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Technical FAQ: Saving that damaged carbon frame

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Ouch!

Dear Lennard,
I had a bad crash last week where the handlebar swung around and hit the top tube of my Pinarello. Do you have any idea, looking at the pictures, if it can be fixed?

Would x-ray-ing the frame show if the damage is serious or not? Do you have any other ideas on how I can assess the damage and if the frame is safe to ride?
Johnny

Dear Johnny,
Absolutely that can be fixed. And I recommend against riding it without repairing it. There is no question that you now have a weak spot there, so why tempt fate?

I was just at Craig Calfee’s shop in Watsonville, California, last week and I am still shaking my head in amazement at the incredible repair work they were doing there on dozens of carbon frames that most people would assume were totaled. Calfee even is the authorized repair service for a number of brands.

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It can be fixed, but don’t ride it before it is.

I saw Calfee technicians repairing frames that had seatstays that had been completely severed, and they looked good as new when done. In the dozens and dozens of frames of all makes that were in the shop for repair, I saw plenty that had minor cracks as well as ones that were cracked through all of the layers so that, for instance, a big section of the down tube was gushy and would push in with light thumb pressure. And all of these they could fix.

If your tube is cracked all of the way through all of the layers, then that entire section must be sanded, all of the way through, before the patch is applied, whereas more surface damage requires a larger surface patch. And Calfee has sent repaired tubes out for testing, comparing them with new tubes, and found that the repaired tube is at least as strong and fatigue-resistant as the original tube.

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It's hard to tell that there was major damage.

Most amazingly, when the repair is done, it looks like a new frame again. Calfee has an amazing painter who can match all of the painting detail on even a frame like yours with a complex paint job. The accompanying photos I took of a recently repaired Trek Madone illustrate what I’m talking about.

This frame had a large crack at the letters “R” and “E” on the main down tube decal. Now, if you look closely, you can see that after the repair, the black area of the down tube looks slightly different, showing some woven carbon fibers under the clear coat. And the pink stripe on close inspection is a slightly lighter color and more metallic, but at a distance, nobody would guess that this frame has had a major repair done on it.

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Ready to ride

The only question for you is cost. The minimum repair price is $200 ($50 to do an inspection and price quote that is credited toward the repair), whereas a crack penetrating all of the layers carries a $300 repair price. Of course, paint will cost you extra.

Heather Ross manages the Calfee carbon repair department. Contact her or email the repair shop directly for estimates and lead times.
Lennard

Got some mountain bike tech questions? Check out Lennard’s FAQ on Singletrack.com


Follow Lennard on Twitter at www.twitter.com/lennardzinn


Technical writer Lennard Zinn is a frame builder (www.zinncycles.com), a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides “Zinn and the Art of Mountain Bike Maintenance” – now available also on DVD, and “Zinn and the Art of Road Bike Maintenance,” as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.

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  • ruckuscomponents
    or if you are in the Portland area you can bring it straight to Ruckus Components without having to pay someone to tear down your bike.
  • RR Velo also does a lot of carbon frame repairs and repaints.
    Edgar Chavez from RR Velo was one of the main men over at Calfee before leaving to start on his own, he manufactured and repaired carbon frames for many years at Calfee before starting on his own togehter with "'Fast Freddy" Markham who held the world record for human powered vehicle hour record in 2006 (not to be mistken with roadbike sprinter "Fast Freddy" Rodriguez). Freddy Markham also worked for Calfee and designed and test rode the Calfee Stilleto Recumbent before Freddy Markham and Craig Calfee had quite a fallout: http://www.serotta.com/forum/showthread.php?t=999
    RR Velo is located only 15 miles from Calfee at Watsonville just south of Santa Cruz in California.
    RR Velo is said to be substantially less expensive than Calfee for frame repairs.
    http://www.roadrunnervelo.com
    [quote="RR Velo"]RR Velo has mastered the art of carbon construction. For over 14 years our carbon craftsmen have been manufacturing and repairing carbon fiber bicycles for other brands.
    ...
    we've repaired over 2,100 frames since 2003.[/quote]
  • KK
    My carbon frame had a major break in the chainstay and downtube. Calfee did a fantastic job repairing it at a very reasonable price. I'm tempted to say the frame is better than new. I didn't think it was repairable but they said no problem. They'd seen worse.
  • marko
    for those who dont realize it yet ,carbon makes a superior frame, people who enjoy efficiency can get it from carbon like no where else., and its not delicate not really , or it wouldnt be used by the aerospace ind. ,when you just have to have the strongest, it has to be carbon..period.,for longer rides or excursions i carry an epoxy repair kit, i can repair my carbon bike in less than an hour on the road,i can even repair a steel or aluminum frame using an epoxy / kevlar/carbon fiber repair kit. ,try carrying a welder with you !
  • marko
    i had to learn how to repair a carbon frame .after i got tired of looking at it hanging in the garage, two years later, i have now repaired and modified ( changed into across frame)10 carbon frames and more..mbgirod@gmail.com
  • Ray
    Stories like these fly in the face of internet myths about carbon not being fixable, or the other great myth, that steel frames are easily fixable. With a carbon fix, the fix is likely stronger than the original part, with steel, the fix cannot be as strong.
  • denisbrown2
    G'day Ray, steel lugged frames are reasonably easy to repair, just sweat out the old tube and replace with a suitably mitered new one.
  • Ray
    ...and it will never be a as strong as the original frame. You cannot reheat modern steel alloys without affecting strength.
  • Jim_Gillan
    it all depends on the steel alloy, and today there are more formulations available than ever before. The air hardening stuff will go back to where it came from, the old-school work hardened steels as well as the new fangled 'maraging' (martensitic structure with post production aging) like 953 require care.
  • How is the fix likely stronger than the original part?
  • Ray
    Read the article -they can actually make a frame stiffer if you want, or beef up the bottom bracket, because bottom brackets can never be beefy enough, apparently.
  • marko
    the fix can be as strong as you want or need..depending on how many layers added..
  • DirtyWorks
    I may be the odd rider out here who would much rather ride something that I can reasonably crash. I don't want a bike that needs another $200-$300 bucks in repairs when I crash a $4000 bike.

    Am I the odd man out now?
  • pete
    no you are not the odd man out. carbon fiber has its merits but as for me i will take titanium anyday. my 97 litespeed classic has over 60k miles on it with all types of riding. it has been crashed a few times. it is impermiable to any type of weather or abuse and is comfortable as all get out. it only takes a few minutes with scotchbrite and it looks like new. unbeatable as frame material.
  • Ray
    It sure is beatable, Ti frames have poor torsional stiffness relative to most carbon, and they are heavier, and far more expensive.
    They are also notorious for cracking (see EFBe testing) and galvanic corrosion with other metals. They had a brief heydey in the steel/aluminum era, but even good modern aluminum frames will outperform Ti.
  • Mike
    I have a friend who's Lightspeed cracked at the seat tube / top tube junction. And it wasn't from a crash.
  • Billy-goat Gruff
    Wow, pretty impressive. I'd show off the repair! Makes me more likely to worry less!
  • Mike
    Any thoughts or information with relation to original manufacturers warranty?
  • pjc
    had a pinarello paris with a cracked seat stay (hit by a car) repaired by calfee, they do good work. like putting a bike together, people seem afraid, but repairing carbon fiber isn't at all complicated. it a hollow tube made of layers of cloth (fiber) and epoxy--same basic technology as old airplane wings and surfboards.
    the repair can be made even stronger than the original tube, and any frame can be reinforced and stiffened with additional layers at strategic points.
    it's not really rocket science, and you can construct your own carbon fiber pieces very easily with a bit knowledge, though others would love you to believe otherwise.
    but when it comes to your dream bike, just breathe easy and use calfee or any other carbon frame maker.
  • stevescarich
    The best part of getting Craig to repair your bike is now you are riding a Calfee; well, sort of.

    Steve (proud owner of complete Calfee TetraPro)
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