when your frame flexes during riding the bb acts as pendulum and counter acts weight above it, making the bike seem a little lighter, this can be most felt when sprinting, more force on the pedals= more flex= more pendulum, and your arms are pumping on the bars, which now feel like they weigh less due to the pendulum effect.
when your frame flexes during riding the bb acts as pendulum and counter acts weight above it, making the bike seem a little lighter, this can be most felt when sprinting, more force on the pedals= more flex= more pendulum, and your arms are pumping on the bars, which now feel like they weigh less due to the pendulum effect.
the more you know, the further you go.