HOW TO SPOT A CARBON FRACTURE

Carbon is incredibly honest material. It’s best to compare to an egg. It’s primary function is to hold shape under high pressure. It doesn’t like hard or focussed objects on one point otherwise, like an egg, it will fracture and you will know about it!

If you have had a crash and you are wondering whether the bike is ok, simply look for signs of paint cracking. It is not common for carbon to crack under the paint without it showing somewhere, however it can travel under the paint from a fracture.

If you have had a graze and the carbon is showing bare, press to see if there is any movement or get it checked out. Don’t leave it bare!

I will address the issue of bike paint in my next rant…

TEAM SKY DOGMA BRAKE ARCH FRACTURE

The frame hit the deck and the bulge on the rear brake arch got crushed. Rider safety is important in all repairs, no more so then the braking areas. Bike back in commission and being re-built for more punishment!

PINARELLO CHAIN STAY FRACTURE

Customer said this crack appeared one day and couldn’t understand when it occurred. You can see clearly the old bond line of the BB lug connected to the chain-stay tube after grind out. Sometimes on ‘Monday’ bikes this can be where a crack in the paint shows a fault inside. As it turned out there where cracks either side of the join so I sorted that out to re-instate the stiffness back into the stays.

GIANT TCR SEATSTAY FRACTURE

The only reason I am showing this 1 example of the many seat/ chain stay repairs I do every day is that occasionally I will have a go at re-enstating the graphics. It’s good practice for me and the bike looks better for it.

FONDRIEST SEAT POST REPAIR

A poor design from a great bike company. The seat post bolt hole was far to big with not enough shoulder to stop a potential pull-through. I had to bore out what was left and re-build the area with my special CF/Colloidal paste. Job done. Happy customer.

CUSTOM VITUS 992 10 speed

Occasionally I will turn my hand to other materials such as aluminium and leather…OK there is some carbon in there as well. I looked like a blacksmith at the end but absolutely worth it!

CBR GOES INSIDE!

We can now go right inside the frame with a video scope! This will save on a lot of un-necessary cutting away of good carbon, something I hate seeing in CF repairs. More importantly we should be able to find the exact source of the fractures to ensure we get them all.

This month has been epic with all sorts of summer ‘breaks’ and de-laminations. Thanks again for trusting CBR with your precious bikes!

Rob

ARGON 18 MULTI FRACTURES

This poor TT bike came 2nd best to the tarmac. Especially the down tube, end bar and Zipp disc. The down tube fracture was extensive and took some work to re-build and profile but it came out perfectly in the end and saved on a replacement frame now out of warranty.

ZIPP 808 DISK PUNCTURE

As part of a larger bike repair this rear 808 disk needed to be repaired to ensure no de-lamination would occur at high speeds. The Zipp texture is interesting, at first I thought it was a fabric coat over the CF but it turns out that it’s only a mold texture. I think it adds additional structural stability across the surface and golf ball air resistance maybe? Anyway I applied a patch and profiled it as close as possible without damaging the surrounding surface.

COSMIC CARBONE SLR CRACKED RIM

This front wheel hit a pot hole and the customer was hoping this could be repaired considering the cost of such a tub. With a profiler to ensure the repair set true he now has his beloved wheel back and ready for a trip up the Alps before summer is out