Cyclo-therapy: How much have you thought about your posture and set-up? Getting it wrong can cause injury

It's over a year since I drove past a little bike shop in Sussex and popped in for some socks. About an hour later I had the socks. And a new pair of shoes. Oh, and a gleaming new roadbike worth £2,000. I've cherished my Trek Madone, with its blue carbon frame and wispy wheels, but last week I was reminded of the perils of the impulse buy – my companion over hundreds of miles is completely wrong for me.

That was the verdict of Phil Cavell at Cyclefit, a London bike shop dedicated to blurring the boundary between man and machine. How much have you thought about your posture and bike set-up? From the height of your seat to the length of your crank (bigger is not better), there's a lot that can be out of kilter. And getting it wrong can cause inefficiency and injury.

Phil's Covent Garden store is part-Savile Row atelier and part-Loughborough Uni sports lab. The science happens in the back room, where, after taking my inside leg, Phil watches me ride my Trek on a trainer. Turns out the frame's way too small, so my seat's very high, with a big drop to my bars. To reduce discomfort, I've shifted my saddle forwards but that's skewed my knee alignment.

Next I switch to the Sizecycle, an adjustable bike jig linked to a computer. Phil quickly determines the perfect set-up and, as he tinkers, my power readouts creep miraculously higher. The biggest spike comes when he tells me simply to stop slouching (to give my tight hamstrings more freedom). To help even more, Phil moulds hi-tech footbeds for my shoes, whose position on my pedals he also fine-tunes.

It's as hi-tech as it sounds and isn't cheap, but Cyclefit's service is an investment worth considering if you're serious about cycling (those footbeds are a revelation). For general tips on posture and bike set-up, whether you're a weekend warrior or occasional commuter, visit our cycling blog.

Meanwhile, I have a choice – order a custom frame (upwards of £2,000), or tweak my bike so it's as close as possible. I opt for the latter, which improves things, but there's only so much Phil can do with my ill-fitting frame. I leave dreaming of a bespoke bike – I've heard riding one gives the sensation that the machine is an extension of the body. But this time I'll think before reaching for my wallet.

s.usborne@independent.co.uk or see independent.co.uk/cyclotherapy