What happens when you break a spoke at 30 mph?
#1
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What happens when you break a spoke at 30 mph?
Well it wraps into your chain, gets sucked into the cassette and then causes a kink in the chain line as well as twisting the aforementioned spoke.
I was on my way home and I made my right hand turn onto the MUP. A turn that I had made a hundred times before. I heard what sounded like a twig getting spit out of my rear wheel. I continued down the MUP and listened and listened. Nothing not even a rattle. I figured it was a twig cause it is fairly wooded where I am. I stopped at a stop sign and another and another. No sounds. Made my last left hand turn for the home stretch and while I was bombing down the last hill at 30 mph I heard another "twing" and then by bike stopped.
Here I am tires are burning, bike is twitching left and right, cars are going past me like I am standing still, feet are still clipped in. My brain is fighting with my body telling me that this is all a bad dream and to stay clipped in. My body won out and I got out of the clips before I fell.
I pulled my bike off to the curb and looked at the carnage. Two spokes broken. One was cleanly sheared about .5 inches from the hub flange and the other snapped at the nipple. the one that snapped at the nipple got caught in the chain and was sucked into the cassette and wrapped it self around the cassette and chain hyperextending the rear d. The rear d at this point is horizontal, literally. I took off the rear d and managed to work the spoke out.
The spokes have 3000 miles on them all commuting miles. So I am a little disappointed in Pilar bladed spokes.
I had three cyclists ask me if I needed tools I asked if they had a cassette tool and a truing stand. They smiled and rode on. I had two people ask me if I needed a ride. One of them was a mother with a newborn.
After calling the wife to get me and assessing the damage at the house I noticed the rear hub may be shot as the spoke that got mangled pulled on the AL flange and elongated it. Just a little, but enough that I may worry about it.
Anyway much fun was had and another lesson learned. I call my bike heartbreaker for a reason.
I was on my way home and I made my right hand turn onto the MUP. A turn that I had made a hundred times before. I heard what sounded like a twig getting spit out of my rear wheel. I continued down the MUP and listened and listened. Nothing not even a rattle. I figured it was a twig cause it is fairly wooded where I am. I stopped at a stop sign and another and another. No sounds. Made my last left hand turn for the home stretch and while I was bombing down the last hill at 30 mph I heard another "twing" and then by bike stopped.
Here I am tires are burning, bike is twitching left and right, cars are going past me like I am standing still, feet are still clipped in. My brain is fighting with my body telling me that this is all a bad dream and to stay clipped in. My body won out and I got out of the clips before I fell.
I pulled my bike off to the curb and looked at the carnage. Two spokes broken. One was cleanly sheared about .5 inches from the hub flange and the other snapped at the nipple. the one that snapped at the nipple got caught in the chain and was sucked into the cassette and wrapped it self around the cassette and chain hyperextending the rear d. The rear d at this point is horizontal, literally. I took off the rear d and managed to work the spoke out.
The spokes have 3000 miles on them all commuting miles. So I am a little disappointed in Pilar bladed spokes.
I had three cyclists ask me if I needed tools I asked if they had a cassette tool and a truing stand. They smiled and rode on. I had two people ask me if I needed a ride. One of them was a mother with a newborn.
After calling the wife to get me and assessing the damage at the house I noticed the rear hub may be shot as the spoke that got mangled pulled on the AL flange and elongated it. Just a little, but enough that I may worry about it.
Anyway much fun was had and another lesson learned. I call my bike heartbreaker for a reason.
#2
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Did that bombing home down Barbur near the Burlingame Freddies. Popped the spoke right before the I5 on-ramp. Sure does sound like a twig. Fortunately I was able to dig the spoke outa the drive-train and wrap it around another spoke and continue home.
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That hill is scary because of the traffic and road. Hats off brother. Mine was busy, but residential.
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Wow, that all sounds like a nightmare and very dangerous.
Glad you're ok.
I was amazed at how easily things get sucked into my drivetrain.
So far nothing more concerning than a papertowel and a plastic bag.
I would never dreamed it was possible to suck a spoke into it....
Glad you're ok.
I was amazed at how easily things get sucked into my drivetrain.
So far nothing more concerning than a papertowel and a plastic bag.
I would never dreamed it was possible to suck a spoke into it....
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Do you have low spoke-count wheels? Sounds like it since you said they are bladed. My bikes all have 32H Open Pros laced to Ultegra rims. When I break a spoke, the only thing that happens is that my wheel wobbles a little. I just open up the brake calipers and continue riding. Once I had to twist a broken spoke around another one to keep it from flopping, but I was able to ride another 15 miles. There are a lot of advantages to old-school technology when it comes to wheels.
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My spoke count is 20/24 Pillar bladed.
I weight 146 pounds prolly 150 with clothes and jacket. I am well under the weight limit for the wheel.
I weight 146 pounds prolly 150 with clothes and jacket. I am well under the weight limit for the wheel.
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The weight limit isn't the problem, it's the spoke count. When you break a spoke on a low-count wheel, it is much more likely to get way out of true and become unrideable. In almost every case where I've been riding with someone who broke a spoke in a low-count wheel, they were not able to ride their bikes. That's usually not the case if your wheels have 32 spokes or more.
#8
You gonna eat that?
Do you have low spoke-count wheels? Sounds like it since you said they are bladed. My bikes all have 32H Open Pros laced to Ultegra rims. When I break a spoke, the only thing that happens is that my wheel wobbles a little. I just open up the brake calipers and continue riding. Once I had to twist a broken spoke around another one to keep it from flopping, but I was able to ride another 15 miles. There are a lot of advantages to old-school technology when it comes to wheels.
36 all the way for me.
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I don't know how many spokes the stock wheels for the giant escape two has, but I'm 260lbs and apparently was riding with a completely loose spoke and a couple badly warped ones for a while earlier this year.
After a while I noticed how far from true the wheels were and when the mechanic at my LBS shown me how one spoke was completely out of the rim and how loose some others were I was impressed that the wheel was ridable for so long like that....
After a while I noticed how far from true the wheels were and when the mechanic at my LBS shown me how one spoke was completely out of the rim and how loose some others were I was impressed that the wheel was ridable for so long like that....
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One day on the way in to work, I was coming down a hill, just a hair under 30 mph, and my chain jumped off the biggest cog on the cassette - I was cross-chaining, big-to-big. The chain wrapped around my hub, seizing it up, destroying all the drive-side spokes, and stopping the wheel. At speed. I'm still amazed I didn't crash, but it scared the bejesus out of me. Probably almost as much as you just experienced. I replaced the entire wheel, and, not terribly long afterwards, I traded the bike in for a different one. If you've already taken to calling yours the heart breaker, maybe you should consider doing the same.
#11
You gonna eat that?
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I'm building new commuting wheels and although I considered 32h hubs, I figured that the weight penalty of a more sturdy wheel was nowhere near the weight penalty of toting my dirty laundry home on Friday afternoon. I am going with 36H hubs and 14g straight spokes (which I do break occasionally).
I had read something recently (on Sheldon Brown's site maybe) where the trend towards lower spoke counts was a marketing strategy for manufacturers to convince consumers that fewer spokes was racier, while saving manufacturing costs.
-G
I had read something recently (on Sheldon Brown's site maybe) where the trend towards lower spoke counts was a marketing strategy for manufacturers to convince consumers that fewer spokes was racier, while saving manufacturing costs.
-G
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Of course, crashing a bike is more pleasant than working in FoxPro.
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I just bought a new rear wheel for my main road bike for longer rides. The Open Pro 32H rim had some serious cracks in it and had to be replaced. It didn't cost much more to buy a whole new wheel compared to rebuilding it, so I replaced it with a 36H OP rim. When I compared weights, the 36H wheel weighed only about 20 grams more than the 32H, so I figured that was a no-brainer, but I am no weight-weenie.
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Those Open Pro rims are really nice actually. Not really sure how much one really gains going from 32 to 36 spokes. I have both and can't personally tell the difference. Both are really nice wheels that ride very well and they can stand up to quite a bit of abuse. I try to baby my 24 spoke wheels a bit which is something I dont have to do to my other wheels.
Last edited by pityr; 10-27-11 at 11:45 AM.
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She is a heartbreaker cause I fix one thing and something else goes out.
Honestly I think this was a manufacturers defect given the way the drive side broke. I sheared clean off like someone took a razor knife (a stanley for those of you across the pond) and just cut it at an 80 deg angle. The next spoke broke off at the thread in the nipple. This was probably caused by the rotational stress of the wheel minus a spoke. Had I known that I blew a spoke I'd have puttered my way home.
I disagree that low spoke counts are accidents waiting to happen. I could run a 28, but I chose, based on my weight and my riding style that a 24 would be better for me. I also believe that you could run a 12/16 for a commuter if the wheel was built well enough. Straight gauge and all that.
On the bright side the dealer is sending me a return label for shipping and will either rebuild the wheel or replace it. I think given the damage to the spoke hole he will probably put a new hub on it or give me a new one. Glad I have a spare wheel even if it is a tank.
Honestly I think this was a manufacturers defect given the way the drive side broke. I sheared clean off like someone took a razor knife (a stanley for those of you across the pond) and just cut it at an 80 deg angle. The next spoke broke off at the thread in the nipple. This was probably caused by the rotational stress of the wheel minus a spoke. Had I known that I blew a spoke I'd have puttered my way home.
I disagree that low spoke counts are accidents waiting to happen. I could run a 28, but I chose, based on my weight and my riding style that a 24 would be better for me. I also believe that you could run a 12/16 for a commuter if the wheel was built well enough. Straight gauge and all that.
On the bright side the dealer is sending me a return label for shipping and will either rebuild the wheel or replace it. I think given the damage to the spoke hole he will probably put a new hub on it or give me a new one. Glad I have a spare wheel even if it is a tank.
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The only spoke breakages I've had have been when ramming through snowbanks at high (by winter standards) speed. Those were on 32h machine-built wheels with a great deal of hard trail mileage on them. With a heavy bike, gear, and such, I'm probably around the 280 lb mark.
I will be running 36h wheels this winter. I already run 32/36 on my road bike.
I will be running 36h wheels this winter. I already run 32/36 on my road bike.
#19
You gonna eat that?
I'm building new commuting wheels and although I considered 32h hubs, I figured that the weight penalty of a more sturdy wheel was nowhere near the weight penalty of toting my dirty laundry home on Friday afternoon. I am going with 36H hubs and 14g straight spokes (which I do break occasionally).
I had read something recently (on Sheldon Brown's site maybe) where the trend towards lower spoke counts was a marketing strategy for manufacturers to convince consumers that fewer spokes was racier, while saving manufacturing costs.
-G
I had read something recently (on Sheldon Brown's site maybe) where the trend towards lower spoke counts was a marketing strategy for manufacturers to convince consumers that fewer spokes was racier, while saving manufacturing costs.
-G
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The issue with low spoke count wheels isn't that they aren't strong enough. If they're well made, they are. The issue is that there is less redundancy (so to speak.)
If you're on a 24 spoke wheel, there is a spoke every 15 degrees of arc. Break a spoke, and you have a 30 degree arc of your wheel with no spoke. Which puts considerable stress on the bordering spokes, and has a pronounced effect on the wheel's true.
On a 36 spoke wheel, a broken spoke leaves you with a 20 degree arc, causing less stress and less truing effect.
So really, you probably aren't all that much more likely to break a spoke on a well built 24 spoke wheel than on a well built 36 spoke wheel. However, you are far more likely to break a second spoke. (As you found out.)
If you're on a 24 spoke wheel, there is a spoke every 15 degrees of arc. Break a spoke, and you have a 30 degree arc of your wheel with no spoke. Which puts considerable stress on the bordering spokes, and has a pronounced effect on the wheel's true.
On a 36 spoke wheel, a broken spoke leaves you with a 20 degree arc, causing less stress and less truing effect.
So really, you probably aren't all that much more likely to break a spoke on a well built 24 spoke wheel than on a well built 36 spoke wheel. However, you are far more likely to break a second spoke. (As you found out.)
#21
Commander, UFO Bike
Amazing how many in the PDX area are in this thread.
I've lost a number of spokes over the years, and I've never had anything like that happen though. Then again, I never ride with anything less than 32 spokes (except for when one breaks). However, I prefer 36 spoke wheels due to my weight over the years (330lbs-265lbs).
I've lost a number of spokes over the years, and I've never had anything like that happen though. Then again, I never ride with anything less than 32 spokes (except for when one breaks). However, I prefer 36 spoke wheels due to my weight over the years (330lbs-265lbs).
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has anyone ever thought this could also be caused by a metal grade out of spec? this is a big problem with fasteners made in china.
#23
Banned
!) chain into wheel. ?
Spoke protector is not a nerd disc then, and you regret having removed it.
Jeez
a foolish choice was made to commute on boutique styled time trial wheels .
get something traditional with a lot more spokes, and the result is since each
is sharing a smaller % of the load, they wont go far out of true when 1 breaks.
Spoke protector is not a nerd disc then, and you regret having removed it.
My spoke count is 20/24 Pillar bladed.
a foolish choice was made to commute on boutique styled time trial wheels .
get something traditional with a lot more spokes, and the result is since each
is sharing a smaller % of the load, they wont go far out of true when 1 breaks.
Last edited by fietsbob; 10-28-11 at 01:29 PM.
#24
Cycle Year Round
I have had several spokes over the years break at high speeds, no big deal. Another good reason for using a triple cross spoke pattern - A broken spoke does not nearly kill you.
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I have seen many variations of this "flexibility" idea over the years and believe that it has become confused. It is not about flexibility, it's about stretching under tension. A flexing piece of steel will work harden and be more prone to breakage through metal fatigue. The advantage of butted spokes is not to be more flexible, but allow more tension (which results in a more stable wheel by lowering the probability of loosening nipples) as well as to save weight. The key to wheel durability is to reduce this flexibility. Straight gauge spokes that are tensioned properly will have no durability disadvantage. In demonstration, the straight gauge front wheel on my commuter was built by me almost 30 years ago and is as true and round as anyone but a dial indicator-wielding perfectionist would accept. I tweak it if it needs it whenever I replace the tires every few years. The back wheel of the same age has had a few more problems, but hey, isn't that the way things go!
The problem is that some rims will not withstand the tension required for straight gauge spokes. This is why butted spokes are used. They stretch (not to be confused with flex) more allowing more tension without overloading the rim. Under-tensioning is the culprit - because it allows flexing which in turn leads to metal fatigue and breakage. Under-tensioning also allows spokes to become looser, which then allows flexing, etc. I have helped others others many times with their wheel issues and have found it remarkable that most wheels are under-tensioned when built. I think straight-gauge spokes have gotten a bad rap just because they are easier to build and true without proper tension.
One observation that I have is that when I break a butted-spoke, the wheel reacts a little more than when I break a straight-gauge spoke. This is probably because of the higher tension. The last time I broke a spoke I didn't even notice it until a half mile later when it unweaved itself and started to bang around. I wrapped it around another spoke to stabilize it and rode it for another two weeks before I had a chance to replace it. Try that with a highly tensioned, low spoke count wheel.
-G