Singlespeed & Fixed Gear - chain stretch

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : chain stretch


acoustophile
11-19-09, 04:26 PM
My chain stretched to the point where it skipped off of the cog while riding last night. Being away from home and it being too late to hit up my nearest LBS, I used my chain tool and removed a link and then tensioned it up.

I realise that this is bad for my cog and chainring, but is there any risk of the chain snapping or breaking off?


mihlbach
11-19-09, 04:53 PM
are you sure your wheel isn't slipping?

Tomo_Ishi
11-19-09, 05:03 PM
It's gonna be bad for your cog/chainring, but that's if you ride that for days and months on it.

I don't think chain is going to break if properly done and done on a link you have never "touched" before. I would get straight home not doing any sprints and hard-climbing. Then have the chain replaced tomorrow.

I would have moved back my rear axle back on the track ends. You ought to buy a chain length checker. It's geeky, but it's convenient. Most of LBS people seem to eye-ball this type of stuff unless you specifically ask for it.


DMF
11-19-09, 05:09 PM
Removing a link is not going to have any affect on the chain skipping or anything else caused by wear (what you are incorrectly calling "chain stretch"). It's not that the chain is too long overall, it's that there is too much distance between each link - more distance than there is between each tooth on the sprockets. A chain that is too long will just be saggy; a worn chain is what cause it to climb off the sprockets.

You probably need a new chain. Measure the amount of stretch and report.

No, don't buy a chain checker. They are all inaccurate and will have you replacing your chains too often. All you need is a 12" steel ruler and knowing how to use it.

tgscordv6
11-19-09, 05:21 PM
Removing a link is not going to have any affect on the chain skipping or anything else caused by wear (what you are incorrectly calling "chain stretch"). It's not that the chain is too long overall, it's that there is too much distance between each link - more distance than there is between each tooth on the sprockets. A chain that is too long will just be saggy; a worn chain is what cause it to climb off the sprockets.

You probably need a new chain. Measure the amount of stretch and report.

No, don't buy a chain checker. They are all inaccurate and will have you replacing your chains too often. All you need is a 12" steel ruler and knowing how to use it.

Chains shouldn't stretch if they are tensioned properly. Is this a conversion that doesn't have track ends?

DMF
11-19-09, 05:28 PM
Huh? Chains can't "stretch" at all. They are made of metal (or at least mine are).

What y'all are calling "chain stretch" is accumulated wear. Tension adjustment has no effect on wear.



FYI, each full link is 1" long. To check wear, measure 12 links of the tensioned chain, pin center to pin center. Up to 12 1/16" (1/16" of "stretch") is okay. 1/8" is sketchy. Over that and you should start thinking about replacing the small sprocket. There is some controversy about how much wear you should allow. Check the Bicycle Mechanics forum for more info.

NickDavid
11-19-09, 05:29 PM
Huh? Chains can't "stretch" at all. They are made of metal (or at least mine are).

What y'all are calling "chain stretch" is accumulated wear. Tension adjustment has no effect on wear.

Thank you for this intelligent post. You'd be surprised how many people think that chains actually stretch.

Grand Bois
11-19-09, 05:34 PM
There is no way that your chain has worn so much that you can remove a link.

DMF
11-19-09, 05:49 PM
Thank you for this intelligent post. You'd be surprised how many people think that chains actually stretch.
Heh. Thanks. I normally don't visit here, but I saw this one scroll by on the ISpy page and couldn't help replying. ISpy is pretty cool. If it's a feature of the new forum software then the change-over is a net gain.

hairnet
11-19-09, 05:51 PM
There is no way that your chain has worn so much that you can remove a link.

lolwut?

acoustophile
11-19-09, 06:33 PM
I knew that the chain was on it's last legs. It was super saggy and I was just too lazy to do anything about it until it jumped off the cog. It's a conversion and I had the chain tensioned all the way to the back of the dropouts. After falling off and removing a link, I moved the wheel a little bit forward and tensioned from there.

preston811
11-19-09, 06:58 PM
Heh. Thanks. I normally don't visit here, but I saw this one scroll by on the ISpy page and couldn't help replying. ISpy is pretty cool. If it's a feature of the new forum software then the change-over is a net gain.

pretty sure it was there before.