DIY Carbon Frame Repair

[ibwhaley96]

Never done my own carbon repair before and i have a small (2cm) crack in my top tube.

Whats the cheapest and most effective way to repair it myself?

[JWDR]

I am no carbon fiber repair expert in any way but what is the bikes purpose?

And why is this in production bikes?

[Heisenberg]

Do you like your face/teeth, or are you more fond of exorbitant reconstruction surgery bills?

If the latter, a sheet of fiber and some superglue. Done! If the former, call a reputable carbon repair shop (Calfee) and have it fixed. If you're not sleeving the damage, you're pretty much doing nothing.

[gavingould]

carbon repair is not for the home DIYer in my opinion, unless you already have extensive background in carbon fiber/composites... there is no cheap/effective way to repair it yourself.

send it to a professional, ie Calfee, Ruckus, etc.

[rice rocket]

It's cheap (maybe a dollar with of carbon and 10 cents in sandpaper, and a few pence in epoxy), and pretty simple if you know what you're doing.

Leave it to the pros if you're a wuss though. ;)

No but really, composites are simple. Search Youtube. Attempt at your own risk.

[Tony]

It's cheap (maybe a dollar with of carbon and 10 cents in sandpaper, and a few pence in epoxy), and pretty simple if you know what you're doing.

Leave it to the pros if you're a wuss though. ;)

No but really, composites are simple. Search Youtube. Attempt at your own risk.

I agree, I've built several composite kayaks and repaired many. This is not a difficult repair. You can also use S glass for the repair. It is transparent, very strong, and easier to work with. Like mentioned there is a lot of how to videos that will help you. Several things I would do is cut the fabric on the bi, this will make it easier to conform to the tube. Remove as much of the epoxy as possible, excess epoxy just adds weight. You can do this by using a air filled bladder laid on top of the repair and taped down to squeeze the fabric tight against the damaged area while it cures, heat will speed up the curing process of the epoxy

[carpediemracing]

I haven't worked with carbon but I have worked with fiberglass. Both are fiber reinforced composites/plastics. The principles are the same but the carbon is so much stronger that you can really reduce the amount of material and still have sufficient strength.

I know two racers that have made repairs on their own frames (Tarmac and a Scott something). Neither are "trained" in carbon. I know one part-time racer that installed an electric motor (a la Cancellara) in a Cervelo, including cutting the frame open and then closing it back up. I think that guy used to be in motorsports so he has some experience with stuff like that. All those fixes have been reliable for at least a couple years. The two homemade patches are not pretty but they work. The Tarmac frame was in pieces at one point so the fact that the bike works at all is pretty amazing. The motor one you can't tell it has been opened up (I guess that was the point).

If it was a fork, bars, rim I wouldn't chance it, even to if a pro did it. Top tube crack, well, do it but I'd overbuild it if it were something I was going to ride.

Or ante up the few hundred dollars and have a pro do it.

[Saint Vitus]

Do you like your face/teeth, or are you more fond of exorbitant reconstruction surgery bills?



Maybe the OP is able to perform DIY maxilliofacial procedures, so DIY CF repair is just up his alley?

[texbike]

There's a local guy that I bump into regularly that has an old, beat-to-crap C40. About 5 years ago he cracked one of the seat-stays and decided to repair it himself to get him through until he found another frame.

I saw him out on a ride last week and he's still riding the bike.

Of course, that's a seatstay. I'm not sure that I'd roll the dice on a top tube like that.

Texbike

[bigreen505]

Youtube is your friend and attempt at your own risk. Lots of good info here. Use a good quality resin like West 105/206. Sand the area down a couple inches beyond the crack. Clean with acetone or alcohol. Fill the crack with resin and possibly some filler depending on the size. Cut your carbon and make sure it will lay up properly. Wet it out before you put it on the bike. I don't know what a professional repair costs, but you will probably spend close to $100 if you don't have any carbon, resin or tools.

[Tony]

I can understand the hesitance being the top tube. However, if one didn't care about a little additional weight this repaired tube could easily be as as strong, if not stronger depending on how much material is added in the appropriate areas of the tube. The west systems epoxy mentioned is good. You can purchase a small amount in a kit form to do this repair, $17.00 - $40.00 Tap Plastic http://www.tapplastics.com/ is a good source for material.

epoxy kit
http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?productId=15002&catalogId=10001&langId=-1&storeId=11151&storeNum=50218&subdeptNum=50219&classNum=50220#.UnE261PJz90

[nicrump]

key things to know are being sure your patch is being applied to bare carbon and not paint, primer or clear as it will not bond correctly to those substrates.

second is to use a proper laminating epoxy and not some home center 5 minute crap.

something as simple as that crack, sand off all the paint/clear past the damage in all directions by a ratio of say 1/2 distance of the largest damaged area, you know you are in bare carbon when the dust is black(assuming you are not sanding black paint DOH!)

clean it all well with acetone. scuff again with ~ 120grit, acetone wipe again. once you have laid on a few layers of whatever wetted out carbon you chose(less is more on the epoxy) just compact the bloody thing with electrical tape and let is set you a day or so.

there are a couple pretty good tutorials on youtube.

IMO the top center of the top tube is no big deal.