armybikerider

Greetings.

I've got a 2009 Lynskey R330 that I've had for 7 years (and 2 days). I've been fortunate enough to put 39,230 miles on it to date.

I'm pretty sure that the frame won't give me any issues down the road as I continue to put miles on it - especially since I'm newly retired and significantly increasing my miles to 8,000 per year. (My goal is 100,000 miles by the time I'm 65.)

My question is with the Alpha Q GS10 fork that came stock on the bike. I hate to think about a catastrophic failure of a fork!

Do carbon forks have a typical "lifespan?" Is it based on time?...miles??

I don't ride gravel or cyclocross trails, have never crashed it and I'm a small-ish guy. I'm 54, 5'8 and 155 on a heavy day.

Thanks.

69chevy

“Composites do not behave like metals,” explained Chuck Texiera. “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.”

armybikerider

Thanks. Do the "ride characteristics" of the carbon fork change over time?

indyfabz

And they're off!

C_Heath

in before lock.lol

seypat

You might check in over on the "Carbon Fiber Sucks" thread. If anything, you will get a laugh or two out of it.

RPK79

From what I hear lynskey crabon forks should be replaced every 5 years.

seypat

My bad, looks like the CFS thread got closed. I did find this technical article:

https://velonews.competitor.com/2002/...n-forks-2_3270

datlas 

I posted something about this a couple years ago. My friend has a Lynskey and he said his contact at Lynskey told him to change the fork every 5 years.

Personally, I think that's BS and if not crashed or abused, it should last indefinitely.

PepeM

If you've checked it with UV light after every ride and found no flaws, you should be fine. Otherwise you're already dead.

indyfabz

Dan333SP

What'd you guys do for her birthday? Take her out for a night on the town?

RPK79

Yes. I almost quoted your original post. Per Datlas' friend per lynskey the answer is 5 years. This is gospel.

Jarrett2

If the builder of the bike says 5 years, seems like a good idea to follow their recommendation.

OnyxTiger

Infinite fatigue life sounds like a good amount of time.

If ride quality was altered by a change in resin and carbon shifts and/or delamination, then that would fly in the face of an "infinite fatigue life". Therefore, a change in ride quality and infinite fatigue life is impossible. Unless there's already minor cracks caused by blunt forces, I wouldn't be too worried. Looks like you're getting your money's worth out of the Lynskey.

Dave Mayer

I would be more worried about the installation of your Alpha Q fork than the fatigue characteristics.

These are great forks; I've owned one. However, many of them were installed incorrectly, with potentially catastrophic consequences.

Listen up: these forks have a very thin wall carbon steerer tube. The steerer must be reinforced with the originally-supplied 4" long alu insert, which must be properly epoxied in place before use. The depth of the insert must be below the level of the top headset bearings.

So you cannot install the insert and then cut the steerer to size.

Most of the used Alpha Q forks I've seen are dangerously compromised due to original install problems, or that they were cut afterwards.

popeye

Unlike TI & AL which have a finite life and for all practical purposes are unrepairable.

Redbullet

Carbon fiber may delaminate. This is different from "fatigue", but may have very similar catastrophic failure effects.
Many bike producers still offer lower warranty periods for carbon forks, compared with the carbon frame (e.g.: 6 years for frame and 2 years for forks). They probably know something...
The association of composite carbon fiber bikes with "infinite life" just because the fiber itself does not fatigue looks to me as an obvious marketing bs. If the fork delaminates and puts me down, there is no relief in knowing that, in fact, the fibers of the cracked fork did not fatigue...

RoadLight

Hi armybikerider,

In your post, you ask about a specific model fork from a single manufacturer. Yet your title is general.

As some others have suggested, in your specific case, the place to start is your manufacturer. Get their opinion based on your riding conditions. They should be able to provide the best answer because they will be familiar with the problems their customers have reported.

However, some readers will read this thread looking for a general answer about "carbon fork lifespans" and there is no single answer. A well-designed, well-made composite fork can serve a rider well for a very long time---many decades. But there is a lot of variation in design goals for the fork, the skill of the designer and the manufacturing quality. These factors have a larger bearing on lifespan than the material used. I think composites probably require a higher skill level on the part of the designer than forks made from other materials.

I'm a larger, heavier cyclist so my fork is under more stress than yours. I'm 6'2" tall and used to be a body-builder. An injury to an Achilles tendon forced me to return to cycling. I was a muscle-bound 240 lbs when I started. Now I'm down to 185 lbs and have a more typical cycling build (small muscles up top but I still have big legs). The fork of my 2008 Team Fuji (composite frame and fork) is going strong and is showing zero problems or defects. The same is true for my wife's 2008 Specialized Ruby Elite (composite frame and fork). I expect our forks to last indefinitely and the only reason we'll replace them is because we decide to upgrade to road bikes with different features.


As far as I'm aware the answer is: No, they should not. Composite carbon doesn't have a "break-in" period. If you believe your composite fork "rides" differently than it used to, I would have it inspected by a pro to identify the source of the change. I think a more likely explanation for this perception is a change in the tire model or construction, tire pressure, wheel model or wheel condition. Even the stem and handlebar could be the source of the effect.

Kind regards, RoadLight

zonatandem

Have had an Alpha Q c/f fork (without alu insert) on our custom Zona tandem for well over 40,000 miles. So far so good,
Oh, for you anti -carbon folks: broke a steel fork on one of our other tandems after 13,000 miles . . .
Anything eventually can fatigue/break.
Pedal on TWOgether!
Rudy and Kay/zonatandem

FBinNY 

This is one of those good news/bad news kind of things.

The bad news is that manufacturers are becoming concerned about failures and potential failures, and many are joining the "limited useful life" bandwagon. Very little is actually known, and in theory, without the effects of various insults, properly built CF components should last forever.

However we are seeing some failures, and it's difficult to know if they're the result of quality control, poor underbuilt designs, or the cumulative effects of hard use. So we (or at least I) don't know if there's something there or if makers are simply covering their rears while at the same time creating more business through fear.

On the bright side, if there were serious issues relating to useful life, we should be seeing steadily increasing numbers of failures, as more and more forks are coming into "middle age". And we're not seeing a pattern of older forks failing.

So, so far, it's a question of "you pays your money, and you takes your chances".

popeye

CF does not "delaminate" without damage. As for the "BS" the airlines bought it, you had better not fly. Before making blanket statements you should do a little research first.

Carbonfiberboy 

Carbon fork on my '99 Trek still perfect, maybe 60,000 miles. Carbon fork on our '03 tandem still perfect. Maybe only 30,000 miles. The only dangerous failure I've had has been an aluminum stem. Fortunately I was able to baby it back to the parking lot.

Redbullet

There are no "blanket statements". I do ride CF bike and the producer just changed my frame with no contestation, after 10 months of riding. Reason: unexpected and non explicable cracks. The cracks were absolutely silent and hidden. It was a luck that I observed them - some dirt made me dismount the clamp from the frame - and there they were!

Airplanes and bikes technologies are very different. One should not expect the expensive research and testing from aircraft industry to be applied to bikes. And the insane race toward continuous lightening of bikes frames / forks worse the problem, while aircraft industry still place safety standards way above the lightening of the device.

Redbullet

P.S.: The "BS" does not stay in using of carbon fibers, but in the stupid marketing claim that try to make the users believe that CF bikes will last forever.