trackdropouts - Topic: Chain came off

Adam EF on Chain came off

Thu, 18 Mar 2010 17:36:16 +0000

Surly look good but can't afford new 130bcd cranks to fit. Current cranks are 144bcd.

Anyone used Token chainrings?

43t is still difficult to find. Might go for 45t instead for more options.

Cab on Chain came off

Thu, 18 Mar 2010 06:24:59 +0000

Surly chainrings. Dearer to start with, but got big teeth & last longtime. I've lost chains off road rings, but never a Surly one.

Adam EF on Chain came off

Wed, 17 Mar 2010 20:20:49 +0000

I checked this when fitting the chainring. It is very close. Angle of that photo makes it look slightly further out. There is actually a 1 or 2mm gap between the chain on the chainring and the end of the arm of the spider.

I'm fairly sure that the chain coming off was a result of the (increasing) flat spot on the chain ring. It occurs exactly at the point that I usually jam the cranks with my right leg back, causing the chain to be slightly slack at that point. No amount of adjusting the chainring position will fix it either.

I'm going to try and get a good strong chainring on there for peace of mind. The thin 42t road ring that came with the cranks isn't really up to it.

The extra grip of the Randonneur rear tyre seems to be exerting more stress through everything when I stop too. Tempted to go for something slightly less efficient that will skid a bit more rather than glue me to the spot suddenly. Gatorskin maybe?

whatfriends on Chain came off

Wed, 17 Mar 2010 20:01:04 +0000

it also looks like the chain might touch the spider arm every time it goes by one and not sit all the way onto the ring. shouldnt throw a chain off but something to look out for...

Adam EF on Chain came off

Wed, 17 Mar 2010 18:12:46 +0000

This happened again last night. I'd previously worked out that my chainring was not totally round and was becoming progressively less circular (chain slackening with cranks in one position).

Last night chain came off when stopping at a junction again. On closer inspection after riding to the workshop with the chain put back on it appears I lost a tooth.

I'd like to put it down to my brute strength and stopping power, but it's more likely to be the weak old metal.

New chainring time.

Adam EF on Chain came off

Sun, 07 Feb 2010 20:46:29 +0000

Thanks guys. Chainline is good (about 0.5mm out — not bad ) Tension seemed good afterwards when I got it back on in the road (without removing wheel etc) Wheel straight in frameetc. Going to have a closer look at the chainring to check it's not warped.

I hadn't thought of something like a bit of grit getting in and throwing it off. It's quite slim odds but a chance that could be what happened.

I rode it again today and all ok.

joaoccdj on Chain came off

Sun, 07 Feb 2010 19:05:06 +0000

something from the road might of got into the chain/ring/cog and made the chain jump

single speed chainring will be more secure hold but multi-speed chainring should do the job!

make sure the cog and chainring alignment is right (i think this is the common cause of chains jumping)

whatfriends on Chain came off

Sun, 07 Feb 2010 11:47:56 +0000

hmmm, id say check not just the wear on the teeth but also if any of the teeth are bent out of shape. similarly, if your chainring is true or not.

did you check if the wheel was in straight when you went to put the chain back on and re tension it? maybe the wheel slipped foreward in the drop out making the chain super slack at the last minute?

i cant see that using a geared chain ring would make any difference if its set up properly. i mean they have deeper teeth of course but unless you have a too slack chain i cant see how it would have the ability to move enough to jump off. check the chainline too by the way, if that is out it will always compound problems if there is a fault somewhere else.

niceone for having a brake though...

Adam EF on Chain came off

Sat, 06 Feb 2010 21:17:41 +0000

Simple topic.. chain came off today even though tension was good and tight (not binding). Can anyone offer any advice if it's likely to be due to using a chainring from a double chainset instead of a dedicated single speed chainring? Would a true single speed chainring help avoid it happening again. They have deeper teeth yes?

The teeth seem fine on the chainring that's on there, not new but ok.

Happened as I was slowing down, not quite skidding but plenty of pressure backwards on the cranks. I was thankful for my front brake and to be approaching a relatively quiet junction.

Any advice appreciated. Cheers.