barely) in spec, and there is no obvious wear on the cassette, nothing like in the pics on Sheldon's site.
    – Dan Catlin
    Commented Feb 26, 2013 at 21:20
  • I seldom allow a chain to run more than 2000 or so miles, especially on bikes that are run in foul weather and almost never have to chain cassettes.
    – Rex Kerr
    Commented Feb 26, 2013 at 22:18

After 15000 miles on the same 9 speed chain, same cassette, and same chainrings on a Jamis Aurora 2010, my chain starting skipping when up off the saddle. One day the skipping caused me to flip forward onto my helmet/shoulder/left hip. I'm an advocate of always wearing a helmet now. I suspect I'd have a broken eye socket if I had no helmet. I too thought the skipping was on the rear cassette. But I was wrong. I first just changed the chain. Problem got worse. Then changed the cassette. Problem same. Did some closer testing and found when on the smallest chainring there was no skipping. Changed the two largest chainring and the problem was fixed. When purchasing a chainring you'll need to know the bcd (bolt circle diameter). It should be marked on the large chainring.


You might need to get your derailleur adjusted; the new chain would be shorter than the previous chain and one might have bumped the derailleur upon installation.

  • Hmm. I would have thought the new chain would be a tad shorter, but the shifting is flawless. The only problem is those skips on the maiden voyage. Unfortunately, it's raining bad today, so I can't give it another try... I'll bring it into my favorite shop over the weekend if I don't get it sorted. Thanks.
    – Dan Catlin
    Commented Feb 26, 2013 at 21:22
  • A new chain is not necessarily longer. New chains typically come with extra links that you can take off to meet your needs, but if both chains have the same number of links, the old chain is longer as it has been stretched. Commented Feb 26, 2013 at 23:14
  • ugh, I meant shorter. Should have proof read... adjusting.
    – Mimi Flynn
    Commented Mar 1, 2013 at 16:59
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    If you've sized the chain correctly, the derailleur adjustment shouldn't have to change.
    – Batman
    Commented Aug 2, 2014 at 19:19

I have the same issue having changed the chain and cassette. The chain moves between the biggest cogs at the back when in the smallest at the front. Its also came off twice on first ride. Bike shop now says straighten hanger, adjust cable and derailler then replace jockey wheels. Says chain rings look okay. Have you tried those solutions?

  • Hi, welcome to bicycles. Have you tried their suggestions? Did they work? This would be a much better answer if you could confirm that the advice you're passing on has some value.
    – DavidW
    Commented Mar 23, 2021 at 20:10
  • I'll know tomorrow when I get the bike back and then I'll report what the solution was for me.
    – James909
    Commented Mar 24, 2021 at 21:11

If you have a new chain and your derailleur is in good condition (or everything was working before changing the chain) I'd look at the cassette. they wear together and as you go through chains the cassettes tolerance to adapt to new chains diminishes to a point where it won't ride a new chain efficiently. It'll be more noticeable in the gears you ride the most.

  • Hi, welcome to bicycles. This would be a better answer if you weren't repeating information that's largely covered already. (You could improve it by adding more details or links.)
    – DavidW
    Commented Jan 21, 2023 at 20:19

If you change your chain you must change the cassette or you're looking for problems.

The chain basically molds the cassette and when you put a new one on, it's fresh but the cogs are shaped by your old worn out chain.

So the new chain will not work well with the old, worn cassette.

  • Welcome to Bicycles @roy. Please write with normal English punctuation and a little formatting; it makes your post much easier for others to understand :-)
    – andy256
    Commented Apr 3, 2015 at 5:51
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    This isn't true unless you've worn out the cassette. Generally, you should get at least 2-3 chains out of a cassette if you're changing your chains at appropriate times.
    – Batman
    Commented Apr 4, 2015 at 2:24

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