Bicycle Mechanics - Do I have a Cracked Frame
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Hi I recently bought a Kestrel Talon SL 2010 about 5 months ago, with an estimated mileage of 2000, so its fairly new.
While I was lubing my bike, I noticed a really thin absolutely straight line run across my drivetrain side chainstay.
I was wondering whether this was an intentional manufacturing detail, or a I pray not a cracked frame. :(
I just bought this bike really recently, so I'm very worried.
Here are two pictures I took, sorry for the bad quality, its the best camera I could find.
(I noticed all the thin lines you see are all connected, and are hairline straight, except for the curves you see, if that helps in anyway)
10-21-10, 11:41 PM
Looks too straight to be cracked. Cracking would have irregular lines going in every which direction. I think it is fine, but I'm no expert in carbon fiber.
It doesn't look like this: http://www.bustedcarbon.com/2008/12/cracked-frame.html
10-21-10, 11:51 PM
Egde of chainstay protector?
10-22-10, 02:15 AM
Looks like a scratch to me. To see if it is structural take your thumbs next to the crack and see if you can flex the crack of the carbon or get the crack to move, if notthe frame is fine. If it does flex then there is probably a crack and you can get that fixed through Calfee Design, And I have seen there work and it is excellent. Good luck
10-22-10, 08:15 AM
The lay of the carbon in the second picture and looks like a scratch in the 1st one to the right.
10-22-10, 09:20 PM
if it is cracked and 5 months old it should still be under warranty. take it in to have a professional check it out if you are in doubt. just my 2 cents.
10-23-10, 12:48 AM
It's not a crack, which is evident in the picture 531phile posted. Cracks have chipped clearcoat (top layer of resin) and frayed edges with fibres poking everywhere.
What you see in your photos is an artifact of production methods. The real structural part of the frame is not visible and is composed of multiple layers of unidirectional carbon-fibre. The final layer on top is mainly a cosmetic weave for the carbon-fibre "look". This weave comes in flat sheets like fabric. It's cut to a particular pattern (like a dress) that fits around the frame evenly. To fit flat sheets around round and curved parts requires elaborate cutting to make all the pieces fit with uniform coverage. Even then, there are still edges and overlaps. What you see there is a seam where two edges meet. If you feel it, it should be perfectly smooth due to the frame being compressed into a mould.
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