Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Carbon Fork Lifespan?

Notices
Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

Carbon Fork Lifespan?

Old 11-30-02, 02:59 AM
  #1  
rchan
Member
Thread Starter
 
Join Date: Nov 2002
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Carbon Fork Lifespan?

I've recently purchased a new road bike to replace my old all steel one. I was a bit wary about getting this one because it had a carbon fork instead of a steel one, but I got it anyway, because I figured I can get the info about the average lifespan of this type of material on the Internet.

Well, since I am writing here, you can probably guess I couldn't find anything useful at all. Occasionally I'd find something about how many cycles a carbon fork would last, but that isn't very useful since I don't know how many cycles a fork will go through in one of my typical rides, and usually the info is about a specific brand and model.

Does anybody know what is the average life of a carbon fork in terms of years or distance? I average about 1800 miles a year, pretty low milage in the grand scheme of things. Normally I wouldn't be so concered if it weren't for the fact that unlike steel, which usually bends when it fails, carbon tends to snap. Or is my concern outdated? Do recent carbon forks have something in them that will keep them from failing catostrophically?

Any info or web site referrals will be greatly appreciated.

Last edited by rchan; 11-30-02 at 03:06 AM.
rchan is offline  
Old 11-30-02, 03:48 AM
  #2  
Patricia
Junior Member
 
Join Date: Nov 2002
Posts: 24
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I can tell you I've seen full carbon fiber forks that have 28,000 miles on them with no problem.
If you are using them for under 2,000 miles a year than it will probably last you the lifespan of the bike.
Patricia is offline  
Old 12-02-02, 02:00 PM
  #3  
Xavier
Moderator
 
Join Date: Apr 2000
Posts: 531
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I do not ride nearly as much as when I was racing Elite but I am basicly putting basic miles than most 'recreational' riders are putting. I have had an original AME fork (Not the True Temper) for about 3 years now. Been on 2 bikes and I am sure I will get many more years out of it.

Carbon forks shouls last many years of not crashed.
__________________
Xavier Cintron - www.bullteksports.com
Xavier is offline  
Old 10-31-22, 08:28 AM
  #4  
datlas 
Should Be More Popular
 
datlas's Avatar
 
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 42,957

Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix

Mentioned: 560 Post(s)
Tagged: 2 Thread(s)
Quoted: 22513 Post(s)
Liked 8,841 Times in 4,113 Posts
Inspired by a recent posting of a cyclist getting rid of a carbon fork because it was "old," I decided to resurrect this thread. Plus it's Halloween so a Zombie post is possibly appopriate.

I have occasionally heard people say that their fork should be replaced periodically. One of my friends rides a Lynskey and he swears they told him to replace the fork every 4-5 years.

I suspect that a well designed CF fork should last indefinitely unless it's crashed or damaged.

Comments??
__________________
Originally Posted by rjones28
Addiction is all about class.
datlas is offline  
Old 10-31-22, 08:39 AM
  #5  
GhostRider62
Senior Member
 
Join Date: Apr 2021
Posts: 4,083
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2332 Post(s)
Liked 2,094 Times in 1,311 Posts
Carbon fibre does not have a fatigue limit

I have two carbon forks with over 50,000 miles each on them. YMMV
GhostRider62 is offline  
Likes For GhostRider62:
Old 10-31-22, 09:06 AM
  #6  
eduskator
Senior Member
 
eduskator's Avatar
 
Join Date: Aug 2019
Location: Québec, Canada
Posts: 2,064

Bikes: SL8 Pro, TCR beater

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 957 Post(s)
Liked 562 Times in 423 Posts
Carbon Fiber HAS a fatigue limit. It's physics. Everything deteriorates in this beautiful universe.

Not sure that OP will experience it though as CF holds its properties for a very long time.
eduskator is offline  
Old 10-31-22, 09:11 AM
  #7  
big john
Senior Member
 
big john's Avatar
 
Join Date: Sep 2005
Location: In the foothills of Los Angeles County
Posts: 25,099
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 8185 Post(s)
Liked 8,843 Times in 4,391 Posts
Originally Posted by eduskator
Carbon Fiber HAS a fatigue limit. It's physics. Everything deteriorates in this beautiful universe.

Not sure that OP will experience it though as CF holds its properties for a very long time.
Well the OP was 20 years ago. Maybe we could find him and ask if he's still using the same fork?

fwiw I have well over 50K miles on one cf fork and about 35K on another. Also have a cf mountain bike which has been slammed around for 4.5 years.
big john is offline  
Likes For big john:
Old 10-31-22, 09:26 AM
  #8  
Branko D
Senior Member
 
Join Date: Feb 2018
Posts: 786
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 338 Post(s)
Liked 408 Times in 252 Posts
CF fatigues (like anything does which is light enough that you'd put it on a bicycle), the mechanism is different than for metals.

It will eventually become progressively less stiff, after which it will eventually fail. How long is that eventually depends on how it is made (it is the defects in manufacturing which greatly accelerate the process), how heavy you are, how often you bomb full speed into potholes and speed bumps and so on, but anecdotally, it's about as long as you'd expect a nice metal frame to last before it dies out of fatigue.

Here's some reading;
https://www.academia.edu/30520244/Fa..._Bicycle_Forks
Branko D is offline  
Likes For Branko D:
Old 10-31-22, 10:02 AM
  #9  
base2 
I am potato.
 
base2's Avatar
 
Join Date: Jun 2015
Location: Pacific Northwest
Posts: 3,073

Bikes: Only precision built, custom high performance elitist machines of the highest caliber. 🍆

Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1764 Post(s)
Liked 1,577 Times in 910 Posts
Happy Halloween!
5E8F74B9-EED9-49E5-B2C8-508EC10D41B1 by Richard Mozzarella, on Flickr

Zombie thread, indeed.

The guys in Formula 1 racing do deflection tests on their composite parts. The purpose is to Suss-out the added flexibility of the 100's of thousands to millions of tiny micro-cracks in the resin matrix that cumulatively lead to a part no longer performing as designed.

For this to work, you need a reference point. This is usually the logged test results from the very first time a newly manufactured part is put in a test rig to be tested. As a part is put in service the micro-cracks accumulate & this is revealed by increased flexibility (deflection) under test load during periodic testing.

Carbon fiber doesn't assplode. It tends to fail gracefully. With careful examination the damage is detectable & actionable.

What we're talking about here is mode of fatigue failure. Steel, Aluminum, Titanium tend to fail at some stress concentration & then concentrate at the concentration.

Like so many other things, it's down to design & execution.























(...and of course catastrophic failure is by definition: catastrophic. This comes from exceeding engineering designed capacity. That's not a question of material, that's a question of designed capacity. Take that up with the parts engineer. )
__________________
I shouldn't have to "make myself more visible;" Drivers should just stop running people over.

Car dependency is a tax.
base2 is online now  
Likes For base2:
Old 10-31-22, 10:15 AM
  #10  
datlas 
Should Be More Popular
 
datlas's Avatar
 
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 42,957

Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix

Mentioned: 560 Post(s)
Tagged: 2 Thread(s)
Quoted: 22513 Post(s)
Liked 8,841 Times in 4,113 Posts
Thanks for the Zombie updates. I don't know if OP can chime in.

My Habanero has about 60K miles on it, as does the Ritchey WCS fork. I have no plans to replace either. I am suspicious the Ti frame might fail before the CF fork does.

Happy Halloween!
__________________
Originally Posted by rjones28
Addiction is all about class.
datlas is offline  
Likes For datlas:
Old 10-31-22, 10:35 AM
  #11  
GhostRider62
Senior Member
 
Join Date: Apr 2021
Posts: 4,083
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2332 Post(s)
Liked 2,094 Times in 1,311 Posts
Originally Posted by Branko D
CF fatigues (like anything does which is light enough that you'd put it on a bicycle), the mechanism is different than for metals.

It will eventually become progressively less stiff, after which it will eventually fail. How long is that eventually depends on how it is made (it is the defects in manufacturing which greatly accelerate the process), how heavy you are, how often you bomb full speed into potholes and speed bumps and so on, but anecdotally, it's about as long as you'd expect a nice metal frame to last before it dies out of fatigue.

Here's some reading;
https://www.academia.edu/30520244/Fa..._Bicycle_Forks
I did not read the references. If carbon fibre lasts on fighter jets, F1 cars, and commercial aircraft over my lifespan, in effect it does not fatigue. The resin? That is a more nuanced discussion. But I have a 30 year old fork hanging in the garage in the sun and it is still holding up.

A bigger issue is probably the extreme light and brittle layups being used where even the bike rack clamp on your car will damage the toptube permanently.
GhostRider62 is offline  
Likes For GhostRider62:
Old 10-31-22, 10:47 AM
  #12  
Branko D
Senior Member
 
Join Date: Feb 2018
Posts: 786
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 338 Post(s)
Liked 408 Times in 252 Posts
Ritchey CF forks seem like a seriously beefy piece of fork. I was highly impressed with the build quality inspecting one, and I'd wager the steel frame it's on is going to die sooner.

The CF fork on my road bike doesn't look nearly as well built as the Richey one, but I still don't fuss about it. The frame and fork are going to get replaced eventually - I told myself it's fine to treat myself to a new road bike every six, seven years or so - or I'll crash hard enough that it'll need replacing.
Branko D is offline  
Old 10-31-22, 11:04 AM
  #13  
Branko D
Senior Member
 
Join Date: Feb 2018
Posts: 786
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 338 Post(s)
Liked 408 Times in 252 Posts
Originally Posted by GhostRider62
I did not read the references. If carbon fibre lasts on fighter jets, F1 cars, and commercial aircraft over my lifespan, in effect it does not fatigue. The resin? That is a more nuanced discussion. But I have a 30 year old fork hanging in the garage in the sun and it is still holding up.

A bigger issue is probably the extreme light and brittle layups being used where even the bike rack clamp on your car will damage the toptube permanently.
Well, I'll be turning 40 next year, so by the time I finally hang up the wheels, I hope the current commercial aircraft and fighter jets will be binned old junk. They do go through inspections and so on and so forth, and the QC is miles ahead of bicycle manufacturing. It's the forks with manufacturing defects which are fairly short lived.
Branko D is offline  
Old 10-31-22, 11:08 AM
  #14  
GhostRider62
Senior Member
 
Join Date: Apr 2021
Posts: 4,083
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2332 Post(s)
Liked 2,094 Times in 1,311 Posts
Originally Posted by Branko D
Well, I'll be turning 40 next year, so by the time I finally hang up the wheels, I hope the current commercial aircraft and fighter jets will be binned old junk. They do go through inspections and so on and so forth, and the QC is miles ahead of bicycle manufacturing. It's the forks with manufacturing defects which are fairly short lived.
Interesting.

Having spend almost 40 years working in Quality Control, Assurance, Engineering, and Management and as an engineer, I don't know much about this stuff anymore, my brain is mush.
GhostRider62 is offline  
Likes For GhostRider62:
Old 10-31-22, 11:35 AM
  #15  
tomato coupe
Senior Member
 
Join Date: Jul 2009
Posts: 5,879

Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3905 Post(s)
Liked 7,181 Times in 2,905 Posts
Originally Posted by GhostRider62
If carbon fibre lasts on fighter jets, F1 cars, and commercial aircraft over my lifespan, in effect it does not fatigue.
F1 cars have to last only one season, and commercial aircraft must pass inspection every 100 hours.
tomato coupe is offline  
Old 10-31-22, 11:49 AM
  #16  
Bob Ross
your god hates me
 
Bob Ross's Avatar
 
Join Date: Apr 2006
Posts: 4,580

Bikes: 2016 Richard Sachs, 2010 Carl Strong, 2006 Cannondale Synapse

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1233 Post(s)
Liked 1,241 Times in 689 Posts
Originally Posted by GhostRider62
If carbon fibre lasts on fighter jets, F1 cars, and commercial aircraft over my lifespan, in effect it does not fatigue.
Originally Posted by tomato coupe
F1 cars have to last only one season, and commercial aircraft must pass inspection every 100 hours.
Okay, how about the telemetry antenna masts on the Voyager spacecraft? They've had to last 45 years and counting, with no possibility of inspection after the original deployment date. Currently moving at >30,000 mph and still working.

Of course, there aren't any potholes or garage doors in space...
Bob Ross is offline  
Old 10-31-22, 11:53 AM
  #17  
tomato coupe
Senior Member
 
Join Date: Jul 2009
Posts: 5,879

Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3905 Post(s)
Liked 7,181 Times in 2,905 Posts
Originally Posted by Bob Ross
Okay, how about the telemetry antenna masts on the Voyager spacecraft? They've had to last 45 years and counting, with no possibility of inspection after the original deployment date. Currently moving at >30,000 mph and still working.
Those masts are subjected to zero stress, and speed while traveling through space is irrelevant.
tomato coupe is offline  
Likes For tomato coupe:
Old 10-31-22, 02:00 PM
  #18  
thin_concrete
Achtung!
 
thin_concrete's Avatar
 
Join Date: Oct 2015
Location: New England
Posts: 1,673

Bikes: 60.1, Marvel

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 515 Post(s)
Liked 268 Times in 161 Posts
Originally Posted by tomato coupe
F1 cars have to last only one season, and commercial aircraft must pass inspection every 100 hours.
No F1 car lasts an entire season though. Whether practice, quali, or racing, it’s going to get damaged to the point it’s no longer usable for their purposes (going as fast as possible; serviceable to the ordinary schmoe - maybe). Not to mention the upgrades over the course of the season. The monocoque they finish with is generally not the one they started with.
thin_concrete is offline  
Old 10-31-22, 02:11 PM
  #19  
indyfabz
Senior Member
 
indyfabz's Avatar
 
Join Date: Jan 2010
Posts: 39,053
Mentioned: 210 Post(s)
Tagged: 1 Thread(s)
Quoted: 18319 Post(s)
Liked 15,286 Times in 7,226 Posts


Fresh, not 20 years old.
indyfabz is online now  
Old 10-31-22, 02:11 PM
  #20  
Bacciagalupe
Professional Fuss-Budget
 
Bacciagalupe's Avatar
 
Join Date: Aug 2005
Posts: 6,494
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 24 Times in 14 Posts
Originally Posted by datlas
Inspired by a recent posting of a cyclist getting rid of a carbon fork because it was "old," I decided to resurrect this thread. Plus it's Halloween so a Zombie post is possibly appopriate.
Good grief, how did you even find this thread? Or do I not want to know?


I have occasionally heard people say that their fork should be replaced periodically. One of my friends rides a Lynskey and he swears they told him to replace the fork every 4-5 years.
I've... never heard anyone say that, and can't imagine a manufacturer saying that. Personally, I wouldn't drop 2 large on a frame with a disposable fork. Or perhaps I should say, I wouldn't drop 2 large on a frame where the manufacturer has so little confidence in its own fork that they recommended a full replacement every 5 years....


I suspect that a well designed CF fork should last indefinitely unless it's crashed or damaged.
Pretty much.

While the term "Retro Grouch" has slowly come to the surface of my addled brain, I find it hard to imagine that serious cyclists today have any concerns about CF... or road disc brakes... or hydraulic brakes... or electronic shifting, or any of the other innovations that stuck despite the moral panics over the impending doom of using them.
Bacciagalupe is offline  
Likes For Bacciagalupe:
Old 10-31-22, 02:47 PM
  #21  
PeteHski
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 8,174
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 4273 Post(s)
Liked 4,709 Times in 2,909 Posts
Originally Posted by tomato coupe
F1 cars have to last only one season, and commercial aircraft must pass inspection every 100 hours.
F1 is not a good example for carbon component longevity. I worked as an engineer in F1 (not a composite specialist, but saw a lot of it). Critical structural carbon components are typically proof tested every 1000 km. The two biggest issues (aside from a crash) in their case are stone chips and exhaust heat.
PeteHski is offline  
Likes For PeteHski:
Old 10-31-22, 02:56 PM
  #22  
tomato coupe
Senior Member
 
Join Date: Jul 2009
Posts: 5,879

Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3905 Post(s)
Liked 7,181 Times in 2,905 Posts
Originally Posted by PeteHski
F1 is not a good example for carbon component longevity.
Exactly. Which is why I objected to the idea that the longevity of F1 cars implies carbon fiber does not fatigue.

Originally Posted by GhostRider62
If carbon fibre lasts on fighter jets, F1 cars, and commercial aircraft over my lifespan, in effect it does not fatigue.
tomato coupe is offline  
Old 10-31-22, 03:06 PM
  #23  
GhostRider62
Senior Member
 
Join Date: Apr 2021
Posts: 4,083
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 2332 Post(s)
Liked 2,094 Times in 1,311 Posts
Originally Posted by tomato coupe
F1 cars have to last only one season, and commercial aircraft must pass inspection every 100 hours.
My bike passes every ride. Inspection does nothing to increase the inherent durability of something. F1 cars crash, rocks hit them, and certain structures deal with a little bit of heat. Part of my bmw's structure is carbon fibre and it should outlive me.

I could be wrong but I doubt any commercial aircraft has its fuselage checked for cracks every 100 hours. Not even the new Marine One gets that treatment.
GhostRider62 is offline  
Old 10-31-22, 03:09 PM
  #24  
genejockey 
Klaatu..Verata..Necktie?
 
genejockey's Avatar
 
Join Date: May 2007
Location: SF Bay Area
Posts: 17,651

Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace

Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 10243 Post(s)
Liked 11,596 Times in 5,943 Posts
Originally Posted by Bob Ross
Okay, how about the telemetry antenna masts on the Voyager spacecraft? They've had to last 45 years and counting, with no possibility of inspection after the original deployment date. Currently moving at >30,000 mph and still working.

Of course, there aren't any potholes or garage doors in space...
Also, moving at a constant speed in zero G, so there's little if any force in any direction on them.
__________________
"Don't take life so serious-it ain't nohow permanent."

"Everybody's gotta be somewhere." - Eccles
genejockey is offline  
Old 10-31-22, 03:13 PM
  #25  
datlas 
Should Be More Popular
 
datlas's Avatar
 
Join Date: Dec 2007
Location: Malvern, PA (20 miles West of Philly)
Posts: 42,957

Bikes: 1986 Alpine (steel road bike), 2009 Ti Habenero, 2013 Specialized Roubaix

Mentioned: 560 Post(s)
Tagged: 2 Thread(s)
Quoted: 22513 Post(s)
Liked 8,841 Times in 4,113 Posts
Originally Posted by Bacciagalupe
Good grief, how did you even find this thread? Or do I not want to know?



I've... never heard anyone say that, and can't imagine a manufacturer saying that. Personally, I wouldn't drop 2 large on a frame with a disposable fork. Or perhaps I should say, I wouldn't drop 2 large on a frame where the manufacturer has so little confidence in its own fork that they recommended a full replacement every 5 years....
The search function is quite powerful if you know how to use it.

I suspect the folks that suggest a new fork every 5 years are the ones who sell forks. Kinda like the helmet manufacturers saying you need a new helmet every 3 years.
__________________
Originally Posted by rjones28
Addiction is all about class.
datlas is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.