Broken chain mystery

Hi WER,
looks like I'm late for the parade on this one and you have gotten all the problems diagnosed before I opened the file.
And my mantra that chain and sprockets should be changed as a set and that everybody should run a ScottOiler seems to be well enough known that other folk's posts mention it.
A test for chain wear. Pull the chain away from the rear sprocket.
If it lifts off more than half a roller's worth, you've had your value out of it and it's replacement time.
I've only found two options when removing the sprocket retaining nut.
1) It's so loose it'll spin off by hand after the tab washer is straightened.
2) It's so tight it'll take an air impact wrench to loosen it.
Never anything between. Posts here say if that nut ain't tight the shaft seal may leak.
Note to self:- Best check that, perhaps it's not just that I've owned the bike from new that makes it drip oil like a Britbike
 
I agree with Gary's "stay bent" method of assessing chain condition. I've replaced several over the years on various bikes because of this. They weren't totally stretched out but had developed some stiff links, in spite of what I thought was adequate lubing (guess it wasn't, lol). In fact, that was the reason for replacing the chain on my 650 late last year.

I broke a chain just like you did some years back. Luckily it was in town close to home. That chain had some stiff "stay bent" links and I think that's what caused it. One obviously hit and/or caught on something and that broke one of the side plates.

I noticed several years back that the back side of my chain wasn't as lubed as the front. If a little rust appeared, that's usually where it happened. I make it a point now to squirt those rear plates and pivot points as well as I was doing the fronts.

I also agree with Gary on sprockets. I don't always change them. My new 650 chain went on the existing sprockets. They were replaced when I got the bike (front was cheap, rear for a gearing change). I just carefully inspect them for the tell tale "fish hook" wear pattern on the teeth.
 
5-twins, I know it seems like everytime I'm replying to something you say it seems like I'm not agreeing with you......I am a bit hard headed but mean no disrespect.

I could be wrong....I am about a lot of stuff and the older I get the more I forget. But.....I've always thought a chain is lubed from the inside. Spraying the sideplates from the outside really doesn't do any thing but waste lube. It's my understanding that the wear is on and around the rollers......the pins on the outside of the plate aren't moving. It's one of the reasons you lube a hot chain because the heat has opened up all those joints. You need to be sure you're getting lube on BOTH sides of the chain from the inside.

Things might have chainged with all the O X Y Z?????? type chains......I might have fallen behind keeping up with all the changes?????

I'm with you on sprockets....there are times I change them as a set but I'd go broke doing so if I did it all the time. Just depends of condition. I will admit......I don't use cheap chains.

Gordon
 
You're not disagreeing with me. I guess I just didn't explain things well enough. I do apply the lube to the inner side of the chain. I put it on the top of the lower run, the side that contacts the sprockets, and I do it on a warm chain only, like after a ride. This is the proper way to lube a chain. Centrifugal force then pushes the lube through and to the outside of the chain.

I was talking about the left and right side plates and the left and right roller/plate pivot points between each link. I wasn't getting the inside ones (right side), the ones closer to the tire, as well as the outer side you see when you look at the chain. I make sure I do now.

I'm also going to mention my current favorite chain lube, Kal-Gard Chain Kote. It has moly in it and comes out as a dark gray foam. This stains the silver rollers gray. When they start turning silver again, you know it's time for a re-lube. But I think I may do it even more often. I pretty much followed this routine on my last chain and it still kinked up on me, lol. I may switch to a mileage interval, like 400 to 500, regardless of how lubed the chain still looks.

http://www.webbikeworld.com/t2/motorcycle-chain-lube/kal-gard/moly-chain-kote.htm
 
weekendrider said:
...You good with the vent tube theory?
Click to expand...

I noticed some zipties that appear to be the same size.
WER-ChainFail03.jpg
WER-ChainFail04.jpg


But, now that you say it's hollow, I suppose it could be a vent tube. I like gggGary's idea of the cable elbow's tube. Maybe an errant schnozzle from a can of chain lube.

I dunno. That's one of those things that I'd need to have "in hand" to examine, rub it against my cheek, smell, taste...
 
5-Twins......I should have known better. :rolleyes: :oops: You sir are and will continue to be DA MAN!!! :bow2:
2M.....damnit man....how do you do that? :umm:

Watching the clock in NC........crawling back under my rock.......Gordon
 
[QUOTE="5twins, post: 474560, member: 156" - - - I also agree with Gary on sprockets. I don't always change them. My new 650 chain went on the existing sprockets. They were replaced when I got the bike (front was cheap, rear for a gearing change). I just carefully inspect them for the tell tale "fish hook" wear pattern on the teeth.[/QUOTE]

Hi 5twins,
I'm not so sure about that.
A bike chain runs at maybe 5 times the speed and transmits perhaps 10 times the power than Renold's industrial chain chart says it's good for.
I reckon to do that a bike's chain drive must, besides being made from high strength materials, have it's components made with gear tooth levels of accuracy.
And you can't tell a good gear tooth from a bad one by looking at it, you need to use an optical comparator.
Yes, you can eyeball a fish hooked sprocket but by the time it's fish hooked it ain't just worn, it's fucked.
I reckon for what sprockets cost it's well worth paying the extra up front rather than living with the risk of an increased chain wear rate.
 
Last edited:
But, but, but LOL
See above, many times the chain is shot because of disuse. Not because it's worn out so it's easy for the chain to be junk while sitting on perfectly good sprockets. Don't know about your optical comparators Fred, but by laying an old over a new sprocket mine can detect differences of a few thousandths yet. If your chain really has worn out with the axle adjusters at the far end it's certainly good to change them with the chain. You decide.
I have seen a major improvement in the quality of both chain and sprockets used on Japanese motorcycles in my life time. The early XS (and other 60's bike's) chain and sprockets were PP and wore out rapidly, By the end of the run the factory parts had improved a bunch. With the latest materials using chains for long distance touring is not a stretch. :wink2:
PS props to WER for putting this up here. Not easy to use yourself as an example of what can go wrong when maintenance is delayed.
 
QUOTE="Gordon in nc, post: 474565, member: 22079" - - - I've always thought a chain is lubed from the inside. Spraying the sideplates from the outside really doesn't do any thing but waste lube. It's my understanding that the wear is on and around the rollers......the pins on the outside of the plate aren't moving. It's one of the reasons you lube a hot chain because the heat has opened up all those joints. You need to be sure you're getting lube on BOTH sides of the chain from the inside.
Things might have chainged with all the O X Y Z?????? type chains......I might have fallen behind keeping up with all the changes?????
I'm with you on sprockets....there are times I change them as a set but I'd go broke doing so if I did it all the time. Just depends of condition. I will admit......I don't use cheap chains.
Gordon[/QUOTE]

Hi Gordon,
you may be old but are you old enough to remember LinkLyfe?
A container the size and shape of a movie film can full of solid moly-based chain wax.
You waited until your mom was out (just like when you stove-enamelled bike parts in the oven) then warmed the can on the stove until the wax melted.
You removed the bike's chain and washed it off in kerosene. Then you lifted the bike's other chain out of the melted LinkLyfe where you'd left it the last time and hung it up over the can to drain.
Then you lowered the first chain into the melt and set the can aside to solidify, chain and all.
Then you put the LinkLyfed chain on the bike. Repeat every 500 miles or so.
But that was then. Way before you knew that sprockets wore out too.
So yeah, normal chains are best lubed when they are warm and dry so the externally applied lube can more easily get to the chain's innards.
OTOH, sealed chains are factory lubed and the whatever alphabet seals keep the lube inside so it can't get out.
Which means the internal lube can't leak out and the chain/sprocket interface, which also needs lube, will run dry unless you lube it manually when you remember to do it. Or when you pony up for a ScottOiler.
 
Gordon in nc said:
- - - I'm with you on sprockets....there are times I change them as a set but I'd go broke doing so if I did it all the time. Just depends of condition. I will admit......I don't use cheap chains.
Gordon
Click to expand...

Hi Gordon,
I must confess that I can afford new sprockets every time because I'm a really low mileage guy these days who's down to two bikes and the other one is a shaftie.
And yeah, cheap chains are a snare and a delusion. If you calculate you broke even on the less mileage at less initial cost equation you didn't.
Even if you reckon getting grease up to your elbows more often is a bonus rather than a chore it's a sure bet that the worn chain has prematurely degraded the sprockets and there ain't no cheap sprockets. Just expensive ones and really expensive ones.
 
TwoManyXS1Bs said:
That's one of those things that I'd need to have "in hand" to examine, rub it against my cheek, smell, taste...
Click to expand...
That could be arranged. And yes the bike has more zip ties than porcupine has quills. Like Gordon says good eye.

gggGary said:
Not easy to use yourself as an example of what can go wrong when maintenance is delayed.
Click to expand...
Ahh but if others can get value from it, the cost is cheap. Maybe some of the new riders/members are soaking some of it up. Maybe not.

fredintoon said:
Or when you pony up for a ScottOiler.
Click to expand...
Thanks Fred. I was about to think I'd pissed you off enough you wouldn't show up.
 
Our old-school shop practices manuals mentioned that the "flat tops" of motorcycle sprockets were intentionally there as a wear indicator. Kinda like the modern tire wear indicators. When the flat top became pointed, time for a new sprocket. Of course, that's back when not much made over 50hp...
WornSprocketIndicator.jpg
 
No branding on the chain that I can see.
IMG_20160922_221835_104.jpg

IMG_20160922_221914_827.jpg


The master link location and the break didn't have a connection.
IMG_20160922_221629_295.jpg


Example of pin and link wear causing side deflection/whip.
IMG_20160922_222031_969.jpg
 
Looking at yer pics, I couldn't see any split rollers, but that'll take a good cleaning to see those. There's definitely severe wear in a few links. Have you inspected the sprockets for significant nicks/gouges (as though something flew up and got jammed in there)?
 

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