How much force on each pole?

I was recently talking with a fla****er/seakayak coach friend. He said
that canoes have hullspeeds of about 5 pounds resistance. So that if
you paddle with about 5 pounds of force the boat goes at maximum speed.
No amount of human force will make a boat go much faster. He said that
paddle-racing is mostly a matter of negativity: he who makes the least
mistakes wins. Everyone can readily get a hull up to its speed. Keeping
it there thru the whole course is the trick.

He also said that he thought that about 7 pounds per pull would be
about all that a human could do for 60 strokes rapidly. ...And that a
carbon paddle would break at about 15 pounds force.

Now, he was speaking off the cuff to an extent, but still. They were
surprising ideas to me.

So... How much force are we really putting into ski poles with each
stroke?

Offhand, I'd think it to be about the same as paddling: maybe 5-10 lbs.
?

--JP
outyourbackdoor.com

Jeff - those forces sound pretty low to me. Just imagine yourself with
cables on a gym machine. 5 lbs. of force down through your hand would
be enough to balance a 5 lb plate on the machine: not much. Imagine
yourself with a pair of cables pulling down in a swimming/pole thrust
kind of motion; I think 15 or twenty pounds of weight on each hand
should be sustainable at a comfortable poling rhythm and the forces
coming from your hand are even greater than the weight as you are
accelerating the plate up, not just in static balance.

Chris

j
So... How much force are we really putting into ski poles with each
stroke?

Offhand, I'd think it to be about the same as paddling: maybe 5-10 lbs.
?

No way. I have some Exel carbon poles and skating hard up steep hills,
they will flex/bow outward/backward as much as 12 inches. I have yet to
use an aluminum pole that does not get bent on it's maiden voyage.
That's way more than 5-10lbs. Maybe 50 or more. Classic double poling
isn't as much, but I can still get good flex even with the load
distributed to 2 poles at once.

Maybe the force limit in paddling has more to do with cavitation than
physiological limits.

Joseph

OK, so we think we put a lot more than 5-10 lbs into our poling... : )

My coach pal says to try putting like 15 lbs onto plates at the gym and
snap those puppies up and down however you like---with true XC
cadence---say, 50 times and see what happens. : )

C'mon, someone try and report back!

--JP

3 sets with one pulley high and one low, using handles pull/push one
down diagonally and other to me, alternating sides, starting at 40 lbs
warmup to 60 lbs, sets 15-30 reps. Actually snapping faster than ski
poling. Good for core. Or poling-like pull-downs on single pulley with
rope or curled bar, 40-60 lbs, up to 50 reps. Or an exercise no longer
done, on a regular gym machine pulling down bar underhand seated
(like chins) or overhand pull-downs standing, 60-80 lbs. Weight
on all limited by shoulder concerns.

RM

"jeff potter" wrote:

OK, so we think we put a lot more than 5-10 lbs into our poling... : )

My coach pal says to try putting like 15 lbs onto plates at the gym and
snap those puppies up and down however you like---with true XC
cadence---say, 50 times and see what happens. : )

C'mon, someone try and report back!

--JP

jeff potter wrote:
OK, so we think we put a lot more than 5-10 lbs into our poling... : )

My coach pal says to try putting like 15 lbs onto plates at the gym and
snap those puppies up and down however you like---with true XC
cadence---say, 50 times and see what happens. : )

C'mon, someone try and report back!

--JP

I don't have access to any fancy contraptions, so I tried to mimic the
effect using dumbells. Not ideal. Standing and swinging the arms back
and forth and the forces are all wrong. Lying on a sit-up board head
down, swinging arms upward to use gravity to mimic poling was a little
more realistic, but still more taxing than poling IMO. I tried with
10kg on each side. A bit tiresome, but I could do that all day, even in
my current weakend state!

Joseph

Offhand, I'd think it to be about the same as paddling: maybe 5-10 lbs.

I'd think about 4-5 times higher. And I'd estimate paddling forces as
being higher than 5-10 lbs (2-5 kg) too.
Check http://biomekanikk.nih.no/xchandbook/ski2.html
And you can figure out for yourself : put the tip of your pole on the
bathroom scale (better on the wooden brick on top of it so that not to
damage your scale) and press with about the same force you use on skis.

Hmmm, I wonder why this coach guy thought differently? Maybe he wasn't
being as scientific as I thought, but it seemed like he was checking
data. Still, maybe his own tests were off. But I thought it was
something he'd looked into, etc., or knew about. Oh well! Maybe more on
this later, if I can get some expert clarification. So much for that!
: ) --JP

Jeff - perhaps this coach was mixing units and was referrring to the
forces on the paddle per square inch or centimeter.

Chris

Jeff, perhaps you could speak with this paddling coach and figure out
what he means by "hullspeeds of about 5 lbs resistance". If he means
that the water offers 5 lbs of resistance, then the analysis is way
wrong. If this is the case, 5 lbs of force would be the minimum for
the boat to overcome friction and actually move forward. I think some
clarification about his wording might bring some light to this thread.
I'm also curious about what he said about 15 lbs breaking a carbon
paddle. I think this is way wrong. If anyone is curious enough they
could take a carbon paddle, set it handle side on a desk, about 1/3
supported and hang 15 lbs from the paddle side. I would be very
surprised if it broke.