# Pump track, dirt on concrete?



## Mr.Bee (Aug 22, 2010)

Has anyone built a dirt pump track or dirt jumps on top of concrete? I would like to believe it's not much different then building on top of dirt. 
I'm in the planing stage of building a pump track for the company I work for. We have two possible areas to build on. One is a area that's 40'x60' on top of concrete the second area is 100'x30' on top of grass with several trees that can not be removed. Ideally the grass with the trees would be good but we are somewhat limited to design because of the trees. 
I have some concerns on the concrete such as drainage and maintenance and was wondering if anyone has done something like this. I'm also considering the possibility of building it out of wood on the concrete but don't like the idea of it being so permanent or not easily changeable like dirt is. I'm pretty new to posting here so please excuse me if I have posted in the wrong area or these are dumb questions.


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## cmc4130 (Jan 30, 2008)

Mr.Bee said:


> Has anyone built a dirt pump track or dirt jumps on top of concrete? I would like to believe it's not much different then building on top of dirt.
> I'm in the planing stage of building a pump track for the company I work for. We have two possible areas to build on. One is a area that's 40'x60' on top of concrete the second area is 100'x30' on top of grass with several trees that can not be removed. Ideally the grass with the trees would be good but we are somewhat limited to design because of the trees.
> I have some concerns on the concrete such as drainage and maintenance and was wondering if anyone has done something like this. I'm also considering the possibility of building it out of wood on the concrete but don't like the idea of it being so permanent or not easily changeable like dirt is. I'm pretty new to posting here so please excuse me if I have posted in the wrong area or these are dumb questions.


Yes, people have done wood, concrete, and asphalt. This thread is mostly about wood, but I posted some concrete ones as well.

Wooden Pump Tracks . . . . - Pinkbike Forum

Are Asphalt Pumptracks the Future? - News Blogs - Vital MTB

Because pump tracks often require "tweaking" to get exactly right, I think it could be problematic to go from paper plans to concrete without getting to ride/test in between.

I think you'd have to have test ridden the design already before committing to the expense of concrete.

Velosolutions in Switzerland has been doing asphalt pump tracks.  





Aint gonna lie though, it sounds like a rad challenge.


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## Mr.Bee (Aug 22, 2010)

I'm sorry maybe I have worded this wrong. What I have in mind or what I'm asking is to build with dirt on top of a already existing concrete slab. We would have the dirt brought in and build the pump track out of dirt but it would be on top of concrete. Sorry about that.


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## motomike (Feb 4, 2005)

Mr.Bee said:


> I'm sorry maybe I have worded this wrong. What I have in mind or what I'm asking is to build with dirt on top of a already existing concrete slab. We would have the dirt brought in and build the pump track out of dirt but it would be on top of concrete. Sorry about that.


Definitely possible, however I think you may run into some long term issues with the dirt eroding off the concrete since it won't bond to it like it would if you built it over dirt. As long as you are aware of that and don't mind a little extra maintenance, go for it!


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## cmc4130 (Jan 30, 2008)

Mr.Bee said:


> I'm sorry maybe I have worded this wrong. What I have in mind or what I'm asking is to build with dirt on top of a already existing concrete slab. We would have the dirt brought in and build the pump track out of dirt but it would be on top of concrete. Sorry about that.


No, my bad. I didn't read it close enough--I thought it might have been typo 'dirt OR concrete' . . . .

I think 100 X 30 is a better idea than 40 X 60. It feels better when you can get some good momentum and flow going before you have to turn.


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## cmc4130 (Jan 30, 2008)

motomike said:


> Definitely possible, however I think you may run into some long term issues with the dirt eroding off the concrete since it won't bond to it like it would if you built it over dirt. As long as you are aware of that and don't mind a little extra maintenance, go for it!


Yeah. And maybe there's a chance it would stay muddy longer after a rain because the water can't soak downwards.... But, that would totally depend on the dirt, how much rain, etc.

I think rodeos at indoor arenas put dirt on concrete all the time. So do indoor BMX track races at rodeo-style areas and coliseums.....


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## The Sagebrush Slug (Jan 12, 2004)

cmc4130 said:


> I think rodeos at indoor arenas put dirt on concrete all the time. So do indoor BMX track races at rodeo-style areas and coliseums.....


Not to mention Supercross when it's in a dome.

My guess is you just need more dirt, so you've got a 6" or so layer underneath the entire track.

I do agree longer is better. My area is roughly 40' x 60' if you include the backs of the berms, and I'd really love to have a line that's longer. A 10' radius berm at either end will use up a total of 30', so there's only enough room for a 30' straight.

If you go to 100', you could easily have a straight that's twice as long.


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## slapheadmofo (Jun 9, 2006)

A few trees isn't necessarily a bad thing. Shade is nice to ride/dig in, and can help keep the track from drying out as quickly.


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