Marsh Jones wrote:

On a smaller scale, it breaks down somewhat. In bicycles, you aren't
moving enough fluid medium (air) to come near 'hull speed' - it's a
matter of how much power you can generate to make the bike go. My
"proof" is that while I can still briefly go 30MPH on the flat, I
can(used to) go 64MPH down a mountain. There is no 'hull speed'
limitation until a bike is moving faster than mere mortals dare tread.

On a bike, the force due to wind resistance increases with the square of the
velocity. Add to that the rolling and friction resistance and the overall
effect is pretty much the same as resistance felt by a boat in water. Take a
look at the drag versus velocity characteristics of a boat and note the somewhat
arbitrary point chosen for "hull speed". Try Marchaj's "Sailing Theory and
Practice" at your library. Then compare it to a graph of total resistance
versus velocity for a bike and see if you can find a meaningful difference.

If you want to see a kayak or canoe move faster than hull speed without a lot of
paddle effort, try surfing a big wave. That's just like riding a bike downhill.

Boats and bikes pretty much follow the same behavior. Both are moving in fluids
and whether air or water, the physics is the same.

So there's a short and possibly refutable summary of why drafting on a bike
can't directly be compared to drafting/riding in a boat.

I promise not to write about business if you stop making up physics. :-)

Mike