Repair Scratches and Chips on Your Carbon/Aluminum Bicycle Frame

Disclosure: This article may link to affiliate sites/feature complimentary products for review purposes.
A slight scratch on my Cervelo top tube.
A slight, and difficult to photograph, scratch on my Cervelo top tube.

A slight scratch on my Cervelo top tube.
A slight scratch on my Cervelo top tube.

Yesterday, on a long ride with my best friend, I was having a bit of trouble with sore legs. So I decided to unclip and pull my foot up over my top tube to stretch it . . . I know, it’s starting off bad. As I slid it back down, happy with showing off, my cleat just scraped the edge of the top tube and put a set of dimpled scratches right into the red stripe of my carbon frame. Ignoring the lesson about being a show-off, I tried in desperation to buff the marks out with my fingers, but no luck. I learned something in the exchange: always keep your hand under your cleat when pulling such an awesome trick like stretching on the top tube. 😉

How do we repair small scratches and chips in our frames? First, do a close inspection of your bike–top to bottom–and look for cracks or deep scratches. If you see anything that looks a bit sketchy, take it into your local bike shop and ask the mechanic to take a look. He or she can make sure you don’t have any structural damage. It’s always best to make sure everything really is just cosmetic. If you do have serious damage, your frame can probably be fixed as well–simply ask your LBS for a local frame guru who can repair it.

Fixing That Scratch

Depending on the ferocity of your scratch, and the level of your resolve to repair it, you have a couple of options for getting that shine back.

First, you can take the easy route and simply cover the scratches with a clear coat to protect them. Some use high-quality, chip-free nail polish clear coat such as CND Speedy Clear Coat. Just paint a layer or two of the polish for a quick, easy, and no-effort protective coating for your carbon. You can also try to match the paint color in a high quality nail polish–so long as it’s enamel, it should work just fine. The difficult part here is getting the proper color match, and painting it without letting it glob up. I recommend using a better brush than the one in the polish bottle. If it looks rippled, you can use a very fine buffer to shine it up and smooth it out.

Read Also >>  Ride Safely in Traffic

If you feel a bit funny about putting nail polish gloss on your frame, you can also use Testor’s Glosscote spray, which is manufactured for model builders to seal in their decals and add a glossy shine. Before spraying the area, make sure you mask and cover everything you don’t want coated! You’ll be surprised at how wild this stuff can spray–and it can be tough to get off of places you didn’t intend on coating. Of course, your bike may not be a high-gloss finish–in which case, look at Testor’s other options in clear coats.
For Tougher Scratches/Chips

You’ll probably want to sand the area smooth before coating it with anything. Try wetsanding the area with a fine grit paper. If it’s a tough scratch, use a progression of rough to fine grit papers like 240, 400, and 600 on up to 1000 until you can’t feel the difference between the damaged and non-damaged areas.

It’s vital to keep everything clean! Make sure you don’t have residual dust, grit, or other things in the area you’re fixing.

Unless you’ve got a fairly large chip in the frame (in which case you’ll have to deal with primer and putty and stuff that’s beyond my experience-level), you should be able to get away with simply finding a matching paint. Go to your local automotive store and find the closest match you can find. With all sorts of colors of cars, they should have one that will blend in perfectly with your paint job.

Read Also >>  What Are Those Black Sticks Under Tour de France Rider's Saddles?

Fill in the missing paint area, let it dry and sand at your own discretion (in case you’ve got spots that need it), and you’re on to the clear coat. If you need to do any layers of paint before that, make sure to sand between each, and let them dry completely before adding the next coat. The key here is to get a smooth finish without having a noticeable shift between the fixed area and the original paint. You can use a nail buffer to get a really smooth finish on the top, then add another coat of clear gloss.

Et voila! Your bike should look back to normal. Make sure to let it dry completely–like for a week–before putting it through the wringer on a weather-torn day.


Tried this method and it worked well for you? Have some tips you’d like to add? Need clarification? Comment below!

Disclaimer: Complete all repairs at your own risk! I’m not responsible if you mess up your frame/bike/components/wheels using this method. Above all else, please be careful!

About Bek 301 Articles
SLO Cyclist's former chief editor and recovering road snob, Bek made sure everything ran smoothly around here. She was also the one who reminded us not to take ourselves too seriously--unless it involves black socks. Black socks are always serious.

1 Comment

  1. I’d just like to add, I have a matt/silk finish to my frame so clear gloss doesn’t cut it. (Tried it) I’ve found that really fine emery paper will take out scuffs and light scratches (nothing that’s down to the metal/alloy) then buff out with ‘T’Cut, works magic for my ride. If your a bit of a snob, perfection is attainable. I’ve had seamless repairs, but I do stress the emery paper has got be so fine it feels smooth to the touch. A little convoluted as a comment but wanted to pass on a tip I’ve used myself.

Leave a Reply

Your email address will not be published.


This site uses Akismet to reduce spam. Learn how your comment data is processed.