Ponder this scenario: crank arm/pedal snaps off
#1
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Ponder this scenario: crank arm/pedal snaps off
Ponder the following scenario:
You are standing on the pedals on a climb. All of a sudden the crank arm or pedal snap off, separating completely from the bike.
Is there any recovery, or are you simply going down?
You are standing on the pedals on a climb. All of a sudden the crank arm or pedal snap off, separating completely from the bike.
Is there any recovery, or are you simply going down?
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Prepare for your heels to smash into a million pieces. I rode on metal platform pedals in the rain once and slipped, hitting the ground really hard. Your body should tense up and reduce injury by bracing against the handlebars. I don't run those pedals anymore, now I have those grippy mtb style ones.
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I snapped a steel crank arm right in the middle on my Robin Hood climbing a 15% grade, and surprisingly it was a total non event. Just mashing on the pedals, and suddenly no resistance on the left, like WTF? Really?
I wasn't sanding so I don't know if it would have made a difference.
FWIW, I welded it back together, and it snapped again with the same non event result, except it wasn't a surprise.
I wasn't sanding so I don't know if it would have made a difference.
FWIW, I welded it back together, and it snapped again with the same non event result, except it wasn't a surprise.
Last edited by kickstart; 02-07-16 at 01:19 AM.
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I haven't broken a crank, but I've yanked cleats loose, had a chain skip, and spun the tires without traction. They don't have to be catastrophic failures.
Also missed a clip-in, and had the feet slip off of the pedal (standing). It gives a bit of a jolt, but one doesn't go down.
Also missed a clip-in, and had the feet slip off of the pedal (standing). It gives a bit of a jolt, but one doesn't go down.
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Not all bike shops bother using torque wrenches, nor follow the specific directions to stagger the bolt-tightening sequence, but I do now. It might have been a fluke that nothing happened, that the crank popped off at just the right moment, but I can imagine 359 worse alternate outcomes.
Last edited by calamarichris; 02-07-16 at 05:39 AM.
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There is a famous picture of Laurent Fignon who crashed when the bottom bracket axle on his bike broke; you can see the crank arm and pedal next to him after the crash:
inrng : fignon remembered
inrng : fignon remembered
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There is a famous picture of Laurent Fignon who crashed when the bottom bracket axle on his bike broke; you can see the crank arm and pedal next to him after the crash:
inrng : fignon remembered
inrng : fignon remembered
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During a full sprint, in traffic to get through a Red Light.
My Left Crank arm came OFF.
I was able to put it back on and slowly pedal home.
My Left Crank arm came OFF.
I was able to put it back on and slowly pedal home.
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I've worried about this when climbing and out of the saddle. I know that I would go down hard and probably do some major damage to myself.
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Something that makes this scenario even more daunting, is that if you snap a crank arm while climbing, the chain is likely on the small ring. This means that the big ring has exposed teeth (ie. not covered by the chain) and is posed to do more damage to your unsuspecting flesh.
Having said that, I did have a crank arm come off (on level terrain) and to coin the phrase, "it was a non event".
Having said that, I did have a crank arm come off (on level terrain) and to coin the phrase, "it was a non event".
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I had a pedal fall off while accelerating through an intersection. No injury, just very surprised. I'm still not sure how it happened: the threads were perfectly fine, and I just re-installed it a rode home. And it's been fine ever since.
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I dont want to think about this. OTOH, breaking a crankarm on a sprint puts you in the beast category.
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I don't think you can prepare for it, and it's going to hurt if you are not incredibly lucky.
A friend had that happen and had 17 staples in the back of his head.
A friend had that happen and had 17 staples in the back of his head.
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This is making me think I may just get a new crank for a bike I'm building on rather than relying on some old ones in my parts bin; geez thanks.
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Something that makes this scenario even more daunting, is that if you snap a crank arm while climbing, the chain is likely on the small ring. This means that the big ring has exposed teeth (ie. not covered by the chain) and is posed to do more damage to your unsuspecting flesh.
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There is a famous picture of Laurent Fignon who crashed when the bottom bracket axle on his bike broke; you can see the crank arm and pedal next to him after the crash:
inrng : fignon remembered
inrng : fignon remembered
#20
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I had this happen one time in recent years. The right crank arm broke on a road bike I had and I went down but not hurt minus a few scrapes. All my bikes but one have a one piece (Ashtabula Crank) on them and I don't think I will ever have to worry about breaking one of them. However, when I was a kid I remember jumping my Huffy BMX and I did bend the one piece crank on that bike.
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Over my 50+ year cycling career I've snapped a decent number of cranks and/or pedal spindles. Of course they always snap under peak load, but only once in the well over 10 incidents has it led to a crash or injury. The one exception was a cut over my ankle bone caused by the stub of a pedal spindle.
Broken cranks and pedals happen, but aren't a worry except for the inconvenience factor.
Broken cranks and pedals happen, but aren't a worry except for the inconvenience factor.
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#22
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I think this video shows it pretty well. And, as my story below underscores, note how the helmet probably saved his life.
As for the famous photo of Fignon, that was the first generation Titanium Campy spindle that was hollow and they all broke. It was quickly replaced by a solid Ti version.
My own experience was quite recent. I was out for a nice ride on a lovely afternoon just pre-Xmas, and into a standing mash up a residential hill as I headed home when . . “BAM” My left leg suddenly cut loose from the bike and I went tumbling.
At first I thought I’d broken the crank arm, but discovered it was the left steel spindle of my pedal. I have never, ever, snapped a steel pedal spindle before. Call me shocked.
And I was lucky, as I did my inelegant cartwheeled in the middle of an otherwise empty residential street. Sadly, no video of the acrobatics. Bummer. But that video above feels very, very familiar. Surprisingly, there was almost zero bike damage, although I was a tad stiff and sore. The bike rotated right-round with me and stayed hoisted in the air due to my right foot remaining connected.
The most important lesson came as I rolled onto my back at a speed just a bit too fast to keep my neck muscles tight. As I heard/felt my helmet crunch as it performed the bounce off the pavement, “Thank you, dear helmet,” I whispered. Hence: Always wear your helmet!
For the record, going up hill when this happens is much better than flat out racing or mashing down a hill. Gravity kicks in and your forward motion is slowed. So it is mainly how your leg/foot comes down and how nicely you do that 1/2 cartwheel. At speed? Major road rash, just to begin. I shudder to think.
As for the famous photo of Fignon, that was the first generation Titanium Campy spindle that was hollow and they all broke. It was quickly replaced by a solid Ti version.
My own experience was quite recent. I was out for a nice ride on a lovely afternoon just pre-Xmas, and into a standing mash up a residential hill as I headed home when . . “BAM” My left leg suddenly cut loose from the bike and I went tumbling.
At first I thought I’d broken the crank arm, but discovered it was the left steel spindle of my pedal. I have never, ever, snapped a steel pedal spindle before. Call me shocked.
And I was lucky, as I did my inelegant cartwheeled in the middle of an otherwise empty residential street. Sadly, no video of the acrobatics. Bummer. But that video above feels very, very familiar. Surprisingly, there was almost zero bike damage, although I was a tad stiff and sore. The bike rotated right-round with me and stayed hoisted in the air due to my right foot remaining connected.
The most important lesson came as I rolled onto my back at a speed just a bit too fast to keep my neck muscles tight. As I heard/felt my helmet crunch as it performed the bounce off the pavement, “Thank you, dear helmet,” I whispered. Hence: Always wear your helmet!
For the record, going up hill when this happens is much better than flat out racing or mashing down a hill. Gravity kicks in and your forward motion is slowed. So it is mainly how your leg/foot comes down and how nicely you do that 1/2 cartwheel. At speed? Major road rash, just to begin. I shudder to think.
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1959 Hilton Wrigley Connoisseur (my favorite!)
1963 Hetchins Mountain King
1971 Gitane Tour de France (original owner)
* 1971 Gitane Super Corsa (crashed)
* rebuilt as upright cruiser
1971 Gitane Super Corsa #2 (sweet replacement)
1980 Ritchey Road Touring (The Grail Bike)
1982 Tom Ritchey Everest
(replacing stolen 1981 TR Everest custom)
1982 Tom Ritchey McKinley (touring pickup truck)
1985 ALAN Record (Glued & Screwed. A gift.)
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The closest I've come was cracking a plastic pedal in half while climbing a hill. No drama, but I was much slower back then... Plus it gave me good reason to try clipless...
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I've been having troubles with cross-chaining under full power off of the big ring causing my chain to drop
But, fortunately I don't go down. I suppose one difference is one still has the feet in the pedals even with a dropped chain, whereas a broken crank, and one side is just hanging.
But, fortunately I don't go down. I suppose one difference is one still has the feet in the pedals even with a dropped chain, whereas a broken crank, and one side is just hanging.