Engineers Advice on Pantours

Not an engineer here, but I'll take a shot. Any real engineer types, please feel free to
contradict me.

I'd say aft of perpendicular (which is indeed what Pantour recommends).

Here's why:

The bike is moving forward as the wheel strikes a bump. So if you add up the vectors (you do
remember those, right?) you get the bump imparting a rearward force (opposite the direction of
travel) plus an upward force due to the height of the bump. The resulting force points up and aft at
some angle which probably depends on the speed of the bike and the stiffness of the elastomer.

So, logically...if she weighs the same as a duck...she's made of wood...

(sorry, wrong movie).

Logically, if the force is pointing up and aft, then that's the axis along which the suspension
should move.

There's also the fact that the fork and frame flex (lock your front brake and move the bike fore and
aft to see how much flex there is...you might be surprised), but I'm not even remotely qualified to
consider the effect that might have.

In article said:

Any of you engineering types .....

On my Pantour hubs I can adjust the angle of deflection. In order to attain the softest ride do I
want the deflection directed:

A) Perpendicular to the ground

B) Slightly rearward of perpendicular (this SEEMS to be what Pantour advises)

C) Parallel to fork

D) Directed toward the seat or
E) Some other direction??

Andrew Douglas <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Not an engineer here, but I'll take a shot. Any real engineer types, please feel free to
contradict me.

I'd say aft of perpendicular (which is indeed what Pantour recommends).

Here's why:

The bike is moving forward as the wheel strikes a bump. So if you add up the vectors (you do
remember those, right?) you get the bump imparting a rearward force (opposite the direction of
travel) plus an upward force due to the height of the bump. The resulting force points up and aft
at some angle which probably depends on the speed of the bike and the stiffness of the elastomer.

So, logically...if she weighs the same as a duck...she's made of wood...

(sorry, wrong movie).

Logically, if the force is pointing up and aft, then that's the axis along which the suspension
should move.

That was my original inclination as well. But does it matter that what I wish to minimize is force
to the seat, as opposed to force to the dropout? .... in other words, does it matter how the force
is transferred from hub to seat .... or am I overthinking this?

It would be really nice if one could change angle of deflection much as the optometrist changes
lenses to optimize clarity .... "#1 or #2? .. now #1 or #2?", but of course a trial, followed by the
15 minutes or so it takes to change the deflection angle, followed by another trial, is much less
conducive to the trial and error approach.

Can you tell the weather is pretty bad for riding in northern IN (too much analysis/too
little cycling)?

A side note FWIW .... just had opportunity to have a "product support" discussion with the good
people at Pantour. After a couple of emails went disappointingly ignored, I got on the phone and, as
usual, found
Mr. Lund extremely helpful and accomodating ... like I said these are truly "GOOD people".

DeVon

I do believe you might be overthinking it. Consider that the resultant vector's direction should
change with velocity of the wheel.