Unfortunately you are talking about the difference
between a steady state equation and a transient
equation (although vanagons generally = transients)

To maintain speed, you are actually *not*
accellerating, so your f=ma equation kind of falls
apart.  F= Cd * A * .5 * r * V^2 is more of what you
are looking at (air drag) and then some other more
cryptic drags that deal with rolling resistance,
drivetrain losses, etc. that don't really care about
the rotational component of wheel weight.  So
ultimately, assuming the net weight of your wheel is
the same, just heavier on the outside, you van doesn't
feel a thing cruising along at a steady 65mph.

-Damon

--- John Jensen <mudbug@TOAD.NET> wrote:
> What you say is true, but also consider: What we are
> talking about is
> acceleration (F=MA).  Without input of energy, the
> rolling tire is going
> to decelerate due to friction.  The energy required
> to maintain a given
> speed  is an acceleration and therefore is greater
> for a greater mass.
> IMHO.
>

=====
'84 Westy (Sparky)
'65 Kharma Ghia (Dharma)

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