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Building wood slopestyle booters

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Building wood slopestyle booters
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flag booMcaT
Posted: Jul 9, 2012 at 11:14 Quote
Get large plywood sheets, lay it out on the floor. Get some rope and something to hold it down. Measure a piece to the radius you want(I think most well shpaed jumps are ~12ft radius), trace it onto the plywood. Cut out two of these pieces- they are your curved walls to the jump (see OP's pic). Cut 2x4's or larger lumber to the width you want your jump. Screw these pieces roughly every 6-12" up your curved pieces, tying them together. After this, cut legs to your jump, get the length by holding your jump upright and measuring lip to ground. Attach these pieces. Then cut long supports to run from your legs to the start of the jump. You may want to support the middle of the jump by placing supports up from the bottom(may want to = you really should) most of your force is applied to the middle and upper section of the jump (see: physics). The last step is to cover the jump with plywood. Cut to the width of the jump and screw it into your stringers (every 6-12").

This requires serious visualization... Hope it helps!
flag cmc4130
Posted: Jul 24, 2012 at 13:05 Quote
gravityhelps wrote:
i just did a quick google search and found a website and they are saying for the AT jumps they used a 14' radius and it usually ends up being slightly less than half the height of the radius. one guy said he used a 12 ft radius and it ended up being 5'6" inches and it was a 20ft gap give or take depending on speed. they also said most jump ramps are 10ft to 14ft radius.


The idea of the ramp being half as tall as the radius length is correct. So a 12 foot radius and 6 feet tall will give you about 60 degrees of arc. Although sometimes bmx box jumps are steeper (like 65 or 70 degrees), for a big slopestyle ramp, you don't want or need it to be.

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http://forums.mtbr.com/trail-building-advocacy/dirt-jumps-specs-599573.html

http://www.ridemonkey.com/forums/f61/i-want-build-something-help-225569/

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This guy is using the 2 X 12 method of under-support, rather than the 3/4" plywood method.

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Even though these ramp plans are old school and relate to skateboarding, the principles in it are still really good and it will give you an idea how to plan a ramp of whatever style you want.

http://forums.mtbr.com/urban-dj-park/thrasher-80s-ramp-plans-jpg-intensive-485306.html

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click on the link for more:
http://forums.mtbr.com/urban-dj-park/thrasher-80s-ramp-plans-jpg-intensive-485306.html

 


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