dhb R1 Shoes
If you want to get semi-serious about biking, be it on the road or mountain, I say the single best investment is a pair of proper shoes. Their lightweight and stiff soles combine with pedals and clip-in cleats (which screw to the soles of the shoes) to transfer every ounce of energy from leg to wheel, allowing you to go faster and farther more easily. Dhb's R1s, which have velcro straps and hard-wearing soles, are top-notch and great value entry-level shoes.
Where: Wiggle (www.wiggle.co.uk)
How much: £47