oilman_15106

This is a new one for me. Going up a nice steep hill in the 50 ring in front and 26 rear. Got to a point where I thought I would stall and tried to drop to the smaller front ring. The chain did not drop to the small ring so I just tried to push to a logical stop point. Blamo! The chain, unfortunatly an expensive Connex 911, just snapped into 2 parts. A rivit looks like it failed.

What could be the cause of this failure? I could not see where the chain and front der were positioned when the thing broke so all I can assume is that it was still on 50/26 when it went. Any ideas would be appreciated.

nycballer0591

umm it could of been an old chain, not enough lube, or just like u said as rivet failed. or the derailer might of been bent . i'm not a mechanic but these are what i think could of caused the chain to break

spinbackle

Sounds like your choice to drop to the small chainring was at a bad time when you had quite a bit of tension on/in your entire drivetrain. Did you ease up a bit on the pedals before you changed from big to small chainring to offer a little bit of slack in the chain? I've heard of people slamming into gears whilst cranking pretty hard and breaking chains. One should soft pedal (is that the right term?) when shifting.
Could have been a defective/old chain. I've had good luck with those Connex (Wippermann) chains.

oilman_15106

Entire drive train has less than 500 miles. Everything was new with no real signs of wear. Chain was properly lubed.

I suspect that attempting to down shift is a component of this failure but I have done this same thing many times before without the current results. Just a defective chain? Have several Connex chains on other bikes and never a problem.

operator

I vote for incorrect chain assembly.

rmfnla

And I vote for Osama; it was just a matter of time before he went after us poor cyclists...

Eatadonut

+1. Call them, and see what they have to say about it.

concernicus

i vote for you down shifting at a terrible time. shift down before you are at a standstill. you put way too much force on your chaing. it was at a wierd angle and snapped.

Al f R

I vote for catastrophic operator error, what were you thinking, 50/26 almost stall, then looking for a front change, got to be joking. Everywhere on the forum people try to get across DO NOT CROSS CHAIN. This experience is probably a good example of why.

SingleSpeeDemon

Damn the Terrorist Networks! I had a feeling they were up to something.

cyclezealot

My policy has always been to change a chain at 3000 miles no matter what degree of stretch the chain shows. But, my bike mechanic said he disagrees. He goes solely by stretch.
Mileage has no effect on rivet wear?

nycballer0591

yea i didn't think about the chain being at a weird angle but i think that could be the cause so watch out how u shift next time. hmm i need to get something to check my miles now so i can know whento change my chain i sure don't want this happenein to me . i never had to change a chain b4 lol. and u ppl r funny u brought osama in this i bet he's probably in hawaii sittin in a hammock.

Eatadonut

Don't type like that. Get a dictionary, and spell all your words out.

I didn't notice you were crosschaining. My vote now goes towards user error. 39x21 gives you almost the same ratio as your crosschaining, but without the added fun of exploding chains, and with the added ability to drop cogs on your RD, something that's much easier to do under load.

nycballer0591

um you can't tell me what to do since i don't tell u want to do so please don't start with me i type how i want to as long as u can understand it i see no problem.also i know how to spell so Go Eat A Donut!

rmfnla

Besides, isn't it really doughnut..?

rmfnla

They have their own TV networks, too? I thought the home shopping craze was bad enough!


Current Ride: 1980something Schwinn Caliente SS conversion
Future Ride: 1970something MilanoSport (gonna be a fixie) scored on ebay
After That: Mid-90's Hollands TT bike with 650c wheels (yep--destined to be a fixie) scored on ebay

Do I detect some sort of theme here..?

oilman_15106

Wow. 50 front to 26 rear 9 speed creates a dangerous cross chain situation? If it were a triple front I might go along with this. There is another recent post about Connex chain failure(s) happened to the guy 2 times.

I was a big fan of these chains but if they can not take even minimal stresses? Any more brillant theories or cheap sideswipes to offer? The problem is when you want to try to solve a problem you get more than a few j**k a** replies.

Eatadonut

Calm down, buddy. yeah, 50-26 is pretty well crosschained, and he was under full load when he tried to shift. I don't see what you're getting all in a tizzy about. It seems perfectly logical to me that this would place pretty extreme stress on the chain. He even said, he's done it before. Maybe the chains aren't quality, but I run wal-mart cheapo chains on my commuter, and they last more than 300 miles. There is a user error associated with this failure.

OneTinSloth

wow. yes. big ring in front and big cog in the rear, creates a cross-chain situation. it causes too much deflection in the chain, and also puts too much stress on the rear derailleur, and as mentioned earlier, the same gear ratio can be found in the smaller ring and a cog somewhere in the middle of the cassette range.

LóFarkas

Crosschaining is bad for all sorts of reasons, but it doesn't make the chain snap in half. Trying to go up a hill in a way too big ratio, realizing it too late and then trying to shift on the front without easing up on the pedal can... When you shift, you have to take the pedaling bit easy until the chain engages the new ring fully. And you have to shift earlier on uphills. When you are struggling to get the crank through the dead spot, there is no way of shifting smoothly.

Al f R

Accept that you should not be sooo laazy when it comes to the front ring changes, practice doing it regularly.The best angle for a chain [indeed the whole drive train] is STRAIGHT, but unless we have as many fronts as rear it can not be done.
You have to realize you wear everything that the chain touches, the greater the angle the greater the wear. Think of an 18 speed as a 14 or even less particularly under high stresses.
You have the answer, at least in part, to your Q, LIMIT CROSS CHAINING Your drive train will love you for it.

Moose

I would not consider the situation described by the OP as minimal stress. And he admits to downshifting under load regularly. The fact that he has done this before, presumably with this same drivetrain which failed catastrophically, is good evidence that cross chaining and shifting under load is b a d.

On a side note, using AOLese on a forum where you are not compelled to get your message across as fast as possible is silly. If you want to make an intelligent contribution then use complete words and sentences. I believe this is addressed in the forum's guidelines. It is a free world, so type however you wish but don't expect to be taken seriously using corny abbreviations.

lymbzero

Agreed' This happened to me cuz I didn't put the chain pin in exactly even.
When you installed the chain did you make sure without a doubt that the pin was installed evenly on both sides? or did you just a powerlink?

If it was a powerlink then the chain was just faulty.
Otherwise, the chain reassembly was just botched.

No worries, just pull out those 2 links and make sure the assembly is perfect.

operator

And what's the point of that changing at 3000 miles if the chain hasn't shown any wear? Chain wear is a function of a million variables, all different for everyone. If there's one constant, it's that the chain will "stretch" sometime.

There's no advantage to limiting yourself to some arbritrary number. The chain could've worn less, or more than ideal in that distance.

Measure your chain.

Trakhak

It seems most likely that this chain broke has nothing to do with improper assembly or a chain defect - it's pilot error.

Experienced bike store mechanics can attest that when bikes are brought in dragging a snapped chain, the derailleurs are usually parked in the large chainring/large cog position.

Cross-chaining between the small chainring and the small cog, the combination preferred by novice cyclists everywhere, usually doesn't break the chain, but it rapidly reduces the life expectancy of the small cog.

Cross-chaining isn't a new problem. The big blue Cinelli bike racer's bible from the early '60s shows what was considered proper gear use at the time: with two chainrings and four (!) cogs, you're told that you must use the outer two cogs with the big ring and the inner two cogs with the small ring. Period.

And when the Italian demigod professional racer Francesco Moser retired in the mid-'80s and was asked to name the biggest change in pro racing during his 15-year career (i.e., from the 10-speed to the 14-speed era), he said wistfully, "Chains don't last as long as they used to."