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  1. #1
    Senior Member OldsCOOL's Avatar
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    Carbon Fiber Forks

    I wanted to post this question to our seasoned veterans rather than the other forums. My question is the durability of CF forks. My Raleigh Technium PRE is a nice enough platform for me to upgrade in terms of weight loss. Right now it weighs far too much for an aluminum tri-framed bike even though the steel stays and forks are Tange cro-mo.

    My main concern is durability when I ride our local MUP with the low curbs. As it stands I'm doing mild bunnies to get over them and I'm not sure that would be the better than going slow. This is a 30mi ride I dont really want to cut out of my training arsenal unless needbe.

    What are your thoughts and experiences on my putting CF up front?
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

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  2. #2
    Senior Member big john's Avatar
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    I don't think durability is an issue with cf forks. I've put close to 60K miles on two of them on some awful roads with no problems.

    If you're looking for a fork for a 23 year old frame I assume it's a 1" threaded steerer, which will limit your options.

  3. #3
    Senior Member OldsCOOL's Avatar
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    Quote Originally Posted by big john View Post
    I don't think durability is an issue with cf forks. I've put close to 60K miles on two of them on some awful roads with no problems.

    If you're looking for a fork for a 23 year old frame I assume it's a 1" threaded steerer, which will limit your options.
    Correct. They are available and probably going to need some cutting and threading. Wont be cheap but it's an easy way to time a 1.5lbs off the front. My only reservation in the handling will be the already heavy rear weight bias. Thanx for the input
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

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  4. #4
    Senior Member tony2v's Avatar
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    Get this from Bike Island:
    http://bikeisland.com/cgi-bin/BKTK_S...ls&ProdID=2341

    No need to thread the steerer tube just use a clamp-on stem.

  5. #5
    Senior Member OldsCOOL's Avatar
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    Quote Originally Posted by tony2v View Post
    Get this from Bike Island:
    http://bikeisland.com/cgi-bin/BKTK_S...ls&ProdID=2341

    No need to thread the steerer tube just use a clamp-on stem.
    Looks like a good option. Sure wish they would list the weight in their spec sheet.
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

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  6. #6
    Climbing Above It All BikeWNC's Avatar
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    Carbon forks certainly can handle jumping curbs and riding gravel. Cyclocross riders use carbon forks and they put them through a lot more abuse than you would. I will say though that trying to upgrade or retrofit and older bike is less cost effective in the long run than just buying a new bike. Especially if you buy that "new" bike used.
    FS: Shimano DA 7900 brake calipers, DA 7900 Crankset 50/34 175mm and BB

  7. #7
    Senior Member OldsCOOL's Avatar
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    Quote Originally Posted by BikeWNC View Post
    Carbon forks certainly can handle jumping curbs and riding gravel. Cyclocross riders use carbon forks and they put them through a lot more abuse than you would. I will say though that trying to upgrade or retrofit and older bike is less cost effective in the long run than just buying a new bike. Especially if you buy that "new" bike used.
    Not when I find them for less than 100.00

    The bike is pristine, a great rider, and light enough to be lots of fun on the personal TT routes.

    And I dont want a new bike, being I'm into the more classic and vintage scene (though my PRE pushes the timeframe a little).
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

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    '79 Motobecane Super Mirage

  8. #8
    Senior Member big john's Avatar
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  9. #9
    Senior Member NOS88's Avatar
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    Nashbar has a 1" threaded carbon fork on sale for $90 right now: http://www.nashbar.com/bikes/Product...2_174894_-1___

    I updated two classic bikes with carbon forks. Both were 1" with one threaded and the other not. They have performed reliably. I don't remember the weight difference being terribly significant (there was some advantage, but not all the much, as I recall). However, the handling difference was significant and I was VERY glad I made the upgrade. Both bikes have long since left my stable and ended up in the hands of my sons. One son seems capable of breaking anything over time, yet the fork on that bike is still sound.
    A conclusion is the place where you got tired of thinking. - S. Wright

  10. #10
    Senior Member OldsCOOL's Avatar
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    Quote Originally Posted by NOS88 View Post
    Nashbar has a 1" threaded carbon fork on sale for $90 right now: http://www.nashbar.com/bikes/Product...2_174894_-1___

    I updated two classic bikes with carbon forks. Both were 1" with one threaded and the other not. They have performed reliably. I don't remember the weight difference being terribly significant (there was some advantage, but not all the much, as I recall). However, the handling difference was significant and I was VERY glad I made the upgrade. Both bikes have long since left my stable and ended up in the hands of my sons. One son seems capable of breaking anything over time, yet the fork on that bike is still sound.
    Excellent report, the one I was looking for. I have my sights on the Nashbar fork. From what the specs list it looks like at least a 1lb difference. Not everyone is concerned about the weight difference as I am but it sure is nice getting a review from the BF bunch.

    thanx.
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

    '89 Raleigh Technium PRE

    '79 Motobecane Super Mirage

  11. #11
    Senior Member OldsCOOL's Avatar
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    Thanx, Big John!
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

    '89 Raleigh Technium PRE

    '79 Motobecane Super Mirage

  12. #12
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    I've worked as a shop monkey in yacht building as well as work for the military and Boeing and MacDonald Douglas. Military work has detailed specifications to be met including wearing gloves to keep body oils off laminates. The carbon plies themselves, whether woven or unidirectional, are only one part of the process. The epoxy resins used can have scores, even hundreds of similar or quite different characteristics. Most often, but not always, bikes manufacturing will use carbon fabrics that are pre-empregnated with epoxy resin. In this case, the prepreg supplier will have selected the resin used.

    As an example, at a shop where the work was mostly for the military or aircraft industry, we had a small lab in which to test samples of epoxy. Each week we would receive several samples of different resins from various manufacturers. Each resin can be used with different catalysts that in themselves alter the cured epoxy properties. This testing went on week after week. Some resins were hard but brittle. Others might be very flexible but be too reactive. Chemical engineers continually concoct different formulations.

    My take from this experience is that if I were buying a carbon fork for my bike I would buy only from a well known manufacturer or reseller because there is no way to judge the quality of that fork. Most of us would not jump out an automobile traveling at 25 miles an hour just wearing underwear. Just a few week ago in my area, a cyclist had a fork failure and died of his injuries. This sort of failure can happen from any bike manufacturer but less likely than an unknown, unnamed and unlabled product build to unknown standards.

  13. #13
    Senior Member OldsCOOL's Avatar
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    I'm putting the Technium PRE on a diet. What really grabs my curiosity is the frame differences between the PRE and the Trek 460. The Trek has True Temper steel and the PRE has aluminum triangle tubes with Tange stays, forks. Both frames are the same size, yet the Trek is lighter and noticeably so. That speaks well of the Trek framework.

    This is why I'm looking to swap over to the Krylion 23's and CF fork on the PRE. That would make this bike very, very responsive (read: quick)....and that's what I want for the fast 20mi and 30milers.

    Tires first and then comes the CF fork. The fork/headset work will be toward the end of summer. The Nashbar CF wins the bid
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

    '89 Raleigh Technium PRE

    '79 Motobecane Super Mirage

  14. #14
    Senior Member
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    A CF fork from any reputable reseller should be fine. I'm thinking about a new CF fork myself that will take 28mm tires.

  15. #15
    Dharma Dog lhbernhardt's Avatar
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    I've got a 32-year-old steel tandem that's running a carbon fork with 1" steerer designed for tandems. Previous to that, I used a VERY light Reynolds Ouzo Pro fork with carbon 1" steerer. I used it for over 4,000 km with no problems (it's not "officially" rated for tandem use, but is strong enough for a 320-lb team). It was a bit flexy, though, under hard braking, which is why I switched to a heavier officially tandem-rated fork (a Woundup X-2, which I think is overbuilt and looks really stupid, more like a mountain bike fork). I think that as long as the fork doesn't suffer any impact trauma, it should be OK. Carbon fiber is good at handling numerous cycles of flex, unlike aluminum, which starts to get brittle as soon as it bends. As long as the cf fork is brand new and from a reputable company, you should be OK. I use cf forks on all my bikes. I like the aluminum dropouts; very easy to file off those stupid lawyer tabs (the first thing I do with any fork).

    Luis

  16. #16
    Si Senior dbg's Avatar
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    No mention of tire clearance in the Nashbar specs. They call it 700c so I assume precludes any 27" wheels and probably tops out at 700x25.
    David Green, Naperville, IL USA "The older I get, the better I used to be" --Lee Trevino

  17. #17
    Senior Member bigbadwullf's Avatar
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    I'd seriously consider jacking the bike up and putting a new one under it. Not trying to be mean. Just trying to help face the facts.

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  18. #18
    rugged individualist wphamilton's Avatar
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    Quote Originally Posted by dbg View Post
    No mention of tire clearance in the Nashbar specs. They call it 700c so I assume precludes any 27" wheels and probably tops out at 700x25.
    I'm a believer in the Nashbar fork. I have the one with 1 1/8" steerer but I'm using 700x28 on it.

  19. #19
    Resident Alien Racer Ex's Avatar
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    Quote Originally Posted by berner View Post
    My take from this experience is that if I were buying a carbon fork for my bike I would buy only from a well known manufacturer or reseller because there is no way to judge the quality of that fork. Most of us would not jump out an automobile traveling at 25 miles an hour just wearing underwear. Just a few week ago in my area, a cyclist had a fork failure and died of his injuries. This sort of failure can happen from any bike manufacturer but less likely than an unknown, unnamed and unlabled product build to unknown standards.
    Virtually all the carbon forks are coming from a few factories in Taiwan, and every failure or recall I've seen have come from "name" brands. Some of the worst examples came from one of the larger boutique manufacturers. A name is zero assurance of QA/QC.

    The only thing the name might bring you is a settlement down the line should something happen.

    That said I'd be a lot more circumspect buying a used fork vs. new.

  20. #20
    coprolite fietsbob's Avatar
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    They are available and probably going to need some cutting and threading. Wont be cheap but it's an easy way to time a 1.5lbs off the front. My only reservation in the handling will be the already heavy rear weight bias.
    I recommend threadless conversion, over threading an aluminum steerer fork.
    you want to shave weight, I read..
    you want to put on fresh bar tape anyhow.. once you fit the bars
    in an open face plate stem, you can change stem choices without re-taping ..

    And the stems are lighter ..

    But realistically N+1, buy a new bike .. ride the one you have to the LBS,
    so they see what size bike you are so comfortable on ,
    that you want to spend the Majority of a new bike's cost fixing up..
    and take some test rides on new stuff..
    Last edited by fietsbob; 05-17-12 at 04:04 PM.

  21. #21
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    I happen to think that carbon/epoxy laminates can be amazingly strong when properly built. I also think that the majority of carbon composite forks will be well built and will last as long as the rest of the frame. The real problem is that frame sets are not built to any known standards. Even my bike helmet has stickers inside identifying the standards under which it was produced. A bread toaster will have stickers identifying electrical standards and the engineering agency that produced those standards. Rolled and extruded steel or aluminum beams, tubes and plate will be produced to identifiable standards established by engineering agencies as well as the batch and mill that produced those products.

    At one place where I worked, the company produced for NASA a simple carbon/epoxy tubelike structure, approximately one meter in diameter and one meter in length and was an inlet duct for jet engines. At the same time the part was produced, a sample carbon/epoxy piece was produced using the same laminate schedule and resin and cured in an oven at the exact same time and temperature. Subsequently, when the part was trimmed to its final dimensions, several cutoffs were saved for later testing. Every step of the process was spelled out and followed with care to end up with a consistent finished part and accountability.

    The key to manufacturing success is repeatability. Every part produced must be of the same quality - from trucks to tooth brushes.

  22. #22
    Senior Member OldsCOOL's Avatar
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    Quote Originally Posted by bigbadwullf View Post
    I'd seriously consider jacking the bike up and putting a new one under it. Not trying to be mean. Just trying to help face the facts.
    Facts? What if I like the bike? It's a fast enough bike for me.
    Having a flat tire as part of the total cycling experience is highly overrated. Knowing how to fix one quickly is not.

    '85 Trek 460 road racer

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  23. #23
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    Two comments, possibly irrelevant: a friend of mine replaced the steel fork on his high-end college Centurion (don't remember the model, but we were all amazed when he paid ~$1000 in the late '70s) with carbon. He loves the bike, completely rebuilt it and planned to keep it forever. He says the fork was a major disappointment, didn't make a significant difference. YMMV, of course--this was probably six or seven years ago.
    And a neighbor is an aero engineer in charge of testing carbon fiber components for an aircraft parts manufacturer. I've watched some of the testing, and the CF just goes and goes and goes forever, millions of cycles. When it fails, though, it tends to go suddenly, with no warning at all. He says it's far more durable than other materials, and I believe him, but that still makes me nervous...

  24. #24
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    Long ago, probably in the very early 1970s, when carbon composites were very new and not yet widely used, I had a long conversation with a physicist who worked for Grumman Aircraft in Long Island. At that time Grumman and the Navy was interested in carbon composites. He told me then that their testing showed such laminates had infinite fatigue strength. Within allowable limits, it could be flexed, like a tree, forever with no loss of strength. The issue is not suitability as a structural material. The issue is manufacturing standards and repeatability.

    By the way, I'm sort of in the market for a different carbon fork for myself.

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