Private Property Croftys backyard pumptrack - build log

dcrofty

dcrofty

Eats Squid
Update- excavator is coming, its build time. Will post pics

We went away last weekend and the place we stayed in had a pump track next to it. I had a lot of fun on it and my partner really liked the landscaping effect of the back sides of the berms and the gaps being mulched and planted out so when we got home we've both decided that one would look pretty good in an unused section of our back yard.

So I'm looking for ideas. I added a couple of pics of the land. The block of land is about 11m x 11m . I'm thinking of a Kind of square figure 8 design with a cross over in the middle. Attached a (shoddy) MS paint diagram to show what I mean.

Otherwise it slopes a fair bit so I'm thinking about hiring an excavator to level the ground and get the dirt to build the berms and rollers. I'm also going to try and build the lower lines above the grade so I never have to worry about drainage. Might make a native plant wetland in the middle too if I need to dig down for more dirt. Soil is very loamy so once I shape the basics I might have to barrow down some clay for a topping but I'll see if that's needed later on.

What does everyone reckon? Love to see any other ideas that people might have.

crofty.
P5080147.jpg
P5080148.jpg
Pumptrack design.jpg
 
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my02

Likes Dirt
Looking at your drawing, you have four rounded corners. Could you incorporate in one of them a 360 degree berm/bowl?

Also like the idea of using the rock ledge.
 
dcrofty

dcrofty

Eats Squid
Went down with some linemarking paint yesterday to rough in some lines. Thinking of tweaking things and might get a half bowl in there. I know it goes against a few building rules but now I have a rough plan im just going to jump in the machine and see what comes out.
 
dcrofty

dcrofty

Eats Squid
Fuck I've made a mess, nearly bogged a couple of times, my partner has a doubtful look on her face about the giant hole and the neighbours think I'm nuts.

Think I have a rough shape. Step 1 might have to be a simple oval and alternate lines might need to come later, its getting very boggy in the middle, don't think I can do what I want in there with the machine. Probably would also help if I could actually operate the thing rather than just drive it but that's all part of the fun.

during.jpg
 
dcrofty

dcrofty

Eats Squid
indica said:
How big is your yard?
Click to expand...
I have an odd block, its a normal house frontage wide but over 100m long. So I have front yard, house, normal backyard lawn area, pumptrack and bushland right down the back.

Space I'm working in for the track is about 15m x 15m. Going to mulch and plant out all the rest of it with natives when I'm finished. Inspiration for that is Kram's pumptrack in Squamish.
[video=youtube;REmlsvWKpDc]http://www.youtube.com/watch?v=REmlsvWKpDc[/video]
 
Reubs

Reubs

Likes Bikes and Dirt
Have a look at Leelikesbikes website for layout ideas. I bought his e-book but you can get a lot of useful info off the website by looking at the early posts in the pump track section. Things like berm radius, berm angles etc. Things you would probably work out with time but it can take the guesswork out a little.
 
dcrofty

dcrofty

Eats Squid
Yeah I have Lee's ebook. Most of my turns will be plenty wide so I'm good with that. I'm aiming to have a native plant wetland in the middle so that's not in his plans but I'm sure it will all come together.

Major earthworks are done, just got to pick up some pipe for drainage under the bottom berm tomorrow then I'm done with the excavator and work with the shovel and rake commences.

Told the neighbours that I was building a bike track. "What? For You?"
Plus my partner is quoting The Castle at me in terms of property value. "Adds a bit of Charm" and "What does it do for the value? Hard to Say" is on high rotation.
 
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Genius Josh

Likes Dirt
I had ideas for a pump track in my back yard but it is too small (the flat parts anyway) yours looks sweet. My wife had her doubts , and evidently rightly so, I did get one 180 berm roughed in and your head actually went backwards through the turn. I like your layout and am looking forward to seeing a finished product. I recomend putting a bunch of storm water drain under there (whilst you have it all dug up) on a grid with some sections capped off this will make it a heap easier if you decide to move the centre of a berm at some stage.
 
dcrofty

dcrofty

Eats Squid
Yeah heading to bunnings or where ever else is open this morning for some pipe to drain out the middle then I can fill in the last of the berm and then its shaping and sculpting time.
 
dcrofty

dcrofty

Eats Squid
Shape is roughed in

Before
View attachment 263340

After
after bottom.jpg

Photos don't really show as much as I'd hoped. Perhaps once I mulch and plant the edges and centre it will look a bit more like a track.


and a short vid explaining what I've tried to do
[video]http://s96.photobucket.com/user/dcrofty/media/Pumptrack/20130610_122150.mp4.html[/video]

anyway thats it for now, rain stopped play. Going to let it dry out for a while as its very muddy but now I got the drainage properly dug out that should happen then I can pick the lines out and tweak it a bit.
 
S

si618

Likes Dirt
I know you already started digging, but...11 metres seems pretty short, any chance you can get at least one line lengthened?

Here's a photo of our build after spending last weekend hauling dirt and shaping rollers. The track is ~20 metres in length and ~5 metres wide at the berms.

The berms are slightly past 180º and have a riding line radius of ~1.9 and 2.2 metres, which is tight, but I had a quick spin before starting on the rollers and they are still rideable, plus they are built steep up top to keep you locked in (berm height ~80cm and 95cm). I took advice from mtbr forum and maxed out the berm radius as much as I could, it took a heap of work but I think it will pay off.

The 5 rollers on each line ended up being spaced 3.4 & 3.5 metres apart, and will have a height of around 34 & 35 cm, so near enough to the recommended 1:10 ratio. With 11 metres to work with, you might only get rollers on the berm entry/exits and one in the middle. So say your berms have a 2 metre radius, to get 4 rollers at 31 cm height with a 3.1 m spacing, remembering that your berm entry/exit rollers normally sit a little bit past the berm, you need around 14 metres to play with, 15 would be safe.

//2/-|---3---|---3---|---3---|-\2\\

Don't underestimate the amount of dirt that will be required. Our local dirt is shitty shale limestone, so the clay has all been imported, about 15 tonne so far, with probably another 3 to go. Because everything has to be hauled down three flights of stairs, I also used ~8-10 tonne of bricks and pavers as fill, which is quicker and easier to transport, but at the risk of future hassle if I get the layout wrong (measure twice, dig once), but the last roller layer will all be 50-100mm dirt to minimise the risk, plus I'm riding it next weekend to test it out before adding the final layer. Basically, you'll be amazed at how much dirt berms and rollers chew up :)

Lastly, I love my concrete rake and tamper.
 
dcrofty

dcrofty

Eats Squid
That's a nice looking track.

Excavator has been returned to the hire company so I'm kinda stuck with the shape I roughed in, I was constrained by the fences on 3 sides and the rock shelf as well so lengthening isn't really an option. Have ended up with a basic oval shape, not as many rollers as originally planned and fairly wide turn radius. Once I wait for it to dry out I'll jump on the bike and see how things go and tweak stuff, then I can mulch and plant the edges and do some landscaping. I'm sure there will be some changes to be made but that's all part of the fun.
 
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