Basic Physics of Surfing -

General Discussion
21

Hey Jeff - Inertia is a body’s tendency to stay at rest or to continue at a particular velocity…longboards have more because they’re heavier - you’re right.

BUT the reason for them being easier to paddle is because of their length and buoyancy. (It’s to do with the bow wave you create as you move through the water - google it!)

Having said that - I know what you mean about longboarders being able to pick up momentum and catch waves.

Burnsie - how are you dealing with your rotator cuff prolems? - I’ve got some developing of my own.

22

I’m glad you asked me that, as I just discovered the solution!

I had to give up swimming 12 months ago due to the problem, it didnt impact surfing too much if I kept my back arched and so ensuring my paddle stroke starts below shoulder level. But in general terms I had pain if I extend my arm and raise it above shoulder level. I discovered the rotator cuff video in video stream below and after 2 weeks of the exercise the pain is almost gone away. I intend to start the circuit next week when I have recovered from the flu.

Enjoy

Laird Hamilton Circuit

23

Silverback, with respect to your comment that a longer board will paddle faster than a short one, I believe that doesn’t hold true in all situations. A longboard will paddle faster than a shortboard, no question. But a shortboard seems to paddle better than a funboard (defined for these purposes as a board a foot longer than the surfer) because, since they’re both mostly submerged when paddling, the shorter board serves to improve the streamlining of the board+surfer object in the water, and the longer board just adds more surface area and resistance.

Since it’s not possible to get to planing speed paddling a shortboard, the boards either act as a submarine object attached to you which adds to your drag or as a plate which smooths out you bottom profile.

That’s my take. My 6’4" fish and 6’10" quad both outpaddle a 7’2" thruster I have that feels like I’m dragging a gallon of paint around when I paddle it.

24

Monshine and Silverback,

I agree with you in part. However, if we consider two boards with different lenght but the same flotation (if possible), for instance, a thinner longboard and a fat shortboard in a paddle race test, how could be the possible result? Cold rocker take a major role in this case than floatation as a factor to determine the results? I know we have to consider every surfer+board pound is divided by every squared inch of the bottom area, and then we have viscosity playing its role, too.

25

I just know that my 23" wide, 6’2", 38 liter volume kneeboards are an effort to paddle in flat water but they catch waves well and go veerry fast (assuming you believe top to bottom surfing is faster than a straight line).

I can’t believe how easy 18" wide, 6’2", 30 liter (standup) boards are to paddle (the rockers are too close to bother calling difference) (and submarining - just cruise along the bottom!)

There’s more to it than length and volume - it’s hard work pushing a curvey outline through the water.

26

i like a board i can run people over without getting any damage and one that facillitates easy over shoulder glances to see if anyone saw the cutback i just did . it must look good in the carpak and have as many different design variables incorporated so i can discuss/show how knowledgeable i am about board design

27
Quote:

Hey SF

long time no talk huh :slight_smile:

these threads are fun they are really good for expressing ideas to the masses, and you learn a crap load too!

I havent posted too much as Ive been retrenched from work, moved interstate, missus left, shoulder reconstruction and moved into a low level care government ‘home’. But true to form, surfing is still the best thing in my life, even if I have to do it prone.

Surfing is my saviour.

As for basic principles of design , heres a few…

cant increases volatility,

moving fins forward makes a board looser,

moving fins closer together makes a board looser,

thinner rails makes a board looser,

smaller fins makes a board looser,

less base, height and rake on fins makes a board looser,

increased thickness makes a board looser,

increased rocker makes a board looser,

increased Vee makes a board looser,

less width makes a board looser,

increased planshape curve makes a board looser,

less length makes a board looser.

I think these are all basic concepts that shapers can agree on, all things being equal, of course.