Chain broke while going 110 on I 75 south of Toledo.... why does this happen | GTAMotorcycle.com

Chain broke while going 110 on I 75 south of Toledo.... why does this happen

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bvickerd

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Here is the story in a nut shell - took my 1990 Sportster (that I have been slowly rebuilding) on a ride to Memphis with about 5 friends. It was a great ride the whole way, and the bike held up great. On the way back I was pressed for time so we hopped on the Interstate 75 in Ohio with the plan of taking it to detroit. South of Toledo by about an hour I was passing a slow moving truck (going 110 KM - the speed limit there is about 120) and just when I was merging back into the right lane I heard a horrible grinding noise from my transmission and my rear tire locked up. I resisted the urge to brake, and pulled the clutch instead, which allowed me to coast to the side of the road safety. Once I managed to stop, and after smoking about ten cigarettes I examined the bike. The Chain had broke and jammed itself between the front cog and the housing, while still engaging the rear cog, causing the rear wheel to lock up. Pulling the clutch some how allowed the wheel to brake free and roll again (I can't explain how)

Now I am wondering:
What causes the chain to brake?
I am replacing the chain and both cogs, anything else I should be getting rid of?
I had the bike inspected by a mechanic a few weeks before the trip, is this something that could have been predicted?

I am spending the extra $40 buck on the supper strong chain this time...

And now for the tragic part of the story - once I calmed down I called for a tow - the truck shows up with a bike trailer and we get my ride loaded up and strapped down. As we got rolling the straps holding the bike broke and the bike fell off the trailer! Pipes denter, lights broken, rear electrical system ****ed, and worst of all the handcrafted stainless steel tank I built myself got dented! I cannot even bondo and repaint because it is stainless steel. I just had to laugh, and after nearly putting the bike down on the interstate this was no big deal. The driver was a biker and felt so bad he called in a mechanic to fix the bike (it was Saturday night at 7) and gave me the chain off of his his buddy's sportster. We got the bike road safe and ride ready and I made it back to Toronto the next day (on side roads). Now the repairs begin...
 
Glad to hear u came out alright. I have to put on the master link on my chain still and this is a constant worry.
 
What kind of a chain was it? New or old?

It doesn't make sense to me that if the broken chain was the culprit, how would pulling a clutch in break the rear wheel free spinning .... unless the problem is not your chain, but rather internal to your tranny.
 
If the chain was old or not cared for, there is a chance a link finally gave up. If you had a clip-type master link with the clip on the wrong way, it is very likely to come apart. If you have a clip-type master link with the clip on the right way, some people say they can still come apart.

Do you have the broken chain? Can you post a picture of both ends?
 
If you had the chain on too tight, it doesn't allow for the full range of motion of the rear wheel and it will be getting overstretched when the bike hits a bump. An impractical but accurate way to know how much chain slack you should have, is to disconnect your rear shock(s) and tighten the chain with the swingarm parallel to the ground.
 
The chain came with the bike when I bought it a year ago - the guy said it was only two years old but I cannot verify.
I don't have the chain anymore (left it in toledo) but it looked like it was in decent shape, well oiled, no rust, fairly new looking - but who knows.

As for it not making sense why the bike coasted when I pulled the clutch in if the chain was jammed in the front drive cog and still on the rear cog - I cannot explain this either. All I know is that it happened so fast I didn't even have time to think about it. I just assumed it was a blown tire and resisted the urge to brake, choosing to coast with the clutch in instead. At the side of the road when i looked at the chain it was broken, jammed in between the cog and housing and still on the rear cog. In all honesty I was pretty jacked on adrenaline at the time and could be remembering this wrong - although it did take the mechanic an hour to just get the chain unjammed from the front cog, so I know it was definitely stuck up there.

As for the cause being something internal (ie tranny issue) The transmission works fine for a 20 year old bike, but three days before the incident I did have the clutch adjusted at a dealership, however I do not see how that could affect anything - am I wrong?
 
Glad to hear you're OK, and it could have been worse for your bike as well. When chains are thrown/break and bunch up between the front sproket and the engine casing, quite often it will actually break the casing too!

I guess that's why case-savers are popular, especially for dirtbikes/atvs where chains are really abused...
 
I'm glad you're ok.. Hopefully, the new project won't keep you out of commission for too long. Henerally, when you have to adjust your chain more than once or twice in a season, it came to its EOL.. Usually at about 20-40,000km (depending on the maintenance).
 
This is a bit of topic, but what do you guys use to make sure that the wheel is properly aligned when doing a chain adjustment?
 
_eug_ said:
This is a bit of topic, but what do you guys use to make sure that the wheel is properly aligned when doing a chain adjustment?
Click to expand...

I just mark the top corner of each nut with a bit of whiteout and give them an equal amount of revolutions
 
CSB moment, had the same thing happen to me many years ago on my '89 FZR 400 in a turn at ~25km/h. Managed to keep the bike upright, and I was actually turning to stop into a motorcycle shop. It had just closed with the last employee locking up, and he had one master link left that fit my chain. Managed to ride the sucker home!

Glad you made it out of that, rear wheel lock at 110 is serious ****
 
haisam10 said:
I was told to get the master link on asap when I got the bike or before I went on highway. I am not sure if it is necessary or not?
Click to expand...

lmao, if your chain requires a master link yes it is necessary. It's the link that holds the chain together!! If your chain requires a master link, and you don't have one, you will go no where fast :p
 
haisam10 said:
I was told to get the master link on asap when I got the bike or before I went on highway. I am not sure if it is necessary or not?
Click to expand...

Every chain requires a master link. The question is whether it is a riveted or clip type. Without a master link you will not make it very far ....
 
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This makes no sense at all. If the chain broke, there are now two ends to the chain. Pulling the clutch in does not release the rear sprocket from the rear wheel, so the wheel will still be locked up. And even if it did magically release the rear wheel, the chain cannot stay on the now turning sprocket, and since it is broken, it must eventually come off the rear sprocket. I have zero experience with Harleys, but, what about the primary? Is it still a chain driven component? Could he possibly be referring to that? But even if he was, once the chain is off it is off. No matter what chain it is, if you continue to rotate one end, the chain will come off, or jam solid and stop that piece from rotating.
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