fietsbob

https://www.outsideonline.com/231181...dents-lawsuits

rumrunn6

hmmm ...

"the front fork snapped in half as if it had exploded from within" & “There’s an old saying in bike manufacturing: It can be lightweight, durable, or cheap—pick two. A lot of these carbon-fiber components are lightweight and cheap, but they are not durable.”

gonna be looking at my older (preowned) carbon fork equipped road bike, (with an unknown history), with more doubt now ...

ironnerd

If you are curious about the internal condition of a Fiber Fork or frame, tap it with a quarter. It should sound almost like a "ping". If it sounds flat you may have some delamination going on.

It's called a "Ring Check"

base2 

Assplosion everywhere!



No word on the riders weight, among other factors.

Any one care to venture a guess about her bicycle inspection routine? I know it's crazy, but lot's of things can be found just by looking with a bright light & a close eye for detail.

Sounds to me like she hit something, went to a shop (who wouldn't look for a problem they weren't told about) & kept her mouth shut so she could get a scapegoat & a fat payday. But that is conjecture.

tyrion

Another exploding carbon fork - when will we learn?

livedarklions

Completely unfounded conjecture.

79pmooney

In a different thread, someone posted a pic of a steel MTB with carbon fork. It had hit a tree. Fork looked perfect but both top tube and down tube were almost completely severed and bent about 30 degrees. Frame obviously destroyed but the fork looked ready to go onto another bike. Did it have hidden damage? Then there is the possibility of construction flaws. I used to build fiberglass boats. Work that is pretty can be fatally flawed. (And how much to the factories pay their help to get high quality laminates?)

As one who has paid big time for hidden damage in a fork, I will only ride forks that (almost always) show their damage. And even when I cannot see it, so far, those forks have always made it known something was wrong without me looking.

Ben

base2 

Yep.

Leisesturm

He's right. You are way off ... base. She could have been killed! Even for you that must seem like an awful lot of trouble to go through for a nice fat payday. SMH.

base2 

Well, maybe my experience with trash family members & their repeated insurance fraud schemes, (several of which were successful) has me jaded a bit.

I still stick by my wholly biased and completly unsupported conjecture.

There's no need to lecture me on my view of well trained monkeys when profit is involved.

mr_bill

Someone in this thread survived a steel and aluminum fork “asplosion.” Suggest you broaden your doubts.

-mr. bill

Rick

I worked part time in a bicycle shop in the late 1970s and was told by the owner to let him know if any of a certain brand of bicycle came in for service. I think it was Viscount, the aluminum forks were snapping without warning. They have obviously improved on aluminum over the years but the average person does not know how to detect a problem if it is not visible to the eye. I have always purchased steel framed bicycles. Bottom brackets and seat stays have been failure points on a few bicycles that I have owned. I noticed them through sound or visible damage before it became a safety hazard. I was riding once and the right side of a drop bar broke loose. The bike had been blown over by the wind on more than one occasion. I didn't loose control and learned from the experience.

livedarklions

I cracked my tooth on a carbon spork. Those things a lot tougher than they look.

bakerjw

From the article, she bought a 2nd hand bike and took it to a bike shop for a tune up.

I don't see how the bike manufacturer can be held liable for a bike that has changed hands and is in an unknown condition. That is one reason why warranties rarely are transferable.
It's like if a bad bolt makes it into a car suspension on the assembly line and 1 car has an accident because of the one bad bolt. It will rarely get investigated to the point where it is determined that it was the failure of the 1 bolt. Now if there are multiple failures of the suspension due to a bad design which is breaking the 1 bolt, then a pattern will develop over time.
In this case, if there is a severe enough manufacturing defect that forks and frames are breaking, there should me numerous occurrences of breakage on the one design.
Without professional analysis of the broken fork, it is all conjecture on our part. All that said, it will eventually be settled out of court.

From the viewpoint of the bike shop. What happens in a case like this where someone brings a used bike into a shop for a tube up and then has a failure similar to this and goes after the shop? Will shops have to have customers sign waivers understanding that the bike was tuned up and mechanically inspected but there are no guarantees that the frame is 100% intact?

Our LBS had a warranty for a full suspension Yeti frame that developed a slight crack. It was nearly impossible to find in stripped down and clean condition. I can't imagine finding that crack if it was still cabled up and dirty from use.

It will be interesting to see what happens with carbon frames over the next several years.

Rick

Chromoly steel is the only material I tolerate in a bicycle frame and fork. It shows damage or defects before catastrophic failure.

livedarklions

It would have to be on a strict liability for defective product basis, which means she'll have the burden of proving that the product was defective as manufactured. It will be tough, but she's going after the deepest pocket with this, and the Illinois court decided she can at least try the case:

https://www.illinoiscourts.gov/Opinio...ct/1152293.pdf

Does anybody know if this case settled? I can't find any follow-up to the jurisdiction decision.

rydabent

Not a fan of CF (plastic) bikes at all. But I guess if people think they want one, make sure it is new. That way you will know if any crashes or undue stress was placed on the bike. Buying used is probably a double whammy for having it break.

Notso_fastLane

This is laughable. Some damage would be visible prior to failure, but steel and aluminum are very similar in their 'detectability' when talking about cracks detectable with the naked eye.
Oddly, if people knew the best way to detect damage in CF, it's potentially the most readily inspectable material by a means available to your average person.

Disclaimer: I'm an aircraft structures engineer that works with AL, Steels, and CF on a daily basis, and part of my job is writing the work instructions for inspections.

squirtdad

huge difference between a controlled environment like aviation parts, inspections, logs, time SMOH etc and bike usage. Also the usage of carbon compositesin aviation vs bicycle frames is much different, with aviation often using large areas (wings) compared to the small bonding area of frames. it is not apples apples

Part of the problem is not the material but is people wanting to use race level frames, without considering these are considered disposable by race teams. A carbon bike can be made bombproof (mountain bikes are an example) but it will not be light at that build level.

Rick

Aluminum damage can be invisible to a visual inspection. That is why parts are put through a die penetrate process. This is why there were recalls on aluminum forks and some people did face-plants.
I am interested in finding out how to detect a problem before someone gets hurt. Is there a simple way to detect damage in carbon fiber or should someone never purchase a used or cheap carbon fiber bicycle.

base2 

Don't forget eddy current & ultrasonic inspection for aluminum.

But similar methods work for carbon. "Tap test" can be of use, but it's crude. There's also a bright light & a keen eye. you can stress test if you'd like. I once bought some used carbon bars. When I got home I did my best to twist, bend, & compress the bars. I got a tiny crackle & tossed it in the trash. Sometimes a good deal, isn't. I had some carbon forks I killed with a giant disc rotor. It got "weird" so I replaced it. Hairline crack around where the carbon fork leg inserted to the crown lug.

Any dents, dings, deformation or bubbles would be immediately suspect as already failed or at the very least evidence of fatigue or impact. How's the paint look? Hairline crack?...that's a dead give away.
Any change in performance, however slight might be a good time to thoroughly inspect.

Then tap as crude as it is just to get an idea about any suspect areas. Tap, tap, thunk. Similar to searching for a stud in the drywall.

After that, then Ultrasonic if you feel the cost is justified, as it literally is a window into the structure. I don't know of any where to get that done. But I've seen it done dozens of times where I work. Cool stuff.

79pmooney

The first generation Viscount forks cracked at the bottom of the steerer tube. To see that crack with the naked eye, you have to remove the HS crown race, then the steerer. No one is going to do that except for a forensics exert (and by that time, the fork has failed across the bottom of the plug extending into the steerer and removal of the steerer is no longer necessary). Incredibly poor design. I bought mine as an engineering sophomore. Wondered many times how they did the blind steerer/crown fit. I briefly considered the pressed plug but wrote that off right away. As a sophomore, I knew that no engineer would EVER take that approach.

Ben

Rick

Inspection of parts can be expensive Die penatrate is at least a 3 part process. You take a cleaned part soak it clean it and look for penetrate leaching out for a sign of a crack. I believe this is done with a special lite akin to a dark room when you develop photos. I believe that helicopter parts are rated at so many hours and then the dispose and replace of, or inspection of those parts is done. I use chromemoly steel frames and forks. Seat stay cracks and BB cracks several times over the years.

fietsbob

FWIW, that is the staple bulk of the whole forum ..

I-Like-To-Bike

Not so fast; lots of the conjecture on this forum is solidly founded - on paranoia, Bicycling Correctness (BC) and/or cherry picked factoids gleaned from the Internet.