Deep down, most of us know it's the riders legs not the bike. When British Doc Jeremy Groves upgraded his $50, 30-pound steel commuter clunker to a $1560, 21-pound carbon beauty, he didn't feel like he was riding that much faster. So, he set off on a test. Just published in British Medical Journal this week, he completed a randomized trial. He alternated the two steeds on 26 commutes covering 711 miles. The result: he was equally fast on both bikes. Considering gravity, friction aka rolling resistance, and drag, the 30% reduction in bike weight--which translated to 4% bike+rider weight--made nary a difference in commute time. Incidently, the author preferred the character and comfort of the steel commuter, in addition to its value. Dr. Grove's conclusion: bike commuters may look at weight reduction of the cyclist, rather than the bike, to improve preformance at a much reduced cost.