Heavier Boards Faster?

[refthimos]

So I was reading a post on here from a manufacturer claiming that its heavier board was actually faster in straight line flatwater conditions than a similarly shaped board half the weight.  The claim was that momentum is greater with the heavier board and thus the glide is better.

There were also other claims, such as increased stability and tracking from the increased weight, with it being tougher for chop and wind to push the nose of the board around.  These claims I believe, so I'll leave them alone, but the weight claim gives me pause.

I come from a road cycling background and have heard scores of similar debates regarding what makes a fast bike. There are those that would argue that one a flat course, a heavier bike will actually carry momentum better than a light bike.  But no pro rides a heavy bike; they all ride bikes that are at or near the UCI weight limit of ~16 pounds.

Now, there is very little debate that on a road bike, aerodynamic resistance is by far the most important factor in a "fast" bike...  Followed my rolling resistance (more weight increases this) as well as mechanical resistance (e.g. friction in the drivetrain, bearings, etc).  Now while rolling resistance may not play as large a role as wind resistance, it still plays a significant factor.  Imagine pedaling a 300 pound bike.  Not only would it be a bear to get up to speed, but do you really think it's easier to keep that 300 pound bike moving as it would be the 16 pound bike?  No way.

I think SUPs are similar.  Primary determinant of speed is hull design.  Length, width and shape.  Piercing nose vs. displacement nose.  All the stuff shapers are playing with and figuring out.  Aerodynamic resistance doesn't account for much because we're not going that fast and there is only so much you can do with body position on the board while still maintaining an effective position for paddling.  So it's really just the resistance against the water.

I think a heavier board may be more stable than a lighter board, and stability is speed, but only to a point... There is no doubt in my mind that given the same paddle stroke, less weight (both rider and board) means more speed... think of a board weighing only 10 pounds, no rider and a magic "Harry Potter" style paddle moving it along... that board would glide so easily on top of the water that it would just fly... Now imagine the same board, now with a rider, 300 lbs total... There is no question that with the same paddling power, you are going to go a LOT slower... you have all that weight to push through the water.

[PonoBill]

No question that a heavier board is slower. If you have any doubts just put fifty pounds in the center of your board and have at it. Or borrow my "world's heaviest F18". It's not terrible now, but it's a lot slower than it was when it was light.

Heavier = more wetted surface=more friction. It also takes more energy to accelerate the board--in both directions. We've discussed this before.

[pdxmike]

My brother lives in London, and he said when he used to go to the race track there, every time he put 50 pounds on a horse it always went really slow. 

[Scotty Mac]

What happened to your F18 Bill? We are just dicussing the weight of the naish 17 on the breeze. I loved the boards shape but sold mine cos of the weight. Apparently they are around 16 kg which i think is about 35 lbs. I just found that a bit of a pain to lug around for a regular DW board on off roof etc

[robon]

There are several new plastic SUP designs being released on the market and was i wondering the same thing. The plastic models range from 15 to 25 pounds heavier than the traditional SUPs designs that I'm interested in. It has already been mentioned that it takes longer to get the heavier plastic design up to speed, but I'm wondering about the energy it takes to keep the plastic models at cruising speed compared to a lighter model of the same hull design. The benefits of the heavier plastic models is lower cost, vastly increased durability and more storage space (kayak design storage).

Is it really that much more of an energy expenditure to keep a board that is up to 25 pounds heavier up to speed, compared to a SUP that is around 25 pounds lighter? Assuming the boards are the same length and similar design of course.

[JonathanC]

IMO the 'cruising speed' thing is a little bit of a myth, I find that my speed frequently varies when I'm doing distance. A gust of wind hits you head on-you slow down, you get distracted - you slow down, water state varies or another craft goes past - you slow down. So even a cruising paddle involves re-accelerating the board many many times.
For me the 'feel' of a light board is so much nicer, that surge forward with each paddle stroke is such a great feeling as opposed to the 'leaden' feeling of trying to get a heavy board up to speed, I know it's subtle but I think important.
The heavy plastic moulded boards do make sense from the storage and durability perspective though - would be pretty tough getting a big plastic board on and off high racks on your own. I mainly paddle on a full carbon Starboard Surf Race 14 and I actually get get a buzz out of lifting it on and off the racks so easily, just love a light board!

[1paddle2paddle]

If you think the Naish 17 is heavy, you gotta heft Bill's F18.  I carried it something like 50 yards after a Maliko run and I'm thinking "damn that run tired me out more than I thought!"  Nope, just turns out that a 50 pound board is really tough to carry.

[DavidJohn]

Personally I think the whole light weight board thing is a bit overrated.. Except the part where you're lifting it on and off the roof of the car.. Fast boards.. Light boards.. You still have to paddle them and they all start to feel the same except that one is a smidge faster.. If you're not in a race it doesn't matter that much.. I don't like super heavy and I'm also not a big fan of super light.. There is a nice medium and that's what most boards are.

DJ

[PonoBill]

What happened to your F18 Bill? We are just dicussing the weight of the naish 17 on the breeze. I loved the boards shape but sold mine cos of the weight. Apparently they are around 16 kg which i think is about 35 lbs. I just found that a bit of a pain to lug around for a regular DW board on off roof etc

The F18 I have in Maui is waterlogged. The one I have in Hood River was a very lightweight one that Mark built to win at the BOP. The glass was super light--probably just 1 oz veil. I got tired of punching holes in it every time I looked at it and reglassed it myself--one layer of 6 oz and one of 4 top and bottom. It wasn't so bad at first, but my hotcoat didn't kick and I had to scrape it off and redo it. By the time I was done butchering the poor thing it probably north of 50 pounds. I'm scared to weigh it.

[Scotty Mac]

Geeze Bill, thats a bummer. Your right DJ, not a problem on the water. Its on and off the roof and carrying it long distance is when its noticable.

[LaPerouseBay]

For me the 'feel' of a light board is so much nicer, that surge forward with each paddle stroke is such a great feeling as opposed to the 'leaden' feeling of trying to get a heavy board up to speed, I know it's subtle but I think important.

[1paddle2paddle]

The guys in Oz & South Africa are always arguing this on the surfski board.  The controversy surrounds spending a lot of extra cash on a lighter layup (the manufacturers always seem to make the skis in poly resin and a carbon version, and sometimes two different carbon versions: non-bagged and vacuum bagged).

The argument in favor of the heavier/less expensive boat is that you could lose 5 kg/11 pounds and get the same performance as spending an extra grand (or whatever).

For me its a no-brainer.  It is so easy to tell the performance difference in the lighter boat.  Its the dead weight that is unmistakable when trying to push the boat over the precipice of a bump.

[CMC]

I had an interesting discussion with one of Australias most respected OC1 paddlers.

Anyway we were talking about weights in OC1's.  He said that not so long ago boats were around 15kgs.  He said at that time smaller guys never won races.......  This got me thinking.  Heavier boat, heavier paddler but still always winning.

His reason was that the heavier boats simply took more strength to get moving, off the line, upwind, to re-accelerate etc etc.  The smaller guys were on the same boats but did not have the strength to pull them.

Now at around 10kgs for an OC1 smaller and younger guys are doing very well in comparison to before.  Kind of like at 15kgs Kai Bartlett would have smashed Danny Ching were as now the odds are more a little the other way.

Is heavy or light better?  Lighter the better!

[pdxmike]

For me the 'feel' of a light board is so much nicer, that surge forward with each paddle stroke is such a great feeling as opposed to the 'leaden' feeling of trying to get a heavy board up to speed, I know it's subtle but I think important.

Good point--the feel of the board (due to being lighter) shouldn't be underestimated--same goes for the paddle. 

In swimming, every swimmer shaves down before key competitions.  It does make a difference in speed, and in swimming a tiny time savings can be crucial.  But a big part of the whole thing is the ritual, and the feeling.  You feel like you're slipping through the water effortlessly, and like you can feel every molecule of water.  Some swimmers even rough up their hands and forearms with a loofah* to enhance the sensation.  Shaving makes a difference far out of proportion to what science says the drag reduction should be. 

It surprises me a bit that I haven't heard of people using heavier boards or paddles in training, then switching to lighter ones for competition.  There's the argument that that could throw off your timing, balance, etc. but that's certainly just as true or more so with swimming, and no swimmer ever shaves down until right before their meet. 


*There's some chance Michael Phelps got this advice wrong, and instead of using a loofah he used a hookah. 

[kwhilden]

The answer to this question depends on the intended use. There are indeed situations where a heavier board will be 'faster'. Also, let's be clear that there are two definitions of 'fast"... instantaneous speed, and average speed. The key to answering the question depends on whether the board is being operated at an instantaneous speed that is close to its theoretical wave making resistance speed.
http://en.wikipedia.org/wiki/Wave_making_resistance

For those who like to race and go fast, a lighter hull is faster because board is constantly being pushed to the limits of it's displacement speed ability, beyond which point, resistance increases exponentially. For a 14' board, this speed is calculated at 5.01 knots. So racers, who operate in this range of speed, will be able to briefly accelerate their board to a faster *instantaneous* speed with a lighter board vs. a heavier board. Each stroke allows them to accelerate to a speed greater than five knots for a brief moment, before the wave-making resistance drags them right back down again. The net result of some time being spent at a faster instantaneous speed is to also have a faster average speed.

For everyone else, cruising speeds are much lower and the benefit of quicker acceleration is much diminished. For these people, the weight of the board doesn't really matter for overall speed. However a heavier board will provide excellent glide because it carries its momentum better. It is harder to accelerate, but over a long paddle, it *may* be faster on an average speed basis depending on the sea conditions and the paddler's ability to maintain a constant speed. Definitely, a heavy board will pierce through chop and rough conditions better than a lighter one. Most of the time however, the weight of board will make no difference in average speed.

Off the water, it's a different story. Lighter boards are much easier to handle and throw around. However they are also fragile. Heavier boards are the opposite, and in particular plastic SUPs are significantly heavier but also practically indestructible. Plastic boards are also significantly cheaper, about 50%, compared to fiberglass/foam, because the labor costs are much less... in fact so much less that it's actually cheaper to make them in the USA vs. China.