Wooden Jumps. With pics

PB Forum :: Trail Building
Wooden Jumps. With pics
Author Message
flag KingsgateDirtJumper
Posted: Mar 28, 2016 at 10:48 Quote
tchach11 wrote:
...It is a bit more abrupt of a takeoff than I thought it was going to be
I think it's because the ramp is not long enough to get both of your wheels on it at the same time. It bucks your back wheel up higher than your front, which makes it feel abrupt.
One easy way to correct this will be to add a foot or more of dirt under the entire ramp, and feather it out to the bottom of your runway, thus making the transition much longer, like 4-8 feet. It will feel much smoother. Also adding more flat before the jump will help too
flag cmc4130
Posted: Jun 5, 2017 at 9:52 Quote
Excellent design for a step-up box jump. Nice long landing, with rounded corner.

Screen grab from a GT BMX FREESTYLE show clip.

photo
flag KingsgateDirtJumper
Posted: Jun 21, 2017 at 21:51 Quote
cmc4130 wrote:
Excellent design for a step-up box jump. Nice long landing, with rounded corner.

Agreed, excellent design.... and fuk yeah to rolling in off the roof!
flag jdeans390
Posted: Aug 30, 2017 at 9:45 Quote
hi i am making a kicker that is 6 feet high, what radius should I go with for a dirt jump (2-4 meter gaps)? and also what length should go along with this radius?
flag borisimobike
Posted: Oct 15, 2020 at 9:26 Quote
jdeans390 wrote:
hi i am making a kicker that is 6 feet high, what radius should I go with for a dirt jump (2-4 meter gaps)? and also what length should go along with this radius?

physics is your friend... see the calculator about 3/4 of the way down this page:

https://trailism.com/trail-science/jump-design/

This said, you need to know the following first:
1) your run-in speed
2) how you intend to jump (steep jump to trick high, or distance jump)
3) what type of bike is hitting it (bmx, dh, etc.)

You can cover 2-4 meters a number of different ways with a 6ft high kicker... decide how high in the air you want to go or just design around the speed you'll have.

Below is a link to an album. I've made the first of about 15 jumps I'm converting to wood. This first one is 55 degrees and sends you to a landing 10' away; its 4' tall, about 8' long and with a 9.5' radius. Its designed as a mellow jump to get people accustomed to "steep" doubles. An experienced jumper could easily send this 15' at the speed most would approach, and a beginner might even still case it. The form/mechanics of the person jumping make a huge difference.

https://www.pinkbike.com/u/borisimobike/album/dirt-jumps/

photo

photo

photo
flag chriskneeland
O+
Posted: Oct 15, 2020 at 9:42 Quote
borisimobike wrote:
jdeans390 wrote:
hi i am making a kicker that is 6 feet high, what radius should I go with for a dirt jump (2-4 meter gaps)? and also what length should go along with this radius?

physics is your friend... see the calculator about 3/4 of the way down this page:

https://trailism.com/trail-science/jump-design/

This said, you need to know the following first:
1) your run-in speed
2) how you intend to jump (steep jump to trick high, or distance jump)
3) what type of bike is hitting it (bmx, dh, etc.)

You can cover 2-4 meters a number of different ways with a 6ft high kicker... decide how high in the air you want to go or just design around the speed you'll have.

Below is a link to an album. I've made the first of about 15 jumps I'm converting to wood. This first one is 55 degrees and sends you to a landing 10' away; its 4' tall, about 8' long and with a 9.5' radius. Its designed as a mellow jump to get people accustomed to "steep" doubles. An experienced jumper could easily send this 15' at the speed most would approach, and a beginner might even still case it. The form/mechanics of the person jumping make a huge difference.

https://www.pinkbike.com/u/borisimobike/album/dirt-jumps/

Where were you three years ago?
flag borisimobike
Posted: Oct 17, 2020 at 18:33 Quote
Better late than never? Lol

 


Copyright © 2000 - 2024. Pinkbike.com. All rights reserved.
dv56 0.010489
Mobile Version of Website