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correct way to determine chain length ? help

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correct way to determine chain length ? help

Old 08-11-16, 03:42 PM
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cvcman
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correct way to determine chain length ? help

Ok I chgd the chain on my hybrid Giant bike,,,,the new chain was 116 links with a quick link....I used the old original equipment chain as a guide for length...I didn't have to remove any links..it was the perfect length with two closed ends,,,so using the quick link may make it just a little longer...
Now someone told me to just wrap the new chain around the two largest rings,,,pull it tight ,,,and add 2 links,,,,whats the best way
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Old 08-11-16, 04:02 PM
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There is no BEST way. And on most bikes anything between the minimum and maximum length is fine.

The big/big+2 method determines the absolute minimum length chain, and going shorter can cost your drive train if you accidentally shift into a combination it can't wrap.

The maximum length is the longest whereby the RD can still take up all the slack in the small/small combination. There's a bit of fudge room on the max if you're willing to not use small/small combinations, and unlike the too short issue, no harm comes from a chain that's too long.

Many people, including me, prefer to use a chain nearer to the long side rather than the minimum length. This gives us leeway if, for example, we substitute a wheel with a larger cassette, or break a chain and need to splice it 1 link shorter.

So, since your a free adult in the USA, feel free to run any chain longer than the minimum.
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Old 08-11-16, 06:03 PM
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Originally Posted by FBinNY View Post
There is no BEST way. And on most bikes anything between the minimum and maximum length is fine.

The big/big+2 method determines the absolute minimum length chain, and going shorter can cost your drive train if you accidentally shift into a combination it can't wrap.

The maximum length is the longest whereby the RD can still take up all the slack in the small/small combination. There's a bit of fudge room on the max if you're willing to not use small/small combinations, and unlike the too short issue, no harm comes from a chain that's too long.

Many people, including me, prefer to use a chain nearer to the long side rather than the minimum length. This gives us leeway if, for example, we substitute a wheel with a larger cassette, or break a chain and need to splice it 1 link shorter.

So, since your a free adult in the USA, feel free to run any chain longer than the minimum.



Ok I thought IF you go too long that the derauiler would hit the cassette,,,,
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Old 08-11-16, 06:25 PM
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You didn't specify what RDER yo have and the size of the rings/cogs.
Assuming you have the almost "standard" 11-32T cassette and your largest & smallest chain rings are 20T difference.
That would require (32-11) + 20 or a total wrap capacity of 41T.

Likely you have an Altus or Acera RDER. They typically have a wrap capacity of 43 or 45T.
So, you are still within the capacity, but you are near the limit.

I expect you might have a very slight chain sag as is.
Now maybe the factory chain was sized a little "extra generous" in length and the 1" extra gives you a lot of sag???

For a quick check, you can put the rings on Big:Big.
Now take a couple skinny screw drivers or similar and insert into links several inches apart. (on a straight section)
Now move the screw drivers together, keeping them parallel to each other.
You can quickly get a rough idea of how many extra links you currently have.

Last edited by Bill Kapaun; 08-11-16 at 06:33 PM.
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Old 08-11-16, 08:26 PM
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There is a really good video on YouTube on tbe gcn channel titled installing a new chain. Best directions i have ever seen.
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Old 08-11-16, 09:08 PM
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Originally Posted by cvcman View Post
I used the old original equipment chain as a guide for length...I didn't have to remove any links
That length worked originally, it's working now - no reason to second guess because someone told you how it's "supposed to be." Leave it alone.
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