My bicycle has developed a squeak.It all started when I misjudged a pothole, the helpful road sign warned 'Temporary road surface' but 'Missing road surface' would have been more accurate.At first it was quite a little squeak, the kind you might confuse with a wren bopping about in the bushes, but now it has become so insistent I find myself pretending it's not me as people turn to stare. I must go to the bike shop, they'll sort it out.The Cycle Centre in Penzance is brilliant, everyone is friendly and helpful, they have endless patience with people like me who don't know their cartidges from their cassettes.When I first started going it was crowded into a tiny shop at the top of Bread Street, so small that there wasn't room for the bikes to have pedals.Now its old sail loft shop in New Street has bikes hanging like Christmas decorations from the roof and you can get anything from several thousand pounds worth of bike to a widget costing only a few pence (does anything still cost 'only a few pence?)