Any real problem with a slightly slack chain?
03-17-13, 09:08 PM
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Any real problem with a slightly slack chain?
So today I decided to finally replace the chain on my fair-weather bike. Unfortunately, once I had the old chain off (using the reusable link) I realized that I couldn't find my chain tool. 
Then I realized that the new chain was only an inch or so longer than the old chain, so I just decided to put the new chain on without shortening it. Now the chain is slightly slack in the small chainring/small cog combination, but there is a little tension when it's on the next larger cog on the back.
My question is, since I never use the small/small combination anyway, is there any problem riding this bike until I either find my chain tool or buy a new one? Everything seems fine. If there is any risk in doing so, I won't ride it (I have other bikes I can use in the meantime).
Then I realized that the new chain was only an inch or so longer than the old chain, so I just decided to put the new chain on without shortening it. Now the chain is slightly slack in the small chainring/small cog combination, but there is a little tension when it's on the next larger cog on the back.My question is, since I never use the small/small combination anyway, is there any problem riding this bike until I either find my chain tool or buy a new one? Everything seems fine. If there is any risk in doing so, I won't ride it (I have other bikes I can use in the meantime).
03-17-13, 09:12 PM
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Not a problem at all.
Two of my bikes run 22/32/48 rings with 11-36 cassettes, and I have a little slack in the chain on the small/small.
Two of my bikes run 22/32/48 rings with 11-36 cassettes, and I have a little slack in the chain on the small/small.
03-17-13, 09:14 PM
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No real problem, because as you say you don't ride the combination anyway. As a matter of fact this is the standard fudge when the gear combination exceeds the capacity of the RD.
You cannot cut a chain shorter than the minimum length (large/large + 1") because to the off chance that you might shift into that gear accidentally, destroying drive train parts. OTOH, the worst thing that can happen with a chain that's too long is it sags a bit if you shift into the small/small, and you can correct that easily enough.
In some cases, I've retrofitted "bailout" grannies on road bikes when people were anticipating a hilly tour. I've had some where the grannie could only be used with the largest few rear sprockets, but it was an acceptable trade off to avoid replacing the RD.
You cannot cut a chain shorter than the minimum length (large/large + 1") because to the off chance that you might shift into that gear accidentally, destroying drive train parts. OTOH, the worst thing that can happen with a chain that's too long is it sags a bit if you shift into the small/small, and you can correct that easily enough.
In some cases, I've retrofitted "bailout" grannies on road bikes when people were anticipating a hilly tour. I've had some where the grannie could only be used with the largest few rear sprockets, but it was an acceptable trade off to avoid replacing the RD.
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An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
03-17-13, 09:19 PM
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03-17-13, 10:03 PM
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The other issue with playing with chain length (other then small/small combo) is whether the upper pulley contacts the largest rear cog (pulley knock). If no knock is present and the small/small is good for you then all is right... Andy.
03-17-13, 10:10 PM
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03-18-13, 05:32 AM
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You could also put your old chain back on with it's quick link and ride that until you find your chain tool to shorten the new chain. Just sayin'.
03-18-13, 06:03 AM
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Hi,
Since due to cross chaining and general gearing technique you
should usually never use the smallest derailleur gears on the
small ring (or the largest on the large ring) I cannot see any
real problem here at all. Large/large must be accomodated.
rgds, sreten.
Since due to cross chaining and general gearing technique you
should usually never use the smallest derailleur gears on the
small ring (or the largest on the large ring) I cannot see any
real problem here at all. Large/large must be accomodated.
rgds, sreten.
03-19-13, 08:05 PM
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In my experience, a chain can be long enough to handle the big/big combo, but still be too short to function properly. In any gear in which there is any cross-chaining whatsoever, as the lower pulley is pulled forward of the rear axle, it moves out of the plane in which the chain is running. I had a chain attempting to derail off the side of the pulley in this situation, and had to lengthen the chain to allow the pulley to move toward the back. This was on a 9s Shimano 9s with 22/32/44 and 11-36.
A chain too short is a much more serious problem than having some slack in the small/small.
A chain too short is a much more serious problem than having some slack in the small/small.
03-20-13, 08:44 AM
#13
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In my experience, a chain can be long enough to handle the big/big combo, but still be too short to function properly. In any gear in which there is any cross-chaining whatsoever, as the lower pulley is pulled forward of the rear axle, it moves out of the plane in which the chain is running. I had a chain attempting to derail off the side of the pulley in this situation, and had to lengthen the chain to allow the pulley to move toward the back. This was on a 9s Shimano 9s with 22/32/44 and 11-36. A chain too short is a much more serious problem than having some slack in the small/small.
