shuru421

Im debating whether to ride 'vintage' (20+) year carbon fork, given that its original to the frame. Am I thinking too much or is this something I should DEFINITELY be cautious about? I either ride it, or get a steel fork to replace, and keep the original off to the side.

Whats should I do?

I ride mostly streets that has its unexpected bumps/dips which I try to avoid as much as possible (in general), but its sometimes inevitable, which scares me about the carbon giving out. The thought of it exploding or anything during a 30+ descent....its terrifying to be completely honest..

Any suggestions? Thank you!

randyjawa 

If it were me, I would never be able to get over the worry about it failing. Such a concern would ruin my ride pleasure every time that I took the bike out for a spin. I say this from experience, having owned one vintage road bike that did come fitted with a carbon fork. With every outing, the thought of fork failure plagued me, on and off before and during every ride.

canklecat

My 1993 Trek 5900 OCLV still has the original fork. It's fine. Probably outlast me. When I got the bike a couple of years ago I took it to my favorite LBS, a Trek dealer owned by a guy who's sold Treks since almost the first year models. He seemed pleased to see this particular model, dug out some old catalogs and brochures to check the specs, and said it should last forever. And I'm sure he'd try to sell me a new bike if he could find anything wrong with the old one.

Looks like a conventional steel fork. If you hefted it you'd probably think it was steel, maybe aluminum. Steel steerer tube and fork-ends. It's heavy enough that I suspected it might be carbon overlaid with steel underneath -- my strongest magnet *seems* to detect a very slight attraction but I'm not certain. Anyway, it's strong. Origin8 still sells very similar replacement forks, the Synergy models.

My newer carbon fiber bike, a Diamondback Podium 5 (one step down from their top tier model around 2014), has the more current style all-carbon fiber fork, steerer, fork-ends and all. Large, hollow, very lightweight, unmistakably carbon fiber. It had some chips in the paint on one side, but no apparent damage to the carbon fiber itself. I was a bit nervous the first few rides, rode only on flat ground, stopped often to check the fork. No apparent damage. I've ridden it more than 1,000 miles on all kinds of roads, including blasting downhill at 40 mph, and don't worry about it anymore. I do inspect the bike frequently, but as most experts say, carbon fiber is really strong stuff and short of serious impact damage should last for many years.

Usually it doesn't fail suddenly and unexpectedly, but more often due to neglected damage that gradually worsened. There are a few apparent exceptions, such as a year or so ago when a pro's steerer tube failed "suddenly" during a sprint, leaving him doing an amazing balancing act to avoid a crash as the handlebar came loose. But over the following weeks of investigation, it appeared the carbon fiber steerer tube was damaged by the team mechanics using either an inappropriate technique or unapproved aftermarket stem or all-in-one unified stem/handlebar... I don't recall the details now, but I followed that story closely for awhile. There was no catastrophic failure that could be blamed on manufacturing defects.

But I still am concerned about no-name, generic carbon fiber stuff, and follow a couple of YouTube channel hosts who can be harsh critics of manufacturers with poor quality control, etc.: Raoul Luescher of Luescher-Teknik, a low key, no-drama, techy engineering kinda guy; and Hambini, also an engineer but a sort of punk-engineer, the anti-Luescher, foul-mouthed, sarcastic, brutally honest and often hilarious. He'll never win any sponsors or find anyone to pay him to shill for their products. If you can ignore some of his hyperbole he makes valid points about manufacturers charging top dollar for products with indifferent specs and dimensions that create havoc for precision minded mechanics. So whenever anyone recommends a carbon fiber components, I check those channels to see if Luescher or Hambini have dissected the components to inspect them for evidence of voids and possible safety hazards.

plonz 

I’m squarely in the “it will be fine” camp.

The conjecture surrounding this topic does make me wonder what age represents the threshold for when the concerned camp thinks a carbon fiber bike or fork may be too old? We’re 4-5 years away from when a massive amount of modern-era carbon fiber bikes turn 20. Do we recommend parking that S-Works Tarmac for good when it becomes of age?

steelbikeguy

I see this sort of discussion as two separate questions....

1. how long can I ride it before it breaks?
2. as the fork gets older, the probability of it breaking goes up. At what probability will I decide that it is too dangerous?


For question 1, there is a chance that there might be some external signs that a failure is imminent. With carbon fiber, this is not generally the case. The highest stresses are at the fork crown, where there's not much visibility of any possible flaws and there are large changes in the cross section of the materials, which cause stress risers that contribute to failures. A lot has been learned from those days, leading to larger diameter steerer tubes near the fork crown and smaller stress risers.

2. Manufacturers have much better data on the failure rate of their products than we do. If anyone gets hurt by their products, their losses can be huge. If they find any significant number of forks/frames have failed in the early portion of its lifetime, it is usually cheaper to replace them all than to have to go to court and get fined many millions of dollars.
As consumers, we don't have the benefit of the data regarding fork failure rate. If we know the number of miles and the stresses of those miles (was the rider heavy? were the roads rough and bumpy?), then we have some relative idea of whether the fork's lifetime is used up.
I have one carbon fiber bike, and when I asked the manufacturer what the life of the carbon fork was, they were pretty emphatic in saying that the recommended fork life was defined by the warranty period. I did end up replacing the fork due to some small damage.. which turned out to be due to a design oversight that was corrected on the replacement fork. The bike is 12 years old now, with 30,000 miles. I'm pretty light and the roads are pretty smooth. The risk is relatively small, and since the bike is a recumbent, if the fork breaks, I won't fall onto the ground face first.

If the fork will only be used rarely, then the cumulative risk is fairly small, and it should be fine.
Otherwise, you have to ask yourself how it compares to other risks in your life, and how much you would pay to not fall onto your face at speed.

Also, consider what you pay for insurance for your home and car. Do you expect to get into a car accident, or expect your house to burn down? Probably not, but you pay a fair amount to be insured against those losses. Maybe a new fork is cheap insurance?

Steve in Peoria

Eric F 

Unless it's been damaged by a crash, or some other catastrophic event, it's fine. Seriously. CF doesn't degrade over time.

Quote:

Originally Posted by Specialized

Composites do not behave like metals. In fact, they don’t actually fatigue like metals in the same classic sense of the word. The fatigue life of the fibre itself is just about infinite.

Personally, I have a Trek OCLV MTB that is more than 20 years old. It's pretty beat up...and still rock solid. I have an 18yo Time CF road bike that rides every bit as good as the day it was new, and I have zero concerns about it suddenly failing because i understand the basic properties of CF material, and how durable it actually is.

Chuckk

I've got a super cherry '92 5200 with what must be my oldest CF fork. One of the first things I noticed (just like Canklecat) was that it was no larger than a normal steel or aluminum fork.
(When I got it maybe 15 years ago, most CF forks had large aero sections)
No obvious problems, and I've never had a major failure contributed to vintage parts, but on long straight downhills it actually frightens me with the amount of forward and back motion visible!
I think by '95 they have a more aero look - but I haven't heard any DEATH FORK talk on these old OCLV forks.

AJI125 

For whatever reason I specifically saw several reports of LeMond Zurich carbon forks failing when I was working on my LeMond after I picked it up. Always secondhand, heard it from a friend or at the LBS. I talked myself up to using the ~20 y/o carbon fork on the Buenos Aires for a while as it was a model down in the lineup from the Zurich and a more hefty fork model, who knows if it carried that heft where it would actually help durability or not. Other than a little riding initially, all my riding on the bike has been in 650b. I used the carbon fork at first for a while, but it was the limiting width so got swapped out eventually. Plenty of washboard and potholed riding with the carbon fork though.

Anyways I next went down the low trail slightly wider tire route, so I picked up an old steel Fuji fork to swap in. Then replaced this year with a Soma low trail fork. So now I'm a couple iterations away from the carbon fork. I've thought about going back to 700c and swapping those wheels to another bike. If I did that I'd use a decent chromed Tange Cr-Mo fork I picked up a while back. What got me thinking (after the fact) is the bike had some internal rust in the seat tube and BB when I got it, probably from being left out some, and while I didn't notice much in the steerer tube, it would've been subject to the same exposures (compromised? who knows). All that said, I bet the carbon fork would probably be fine, I've "inspected" it since and haven't found any external evidence which is worth almost nothing of course. But just not worth it to me with plenty of easily swapped options. YMMV

jamesdak 

I honestly don't worry about it. I've had several Lemonds over the years with C.F. forks and rode them like any other bike. I've got two bikes right now running C.F. forks that I have no clue of the age and I don't worry about them either. I figure the odds are better I blow a front clincher on a fast downhill before a fork ever fails on me. I don't worry about my front tire failing either. Life's just to short to spend it worrying.


This one is over 20 years old and I rode it 60 miles yesterday.

Don't know how old or how many miles are on this C.F. fork and I'm just not going to worry about it.

Another one I had with a C.F. fork, rode it for many miles and felt totally safe passing it on to another rider.

Another one I don't know the history of. I'll be taking this up the local H.C. climb soon and then bombing back down at speeds of 50+ mph.

Another 25ish year old fork that's still going strong for me.

No clue when this C.F. fork was added to this bike but I've had this one up to 30 mph so far with no issues. I worry more about the beam since the weight limit tag on it is missing.

Another older C.F. fork on what used to be my main climbing bike. So many fearless, fast descents on this one.

This one replaced the Tourmelet as my main climbing, fast descending bike. Passed on a few months ago when I got the De Rosa above.

Another 20+ year old C.F.er that I don't worry about. In fact I'll be doing at least 50 miles on this one tomorrow. I also had another one of these that was a year older with lots of wear on the body. Didn't worry about that one failing either.

My first ride with a C.F. fork. This one is still going strong in the hands of a friend.

I guess I've had more old C.F. forks than I realized. I honestly just don't worry about it or anything else failing. Hmmmmmm........maybe I'm just too stupid to know better.

clubman 

It also depends on which fork. The first gen Giant Cadex forks were very flat in profile and definitely weren't made for Clydes. I took one high speed corner, it flexed and I think I may have pooped a little.

They were quickly replaced in subsequent models.

easyupbug 

We used at lot of carbon fiber in my working days and it is a fact that even "vintage" carbon fiber does not fatigue the way steel or aluminum do and has for fork purposes a hugely longer fatigue life then steels or aluminum, basically your bike fork will not "wear" out. That said, an impact can have a serious outcome which is why periodic inspection is highly recommended. When we look at the risk of riding carbon or consequence of a frame/fork failure while the likelihood is low the consequence is high and this generates a lot of hand ringing in cycling. I have three carbon forks and one frame from reputable companies and don't give them a second thought. After years of observing the conditions of bicycles that people will ride I also believe these dramatic "assplosion" story failure genesis are the result of unknown or ignored impact damage.