What frame material is safest to crash on?
neeb
Posts: 4,473
in Road general
I was riding my steel bike today (for a change) and musing about that particular type of person (usually North American and of a certain age) who thinks that carbon fibre is inherently unsafe and likely to fall apart if looked at the wrong way... It IS true that when carbon is crashed badly it tends to break rather than bend. But is that a bad thing or a good thing?
If you are in a bad crash how does the frame material affect the outcome? Does the greater tensile strength of steel make it more or less likely to injure you in a crash? Might CF snapping prevent it from snapping your bones instead if the two come into contact, and could it even act as a "crumple zone" by absorbing energy as it breaks? Or are you likely to be better off if your frame remains intact and there aren't sharp bits of carbon tubing flying around..?
If you are in a bad crash how does the frame material affect the outcome? Does the greater tensile strength of steel make it more or less likely to injure you in a crash? Might CF snapping prevent it from snapping your bones instead if the two come into contact, and could it even act as a "crumple zone" by absorbing energy as it breaks? Or are you likely to be better off if your frame remains intact and there aren't sharp bits of carbon tubing flying around..?
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Never heard of anyone being injured by their frame. Most injuries are as a result of coming into contact with the ground, typically.0
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🤣🤣🤣🤣🤣🤣🤣🤣The above may be fact, or fiction, I may be serious, I may be jesting.
I am not sure. You have no chance.Veronese68 wrote:PB is the most sensible person on here.0 -
I got taken out by someone whilst riding a steel frame in May, I'm still nursing a possible broken wrist. Had I been riding a carbon frame I could be nursing a possible broken wrist too.
I might have to take up running as I won't be riding for a while. What trainers should I buy to minimise any possible injury?0 -
While the ground is obviously the main thing to worry about and you don't have a choice as to what it's made out of, there's a reasonable chance in a pileup that you are going to be comng into hard contact with parts of your frame (or someone else's frame). You're possibly not going to be aware of this at the time and able to attribute any injuries to it. Also, in any direct impact (e.g. hitting or being hit by a car) the way that your frame behaves is likely to influence the outcome. Again, you are unlikely to be in a posiiton to notice this at the time..0
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Ones with shock-absorbing rubber/synthetic soles rather than thin leather ones I would suggest, especially if you are running on tarmac..veronese68 said:
I might have to take up running as I won't be riding for a while. What trainers should I buy to minimise any possible injury?
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A folding fat bike is safest. Frame will bend and tyres will cushion impact.0
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Best to crash with a mattress type material. Not sure how good it would be as a bike frame though.0
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That's a fair question to be honest - I started running in my cheap trainers but was always getting pains in my knees and hips and my achilles was ruined to the point where cycling was painful too.veronese68 said:I might have to take up running as I won't be riding for a while. What trainers should I buy to minimise any possible injury?
Went to a running shop and they did the equivalent of a bike fit and suggested some (expensive) shoes and it solved the problem.0 -
This is what you really need.oxoman said:Might be best wearing one of these bad boys.
https://www.telegraph.co.uk/content/dam/Travel/ski/Arva-Reactor-32L-airbag.jpg
https://youtu.be/sLUdtF7aG7o 0 -
Just make sure you've got bar end plugs fitted, even though I hadn't wrapped my bars I had plugs fitted when I came off. An open handlebar end will do some damage if you hit it.0
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Suggestion here that CF is less safe in crashes:
https://www.nytimes.com/2014/07/27/sports/cycling/as-technology-makes-bicycles-lighter-and-faster-it8217s-the-cyclists-falling-harder.html
But nobody seems to have studied it in any depth so it's open season for funny comments..
I was hit by a car a couple of years ago - turned right straight into me as I was barrelling along a main road. The impact was to the fork and front wheel and subsequently to my right side as I bounced off the bonnet and/or windscreen. The fork blades were snapped in two half way down and the front wheel (Campy Bora One 50) was written off. I sustained an AC joint injury and a couple of fractured ribs. No idea what would have happened if the fork, steerer and rim had been aluminium or steel but the outcome would likely not have have been 100% identical.
More signifciant perhaps might be how different materials would behave in a direct impact from the front or rear, such as crashing straight into a wall Froome-style or being hit from behind by a vehicle.
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That's an awesome article. They've convincingly joined the dots between carbon fibre and people having crashes.
I love the passing reference to a Dreamliner*, but that's okay because it has several layers. He's really researched that, you can tell.
*I've seen one of those being built - more impressive in person, but look it up online, worth a watch.0 -
What difference do you think the frame material would have made? Bicycles don't have crumple zones like cars do. If the forks hadn't snapped but had folded what percentage of the momentum in your body would have been dissipated differently? The bike stopped very quickly, you carried on until you hit something.neeb said:
I sustained an AC joint injury and a couple of fractured ribs. No idea what would have happened if the fork, steerer and rim had been aluminium or steel but the outcome would likely not have have been 100% identical.
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I was hit more or less side on I think while travelling forward, so the force of the impact would have been a combination of both my own forward momentum and the car's sideways momentum. Some of that would have been dissipated in the breaking of the forks and the wheel. If those had been metal, maybe more force would have been absorbed by bending (or potentially less I suppose, if the breaking strength of the carbon forks was very high).veronese68 said:
What difference do you think the frame material would have made? Bicycles don't have crumple zones like cars do. If the forks hadn't snapped but had folded what percentage of the momentum in your body would have been dissipated differently? The bike stopped very quickly, you carried on until you hit something.neeb said:
I sustained an AC joint injury and a couple of fractured ribs. No idea what would have happened if the fork, steerer and rim had been aluminium or steel but the outcome would likely not have have been 100% identical.
I don't know what percentage that would be of the total momentum, but I know that if someone hit me with the force equivalent to that required to break the forks it would hurt..
As I say though, more useful to think about direct impacts from front or rear. Bikes may not be designed with crumple zones but that doesn't mean they can't behave in that way.0 -
All the evidence is anecdotal and until someone is able to define and replicate standard crashes for a bicycle there wont be any proof that frame materials perform differently in a crash and represent different risks to the riders.
There are standard safety tests for vehicles because the numbers, the risks and the commercial interests are higher. I doubt bikes will ever get to that stage.
The NYTmes focuses on race bikes which, as the article describes, are designed to the limits (mostly of weight it seems). What %age of cyclists are riding these machines. A percentage of one percent I guess. There's no reason to implement standard crash testing.
If pro riders are concerned then they should speak out just as F1 drivers did back in the 70s and 80s when asked to drive in horrible conditions.0 -
The NYT article makes no link between the outcome of accidents and the equipment material. It simple notes that bike riders crash, carbon fragments and then alludes to something or other.
If you do crash testing if bikes, you will end up with safer bikes weighing about 100 kg soon enough.0 -
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Hmm, most pro teams are riding the same top-end models that are sold to consumers. Most brands have two levels of CF layup, the higher mod ones for the more expensive models. If you're riding a mid or high end road bike chances are it's the same frame as the pros are using. So a low percentage of cyclists in general, but a very high percentage of road cycling amateurs and enthusiasts.navrig2 said:
The NYTmes focuses on race bikes which, as the article describes, are designed to the limits (mostly of weight it seems). What %age of cyclists are riding these machines. A percentage of one percent I guess. There's no reason to implement standard crash testing.
It's all anecdotal of course, but you need to speculate to come up with things to test in the first place. I suspect there are a range of crash situations where steel might be safer than CF, and a smaller range where the opposite might apply.
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If you are travelling fast enough to write off a frame then what the frame is made of is of least concern! Hitting asphalt would be my biggest concern!
Its almost impossible imo to test the crash safety of a bike frame as there are so many variables - On a bike you are the biggest thing of the vehicle, in a car you are inside the vehicle.
Bikes especially lighter weight bikes have weight limits with regards to safety but I have known light riders destroy bike components because they ride 'hard' i.e. hitting pot holes / stamping on the cranks etc and likewise you can get big Clydesdale's that due to smoother riding make light components last years.
In terms of materials you can make any material strong (or not) its down to clever design. BR recently did a review on a steel bike that was a shade over 5kg - Its frame was crazy light - I dare say that would be more fragile than some CF bikes.
CF is ridiculously strong! Danny Mac did a video where he rode some carbon wheels without tyres full bore down about 50 steps again and again and it took ages for them to even start to brake. Likewise GCN has video's of CF having 40kg weights with pointed ends being dropped from about 6 feet onto carbon - Nothing broke!
My take from this is simple - a badly made frame is a badly made frame regardless of material - that is why I don't trust no-name frames as the QC is just not documented.
In terms of high impact crashes the bike makes up a fraction of the total weight of the vehicle and as such its your own weight/kinetic interia (whatever) that will cause serious injury and what the bike is made of is out of the equation. If in a freak accident your frame broke and you got a frame tube shoved into your chest at high speed the material is of little importance!
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Late 1990's...... I was hit head on by a car.
I was doing 20mph'ish......they were doing similar. My titanium framed raleigh special products rig, along with the Time carbon forks took the bang. I rolled over the top and hit the windscreen and pillar.
The fork sheered off at the lower crown race, the aluminium Mavic front wheel was split in two........both left dangling from the brake cables.
Several weeks later, the frame was checked in a builders jig.........straight as a dye.
I wasn't!
...........
Not sure if a carbon frame would have 'walked away' from that?!....
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Carbon is by far the safest material the crash with. Look at Formula 1 were they are crashing with carbon cars with over 200mph in the barriers and walk away safely. However cars made out of metal were killing drivers in the past.
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If only it was that simple. A bit like most of your posts.zest28 said:Carbon is by far the safest material the crash with. Look at Formula 1 were they are crashing with carbon cars with over 200mph in the barriers and walk away safely. However cars made out of metal were killing drivers in the past.
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Ah yes, the good old keyboard warriorwebboo said:
If only it was that simple. A bit like most of your posts.zest28 said:Carbon is by far the safest material the crash with. Look at Formula 1 were they are crashing with carbon cars with over 200mph in the barriers and walk away safely. However cars made out of metal were killing drivers in the past.
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zest28 said:
Carbon is by far the safest material the crash with. Look at Formula 1 were they are crashing with carbon cars with over 200mph in the barriers and walk away safely. However cars made out of metal were killing drivers in the past.
https://youtu.be/NT8PMXCMrsM?t=590
Ironically that's exactly why Gordon Murray hasn't put carbon wheels on the new T50 (Mclaren F1 successor). Starts at 9:50 on the youtube clip.
The issue is fatigue if a carbon frame is damaged and/or laid up poorly.
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Yes, the danger of carbon is that is very hard to tell if carbon is damaged after an impact (assuming it did not shatter). And this situation is quite dangerous as it explode at any time.focuszing723 said:zest28 said:Carbon is by far the safest material the crash with. Look at Formula 1 were they are crashing with carbon cars with over 200mph in the barriers and walk away safely. However cars made out of metal were killing drivers in the past.
https://youtu.be/NT8PMXCMrsM?t=583
Ironically that's exactly why Gordon Murray hasn't put carbon wheels on the new T50 (Mclaren F1 successor). Starts at 9:50 on the youtube clip.
So it makes sense not to have a road car with carbon wheels as it can lead to a dangerous situation if the car owner damages 1 of his wheels by accident without knowing it.
It is also why my mountain bike is just a "low-end" alloy full suspension bike as I expect to have a few crashes. So carbon makes no sense to me for this application also.0 -
Hardly. You are suggesting that a large proportion of road bikes sold to amateurs and enthusiasts are the same technology and build as pro-bikes. I doubt that very much. You just have to look at the number of models the manufacturers of pro-bikes offered for sale to roadies. Then consider the price range, typically £800 - £10,000. Where do you think the volume comes from? It isn't going to be any where near that top end. The percentage of ultra lightweight pro-equivalent bikes on the road generally will be very small.neeb said:
Hmm, most pro teams are riding the same top-end models that are sold to consumers. Most brands have two levels of CF layup, the higher mod ones for the more expensive models. If you're riding a mid or high end road bike chances are it's the same frame as the pros are using. So a low percentage of cyclists in general, but a very high percentage of road cycling amateurs and enthusiasts.navrig2 said:
The NYTmes focuses on race bikes which, as the article describes, are designed to the limits (mostly of weight it seems). What %age of cyclists are riding these machines. A percentage of one percent I guess. There's no reason to implement standard crash testing.
In 2015 the average retail cost of a bike under the enthusiast category was £1295. That's a long, long way from a pro-bike, even 5 years ago.
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This is a silly thing to argue or become dogmatic about as it obviously depends on definitions of the groups we are talking about. And we're discussing frames here, not 10,000 superbike builds.navrig2 said:
Hardly. You are suggesting that a large proportion of road bikes sold to amateurs and enthusiasts are the same technology and build as pro-bikes. I doubt that very much. You just have to look at the number of models the manufacturers of pro-bikes offered for sale to roadies. Then consider the price range, typically £800 - £10,000. Where do you think the volume comes from? It isn't going to be any where near that top end. The percentage of ultra lightweight pro-equivalent bikes on the road generally will be very small.
"Frequent cyclist / Enthusiast" could mean anything. The fact is that many keen amateur roadies (I mean people who are wearing lycra / training / doing thousands of miles a year, i.e. many people on this forum) are riding the same frames as the pros. Maybe not the majority, but a very high percentage. You don't need to spend £10,000 to get a pro-level frameset.
Most manufacturers have two levels of CF layup, with the higher level often specced on bikes from around £3000 up. These frames are the same ones the pros are using in most cases. Many people (myself included) buy the framesets for less than that and build them up with components they already have.
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"High percentage" is relative - if 10% of people who ate hobnobs dropped dead on the spot that would be a high percentage. If only 70% of parachutes opened when the cord was pulled that would be a low percentage.navrig2 said:
Are the not the same?neeb said:
Maybe not the majority, but a very high percentage.
Majority is absolute - greater than 50%.
Well, that's my take on it at least and I'm sticking to it.. 0 -
Can we be clear on whether or not hobnobs are safe to eat?0
