Originally Posted by
Drew Eckhardt
Climbing speed is inversely proportional to total weight.
Assuming you weigh 70kg, dropping that 2.5 kg of bike weight will make speed 80.5 / 78 kg = 1.032 times what it was before; or save 2.5/80.5 x 3600 = 112 seconds per hour.
Just noting that while the gravity term will dominate, there will be rolling friction and air friction terms when climbing. If I climb a 5% grade at 12 mph, the gravity term will be about 250-260W and the other terms will be about 60W. The weight difference would make a proportional change in the gravity term but not affect the other terms.
Otto