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Discussion Starter · #1 ·
Hi all

I have triple chainring (53/39/30) and 11/23 cassette Shimano ultegra on my bike, and recently, my chain falls off as i shift to the smallest chainring (mainly as i start to climb a steep hill). Last week, it happened twice. The second time, when i was pedalling fast trying to catch up with this ******* cyclist who saw me broken down 3 minutes earlier and would not ask whether I was alright or even say hey (and, for the record, was about to overtake his ass on the steepest hill), i demolished my chain. I had to drag my bike 25 minutes to get to the bike shop as i did not have a link. the LBS did the work and adjusted the gears and all that, but on my way back the chain fell off again.

Is it me or the bike? is this normal for a triple? anything I can do about it? I like to go fast with minimal disturbance, so the last thing I want on my mind is trying to be extra careful and on the constant look out, waiting for that chain to fall, so that I can stop peddalling and avoid breaking my chain again.

thanks all for your help
F
 

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NeoRetroGrouch
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fouadaswad said:
Hi all

I have triple chainring (53/39/30) and 11/23 cassette Shimano ultegra on my bike, and recently, my chain falls off as i shift to the smallest chainring (mainly as i start to climb a steep hill). Last week, it happened twice. The second time, when i was pedalling fast trying to catch up with this ******* cyclist who saw me broken down 3 minutes earlier and would not ask whether I was alright or even say hey (and, for the record, was about to overtake his ass on the steepest hill), i demolished my chain. I had to drag my bike 25 minutes to get to the bike shop as i did not have a link. the LBS did the work and adjusted the gears and all that, but on my way back the chain fell off again.

Is it me or the bike? is this normal for a triple? anything I can do about it? I like to go fast with minimal disturbance, so the last thing I want on my mind is trying to be extra careful and on the constant look out, waiting for that chain to fall, so that I can stop peddalling and avoid breaking my chain again.

thanks all for your help
F
If you broke your chain I would guess it came off with 'chain-suck'. Per Sheldon:

"Chain suck

Chain suck occurs primarily when downshifting under load from the middle to the smallest chainring. The bottom run of the chain may not immediately disengage from the middle ring, and can get carried upward until it wedges betwixt the chainwheels and the right chainstay.
This jams the crankset. Since you probably wouldn't have been shifting to the granny if you weren't already climbing, the sudden lock-up of the drive train deprives you of what little momentum you had, and you are very likely to stall and fall.

Chain suck is commonly caused by bent chainring teeth, dirty chains, or, occasionally, burrs on the teeth of new chainwheels.

Jonathan Levy has an extensive Web site about Chain Suck (http://fagan.co.za/Bikes/Csuck/)."

http://www.sheldonbrown.com/gloss_ch.html

This generally happens when you try to shift with too much tension on the chain. I have also seen it happen consistantly on a worn drive train when someone switched from a good lube (Prolink) to a 'cleaner' teflon based lube.

TF
 

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Hard to diagnose

fouadaswad said:
i demolished my chain. I had to drag my bike 25 minutes to get to the bike shop as i did not have a link. the LBS did the work and adjusted the gears and all that, but on my way back the chain fell off again.
Are you saying that the chain broke when you downshifted? Did the LBS replace the chain or just put in a new link? At any rate, there are a number of problems that could be causing this, including having the derailleur mounted too high on the seat tube (should barely clear the large chain ring), having the lower limit screw set in too far (chain should just barely clear the inner cage in the small ring, biggest cog combo), derailleur not properly oriented (typically the outer cage should be parallel to the chain rings, but sometimes rotated out a bit), not having the cable tension set right, worn chain, worn chain rings, poorly lubed chain, or a sticky link (or links) in the chain. It does sound like the chain might be damaged, but you need to clear that up for us.
 

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TurboTurtle said:
If you broke your chain I would guess it came off with 'chain-suck'. Per Sheldon:


This generally happens when you try to shift with too much tension on the chain. I have also seen it happen consistantly on a worn drive train when someone switched from a good lube (Prolink) to a 'cleaner' teflon based lube.

TF
Would you mind explaining this more? SVP.
 

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NeoRetroGrouch
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culdeus said:
Would you mind explaining this more? SVP.
I assume you mean the change in lubes since I could not possible explain chain suck more than the two sites referenced.

Since chain suck is when the chain refuses to drop off the teeth, the better the lube the less likely it is too happen. Last summer, a friend made this switch to keep the chain cleaner for hauling in the van. She walked home twice with the chain jammed between the small ring and the frame. I could make it suck with every middle to small shift with very little tension on the chain. Lubed with homebrew and all was well.

TF
 

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In addition to all the other fine advice offered, if you still keep dumping the chain, get a redline chain keeper, third eye chain watcher, or deda dog fang. Excel Sports has the Redline & Third Eye, and at least one of them is probably available at your LBS as well.

I used to dump chains on my Campy Triple all the time, and no amount of adjustment by myself or the mechanics at my LBS would fix it. I can dial in a Campy double just fine, but the triple remained elusive. Since installing a Third Eye, I have only dumped my chain once in over a year, which was on a very stupid shift.

Good Luck.
 

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Discussion Starter · #7 · (Edited)
clarification and further question

thank you all for the great advice. to build on that i'll clarify that the chain fell when i was down shifting on the front.

I can also say that I have only had this bike for a bit over a month, so i would be inclined to think that there is not much wear on the components including chain crank and cassette. From what was written above, it apears that the deraileurs have been set up properly and I have had the LBS readjust my cables twice since i bought the bike, the second time being right after the incident. I keep my chain nice and slick by cleaning the deraileurs and chain once a week or fortnight max (wiping them extensively with dry cloth and applying lube, as per Zinn's instructions)

the LBS did not replace my chain after the incident. He put a new link, as I broke the chain right at the link (effectively broke the link). He said there was no damage. I looked at the chain later to try and see for my self, but I am no expert at identifying chain damage. So I am going to have to trust him for the time being.

I was shifting under load, as i was climbing, and I shifted quickly too. I was intrending to also shift up on my back deraileur to get the desired gear for the climb, but the incident happened before i could go for it. this raises another question for me. should i shift first on the front and then shift on the back, or vice versa?

One more thing, what exactly are redline chain keeper, third eye chain watcher, or deda dog fang?? never heard of those. I am in Australia, so probably would need to check the LBS for those.
Thanks again
your comments are appreciated.
 

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NeoRetroGrouch
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fouadaswad said:
thank you all for the great advice. to build on that i'll clarify that the chain fell when i was down shifting on the front.

I can also say that I have only had this bike for a bit over a month, so i would be inclined to think that there is not much wear on the components including chain crank and cassette. From what was written above, it apears that the deraileurs have been set up properly and I have had the LBS readjust my cables twice since i bought the bike, the second time being right after the incident. I keep my chain nice and slick by cleaning the deraileurs and chain once a week or fortnight max (wiping them extensively with dry cloth and applying lube, as per Zinn's instructions)

the LBS did not replace my chain after the incident. He put a new link, as I broke the chain right at the link (effectively broke the link). He said there was no damage. I looked at the chain later to try and see for my self, but I am no expert at identifying chain damage. So I am going to have to trust him for the time being.

I was shifting under load, as i was climbing, and I shifted quickly too. I was intrending to also shift up on my back deraileur to get the desired gear for the climb, but the incident happened before i could go for it. this raises another question for me. should i shift first on the front and then shift on the back, or vice versa?

One more thing, what exactly are redline chain keeper, third eye chain watcher, or deda dog fang?? never heard of those. I am in Australia, so probably would need to check the LBS for those.
Thanks again
your comments are appreciated.
I'm still going with chain suck. If the chain just pops off to the inside on the shift, it just gently lays on the front of the bottom bracket shell. I see little possibility that it could damage the chain. Chain suck will jam it between the back of the chain ring and the chain stay. Are there any marks on you chain stay? The cure for this is to NOT shift under tension and to use a slipperier lube. A chain watcher will not prevent chain suck. - TF
 

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Discussion Starter · #10 ·
Thanks all

Thank you for all your help. Hasn't happened in the past tw days. will see how I go and take it from there.

Thanks again
 

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same thing happened to me

My chain slipped off 3 times within about a 10 mile span, all during climbs where I was shifting from the middle chain ring to the granny ring. My chain did not break at any point and I managed to get to a mechanic in a timely manner. He tightened one of the screws (on the derauiller i think) and said he thought my chain was being thrown out to far. Must've been it because that seemed to fix the problem and I carried on my merry way!
 
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