Carbon Bicycle Frame Repair

Road cycling’s new found popularity has many benefits and one of those is attracting some bright people into the industry who would perhaps have gone for something more glamorous in days gone by. Such a man is Rob Granville of Surrey Carbon Repair.

Before embarking on a successful music and media career, Rob’s background was in product design working with polymers for big, reputable brands like BMW and Coca Cola. Luckily for us, he discovered road cycling later in life and immediately fell in love with the sport.
Having taken up road cycling, his background in product design and his knowledge of the use of carbon was soon being tested as he discovered problems with his own frames and, his interest sparked, he quickly started to seek out solutions to other frame issues that he came across.

Carbon repair of serious fracture

Rob then took things a step further. His interest in the exact make-up of his own carbon bikes lead to him buying up second hand, crash damaged frames to see just what he could achieve in their repair. His background and knowledge of the way carbon is best employed gave him the confidence you need to repair a damaged, written-off frame and then speed down the road to test that repair – don’t try this at home!

Rob’s Cervelo P3 project, designed to show just what can be achieved with carbon frame repair
Rob’s ‘carbon knowledge’ eventually allowed him to buy and repair a written-off, crash damaged Bianchi Oltre for around £80 which he fixed and started riding around as his regular ride. Word soon got out and Rob was approached by a member of the local Dorking club who had trashed his Argon 18 frame. After a successful repair, it was from there that the Surrey Carbon Repair Shop was born.

Much of Rob’s motivation to create a business from repairing carbon frames then came from discovering a design fault with Cervelo dropouts found on 2010/2011 frames, which were simply too weak to do their job, especially for anyone fitting Campagnolo to their frame, as the Italian rear mechs apply more pulling forces to the hanger. These expensive frames needed a long-term solution to prevent it happening again, not just a repair, which after much trial and error Rob was able to offer.

Rebuilding the rear dropout from a 2011 Cervelo S5/R3 – this weak design was soon withdrawn by the manufacturer

Though actively involved in the repairs still, Rob now employs fabricators to do the bulk of the work. Rob has worked with kevlar, fibre glass and carbon extensively in his career. He is very confident that he knows how carbon behaves, how to employ compression, the different proportions of epoxy and resin to use, and so on.

And for Rob, carbon compression is the key to the manufacture of a quality frame. By performing carbon binding, manufacturers squeeze the epoxy out of the frame. He is keen to emphasise that it’s controlling the amount of epoxy that comes out that is essential to the quality of the frame, as epoxy is strong but is fragile, unlike the carbon fibres themselves which are flexible. If epoxy shatters it can cut those carbon fibres but at the same time it is essential for the integrity of the whole frame.

Rob is convinced that the manfacturers are simply squeezing more and more of the epoxy out of the frames to get the scarily light frame weights we see today. He is also not certain that this is the best way to go where longevity is concerned and so is wary of recommending the really lightweight frames ridden by the pros – who after all can replace damaged frames with new ones easily – to amateur club cyclists. He believes that most amateurs would be better off with more resilient carbon frames that are one or two models down from the top of the range; performance is not really compromised, yet the frames are tougher and will last longer.

Bianchi Infinito repair

Bianchi Infinito as good as new

Carbon is a great material for making bikes. It is also good at showing up any damage and will not hide cracks like aluminium or steel, making detection much easier after an impact. This includes if a carbon frame is painted, as the paint is much less flexible than the carbon it covers and should therefore crack first clearly showing any damage. Like a bone, a carbon tube can suffer a compression fracture, which typically shows up as lots of tiny hairline fractures and ‘rubbing marks’. Interestingly, with the modern superlight frame’s paint being an integral part of their structure, Rob recommends that if you suffer a chip from out of your frame’s paint, that you should cover it immediately, even if just with nail polish or something similar.

Continued overleaf…