[taeric]

Right, you can hit a higher velocity. You will not get extra acceleration. That is my entire point.

That is to say, the force from the air does not actively slow you down. It prevents you from speeding up, after a point. (Aerodynamics are, of course, more complicated. But this general model is pretty solid.)

Such that if I want to accelerate faster down the hill, I have to pedal to cause that to happen. Or add a motor.

[jstanley]

The heavier bike will reach the terminal velocity of the lighter bike sooner than the lighter bike will. If that's not extra acceleration then I don't think you're looking at the problem from a practical perspective.

Yes, acceleration due to gravity is the same, but air resistance has less effect, at all speeds, on the heavier bike. The rate at which the heavier bike gains speed is higher. It accelerates faster.

[taeric]

This is just disagreement over magnitude. And what it means to hit higher acceleration.

Take my statements to be, it won't hit a meaningful higher acceleration. Not that it won't necessarily accelerate for longer.

In general, you will accelerate down the hill at 9.8 m/s^2 modified by the incline. No matter how heavy the bike is. (Within the realm of realistic weights.).

Yes, the points you are raising are true. But within the realm of the biker and realistic bikes, not really relevant.

[SirLuxuryYacht]

The velocity of the bike+rider is proportional to their mass. Realistically this can range over two orders of magnitude, which can be particularly relevant in a racing context.

[taeric]

I'm intrigued. What are you saying here?

[jstanley]

It sounds like there could be a 100x difference between a light guy on a light bike and a heavy guy on a heavy bike. Sounds hard to believe, so I'm intrigued too :).

[quickthrower2]

Could be 4x if you use mini order of magnitudes, and if you include kids and adult body builders... there’s your 4x!