Carbon Fibre Repair

Carbon Fibre problem

A couple of weeks before PBP I didn’t like a creak from the bottom bracket on my best bike, a 2016 Genesis Datum. I bought all the kit for changing the pressfit bottom bracket

However, when I took it apart I discovered that hiding behind the chainring was a fairly large hole in the carbon fibre. This was probably the reason for the creak. I immediately switched to prepping my spare bike – I rode PBP on the Specialized Roubaix instead

Why it happened

Probably some chain damage when the chain fell off on the frame side. Also the bolts on the inner chain ring were loose and it’s likely these made contact with the frame

Carbon Fibre fix

Once I had recovered from PBP I set about doing the carbon fibre repair. I already had epoxy putty and a basic carbon fibre repair kit. After doing a bit of research I also got some heat shink tape, a heat gun and a can of clear coat varnish

As the pictures below show the process I went through was

Fill the holes with epoxy putty, allow 24h to set

Sand down the epoxy putty and also remove paint near the hole

Mask off the area around the repair with electical tape and cling film

Clean with rubbing alcohol

Apply the 2 part hardener, wait for it to cure

Apply one layer of carbon fibre fabric

More 2 part hardener and another layer of carbon fibre fabric

Cover repair area with heat shink tape

Use heat gun on heat shrink tape

Wait 24h

Remove heat shrink tape

Sand down sharp points and irregularities

Mask repair area again

Clean with rubbing alcohol

Apply 3 layers of clear coat at 15 minute intervals

Wait 24h

Remove masking

stick on piece of old tin can with Sugru to protect area where damage occurred

chain rub plate from tin

The damage

epoxy putty

Epoxy Filler as it was done

filler sanded, masking for CF

after CF repair is set

applying clear coat

with clear coat

sugru to stick tin