Checking Proper Chain Length

Forums Mountain Bike Forum Checking Proper Chain Length


This topic contains 6 replies, has 4 voices, and was last updated by  jasonbikes 2 years ago.

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  • #231040

    It’s time now for a stupid question. I just installed a new chain on a 1X bike for the first time and I’m paranoid about the length. The new chain came about 2 and a half links shorter than the old chain. What’s the best way to determine if the chain is too short or good to go?

    I’ve shifted through all 11 gears and rode around the block and it seemed to pedal/shift alright but I want to be 110% sure it’s not too short before I go on a trail ride and potentially destroy my derailleur or cogs (and have a long ass walk back to my vehicle).

  • #231065

    That’s surprising that the new chain came shorter than the old one. Is the bike a tandem or a Big Dummy or something? Ha!

    Your old chain most definitely stretched over time, though probably not by 2 and a half links (but maybe by a half link.)  So, it is normal for a new chain to be shorter than the old one–the number of links is the important thing to note.

    Sheldon Brown says,

    If the chain is too short, it will be at risk for jamming and possibly ruining the rear derailer if you accidentally shift into the large-large combination. Never run with a chain that is too short, except in an emergency.

    To be safe, you might want to add back a couple links from the old chain to get the right length. I know a guy who allegedly strung together like 5 powerlinks in a row on his chain, but I don’t advise doing this to make up the length. 🙂

  • #231068

    Hmm that’s weird that the new chain came shorter. What brand of chain did you get? Most chains are going to be between 114-118 links long, and you’ll have to trim them on just about any bike.

    Did you put the old chain on? If not, maybe no one took the time to shorten it when new?

    Is your bike a hardtail or a full suspension?


  • #231076

    It was a Sram PC-1130 11 speed, and the bike is full suspension. The old chain was put on when the bike was first assembled. I think I’m gonna take it to my local shop mechanic and have him add some extra links for length if it’s too short.

  • #231079

    Ah, chances are then that the original chain was never shortened. With a full suspension you need to check the chain length at full compression. Shift into your biggest cog on the cassette, then let all the air out of your shock, and compress the shock completely.

    Park Tool has a good video on it, although they suggest just unbolting your shock instead of letting the air out. Either way will work.

    • #231295

      <p>Thanks for the tip on the shock Aaron, always learning something new.</p>

  • #231097

    I didn’t even think about the rear shock compression. Thanks, Aaron & Jeff


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