Dear Matt,

My partner's bike fell on my own shiny and much-loved bike the other day, resulting in an ugly paint chip down to the metal. Past attempts at repairing damage such as stone chips using modelling paint have never been very satisfactory. Is this a job for a professional or do you have any DIY tips?

Philip James, via email

The problem is that a bike frame is painted by spraying (or similar industrial process), so even if you could match the colour precisely, achieving a neat finish for a touch-up would be fiendishly difficult. If there is a risk of rust, it might be worth sealing the chip with a clear lacquer. But your only resort is the cyclist's traditional one of getting the whole frame resprayed every few years. It's not that expensive and it'll feel like a new bike.