Road Cycling - Carbon Giant snaps in half when a piece a car tyre jams in front wheel

http://www.cyclingforums.com/showthread.php?p=2806959#post2806959

Tire belt? That's nothing, check out this Trek carbon fork.
http://bulgier.net/pics/bike/Broken/PoorSquirrel_3.jpg

These events make me very happy I was riding my old bike with 32 spoke wheels when the crow decided to fly through my front wheel. Had that been my Airborne with it's Select front...yikes. I'm almost positive I've seen the crow I hit hopping around near the beach concession. His left wing is in about the same condition as that Trek fork. This bums me out, but I don't know if it's really the crow I hit, or just another victim of 'life is hard'.

Tire belt? That's nothing, check out this Trek carbon fork.
http://bulgier.net/pics/bike/Broken/PoorSquirrel_3.jpgis that for real? Caaarmon! :D

Looks like an alluminum fork on 2004 trek 1000 to me (notice the sora shifters)

Houston, we have a problem.

Alan is gonna get major wood when he sees this thread.

Looks like an alluminum fork on 2004 trek 1000 to me (notice the sora shifters)
+1
and you can see it in the break, i think its al
either way....damn.

That pic's been around for ages. There are two more in the series.

Hope that squirrel's ok. He's going to be sore tomorrow though.

Well depending on the year, the newer trek 1000's have a composite fork. The older ones are aluminium.
Either way.. I know exactly why the trek and giant failed. Notice the promiment "Made in Taiwan" sticker?

Historically, it's been shown that the "People's Carbon" is no match for the sheer strength and construction of the american "Freedom Squirrel" and american "Freedom Tire Belting". In fact, witness reports state not only did the squirrel survive, but managed to subsequently break the fork clean off in the process of wiggling its way free, knocking over a Communist made Hyundai SUV as it dashed back into the forest.

That pic is incredible, It looks as if the spokes are stronger than the fork? that is incredible

That's an American spoke for ya! Be careful though, even though there are so few spokes on the wheel, each spoke, despite its size, weighs in at a whopping 1/2 a pound each.

Either way.. I know exactly why the trek and giant failed. Notice the promiment "Made in Taiwan" sticker?

Historically, it's been shown that the "People's Carbon" is no match for the sheer strength and construction of the american "Freedom Squirrel" and american "Freedom Tire Belting". In fact, witness reports state not only did the squirrel survive, but managed it subsequently broke the fork clean off in the process of wiggling its way free, knocking over a Communist made Hyundai SUV as it dashed back into the forest.

Is that a wholesome American 'freedom squirrel', as opposed to the untrustworthy, oppressive, cowardly, inscruitable 'squirrel cong' from the Communist occupied Peoples Republic of China? You normally can tell them apart as the commo version dresses in boiler suits and carry little red books. Did you know those squirrel cong boiler suits are actually made by seven year olds working as slave labor in communist Chinese sweatshops? Poor kiddies are blind by the time they are eight years old.

Well depending on the year, the newer trek 1000's have a composite fork. The older ones are aluminium.
Either way.. I know exactly why the trek and giant failed. Notice the promiment "Made in Taiwan" sticker?

Historically, it's been shown that the "People's Carbon" is no match for the sheer strength and construction of the american "Freedom Squirrel" and american "Freedom Tire Belting". In fact, witness reports state not only did the squirrel survive, but managed it subsequently broke the fork clean off in the process of wiggling its way free, knocking over a Communist made Hyundai SUV as it dashed back into the forest.

:roflmao: :roflmao: :roflmao: excellent!

If it were a "NYC" Freedom Squirrel, it would have broken the fork clean off, hit the cyclist over the head with it, taken his wallet, given an NYC salute, yelled at the driver of the Hyundai for being in the way, and gone back to Central Park to wait for another cyclist. :D :D

That pic is obviously taken long after the 'squirrel' was hit. Why would it still be there? Wouldn't there be blood everywhere?

That pic is obviously taken long after the 'squirrel' was hit. Why would it still be there? Wouldn't there be blood everywhere?

Would it show blood if it was just blunt trauma but no broken skin?

Would it show blood if it was just blunt trauma but no broken skin?

What are the odds of that, with the force that would be required to break the forks? I'm surpised they didn't go through the thing.

Someone told me that something like that happened in a race at prospect park while the guy was going up the big hill when all of a sudden he just endo'ed for no good reason.


:roflmao: :roflmao: :roflmao: excellent!

If it were a "NYC" Freedom Squirrel, it would have broken the fork clean off, hit the cyclist over the head with it, taken his wallet, given an NYC salute, yelled at the driver of the Hyundai for being in the way, and gone back to Central Park to wait for another cyclist. :D :D

Someone told me that something like that happened in a race at prospect park while the guy was going up the big hill when all of a sudden he just endo'ed for no good reason.

i remember it happening in a pack ride in CP with a cat :)

crikey!!

I hate it when you're just riding along right, and those damn Drop Bears drop down from a tree, land on your helmet and start eating your head.

It's perilous down here I tell ya.

this is completele fiction.... a carbon frame doesn't explode if something is caught in the wheel, the wheel just skids on the pavement or you flip over the bike and do a face plant. I ran my bike into the front/side of a car at 35km/h last year and there was only a hairline crack in the bottom of the downtube where it met the headtube. The Alu steerer was 3/4 cracked in the headtube though, but the carbon fork was fine, and the wheel was a little banged up.

As for the other guy in that thread that said he crashed when a peice of Al siding caught in his wheel.. WTF??? i can bend alu siding with one hand, even a cheap weak wheel would slice thru that like butter, 1/8" strip of Alu MIGHT do some damage but again, nothing like this BS.

I'd have to see this recreated in a lab to beleive a bike would just self destruct like that if a large object was thrown into a wheel.

Of course this isn't going to keep me from sharpening my bladed spokes :)

http://www.cyclingforums.com/showthread.php?p=2806959#post2806959

Can you say STEEL? That's what happens when you buy a plastice frame. He'll probably just go out an buy a more expensive one and hope for the best. When will they learn?


Tim

this is completele fiction.... a carbon frame doesn't explode if something is caught in the wheel, the wheel just skids on the pavement or you flip over the bike and do a face plant.I obviously can't confirm what happned to the bike coz it's on the other side of the worlds, but the guy who started that thread said the break was caused by the big hunk of tyre, or the front wheel, smashing into the downtube.

this is completele fiction.... a carbon frame doesn't explode if something is caught in the wheel, the wheel just skids on the pavement or you flip over the bike and do a face plant.I obviously can't confirm what happned to the bike coz it's on the other side of the worlds, but the guy who started that thread said the break was caused by the big hunk of tyre, or the front wheel, smashing into the downtube.

Can you say STEEL? That's what happens when you buy a plastice frame. He'll probably just go out an buy a more expensive one and hope for the best. When will they learn?
Whether it's a broken CF frame or a broken steel frame, the result is the same.

Grant Peterson, in the "Rivendell Reader" published a detailed article about fork design recently. He compared the forks that were common around 1976, (included the "best selling fork of all time...the Schwinn Varsity) with typical 2005 era forks.

Thirty years ago, most forks on road bikes sold to the "general public" (not to the pro peloton) had a generous amount of clearance next to, and above the tires. The clearance was large enough to use tires that were 32mm or 35mm wide, PLUS use fenders.

Today, most forks on road bikes are copies of the forks used in the Pro peloton. Even the forks on entry level road bikes. They are designed for 23mm tires or 25mm tires. On most, there is not enough clearance for both a 28mm tire and fenders, even slim fenders. Not enough clearance for 32mm tires.

Who cares? Who needs 32mm tires? Who needs fenders? Most the members of "Bike Forums" are hard-core racers who average 35 mph when just riding to Starbucks...we don't need no stinkin' fat tires or fenders.

Grant Peterson thinks we ALL should care. Having a tight clearance between the side of the tire and the fork, or between the top of the tire and the fork, make it much more likely that a bit of road debris can wedge between the tire and the fork. When the debris wedges tightly, the front wheel locks, and the rider goes flying. Oh yeah, the fork may crack, especially if the legs are carbon. The top tube or down tube may fail, especially if they are carbon.

The obsession of "Joe Average" with riding a bike that is a "clone" of the bikes used in the pro peloton has many negative consequences. The "style" of building forks that have little clearance for tires is a consequence that can cost a cyclist his life.

As a result, Grant advocates riders buy a bike with a fork that permits using 32mm tires with fenders. You can use any tire you want with that bike, including the "boy racer's fav, the 23mm tire. But, the design of the frame and fork will greatly reduce the odds of a fork failing because of debris wedging between the tire and fork.

There are no "sure things" in designing safer bikes. But, different designs and different materials have different odds of failure. The Schwinn Varsity (which all loyal Bike Forums members will agree was "'40 pounds of junk") used a solid forged steel fork with enormous clearance around the tires. Odds of failure caused by road debris was close to zero. An ultra-light weight carbon fork and frame, with tight clearance around the tires? The odds of catastrophic failure is higher, much higher.

Whether it's a broken CF frame or a broken steel frame, the result is the same.
Correct, failure is failure no matter what the material. I've never seen a quality steel frame with that kind of failure in 30 years of riding though. Steel usually doesn't have catastrophic failures like carbon fiber. That was the point. Everything comes with a cost. Carbon is light but very brittle. Steel is much heavier but considerably more flexible. That could be why no one uses carbon fiber springs.

Tim

Grant Peterson, in the "Rivendell Reader" published a detailed article about fork design recently. He compared the forks that were common around 1976, (included the "best selling fork of all time...the Schwinn Varsity) with typical 2005 era forks.

Thirty years ago, most forks on road bikes sold to the "general public" (not to the pro peloton) had a generous amount of clearance next to, and above the tires. The clearance was large enough to use tires that were 32mm or 35mm wide, PLUS use fenders.

Today, most forks on road bikes are copies of the forks used in the Pro peloton. Even the forks on entry level road bikes. They are designed for 23mm tires or 25mm tires. On most, there is not enough clearance for both a 28mm tire and fenders, even slim fenders. Not enough clearance for 32mm tires.

Who cares? Who needs 32mm tires? Who needs fenders? Most the members of "Bike Forums" are hard-core racers who average 35 mph when just riding to Starbucks...we don't need no stinkin' fat tires or fenders.

Grant Peterson thinks we ALL should care. Having a tight clearance between the side of the tire and the fork, or between the top of the tire and the fork, make it much more likely that a bit of road debris can wedge between the tire and the fork. When the debris wedges tightly, the front wheel locks, and the rider goes flying. Oh yeah, the fork may crack, especially if the legs are carbon. The top tube or down tube may fail, especially if they are carbon.

The obsession of "Joe Average" with riding a bike that is a "clone" of the bikes used in the pro peloton has many negative consequences. The "style" of building forks that have little clearance for tires is a consequence that can cost a cyclist his life.

As a result, Grant advocates riders buy a bike with a fork that permits using 32mm tires with fenders. You can use any tire you want with that bike, including the "boy racer's fav, the 23mm tire. But, the design of the frame and fork will greatly reduce the odds of a fork failing because of debris wedging between the tire and fork.
+1

I like your style. Give um hell.

Tim

Correct, failure is failure no matter what the material. I've never seen a quality steel frame with that kind of failure in 30 years of riding though. Steel usually doesn't have catastrophic failures like carbon fiber. That was the point.
I understand the point, but since we have no way of replicating the above circumstances with a steel bike, we have no way of knowing how it would have compared. It's very easy to assume that a steel bike would have survived a given incident, but we have no real way of knowing. In fact I know of only one high stress test that performed the same exact test on frames of different materials. Three frames survived, none of them steel (but one carbon). I'm sure fans of steel bikes will be quick to dismiss the test for one reason or another. Oh well.

There are thousand upon thousands of carbon bikes out on the roads. I am sure that were they exploding left and right, there would be lawsuits left and right. I guess what I'm trying to say is gets old to hear the same drivel over and over. 100,000 examples of unbroken carbon bikes isn't enough evidence to convince some people that the material is safe, but one (very old, repeatedly reposted) extreme example of a broken one (which may not even be carbon at all) is enough to make them doom it forever.

I guess my wife should worry about her steel Serotta then, right? It has carbon seat stays, and Serotta must not know what they're doing anymore by using them.

I don't think there is the slightest chance that the bike industry will ever drop carbon forks on road bikes in favor of steel forks. Mass produced carbon forks have become very cheap at the wholesale level. High quality steel forks (the only sort of steel fork likely to be used on a 2006 model road bike) have become very expensive.

That means that buyers of new road bikes are stuck with carbon forks, like it or not. As a customer, they can pretend that all safety issues have been addressed at the factory. Or, they can take responsibility for their own safety.

Safety rule one: make sure that there is substantial clearance between the tires you select, and the sides and top of the fork. On my 1997 era Trek OCLV fork, there is 10mm of clearance between the sides of the fork and the sides of a 23mm tire. That 10mm gap allows sticks, and other typical sorts of road debris to pass through without "locking up" the front wheel.

However, If I were to use a 32mm tire on that bike, the clearance on each side would be reduced to about 5mm. The safety margin has been cut in half. Even a small bit of debris could lock up the wheel. So, although a 32mm tire would fit on that bike, and I prefer that size on my touring-type bikes, it would not be safe to use 32mm tires with my OCLV.

Between 1997 and 2006, the industry trend has been to make all road bikes, at every price level, a clone of pro road racing bikes. A result of that "pretend race bike" trend has been forks that every year fit more clsosely to the tires. You will not have a difficult time finding a 2006 fork where the clearance with a 23mm tire, the most popular size, can be as little as 5mm per side.

The guys who think that ANY discussion of safety is a "joke" will of course contend that the sort of fork that Grant Peterson designs, a fork that fit around a 32mm tire or a 35mm tire, PLUS fits aroound fenders could also suffer wheel lockup if a dog, cat, or small Martian gets wedged between the fork and tire.

And, they are correct. Some stuff is too large to clear any fork. But, in my neighborhood, the road debris consists primarily of small sticks, tree bark, stones, broken glass...stuff that is 2mm wide, 4mm wide, 6mm wide. Hit that stuff every day...it clears the wheel every day. Forty years of bike riding, I've yet to run over a dog, cat, or small Martian (knock on wood). Don't think those are the primary causes of wheel lockup.

As a customer, you can both protect yourself, and put pressure on the industry to build safer forks. If you are trying to chose between bikes "A", "B", and "C", and are looking for a "tie-breaker", buy the one with the most fork clearance around the tires. If you are buying a replacement fork (and you should replace any carbon fork that has suffered a severe impact in a crash) select the fork with the most tire clearance.

When someone pays $500 or $1,000 or $3,000 for a road bike, it ought to be both a "good bike" and a "safe bike". Why do some people keep pretending that we must chose between "good" bikes" and "safe bikes"? Schwinn built bikes that were both "good" and "safe" forty years ago. Rivendell builds them today. We can have both "good" and "safe" in any bike, if customers demand it be done.

At Paris-Roubaix this year, a number of riders refused to ride their sponsor's "stock" bikes. They demanded safer bikes for a one day ride on the beat-up sort of rodes that urban riders face everyday. What did the modified bikes provide? Wider spacing between the forks and chain stays, more room for fatter tires, more room for mud and debris to clear between the tires and fork.

True.



Still can't afford a Rivendell.

I don't know, I don't think a squirrel or an automotive tire is going to fit through a space less than a half-inch (10 mm = .394 inches) any better than it would fit through a space that's less than a quarter-inch (5 mm = .197 inches.)

I think either one is going to fail catastrophically.

This is the most moronic argument I've heard in a long time. That "extra" clearance, oh wait, that extra "10mm" of clearance, would allow for a car tire belt or a humongous squirrel to pass right through.. riiiight. I can guarantee you with as much certainty as the sun will rise tomorrow that it WILL get stuck.

Give me a break. I'll say what you've been biting your lip to hold in for the past few days. That carbon only broke because it was PEOPLE'S CARBON! That's right, PEOPLE'S CARBON! If it were Trek FREEDOM carbon, it would've held. In fact, it would've safely stopped the rider and flexed enough to allow the squirrel to free itself.

LOOOOK STEEL FAILURE, Oooooo....
http://www.trashzen.com/photos/trashfork6-megamo-lucien.jpg
http://pardo.net/bike/pic/fail-009/ccf12_1.jpg
http://pardo.net/bike/pic/fail-009/ccf10.jpg

I love how people love to joke around and say stupid crap that belittle people under false pretenses when they're hurt on a carbon bike and start touting the advantages of steel.

Carbon can be designed so that it will catastrophically fail at much higher loads than a steel frame can handle. Meaning that a thin walled steel frame will buckle and fail, trapping the rider inside a columbus steel pretzel, at a lower impact before the carbon frame will fail, shattering, and sending the rider flying.

Conversely, if you were descending Ventoux at 60mph on a carbon bike and were suddenly hit with a close proximity gamma ray burst, the radiation will instantly degrade the carbon enough that it will shatter the moment you touch the brakes while your friend on the steel bike can slow down safely and seek shelter while the atmosphere's being stripped away.

So.. compromised frame during gamma ray burst or trapped waddling around on the side of the road in a steel pretzel wearing your bike, pick one.

Now... you say Freedom steel would survive but would the People's Steel fail catastrophically... or would it not?

....Conversely, if you were descending Ventoux at 60mph on a carbon bike and were suddenly hit with a close proximity gamma ray burst, the radiation will instantly degrade the carbon enough that it will shatter the moment you touch the brakes while your friend on the steel bike can slow down safely and seek shelter while the atmosphere's being stripped away.....

Would this have something to do with the aforementioned "small martians"? Just wondering.......

I bet the little bastards are everywhere, and I bet they don't want us reaping the tremendous advantages of carbon.

No blood for carbon!!

Carbon can be designed so that it will catastrophically fail at much higher loads than a steel frame can handle. Meaning that a thin walled steel frame will buckle and fail, trapping the rider inside a columbus steel pretzel, at a lower impact before the carbon frame will fail, shattering, and sending the rider flying.
DING DING DING DING DING! we have a winner!

Have you guys ever seen that columbus spirit tubing ? 0.38mm thin.... Light steel bikes are just as "dangerous" as Al or CF bikes, in a really bad crash they all turn into a pile-of-old-tree-branch's-resembling mess, only difference in CF will snap where Alu and steel bend and tear into a new masterpeice of art called shrapnel, sometimes resembling a pretzel :)

This is the most moronic argument I've heard in a long time. That "extra" clearance, oh wait, that extra "10mm" of clearance, would allow for a car tire belt or a humongous squirrel to pass right through.. riiiight. I can guarantee you with as much certainty as the sun will rise tomorrow that it WILL get stuck.

Lower that bet for a second. It's 06-06-06 tomorrow...

Conversely, if you were descending Ventoux at 60mph on a carbon bike and were suddenly hit with a close proximity gamma ray burst, the radiation will instantly degrade the carbon enough that it will shatter the moment you touch the brakes while your friend on the steel bike can slow down safely and seek shelter while the atmosphere's being stripped away.



I thought that was you firing gamma rays at me as I was descending Ventoux !

Good thing I was riding Ti ! :)

I thought that was you firing gamma rays at me as I was descending Ventoux !

Good thing I was riding Ti ! :)

http://www.bromleybike.co.uk/ishop/images/399/frame_pump.jpg

http://www.bromleybike.co.uk/ishop/images/399/frame_pump.jpg\


:roflmao: :roflmao: :roflmao:

OK I admit it, I deserve it.

Save that picture it can come in really handy. :D

FYI, the space between the tire and the fork really doesn't matter, as it's extremely rare to have a tire/fork failure. Things actually get stuck in the spokes - and my carbon fork clears the spokes by about 15 mm.

Of course, it's non-communist chinese carbon, so it'll probably self destruct the next time I look at it, right?

No no that's good, non-communist "freedom" carbon has been personally blessed by Alanbikehouston. His official full time job is to stand at the entrance/exit (it's the same loading bay) of the Trek factory, doubly blessing the incoming carbon fabric and finished bikes.


FYI, the space between the tire and the fork really doesn't matter, as it's extremely rare to have a tire/fork failure. Things actually get stuck in the spokes - and my carbon fork clears the spokes by about 15 mm.

Of course, it's non-communist chinese carbon, so it'll probably self destruct the next time I look at it, right?

Correct, failure is failure no matter what the material. I've never seen a quality steel frame with that kind of failure in 30 years of riding though. Steel usually doesn't have catastrophic failures like carbon fiber. That was the point. Everything comes with a cost. Carbon is light but very brittle. Steel is much heavier but considerably more flexible. That could be why no one uses carbon fiber springs.

Tim

I beg to differ on the catastrophic steel failure. One of my dads friends back in the 60/70's completely buckled a steel fork while in college. Knowing my dad and his friends, there was almost certainly excessive amounts of alcohol (and all the fun that goes along with it) involved. Story goes that the fork buckled - the fork bent 90 degrees or so without breaking - after hitting a manhole cover at speed down a hill. Needless to say Tim took a huge header and knocked out 4 teeth. Although I cannot personally verify with pictures the bike, I do know Tim is missing several of his front top teeth (hes got a bridge now).

there was a good retort 'for' carbon by this guy



I believe the steel frame WOULD fail similarly. Personal experience suggests so:

http://home.comcast.net/~lines_tim/poor_schwinn.JPG


which was answered with probably an even better post:



http://home.comcast.net/~lines_tim/poor_schwinn.JPG

On the contrary, your photo shows precisely not that: bending but not
breaking apart. That's what you want in a bicycle frame failure, not
what happened with the carbon fiber reinforced resin frame

That sounds like catastropic failure to me.
In fact, he's lucky the steel frame didn't completely buckle along with the fork, sending him tumbling down the hill entraped inside a steel pretzel. They would've had to cut the bike off from around him with the jaws of life.


I beg to differ on the catastrophic steel failure. One of my dads friends back in the 60/70's completely buckled a steel fork while in college. Knowing my dad and his friends, there was almost certainly excessive amounts of alcohol (and all the fun that goes along with it) involved. Story goes that the fork buckled - the fork bent 90 degrees or so without breaking - after hitting a manhole cover at speed down a hill. Needless to say Tim took a huge header and knocked out 4 teeth. Although I cannot personally verify with pictures the bike, I do know Tim is missing several of his front top teeth (hes got a bridge now).

Steel=Bend
Aluminum=Tear
Carbon=Shatter

All Hurt

Bicycling = Dangerous
Stay home. Give me your bike to help keep you safe.

Can you say STEEL? That's what happens when you buy a plastice frame. He'll probably just go out an buy a more expensive one and hope for the best. When will they learn?

Tim

That argument makes no sense. First off, carbon fiber is not plastic--it's carbon fiber. Second, while carbon fiber will break instead of bend when it reaches failure, it takes A LOT more force (we're talking multiples, not just a little difference) to make carbon fiber fail than any steel tubing I know of. It's safe to say that whatever caused the catastrophic failure of the Giant (if it truly was an outside force) would've completely destroyed a steel frame too--it would just be bent badly enough to be unridable rather than breaking.

Also, what's wrong with buying a more expensive CF bike? Just like there are different kinds of steel, there are different kinds of carbon fiber. Some are higher quality than others.

DrPete

Ok but what the hell does it matter? If you are riding at a speed high enough that the CF would shatter, the AL would tear or the Steel would buckle when a rodent got in the spokes...the fact is the rider will become a projectile and will have rapid deceleration trauma from his or her face hitting the ground at a high rate of speed. The bike isn't going to freaking matter.

Ok, one of yous lost the bet, 06/06/06 is here and the sun did rise this morning.

Grant Peterson, in the "Rivendell Reader" published a ...

As aThe odds of catastrophic failure is higher, much higher.

oh, shut up.