Advertise on Bikeforums.net



User Tag List

Results 1 to 18 of 18
  1. #1
    Junior Member
    Join Date
    Feb 2011
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    ARRRGG!!! damaged my carbon fork!!!

    stupid dog ran out in front of my bike and i had to serve to miss it

    Ended up hitting a stupid steel park bench, heres a pic

    http://img525.imageshack.us/i/img0134oh.jpg/

    Most of it appears to be cosmetic, but to the left, a bit of the carbon has been damaged, although not very deep (the red is from the park bench).

    Do you guys think i need to change the fork

    And if so would this one be ok? (in terms of sizing etc.)

    http://www.merlincycles.co.uk/Bike+S...LUMBUSTUSK.htm


    I have a trek 1.2 compact 2010

  2. #2
    Senior Member
    Join Date
    Aug 2007
    Location
    Belgium
    Posts
    745
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    This is not a recommendation to ride a structurally damaged fork but if you think that the gouges are just in the outer layer of carbon then you can sand the area smooth, including the paint around that general area of the fork and then lay on some new carbon fiber cloth and resin. There is a youtube video demonstrating repair of carbon fiber tubing/fishing poles that demonstrates wrapping the still wet area with some kind of heat shrink wrapping to help squeeze/form/and set the resin/carbon repair.

    If you have any question whether the fork is structurally sound or not then you should not be asking questions about it...there is nothing anyone will be able to tell you definitively either way about your fork from pictures and you would need special equipment to conduct non-destructive testing to confirm if there is any underlying damage that may affect the structural integrity of the fork.

    But...if you think it is just really bad cosmetic damage the patch will be ugly but is often much stronger than the unrepaired fork if done correctly due to the extra layer of carbon.

    -j

  3. #3
    Junior Member
    Join Date
    Feb 2011
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    thanks, i think i am a little uncomfortable cycling on it, so gonna replace it, do you know whether the one i linked earlier would be suitable?

    the only info i have on my fork is that they are "Fork: Bontrager Approved, Carbon" not sure of the size, if it help my bike frame is 56cm....

    or maybe i should spend a little more and get these:

    http://www.actionbikes.co.uk/bontrag...igid-fork.html

    i think they are the same as the ones on my current bike... maybe?

  4. #4
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,260
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    I agree with your decision to replace the fork. Without an expert apraisal, there is no way to tell if the damage is superficial or structural and it's not worth the risk.

    Either fork you show should be satisfactory except the Columbus fork doesn't specify the steerer diameter (and it's out of stock) while the Bontrager specifies 1-1/8" (28.6 mm) which is what your frame requires.

  5. #5
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    19,916
    Mentioned
    31 Post(s)
    Tagged
    1 Thread(s)
    If it were the seat stay, or elsewhere on the bike, I'd probably patch and ride it. But not a fork blade.

    I always base these decisions on a calculation involving likelihood of failure and possible consequences.

    With carbon fiber it's hard to predict failure, and unlike steel which usually gives plenty of notice, carbon tends to fail catastrophically with no advance warning. So it's hard to estimate the likelihood, and I'd focus more on the potential consequences.

    Fork blades have no redundancy, each being critical. If a fork blade fails the front wheel will cant against the other and probably lock up or at least make the bike difficult to control. There's a very high chance of taking a header. Since failure has a high probably of leading to serious injury, I don't tolerate much risk, and am extremely conservative about fork reliability.

    As I said, the situation would be different if it were a seat stay. If one failed, there'd still be a chainstay providing wheel support, and if the wheel were to lock up, it would be a rear wheel lockup not a front likely causing road rash rather than serious bone or head injury.

    It's just a fork, pony up the dough and replace it. Even if it isn't absolutely necessary, the peace of mind when descending a long hill will be worth it.
    Last edited by FBinNY; 02-22-11 at 08:11 AM.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  6. #6
    Junior Member
    Join Date
    Feb 2011
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    hmmm well according to this ebay listing:

    http://cgi.ebay.co.uk/Columbus-Tusk-...item4153826ec2

    it is 1-1/8

    and may just buy it from the ebay one seeing as the other one is out of stock!!

    just making sure though, you're sure its suitable? cause trek 1.2 does have long drops for its brakes

  7. #7
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,260
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by ryujin View Post
    hmmm well according to this ebay listing:

    http://cgi.ebay.co.uk/Columbus-Tusk-...item4153826ec2

    it is 1-1/8

    and may just buy it from the ebay one seeing as the other one is out of stock!!

    just making sure though, you're sure its suitable? cause trek 1.2 does have long drops for its brakes
    Neither fork specifies the required brake reach but i expect both require a "short reach" (37 - 47 mm) brake caliper.

    Frankly, for someone who isn't certain what he needs, e-bay is a poor source for parts. Your LBS may charge a bit more but at least you will get the proper item the first time.

  8. #8
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My Bikes
    too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
    Posts
    19,916
    Mentioned
    31 Post(s)
    Tagged
    1 Thread(s)
    Unless you know the seller or it's a listing from an established form, I'd pass on an ebay fork. You could go to the LBS, or if you feel that's too pricey, shop an established internet site, of which there are plenty enough to choose from.
    FB
    Chain-L site

    An ounce of diagnosis is worth a pound of cure.

    “Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

    “One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

    WARNING, I'm from New York. Thin skinned people should maintain safe distance.

  9. #9
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,819
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Greenfieldja View Post
    you would need special equipment to conduct non-destructive testing to confirm if there is any underlying damage that may affect the structural integrity of the fork.
    I'd use a dial gauge and some weight to determine if the damaged leg was any weaker than the other one.

  10. #10
    Gear Combo Guru Chris_W's Avatar
    Join Date
    May 2007
    Location
    Switzerland
    My Bikes
    Spec' Tarmac (road), Spec' Secteur Disc (commuter & tourer), Salsa Mamasita (MTB), CoMo Speedster (tandem), Surly Big Dummy (cargo), Airnimal (folder), a train pass, and NO car :)
    Posts
    2,046
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've patched a carbon seat-stay that had worse damage, but I would never try doing so on a fork. As said above, the fork is too much of a safety risk. You need a new one.

  11. #11
    Senior Member jchabalk's Avatar
    Join Date
    May 2008
    Posts
    165
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    bad dog! go to your kennel

    I'd replace it and feel good about doing it. Any injury prevented by replacing a critical piece of suspect gear is well worth the cost. +1 to FBinNY

  12. #12
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,260
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    I'd use a dial gauge and some weight to determine if the damaged leg was any weaker than the other one.
    OK, and let's say the dial gauge says the fork blades are still the same. Would you ride the bike with that fork?

  13. #13
    Senior Member Looigi's Avatar
    Join Date
    Dec 2010
    Posts
    6,993
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Well, on a positive note, judging from the pics, your Crud fenders were unscathed.

  14. #14
    Junior Member
    Join Date
    Feb 2011
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Looigi View Post
    Well, on a positive note, judging from the pics, your Crud fenders were unscathed.
    yea lol, they're completely unscathedwould have been annoyed if they were trashed, seeing as i only put them on last week!

  15. #15
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    38,952
    Mentioned
    20 Post(s)
    Tagged
    0 Thread(s)
    Thy Trek dealer may help you, Perhaps they or Craig Calfee
    [SF Cal carbon builder and repair guy]
    will analyze, the damage, and if not de-laminated,
    patch up the external appearance..

    Or , say "replace" ..

  16. #16
    Hills hurt.. Couches kill RacerOne's Avatar
    Join Date
    Jun 2008
    Location
    Brazil, IN
    My Bikes
    1991 Specialized Sirrus Triple, 2010 Trek Madone 6.5 Project One, 2012 Cannondale Caad10, 2013 Trek Crockett
    Posts
    3,360
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Try your Trek dealer, if you bought it new you might get the crash replacement price.

  17. #17
    Junior Member
    Join Date
    Feb 2011
    Posts
    5
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i didn't buy from new, but i went to my LBS, who have ordered me similar forks, cost me almost double what it would have online, but at least i know it'll be a good match!

    thanks for your help guys!

  18. #18
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,260
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by ryujin View Post
    ....cost me almost double what it would have online, but at least i know it'll be a good match!
    Good. Consider the extra cost as insurance that you will get a compatible fork that fits and works properly.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •