Sudden and Catastrophic Carbon Fork Failure

[CAMPYBOB]

"That's quite a bit of damage to your helmet. Nice to walk away from those."

The outer shell was barely scuffed by the chip & seal road. I guess it was mostly 'thud' without much slide. Going about 20 MPH when the doggie ran out from behind a parked truck. Just like your fall, no reaction time.

I got turned sidewise a bit when the pooch ran into my front wheel...that may have softened the fall by vectoring my direction a few degrees.

You double fork blade failure may have taken you straight down, face first. Your reaction time had to have been next to nothing! Those blades just exploded, that's obvious.

We are both fortunate! Crashing is a part of cycling and it sucks, but we're still on this side of the grass. I hope your new bike fits like a glove and goes like a stolen Ferrari! When you get the bike set up and dialed in, please post up some pics for us!

 

[WillemJM]

First and most important is that you are OK, glad to hear that.

Great for Canondale to take care of you.

Looking at the fracture of the fork, that is a pure stress fracture. It is unlikely or rather impossible for something like that to just happen over time while riding the bike. Carbon fiber does not fatigue like steel, or aluminum. I can't help but think you must have hit something real hard to cause the fracture, either a big pothole, or something like a brick lying in the road?

 

[arnehuse]

Thanks. I am hoping to pick up my new Synapse Hi-Mod Dura-Ace today
I am in agreement with you that something caused the fork to snap, but I have no idea what it was. I believe I mentioned in a previous post that a week prior to the failure, my riding partner's tire flipped a small rock that I think hit my front fork. If I had been left dead or disabled in this accident, the court case would have experts on both sides trying to place blame. Thank God this is not the case (pun intended) and we do not need carbon forensic experts involved. I am sure Cannondale will be having a close look at my bike but their approach has been first to address my recovery and return to riding. My lesson in all this is to conduct an inspection if I experience an impact to my frame and to go a little easier over the train crossings around my city. Then I can go back to just watching vehicle drivers that will try to kill me whenever they get an opportunity

 

[vspa]

its a massive failure... i would understand if the fork had cracked on the crown or at the steerer tube, the most important thing is that you are ok and willing to return to the sport !

 

[trxsale]

pretty interesting post!Keep it up

 

[trxsale]

[SIZE=10.5000pt]1. [/SIZE][SIZE=10.5000pt]Thank you for your effort[/SIZE]

 

[stanfidavid]

[COLOR= rgb(24, 24, 24)]it's great! And be sure and tip your waitress![/COLOR]

 

[gtopawb]

Could make sense if the fork broke in different points along each blades length (the battery couldnt just hit both blades at the same point at the same time... Moncler Vest Outlet Men Moncler Jacket Women Moncler Jackets Moncler Coats Outlet Moncler Vest Outlet probably biggrin.gif) but it doesnt seem like that since the fork broke at exactly the same point along its length in each blade. By the looks of it the fork just broke at some point beyond elastic deformation and carbon doesnt have much of plastic deformation as much as I know, it just brakes. 12k miles is a lot too. I have only 3200km on my bike and I am allready scared about the fork braking due to fatigue damage cause I ride anywhere as long as I dont get punctures in the tires...

 

[CAMPYBOB]

"it just brakes."

...and sometimes it just breaks.

"12k miles is a lot too."

???

There are many riders that do 12K miles in a year. As far as fork life cycles go, that figure is very low.

 

[dhk2]

Originally Posted by CAMPYBOB .

"it just brakes."

...and sometimes it just breaks.

"12k miles is a lot too."

???

There are many riders that do 12K miles in a year. As far as fork life cycles go, that figure is very low.

Agree, 12K miles shouldn't be a problem for a fork. I'm riding Reynolds Ouzo Pro forks with 34K miles on them now, and certainly don't expect them to fail any time soon. But it's really not the miles that stresses the fork, but the number and size of bumps and potholes, as well as hard braking. Those aren't really a function of miles as much as how and where the bike is ridden.

I'm not a CF expert, but just looking at the broken sections of those forks, there isn't much "meat" there. The walls look very thin, and where is all the torn CF? I see a white layer that looks like fiberglass, but not a lot else that looks very strong to me.

Rant Warning: I know there is a lot of marketing pressure for ultra-light everything, but forks aren't the place to skimp on weight, or save money by leaving out the CF. How about a company that shows us the sections of their CF forks (and frame tubes), and brags about the layers of CF materiel and strength of the pieces? You know, here's how our fork is built, vs a "brand-X" ultralight. And how about offering a real "lifetime warranty"......one that doesn't exclude wear and tear, aka wearout of the bike from normal use?

 

[danfoz]

Originally Posted by dhk2 .

I'm riding Reynolds Ouzo Pro forks with 34K miles on them now, and certainly don't expect them to fail any time soon.

Wha!? That thing is due to explode any minute!

Btw, how do those Ouzo forks handle gnarly decents? I had picked up some Columbus Mega Carve forks to drop some weight and they just weren't as confidence inspiring as my Cinelli's OEM Columbus forks (w/alloy steerer) on the fast downhills.

 

[alienator]

Wha!? That thing is due to explode any minute! Btw, how do those Ouzo forks handle gnarly decents? I had picked up some Columbus Mega Carve forks to drop some weight and they just weren't as confidence inspiring as my Cinelli's OEM Columbus forks (w/alloy steerer) on the fast downhills.

Two things: dhk2, you really can't say much about how thin CF might look, because in that "thin" piece might be many more plies of CF than one thinks. danfozzy bear, I had a Reynolds Ouzo fork on my Moots, and I had no problem with descents up to 52mph. I never lacked confidence from the bike's front end. The Ouzo was a well respected fork with good reason.

 

[CAMPYBOB]

"I'm not a CF expert, but just looking at the broken sections of those forks, there isn't much "meat" there."

Snap your index fingernail against some fork blades. Some of them are damned thin-walled.

"The walls look very thin, and where is all the torn CF? I see a white layer that looks like fiberglass, but not a lot else that looks very strong to me."

Possibly Kevlar strands. I can't believe they leave the bladder in place...the gods of weight be damned.

"Rant Warning: I know there is a lot of marketing pressure for ultra-light everything, but forks aren't the place to skimp on weight, or save money by leaving out the CF."

Easton is one of the more popular brands and has some experience with carbon fiber. I rode an Easton EC90-SLX fork for a season. That is, or more accurately was, Easton's lightest road racing fork. The first clue as to the material used and resulting strength is the weight...in this case, 325 grams uncut. Snap your fingernail against it at your own risk. Yeah, it's thin. Very thin. And the blades walk around under sprinting and climbing in a very entertaining and energy-sucking manner.

I've damned near ridden off the road while being mezmorized by a fork could move that much and NOT fail. Sure, it rode like a Cadillac on 80 aspect ratio tires under-inflated by 10 PSI, but efficient it was not. Safe? No clue, but it freaked the hell out of me.

Easton does not offer the SLX version anymore (only the 25-gram heavier 'SL' version) as a top line component. And I think I know why. Too little material, absolutely no stiffness. Probably not lawer-proof even with the marketing dream team "Nano Tube" technology.

 

[dhk2]

Originally Posted by danfoz .


Wha!? That thing is due to explode any minute!

Btw, how do those Ouzo forks handle gnarly decents? I had picked up some Columbus Mega Carve forks to drop some weight and they just weren't as confidence inspiring as my Cinelli's OEM Columbus forks (w/alloy steerer) on the fast downhills.

I'd say the Ouzo Pro fork is great on descents. But it's the only CF fork I've owned, so I don't have much comparison base. I've got a 58cm frame, Columbus Zonal main triangle, and the builder was concerned about solid, wobble-free handling for the fast descents we have here. He had some delay in getting the Ouzo Pro fork, and I recall suggesting maybe we go with another fork option so I could get the bike sooner. His reply was "you want the Ouzo fork....it's worth waiting a few weeks for the back-order".

 

[CAMPYBOB]

Does Reynolds still manufacture forks?

I know they recalled some UL forks years ago: http://www.cpsc.gov/cpscpub/prerel/prhtml08/08040.html

 

[alienator]

I'd say the Ouzo Pro fork is great on descents.  But it's the only CF fork I've owned, so I don't have much comparison base.  I've got a 58cm frame, Columbus Zonal main triangle, and the builder was concerned about solid, wobble-free handling for the fast descents we have here.  He had some delay in getting the Ouzo Pro fork, and I recall suggesting maybe we go with another fork option so I could get the bike sooner.  His reply was "you want the Ouzo fork....it's worth waiting a few weeks for the back-order".    

It's difficult to tease out a comparison of forks unless the forks being compared are used on the same bike. There are so many factors that aren't intrinsic to the fork that affect our perceptions of the fork. My Moots did well with its Ouzo Pro, but all can objectively say about fork is that I never really thought about it. So, I guess that's a small revision to my previous statement. I do think it's sad that Reynolds got out of the fork business. On the custom Paramount OS I had, i found that I liked the Easton EC90SL more than the Paramount steel fork it replaced.

 

[531Aussie]

If I had the money, I'd consider replacing all my forks with all-alu ones. I'm serious.

I'll get one to see what it's like, then go from there. I know that aluminium blades aren't totally immune to failing catastrophically, but can't cracks in alu usually be detected way before that happens, assuming they're inspected regularly?
It wouldn't bother me if they're on the heavy side, coz I'm not a weight weenie (my main race bikes are 9kg aluminium jobs); and if the looks bug me, I can paint them and/or whack on some stickers.

I had 3 or 4 alu forks with threaded steel steerers about tens years ago, and the ride was fine: stable and comfortable enough, without being too flexy. In fact, some of my carbon forks (with alu steerers) are way stiffer than all the alu-bladed forks I had.

 

[CAMPYBOB]

Kinesis forks are one-piece solid forgings.

Gotta be strong...just like the old aluminum Viscount/Lambert 'Death Forks'. (They failed at the steerer IIRC). /img/vbsmilies/smilies/eek.gif

Seriously, the newer aluminum forks have a pretty good rep.

 

[alienator]

If I had the money, I'd consider replacing all my forks with all-alu ones.  I'm serious.  I'll get one to see what it's like, then go from there.  I know that aluminium blades aren't totally immune to failing catastrophically, but can't cracks in alu usually be detected way before that happens, assuming they're inspected regularly? It wouldn't bother me if they're on the heavy side, coz I'm not a weight weenie (my main race bikes are 9kg aluminium jobs); and if the looks bug me, I can paint them and/or whack on some stickers. I had 3 or 4 alu forks with threaded steel steerers about tens years ago, and the ride was fine: stable and comfortable enough, without being too flexy.  In fact, some of my carbon forks (with alu steerers) are way stiffer than all the alu-bladed forks I had. 

How about an aluminum fork with a CF steerer? You could be the first kid on your antipodean block to have one.

 

[CAMPYBOB]

Some fork material info and another Martyn Ashton video of carbon fork abuse: http://isolatecyclist.bostonbiker.org/2011/02/21/carbon-bicycle-forks-cautions-facts-and-misconceptions/