Bicycle cable rub
When I loaded my Giant Escape Disc onto the car rack the evening before a Big Sky Bike Ride with Chris in March I noticed how the brake cable outers had rubbed together and worn through to the wire spirals. I went on my touring bike instead. I've also had to change all the outer cables on Mrs Taylor's Peugeot Scorpion ATB (pictured above). Outer cables rubbing each other to pieces and scratching paint off bicycle frames is taken for granted I suppose, but a rub-free system seems an invention waiting to be invented.
My son's Boardman CompFS is only a few weeks old and already the head tube paint (a nice paint job) is scratched by the outer gear cables. The gear cable outers on my Giant have actually rubbed grooves into the suspension fork crown. My Ridgeback Panorama touring bike is now fitted with small pieces of plastic and rubber tube, plus self-adhesive patches, to protect the head tube paint. And my Peugeot Black Mamba looks a mess with the brake cable outers rubbing as well (click pics below to enlarge).
That's just the head tube. The outer cables on all of our road bikes have rubbed through the paint on the chain stays as they pass to the rear derailleur, except when more sticky patches have been put on. But eventually these patches wear through or slip out of place, then you have to clean up the mess of sticky residue on the paintwork before putting new ones on. 😡
I assume there is no solution to this. It seems one of the few weaknesses in the design of the bicycle. The other weakness is the tendency for the front wheel to swing round when the bike is leaned against something, causing the bike to crash to the ground (more scratches). If someone invented a simple device to steady the fork when the bike is stopped they would become very rich. But the device would need to be very simple and require no conscious action on the part of the cyclist. Bits of elastic that connect each side of the bars to the top tube would not be acceptable as they would rub off even more paint!