On Fri, 11 Apr 1997 thomas_pokrefke@juno.com wrote:
> Don't forgot about the aerodynamic forces acting on the canoe at 55 mph.
> You'll probably have alternating up-forces and down-forces, all of which
> would probably kill your hard top. I don't think there is any room to
Something to keep in mind, whether carrying a canoe on an MG or lumber on
a toyota, is that front and rear tie downs dramatically reduce stress on
roof racks. If you put a 40 lb canoe on roof racks, there is only 20 lb
or so on each rack. If you tie the canoe to the *rack* and drive 50 mph,
there can be severe rocking motions (up and down and side to side) that
dramatically increase the loading. A triangular tie down from the front
and rear of the canoe to the outer ends of each bumper will prevent
this. The load on the racks then is just the weight of the canoe plus
the down force in the ropes (which need not be huge). Any other forces
are borne by the bumpers.
True, I did substitute "Major Religions of the West" for "Statics" in my
engineering program, but I read some on the side.
W. R. Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8629
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