I can't jump any longer than 40 feet!!!

MikeT

~SPONSOR~

Jan 17, 2001

4,095

11

• Oct 29, 2001

• #26

Boys, ease up. Annsi and yardpro are correct about their physics. Just read it and reread it. They are correct. :D

 

Y

yardpro

Gone Bye-Bye

Oct 15, 2001

529

0

• Oct 29, 2001

• #27

thanks mike, it's nice to know my degree was worthwile:cool:

 

Y

yardpro

Gone Bye-Bye

Oct 15, 2001

529

0

• Oct 29, 2001

• #28

whoops,
you said "But, since we are talking about trajectory the riders have to go up before they go down."

trajectory is the affect that gravity has on an ascending object, and gravity pulls all objects at the same rate. therefore it will decelerate a rising object, and then accelerate it downward at the same rate, that's your tracectory, however as anssi stated fat guys have to get on the gass more on the face of the jump to maintain the same upward rate, if properly set up the suspension should have the same affect on both. Of course you can preload, "de-load" and all kind of other tricks to use the return of the suspension springs to add more lift.
If you're still a doubting thomas, either ask a teacher if you're in school, or go to the local community college and ask a physics professor, I'm sure they are are more adept at simplifying the explanation.

 

H

Hucker

~SPONSOR~

Sep 15, 2000

996

0

• Oct 29, 2001

• #29

Kinda like the Simpson's episode.

"Bed goes up, Bed goes down"

:)

 

J

JMD

Member

Jul 11, 2001

1,402

0

• Oct 29, 2001

• #30

LOL, Hucker. You're just like my sons; they can find a Simpson's line to fit any situation. BTW, my personal favorite Simpson's line: "Ooh, you got a head bag. Those are chock full of . . . heady goodness." -- Apu :cool:

 

W

Whoops

Member

Jun 19, 2000

127

0

• Oct 29, 2001

• #31

Okay, I got it. Actually it all came back to me in the shower this morning while remembering a target shooting discussion. I confused velocity and the energy required to generate velocity. :silly:

So, getting back on topic, the simple answer is, plus or minus suspension settings and/or rider preload, more velocity. :)

Whoops

 

Y

yardpro

Gone Bye-Bye

Oct 15, 2001

529

0

• Oct 29, 2001

• #32

bingo:p

 

A

Armadas Racing

Member

Aug 16, 2000

20

0

• Nov 10, 2001

• #33

the nitty gritty of physics

I found this web page that deals with the same physics that one of the members talked about (BIG rider vs. smaller rider when doing jumps) and is quite interesting....just take a few moments to read the page and it will give you an in-depth understanding of motion in air!
http://home.hiwaay.net/~ispellan/AirgunBC.html

 

A

alanreeves

Member

Nov 10, 2001

88

0

• Nov 15, 2001

• #34

There are different ways to hit a jump but to go far you should follow a few simple points:
you need to ba ACCELERATING smoothly from the flat all the way up the face of the jump.
you need to load the suspension as the bike meets the ramp by pushing down on the pegs and keeping your body rigid, as the bike is pushed up toward you you feel the force build up untill the suspension nears the bottom of its stroke (this stores loads of energy in the springs which flies you longer)
and reduces the effective angle of the ramp.
as your front wheel leaves the ramp try to "row" your body backwards, this will help keep the rear shock loaded as long as possible as the rear tire leaves the lip and prevent a hard front wheel landing
hope this helps... "practise makes perfect":)

 

F

FLYIN_KAW

Damn Yankees

LIFETIME SPONSOR

Apr 19, 2000

287

0

• Nov 29, 2001

• #35

Ya banging your balls off the tank sure doesn't feel good.
:)

 

P

Perk

~SPONSOR~

Sep 17, 2001

303

0

• Dec 13, 2001

• #36

my two cents worth

Two guys weighing different amounts hitting the take off at the exact same speed and line would jump exactly the same, all things being equal. All things are not equal though. One guy is going to get a little more boost at takeoff, due to a different suspension setting. I used to race BMX, and we could hit jumps all day long, at the same speed, with completely different results, by pre-loading differently for the jump, you will get a different lift resulting in a longer or shorter jump.
I suck at physics, but I'm fantastic at trial and error. :)

 

High Lord Gomer

Poked with Sticks

Sep 26, 1999

11,788

35

• Dec 13, 2001

• #37

Re: my two cents worth

If they had their suspensions set up correctly for them, they should get approximately the same result.

Originally posted by Perk
I suck at physics, but I'm fantastic at trial and error. :)

Click to expand...

*That* would be an excellent signature line!

 

D

Dvraptor

Member

Jul 12, 2000

25

0

• Dec 14, 2001

• Thread starter
• #38

stiffnes also plays in...

You'r bodystiffnes during takeoff will also affect angle and height.

Loose body = short and low
Stiff body = long and high

Explained better by Motocross action magazine this autumn

Be aware that this NOT include all bodyparts - for Your own safety...:eek:

 

High Lord Gomer

Poked with Sticks

Sep 26, 1999

11,788

35

• Dec 14, 2001

• #39

Good point! For me, it's usually all I can do to make the distance, but it's cool to watch good riders use their bodies to absorb upward energy and fly lower / faster.

(If I ever get to where I can consistently overjump something, maybe I can try that) :eek: