Racking Your Board? Traditional or Aero?

General Discussion
1

Ok peeps, I have been dogged by so many old timers out there about the way I rack my board on my car. I have my fins towards the back because I think it causes less stress on the straps and on the board, because its more areodynamic. My friend “Unc D,” is always knockin my chops about it because he says the fins should be towards the front of the car. We argue about it all the time. Here is my reasoning:

  1. If wind catches the fins at 60 - 70 mph with the fins up front, it will push the fins in off-center to the left or right causing pressure on the board where the straps are. Continuous pressure will cause weak spots on the board, maybe even creating a crease over time.

  2. The space shutte in transport on a B747 has the fins towards the back of the plane. Shouldn’t it be the same for a board on a car?

Tell me what you think and why… Traditional or Areodynamic?

2

The way I see it is, depending on the angle of attack your racks hold the board at, most surfboards would act like a crude wing if placed fins back.

This would tend to try and lift the board off the rack and induce stress at the strap lines.

By placing it Fin forward the board should be less “lifty” if that’s a word.

I’ve always gone fin first, it just looks wrong the other way.

We need to find someone with a CFD analysis tool to flow test rocker templates in various positions and really see what’s going on.

3

Jeeeze, where have you two been? Everyone knows its fins back if you are from Orange County and fins up if you’re from anywhere else…

4

I always rack’m fins first. It’s how I was taught. Common sense says there would be more stress on the strap points if nose first as the wind would be pushing down on the entry rocker.

What about carrying a short board? When I did shortboard, the COOL way was fins first. Now it seems they are always carried nose first. When did this way important change take place?

5

I’ve found that when walking into the wind after a drifty session if you carry your board fins forward you will notice alot less resistance versus carrying it fins back,so fins forward on the car.I put my shortboard in the front seat of my truck,longboard rides in the bed if thats what I take.

6

THANK YOU JESUS!

7

Holy $h!t, a topic I actually know something about.

Nose forward and down - the board will act like an aerofoil, as previously stated, which will create lift - trying to remove surfboard from roof of car, and create drag - increasing fuel consumption. The fins will act just as they do in the water, creating lift - and drag - if they achieve an angle of attack due to swirling vortexes created by the car itself or by engaging in high speed cornering (boy racer?).

Nose rearward and down - the board is pure profile (parasite) drag creating no lift. The fins are not foiled in this orientation and cannot create and lift but will contribute to profile drag as well.

Nose forward and up - dumbass.

Nose rearward and up - see above, but not quite so much.

The shuttle rides piggyback on the Jumbo facing forward because it has foils (wings) that create lift so why not use them to help offset the weight of the shuttle? Neither the wings or the stabilizer (big sticky up bit at the back) of the shuttle were designed, built, tested or certified to fly backwards and I can only imagine the damage if it were tried.

If you’re thinking that the logic dictates that nose forward and up will create lift downwards, towards the roof of the car, helping to keep the board attached to the racks, sorry, the airflow is disturbed by the windshield of the car and will also stagnate because it cannot smoothly flow between the board and the roof. The racks themselves will also break up the airflow and prevent lift from being created.

Oddly enough, being born and raised on the Texas Gulf Coast (where the surf depends on the size of the last oil tanker that went by) boards always went nose rearward and down. I now live in the British Channel Islands where here, and in the UK, it would seem odd to not go with the nose forward and down (aerodynamic??) approach. Bizarre.

At the end of the day, does it really matter? How many of us have lost a board off of the roof? You’re just as well to go with the UK/Orange county - fins back, everywhere else fins forward theory.

Half-assed surfer, half-decent pilot.

Good night.

Buter

8

HIJACK ALERT HIJACK ALERT…

In the olden days there were two rules; carry the board so the wax didn’t rub off on your shirt, keep that big ol’ slab fin in front of you so you could see where it was at all times (long boards, big dangerous swinging arcs).

Well, times and boards changed so; we carried the board so the wax isn’t in the sun, since the boards and fins got short, the swing arc got much more manageable so it made no difference if the fins were out/in/front/back.

I guess I’m way uncool cause nose and tail direction depends on which way I was pointed when I picked it up.

9

No sir, former Texas boy myself. 66 VW bug with permanently rusted on racks, nose forward and down, ne’er a problem.
Nowadays I just toss er in the bed of the Tacoma…nose down, fins to the rear. :slight_smile:

10

Air is a fluid. Water is a fluid. The difference is (aside from denisty) a surfboard in water only has the fluid flowing under it, while a board on a car has the fluid flowing on both sides. If the deck is flat, and the bottom is curved, you have a foil and lift pushing up on the straps. If the deck and bottom are both curved, you don’t have a foil. Most boards are curved on both sides, so you don’t have lift pushing up on a board that’s deck down, nose forward. You have a downward force created by the bottom rocker (which is acutally lift, upside down) and a low pressure area under the deck due to turbulence (creating even more lift by the differential between high pressure over the board and low pressure under).

This downward force on the front of the board can be so great that if the front rack is too far back, there’s enough rocker, you’re driving fast enough, and there’s enough board hanging over the front rack creating enough leverage, you can do damage to your board. I’ve done it. Drove 105 miles at 70mph with a 9’2 on top with the nose forward and bottom up… the board was EPS and only had a fiberglass stringer, to make matters worse, but just to illustrate the point, it’s a perfect example… and when I took the board off the rack when I got to my destination there were stress cracks on the bottom of the board in front of where the front rack was located… it flexed too much and started to fail. Before the drive, no cracks.

Cavitation? Maybe… somebody explain that to me, please.

Shortboards would create less stress and strain due to less leverage. Longboards… look out. Fins forward only and always, bottom up. The only real reason to put a shortboard nose backward is because there’s usually too much rocker, and the nose hits the car. Flip it around, and the nose rocker hangs down over the back.

11

Aloha,

Back in the day the surfboard racks were designed to fit in the rain gutter along the bottom edge of the car roof (yea cars had rain gutters then). The straps were actually a rubber hose with a chain running inside. At the end of the chain was a spring which clipped on to the rack. By placing the skeg up in front of the the forward rack, if the chain broke or the strap unclipped the skeg would still catch the hose strap and stay on the roof. Sooo, it bacame tradition to always go skeg up forward. As stated here, it’s also more aerodynamic I would think. Now all this is for surfboards (longboards). Regarding shortboards…,just put em inside the car on the dashboard or hang them from the rear view mirror. Easy…it’s a joke!

Just Enjoy the ride!

richard

12

I remember reading about tests by Mercedes Benz in which it was found that fins forward and up was the best aerodynamically in a wind tunnel. Someone with an old surf magazine collection might be able to verify.

13

untill you put your board bag on with a fin slot.

I’m with Richard. In the old days, fins front.

Now, fins back, so you don’t make an air sock.

14

I grew up in Orange County back in the olden days. Fins forward wax down or an ass whoop’n was come’n your way…

You’d be amazed at the boards that fit inside my Matrix…Fun stuff…no rack needed…get a new car!!! ha, Ha

15

Hello NJ

Air and water are both fluids, but that is the last statement in your first paragraph that is correct.

It is the air accelerating over the top of the foil (in this case the upside down rocker of the board’s nose if it is pointing forward) that generates lift. There would not be an area of high pressure above the nose - I’m assuming that your 9’2" has a fairly shallow entry rocker so it may well not have generated constant lift but simply fluttered as it alternated between a lift/no lift state. This, combined with what was probably a fair bit of overhang past the front rack, creating leverage, may have been what damaged your board (purely a guess).

If you think that a foil cannot have a curved top surface and a curved bottom surface, I suggest looking at an airplane’s wing. If you were right, I’d be out of a job because we would have over 200 heavy jets at our company that wouldn’t be able to get airborne.

You’re welcome to my Principles of Flight manuals if you’d like to explore the subject further :wink:

If you’ll excuse me, I’m going to toss my board in the back of my rusty old VW van, where it will create neither lift nor drag, regardless of its orientation. I will then ride the board nose up and forward. This evening I, unfortuately, have to go to work where I will be flying a big lump of metal with its two big foils curved on both sides.

Cheers

Buter

16

Eewww, you must be one of them Galveston/surfside boys :0

Buter

17

I am personally of the fin forward and up school of thought, certainly as in my case the predominant board of choice is a long single fin log, however on recent session I had a buddy along who is a relative beginner and can sometimes exhibit humourous kookiness, manifested lately as starting the “which way to strap up the boards on the car” arguments about lift, drag, astrology and stock market influences… not wanting to have this discussion I merely compromised by agreeing to strap them fins back and up in the mornings and fins forward and up in the afternoons…

fins down??? never even thought of that, it would look darn stupid, especially on my small euro hatchback…

18

Do some serious hunting for waves in a typhoon once and you will be a fins front and up surfer real quick, if it wont fit in the cabin area of course, dave-out.

19

http://www2.swaylocks.com/node/1011708

20

My recollection is the Orange County “surfer” always racked their board fin first and deck up. No worries regarding the sun melting the wax since they never put that yucky wax on their boards, let alone remove their boards from the top of their new cars. Except, of course, to wash the racks. Or, maybe I have them confused with the LA “surfer” which was basically the same thing… WahoooOOOOooooo!!! Fin forward, deck down. Mike