chain snapping while in a full sprint
04-04-08, 10:12 PM
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griffin_
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chain snapping while in a full sprint
then getting wrapped up in the rear wheel
i've been over the handle bars a few times before but i think this one hurt the most
the stem is skewed at a different angle from the front wheel
it's going to be a good bruise
edit: i guess snapped is the wrong word
it popped open at a link
probably installed poorly or banged off the steps too many times
by no means was i bragging about my leg strength
i've been over the handle bars a few times before but i think this one hurt the most
the stem is skewed at a different angle from the front wheel
it's going to be a good bruise
edit: i guess snapped is the wrong word
it popped open at a link
probably installed poorly or banged off the steps too many times
by no means was i bragging about my leg strength
Last edited by griffin_; 04-05-08 at 02:00 PM.
04-04-08, 11:04 PM
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i break a chain monthly, but thats also due to my tremendous leg power.
(i've also had to have specially made steel crankarms to account for this power)
(i've also had to have specially made steel crankarms to account for this power)
04-04-08, 11:21 PM
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04-05-08, 12:11 AM
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A 1/8" chain is usually rated to withstand around 8000N or 1800lbf. Assuming you're using a 49t chainring (radius ~100mm) with 165mm cranks your pedal force would be amplified ~1.65x this means you would have to apply a pedal force of 8000/1.65 = 4848.5N or 1089lbf. Unless your name is Bruce and you just finished tinkering with your gamma bomb then I would have to say, prove it. You could on the other hand be telling the truth which would mean that you were riding on a chain that was not cared for properly. Probably a pin pushed too far through the link by a chain tool during adjustment.
Last edited by def; 04-05-08 at 12:16 AM. Reason: fixed typo
04-05-08, 01:08 AM
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04-05-08, 01:12 AM
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Back when I moved to a fixed wheel, I broke a couple chains, after investigating, my chain tool backing plate didn't make contact with the link when I put the pin in, leaving a weak connection, often the link was a little deformed. I tested it out on an old chain and saw that every time I linked a chain up, the link that I used the tool on had a little deformation around the pin (nothing backing up against it). A $15 investment in a better chain tool ended that problem. No broken chains since then.
(been drinking, if this doesn't make sense, I'll post a more cohereant version in the morning)
(been drinking, if this doesn't make sense, I'll post a more cohereant version in the morning)
04-05-08, 01:15 AM
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A 1/8" chain is usually rated to withstand around 8000N or 1800lbf. Assuming you're using a 49t chainring (radius ~100mm) with 165mm cranks your pedal force would be amplified ~1.65x this means you would have to apply a pedal force of 8000/1.65 = 4848.5N or 1089lbf. Unless your name is Bruce and you just finished tinkering with your gamma bomb then I would have to say, prove it. You could on the other hand be telling the truth which would mean that you were riding on a chain that was not cared for properly. Probably a pin pushed too far through the link by a chain tool during adjustment.
Poor maintnence will significantly decrease the ammount of force that needs to be acting on the chain to brake it.
04-05-08, 03:03 AM
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04-05-08, 03:47 AM
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How the hell would lack of maintenance weaken a chain??? It won't, unless you actually leave it out in the rain and wait for it to rust through.
Impact or improper assembly is my guess.
And then griffin never even claimed to have broken the chain with his monster quads alone...
Impact or improper assembly is my guess.
And then griffin never even claimed to have broken the chain with his monster quads alone...
04-05-08, 04:50 AM
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This is BFSSFG, home of the suicide hub and brakeless bike. For all we know the OP stole the chain of his kid brothers bike and, lacking a proper chain tool, used a center punch and rock to accomplish the task at hand.
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This is Africa, 1943. War spits out its violence overhead and the sandy graveyard swallows it up. Her name is King Nine, B-25, medium bomber, Twelfth Air Force. On a hot, still morning she took off from Tunisia to bomb the southern tip of Italy. An errant piece of flak tore a hole in a wing tank and, like a wounded bird, this is where she landed, not to return on this day, or any other day.
This is Africa, 1943. War spits out its violence overhead and the sandy graveyard swallows it up. Her name is King Nine, B-25, medium bomber, Twelfth Air Force. On a hot, still morning she took off from Tunisia to bomb the southern tip of Italy. An errant piece of flak tore a hole in a wing tank and, like a wounded bird, this is where she landed, not to return on this day, or any other day.
04-05-08, 05:07 AM
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Again the most common reason for chain breakage is:
1) Improper assembly
2) Extreme wear
3) External damage
With 1 and 2 taking the cake about 99.9% of the time.
Assuming the chain is new. Which is only true for about the first 2km.
If you want to see what sram says about the technical side of their chains and what the difference between an expensive and cheaper chain of theirs:
https://www.ctc.org.uk/resources/Abou...tsinachain.txt
Their strongest type of rivet is rated for 2000 Nm.
1) Improper assembly
2) Extreme wear
3) External damage
With 1 and 2 taking the cake about 99.9% of the time.
A 1/8" chain is usually rated to withstand around 8000N or 1800lbf. Assuming you're using a 49t chainring (radius ~100mm) with 165mm cranks your pedal force would be amplified ~1.65x this means you would have to apply a pedal force of 8000/1.65 = 4848.5N or 1089lbf. Unless your name is Bruce and you just finished tinkering with your gamma bomb then I would have to say, prove it. You could on the other hand be telling the truth which would mean that you were riding on a chain that was not cared for properly. Probably a pin pushed too far through the link by a chain tool during adjustment.
If you want to see what sram says about the technical side of their chains and what the difference between an expensive and cheaper chain of theirs:
https://www.ctc.org.uk/resources/Abou...tsinachain.txt
Their strongest type of rivet is rated for 2000 Nm.
Last edited by operator; 04-05-08 at 05:15 AM.
04-05-08, 05:20 AM
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Did this a couple of years ago. Snapped my frame in the crash, landed on my recently (about 18months prior) reconstructed knee and ended up underneath an 4WD. Definitely my worst bicycle crash. Thankfully I was still winding my sprint up and crashed at just over 50kph 
it would have hurt even more at a faster speed not to mention the 4WD...
Edit: Oh yeah and I was just recently getting back into riding, I'd put the snap down to poor maintenance.
it would have hurt even more at a faster speed not to mention the 4WD...Edit: Oh yeah and I was just recently getting back into riding, I'd put the snap down to poor maintenance.
Last edited by senator52; 04-05-08 at 05:23 AM. Reason: Addition
04-05-08, 06:02 AM
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Snapped your frame or your chain? You're tough as nails, senator... going down at 50 and under a car sounds like the sort of stuff that makes ppl stop riding, possibly breathing as well.
04-05-08, 07:09 AM
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pics or it didnt happen.