Non-standard berm ideas

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A purchaser of Welcome to Pump Track Nation is thinking outside the box.

Some thoughts:

Hi, Lee!!

We just ordered your Pump Track nation book in PDF format. I am trying to make a “pretty” landscaped pump track, similar to the concepts used in this track: http://www.ihatebikes.net/site/pump-tracks/backyard-spotlight-john-and-maggies-pump-track/

I will be building up a retaining wall at the backside of the berms … I expect to use the 10′ radius dimension to the centerline of the track … and allow for a 3- to 4-foot-wide track.

My question is:

Does the entire berm need to be built up of dirt only? Can the portion of berm that is up against the retaining wall have rock/gravel fill (see blue on diagram below) – to act as a “French Drain” at the base of the retaining wall? The snip below shows what I am thinking …

I’ve even considered making one of the berms with a sloped wooden component — so that we can get higher on the berm as our skills progress … similar to this photo:

Lots of ideas swirling around, and I am heeding your advice of building it RIGHT the first time!! J I guess I just want to verify that my ideas are on the right track (gosh, there has to be a pun here!). I’m sure we’ll figure a lot out as we start building, but I just want to make sure that we are building a good foundation.

Thanks so much!

Denise

Hey Denise,

Thanks for buying Welcome to Pump Track Nation, and thanks for your note.

I’m a pump track purist (all dirt, all round shapes), but I like your thinking. Some thoughts of my own:

• You can bury rocks in your berms, but make sure they’re so deep they don’t affect the stability of the surface.

• If they’re that deep I’m not sure how much they’ll aid drainage.

• Right now at Valmont Bike Park they’re working on something similar (to get water out of the inside of a berm, which is a low spot), but it’s not done yet and I don’t know how it’s going to work out.


I am still stoked on my pump track. Check out the retaining wall. The guts of the berms are also made of endemic rocks.

• Drainage is an exercise in cleverness. Think about the entire site as a 3D object. Consider elevating the insides of your berms then pushing water out the low spot between rollers.


Kidtopia. The inside of the 180 is built up so it drains between the rollers.

• Burying rocks deep in your features can save you money on good dirt. We do that sort of thing a lot. Other useful objects include anvils, toilet bowls and anchors.

• You can certainly incorporate a wall ride. That’s not my style — I prefer hurling my carcass into 70-degree banks of filtered topsoil — but kids these days seem to enjoy them.


Wall rides? We don’t need no stinking wall rides. The pump track I built for Giant Bicycles at Keystone, CO.

• Be mindful of the transition between the dirt and the wood. At Valmont the transitions keep wearing away, and there’s a rough bump as you hit wood.

As always:

Measure twice. Dig once!

Lee

Know more. Have more fun!

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4 replies
  1. chance says:

    for drainage, you can do a couple things. The first and best in my opinion is raise the entire track just a few inches and then find the low spot or spots and run the slope towards that and bury actual drain pipe, pretty cheap like 150ft for 50 bucks, and use that like a culvert also if you have a low spot and the culvert idea doesnt’ work you dig a whole deep enough to bury a 5gal bucket, you drill a bunch of holes in the bucket and fill it with small rock. It works as a modified catch basin. That is what we did with the 3 pump tracks we build at our new bike park, good luck!

  3. Rik says:

    Hi Lee and Denise

    Is drainage gonna be an issue with your pump track? If it is then planning that into the overall design is gonna be very important, always give the water and escape route away from the troughs of the track.

    I’d be very cautious about putting rocks into the berm to act as a drain if they’re much above ground level… If you ever have to reshape your track you’ll have a whole lot of grief digging them out again, and if it’s your first one then you might have to do this.

    Also to get a good steep back slope on your berm you’re quite likely to go deep into the pile of dirt – deeper than you think when it’s just a loos pile and if you hit the rocks, they’ll have to come out..

    Best dig a trench with and escape to a lower area, put in a perforated pipe and cover that with small cleam rocks, use a bit of terram over that then build your standard berm on top with any bige rocks in it, or if you must keep them low and way to the back.

    I’m a trail builder in Scotland where we have to know a thing or two about drainage 😉

  4. Rik says:

    Haha at all the typos!!!!
    Got a bit carried away with my favourite subject, better at drains than spelling !!

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