How to tell if chain is too long?

I believe if I can remember... Have the bike in the large front chainring and the smallest rear
chainring. The rear derailleur should intersect with the ground i.e. the bottom jockey wheel of the
rear derailleur should not be in front of the upper jockey wheel. I believe as close to 90 degrees
as possible...

My2c,

NS

NS said:

I believe if I can remember... Have the bike in the large front chainring and the smallest rear
chainring. The rear derailleur should intersect with the ground i.e. the bottom jockey wheel of
the rear derailleur should not be in front of the upper jockey wheel. I believe as close to 90
degrees as possible...

My2c,

NS>

Another approach: Break the chain and put it around the big-big combination outside the rear DR. You
should have about 1 link of overlap (1/2 to 1-1/2) between the chain ends when you pull 'em tight.
Put the chain back on right. At 1/2 link or so of overlap, make sure that you can shift into the
big-big combination without damage to the rear DR (shifting from the front or the rear) -- not a
normal combination, but most of us hit it by accident on occasion -- for me, it's usually while
night riding.

If you have a full suspension mountain bike, you need to do the above test with the rear suspension
at the point where it needs the most chain (fully extended for most, so not a problem).

Note that by a link, I mean 2 chain pieces 🙂.

David

If it's dragging on the ground, that would be a clue :-3)

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": geocities.comczcornerOpen ↗

parktool.comFAQchainlength.shtmlOpen ↗

~PB

Boyd Speerschneider said:

Hi,

The subject says it all. How can I tell if my chain needs a few links removed?

Put the chain in the small ring and small cog. If the chain drags the bottom of the rear
derailleur, it is too long. You should be able to put the chain in the big/big combination. If you
can do the first but not the second, you need a rear derailleur with a longer cage or a smaller big
ring or low cog.

Paul Kopit said:

Boyd Speerschneider said:

Hi,

The subject says it all. How can I tell if my chain needs a few links removed?

Put the chain in the small ring and small cog. If the chain drags the bottom of the rear
derailleur, it is too long. You should be able to put the chain in the big/big combination. If you
can do the first but not the second, you need a rear derailleur with a longer cage or a smaller
big ring or low cog.

Be wary of this approach. On my mountain bike, it leads to too short a chain and WILL break the rear
DR shifting into the big-big (I know, not normal, but it does happen 🙂).

David

Quoted message said:

Quoted message said:

The subject says it all. How can I tell if my chain needs a few links removed?

Put the chain in the small ring and small cog. If the chain drags the bottom of the rear
derailleur, it is too long.

It doesn't matter if it is too long for small-small, IMO. Low gears tend to work best with shorter
chains. I use chains that are just long enough for the big-big.

~PB