I'm wondering how many people with carbon frames have had problems with cracks. And if so, what caused them?
I bought a Madone 4.7 WSD back in October 2010. Just over a year later, I discovered a crack in the top tube while I was cleaning the bike. I have no idea what caused it -- I've never crashed, I haven't dropped the bike or knocked it over or dropped anything on it. There has been no significant impact to the frame.
The LBS manager sent it to Trek, where they looked at it, scratched off a bit of paint at the end of the crack, and said they thought it was most likely caused by an impact (and therefore not covered by their warranty). In order to give me a definitive answer, they said they would have to cut off the top tube to look inside. After doing the math to determine the cost of buying a new frame under their replacement discount program (20% off) vs having the crack repaired, I asked the LBS manager to tell Trek to just return the bike to the shop so we could send it off to Calfee for repair.
I'm still waiting to get it back -- apparently Calfee has finished their work and it's in transit now.
I know carbon fiber can be very strong. But now I'm starting to wonder about the strength of mass-produced bike frames. Has anyone else had damage that was not caused by an obvious strong impact to the frame? Is this a fairly common problem or did I just get a lemon?
BTW the cost estimates were ~$1200 for a new frame, including replacing a few components that attach differently to a 2012 frame vs the 2010 model, vs < $400 for Calfee to repair the top tube and paint it gray to match the rest of the bike. For an extra $75 they would have repainted the Trek logo on it along with a white stripe that was part of the original design (but was actually painted off-center), but I saw no reason to pay extra for that.
by Chad Grochowina
Carbon fibre is no longer the exotic material that it once was. The cycling industry has embraced its use with open arms and manufactures almost everything with it these days. With proper care, a carbon fibre bike with carbon parts can be a dream to ride and last a long time. When used for how it’s intended, carbon fibre has the upper hand in performance for most situations. Yes, it does occasionally break, and not all carbon fibre is created equal, but no other material can be manipulated the way carbon can. One thing that does ring true with all carbon components: they need to be inspected routinely for cracks or damage.
- Mar 03, 2020 While it is another useful tool for a proper carbon fiber facility, because of the thin materials used on all bike frames and components, you can most likely visually see any cracks developing if.
- In fact, carbon fiber is one of the most repairable materials and each Appleman repair is covered by a 10 year warranty! Repairs add no measurable weight and don’t alter the ride of the bike.
You should inspect your bike after every wash, after a creak develops, and definitely after a crash. Look closely for scratches, especially anything deep or through the paint. With a dollar coin, tap on any suspect area and listen for a change in sound. A normal “tap” sound will become a dull thud when the carbon is broken. Gently push on the suspect area to feel if it’s softer than the surrounding area. For dual-suspension mountain bikes, in addition to the regular frame inspection, look for cracks around pivots and bearings. Also check underneath the down tube for impact cracks, commonly caused by rocks flying up and smacking the down tube.
What you’ll see is some small dots of resin passing through the perforated film. This is excess resin of the saturated carbonfiber cloth that is being absorbed by the breeder. Check for leaks, once you have full vacuum let the pump on for 15min than clamp of the hose and shut down the pump.
“After a crash, a shifter that rotates on the bar can eat into it, and even saw through it over time.”
Once a season, you should perform a more thorough inspection. If your bike has taken a hard hit or been involved in a crash, a good check over is imperative to ensure your safety. Pull out your seatpost and look for cracks around the clamping area. Remove your bar tape, and inspect around the shifter clamps for any scoring or scratching. After a crash, a shifter that rotates on the bar can eat into it, and even saw through it over time. The same is true for mountain bikes as shifters and brake levers often spin on the bar in a crash. Remove the bar from the stem, and inspect the clamping area for any cracks or blemishes.
Tell If Carbon Fiber Bike Cracked Windshield
If your fork is made with a carbon steerer tube, a seasonal inspection is a must. Again, look for scoring or scratching around the steerer. This procedure is even more important if you’ve been riding with a loose headset, which can cut its way through a steerer.
If you have carbon wheels, they deserve a look, too. If they are still spinning true and the spoke tension feels even, they are most likely OK. Wheels that come out of true from a crash or hard impact need to have an experienced wheel builder look at them. There are a number of things that can go wrong that aren’t necessarily obvious to the untrained eye.
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As with steel, titanium, and aluminum, carbon fibre repair is commonplace these days. Abby cadabby svg file. Repairs are usually reasonably priced (that is, much cheaper then a crashreplacement price offered from many manufacturers). If the repair receives some paint, you’ll never know that it was ever broken. (That does open up a whole other can of worms in the used bike marketplace, but that’s another story.) Your favourite bike shop should be able to steer you in the right direction for getting your frame repaired.