How to Repair a Carbon Bicycle Frame

Many riders choose a carbon bicycle because of its lightweight frame,
which makes for easier toting, climbing and control while on trail, road or course.
However, carbon fiber bikes cost more than an average bike and can be less durable than their metal counterparts.
That leads to a problem for many cyclists because a damaged carbon bike frame could mean
spending big bucks to repair to avoid losing it to the garbage pile.

Instructions

1. Prepare the damaged area for work. Use sandpaper to remove any pieces of fiberglass exposed
because of damage as well as removing anything else that could prevent a patch adhering on the frame,
such as decals or dirt. Apply filler putty to the damaged area or hole in the frame. Allow the putty to dry.

2. Sand the hardened putty and the area immediately surrounding the damage to create a level,
porous surface the size of your fiberglass patch. Sand down the dried putty so that it is even with the surrounding frame area.

3. Cut the fiberglass patches into pieces big enough to fit over the damaged area as well as the surround undamaged area.
The larger the area of damage, the more patches required.
Typically, though, three to four patches should do. More than that, and the bike might be beyond fixing.
A pair of heavy-duty scissors or a box cutter will cut the patches easily.

4. Apply an epoxy resin (follow preparation directions on its packaging) to the frame only.
Attach the patches to the frame. Apply pressure to the patched area
for the drying period -- usually about 30 minutes -- using a compress such as
tape with pin holes in it held to the spot. The pin holes allow excess resin to escape.

5. Remove the compress once the epoxy has dried and sand the surface to remove excess material until the area is smooth.