Let’s face it, accidents happen. Even if you have one of the nicest production carbon fiber bike frames in existence, impact damage can still break your frame. That is exactly the case with this Trek Emonda SLR; impact damage busted the chainstay a few inches up from the dropout, so our customer sent it to us for a quick repair.
As you can see by the damage, our customer did luck out a bit: if the damage was even an inch closer to the dropout it most likely would have needed a dropout replacement. However, we ultrasound scanned the damaged area on the chainstay to see how far the damage radiated, and we found no signs of delamination or impact damage that would have otherwise compromised the integrity of the dropout. So, first things first, we sent the frame to our custom wet-sanding booths so we could safely remove all of the damaged carbon fiber.
Damage removal is a delicate art, for you want to remove the exact amount of material you need to without removing too much of the surrounding carbon. This is yet another reason that we ultrasound scan damaged areas on frames, that way we are able to know with almost exacting precision the amount of damage we need to remove from the frame. So we sand, check the frame, sand and check again. One it’s exactly where we need it to be, we push it through the layup process.
The image above shows that we needed to remove about five layers of carbon fiber to correctly isolate the chainstay damage. We went to recreate the original layup based on our scans of the opposite, non-damaged chainstay, and after we did that it went back through the wet-sanding and painting processes. We personally love a flat black paint with gloss black decals, and we did a beautiful job on this restoration.
All said and done, we especially love these Trek Emonda frames and they are one of the pinnacles of modern carbon fiber production methods. We were more than happy to return this to our customer looking like a new bike. Don’t let your busted carbon frames sit sadly in the garage, send them to us for a reNEWed bike day.