Taking Weight into Account for Downhill Skateboarding

[pete..]

But, I think the difference all this sh!t makes, is far out weighed by rider skill, or more importantly lack of rider skill.

+1

but if you do like to worry about physics the more dense you are the faster you will be because this means you will be smaller(more aerodynamic) and heavier(more momentum)

But the heavy skater has more momentum and has a higher chance of sliding in a turn, therefore loosing speed and being slower then the light skater who does not slide. This can be fixed by running softer wheels for the heavy rider, but then he will be slower in the straights.
Therefore, weight, if accounted for while perfecting your tuck and wheel shopping, will not affect your speed.

you forgot that the heavier rider creates more friction and will actually grip better on the same wheels as a light rider

being heavier is better as long as it doesn't interfere with aerodynamics

[NickMoran]

That's why I said the bold part.

oooohhhh ok that makes sense now, i guss it was just worded weird

[thokk2]

oooohhhh ok that makes sense now, i guss it was just worded weird

I tend to do that. Haha.

I sent an email to my physics nerd friend, so we'll see if he can shed any light onto this.

[JamieReis]

i say we put this to the test.
we can have me and jesse go down a hill, we both have basicly the same board, and almost same duro wheels or we could even borrow some wheels. His can be harder mine softer and vice versa.

yea??

It will never happen because you guys won't have identical tucks, and ride on the same path of road.

The main purpose would be a very accurate result...not some kind of homemade experimentation...
To that, we have cases like Teutonia, wich is mostly straight course, and where Kevin, Scoot and many others can keep up with a bigger heavier guy like Dalua.
I think in the end, the things will be pretty similar...

But what would be good was some supportive math and physics.....

Not true. You there aren't considering air resistance. Dalua is fast, but Kevin and Scoot both have less air resistance and a better tuck. If you put Dalua's weight into a ball with a 5 cubic foot surface area, and you did the same with Kevin's weight (just changed the density of the ball to be greater for Douglas,) and there was no wind, Dalua would win down the hill. The picture and explanation at the bottom of this explain a lot.

+1

but if you do like to worry about physics the more dense you are the faster you will be because this means you will be smaller(more aerodynamic) and heavier(more momentum)



you forgot that the heavier rider creates more friction and will actually grip better on the same wheels as a light rider

being heavier is better as long as it doesn't interfere with aerodynamics

Heavier riders don't necessarily have more friction on the road. The friction coefficient of the different wheel material, and surface area of the contact patch makes a huge difference too.


Here is an example of 3 riders who have about as similar tucks as you can possibly have in a single heat. They finished in this order:



1. Peck
2. Freifeld
3. Flis

Guess who weighed the most and who weighed the least?

I'm not sayin anything I'm just sayin.

[guivans]

I


Not true. You there aren't considering air resistance. Dalua is fast, but Kevin and Scoot both have less air resistance and a better tuck. If you put Dalua's weight into a ball with a 5 cubic foot surface area, and you did the same with Kevin's weight (just changed the density of the ball to be greater for Douglas,) and there was no wind, Dalua would win down the hill. The picture and explanation at the bottom of this explain a lot.

How is not taking in consideration air resistance in the Teutonia race???Are they in vaccum in Teutonia????

[JamieReis]

How is not taking in consideration air resistance in the Teutonia race???Are they in vaccum in Teutonia????

No yuh kook. I'm saying. It makes sense that just because Dalua is heavier doesn't mean he automatically beats them. BECAUSE OF AIR RESISTANCE. Because they AREN'T in a vaccuum.

[tomahawk]

let's play a little game here, it's called, "if you dont know about physics, stop posting!!"

[Pat S]

skaters trying to do basic science is just sad.


It's all incredibly fuccking simple: firstly- neglect wheels and all that bullshit- Going really fast is almost entirely a problem of wind resistance. (this is coming from both an engineering background and extensive skating)

There are two variables- Drag and Momentum. I'll explain both:

Drag is the amount of wind force opposing acceleration- a better, tighter tuck will have less drag
Momentum is Velocity * Mass. Assume an equal initial velocity so that the only thing coming into play is Mass

Whoever has the best (lowest) Drag to Momentum ratio (Drag/Momentum) will theoretically be the fastest. So a light person with very little drag can theoretically be as fast as a heavier person with more drag given the ratios are about even.

This of course is only one aspect of being fast- a major thing that gets overlooked all the time is being solid in your tuck. The less fidgeting and readjusting you do- the faster you will be.

ps. This is still a gross simplification of it all, we could get into laminar and turbulent flow but I'm terrible at explaining and most of you are stupid.

[sk8norcal]

let's play a little game here, it's called, "if you dont know about physics, stop posting!!"

haha!
its silverfish, physics don't apply here...

[streetheap]

[MJKam11]

A ping-pong ball will not fall at the same rate as a cannon ball.

Technically it will (constant velocity is the same for all objects) but air resistance changes all that.

To the OP. While I suck at physics, I do realize that you're using a lot of freefall physics terms in your post.......just saying (Pat S the engineer explained it so yah)

[Tagsrover]

a lighter rider will accelerate faster and a heavier rider will maintain their momentum longer. this much i know is true.

Not true.

Gravity affects objects the same regardless of mass (9.8 meters/second). Now their forces of gravity will be different because more mass means more force . But force isn't speed. Velocity=how fast you go, but acceleration = force/mass. Therefore the bigger rider has more force but also more mass, so everyone should accelerate the same (all else being equal)

this is of course assuming slow speeds where wind resistance doesn't really matter, and that bearings, wheels, etc. is all the same.

Therefore weight should really only come into play when talking about carrying momentum, and size should play a difference when it comes to being aerodynamic in a tuck/draft.

[streetheap]

I don't understand why people are throwing around info about vacuum physics. It doesn't matter in the skateboarding world. Generally humans skate on earth, where there is atmosphere.
Georges nailed it when he said density.
A ping-pong ball will not fall as fast as a cannon ball here on earth. It just won't.
Take 2 balloons of equal sizes. One filled with air, the other with water...blah blah blah

[tomahawk]

ooh look! more random fact to make gross (and probably wrong) over-generalizations about!!




hmm...the frontal area is more, and yet there's less drag....this is interesting...

go silverfish go!

[Pat S]

hahhahah Georges. I remember that lab from fluids lab....

[pete..]

ItHeavier riders don't necessarily have more friction on the road. The friction coefficient of the different wheel material, and surface area of the contact patch makes a huge difference too.

which is why i said on the same wheels

are we talking about a drag race for top speed on a straight course or are we talking about a race with turns?

[zprawn]

[Hanael]

Hm..
i kinda remember something..
google "mythbusters golf ball dimpled car"


will having dimples on your racing leathers affect your aero?

[Whereisnumnum]

thokk ur name is devon?

[JamieReis]

thokk ur name is devon?

Mmm hmmmm.