# backyard pumptrack/DJ's



## mistaare (Sep 13, 2005)

First, moderators not sure if this would fall under "Urban/dj/park" so feel free to move it. 

Here is the deal. Just bought a house, I got the go-ahead from the Mrs. to build a pump track/jump section in roughly a 60x100'' ALMOST completely flat section of the yard. Now if it actually happens is another thing, but I am going to try. Being as though its in suburbia and there is a sewer line running underneath digging down for dirt really isn't an option. I will dig down A LITTLE, but that's just to get it nearly flat but I am in no way relying on that for dirt. 

So here's the deal:
- Thinking of a figure 8 that could be ridding as an outside loop with fun roll-able features for my 5yo, or you could hip and/or shark fin into a middle line that would have 4-pack or 6-pack (4' tall, 8-10' maybe, nothing crazy).
- I was checking the municipality for permits/codes and I am allowed up to 25 cubic yards of 'fill' before I need to apply for a permit. How far will 25 yards go? My rough calculations says I will need 45-55 cubic yards.
- for those that have built back yard sections, have you experienced 'cranky neighbors' and/or municipality issues? 
- for those that have built back yard sections, do you know how much of an area it occupies? 
- I know a clay mix is optimal, but the only two descriptions I can find from suppliers around here is, gray clay for ponds, and screened or unscreened topsoil. Experiences with either?


Any input or experiences you guys have feel free to share. I have been researching this like crazy and would like to have all my bases covered before the dirt gets delivered.


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## cmc4130 (Jan 30, 2008)

The LeeLikesBikes "Welcome to Pump Track Nation" e-book is worth buying & downloading. He has some good info on calculating the amount of dirt for pump tracks.

His focus is just on smaller pump tracks though, so for the jump angle, I'd also recommend reading through this entire thread:

*DJ , Pump Track plans*
https://forums.mtbr.com/urban-dj-park/dj-pump-track-plans-402237.html

Are you planning on doing tables, or gap doubles?







(Pflugerville trails, Abel's work)

With 60' X 100' you'll have to figure out how much you can fit in.

As you can see here, if the typical BMX or MTB-DJ jump is around 8 to 10' of gap, then 3 jumps gets you to 90 feet.










You would probably need a roll-in to get decent speed in a small area. Check out this thread on roll-ins Roll-ins | Page 2 | Ridemonkey Forums

If you're starting from a standstill and want to hit a 10' gap jump . . . the roll-in has to be pretty tall.

But, if you're going to be able to get a few cranks in (on top of the platform, then down the slant) it doesn't have to be quite as tall--but it's still a matter of space to get the cranks in.


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