If you've got the space, what could be more fun for the kids than having a dirt bike track? This guide gives you tips on how to build a basic track suitable for mini bikes or BMXs using a tractor and front end loader.
Track design is all about putting the jumps and corners in the right place to make it fun yet keep it safe – well relatively safe! You also need to think about the lay of the land.
Keep the following in mind.
Allow plenty of space around the track away from trees and fences etc. in case a rider ends up off course.
Don't make straights leading up to jumps too long, to avoid reaching excessive speeds.
Don't put corners too close after jumps – give the rider some space to land the jump safely.
Locate jumps and berms (banked corners) keeping drainage in mind. Use the natural slopes of the land to help water flow away – not bank up.
If you are building a BMX track, the area will need to be relatively flat. You need a fair bit of momentum to clear jumps and you won't get this if you are pedalling uphill all the time.
There are a number of different types of structures to consider for your track.
Table Top Jump
A table top jump is a safer jump for beginners. It enables a rider to roll across the top of the jump and down the other side at low speeds. Or for the more experienced rider you can still get "big air".
A table top jump enables a rider to jump high or roll up and over without leaving the ground
A double jump is more challenging. As the name suggests if the rider hits it with enough speed the gap can be cleared. Often these ramps are built on sharp angles to launch the rider into the air. The safer option is to keep the angles rounded so that the rider can roll along the downside of the first jump and up the second one.
A ski jump is a flatter jump that projects the rider further across than up. Always build a landing ramp as this makes for a much smoother landing.
Whoops are a series of small bumps (similar to speed bumps) one after the other. These tend to slow riders down as it takes a lot of skill to negotiate these at speed.
BMX Start Ramp
BMXs benefit from a start ramp. This is simply a large mound with a steep bank where riders can start at the top of. This gives them momentum for the first jump.
Berms are banked corners which enable the bike to be ridden through the corner at higher speed.
Draw up a plan building in the jumps and berms. The kids who designed this track even made a simple clay model so they could visualise what it would look like.
Once you know how many jumps and berms you want, you can estimate how much dirt you'll need.
A single jump about 0.7 metres high and 2 metres wide at the top of the jump (and 3 metres wide at the base) would use roughly 2.5 cubic metres. Make a double jump and you are looking at 5 cubic metres, and a table top jump about 8 cubic metres. A berm about .7 metres high and an 8 metre diameter would use about 11 cubic metres.
If you are working on flat ground it's best not to just dig holes on your track to get your dirt, otherwise they will end up filling with water when it rains. You may need to bring extra dirt in. If you are planning excavations on your property such as building a dam or cutting a pad for a shed this may be an ideal way to use your excess dirt.
Otherwise you can bring it in from somewhere else. Excavators are always looking for somewhere to dump their excess dirt. There are even companies that match people looking to get rid of dirt with people that need it. You should be able to get this for nothing or "dirt cheap".
Also certain types of dirt are more suitable than others. Clay type soils are more likely to hold together on jumps and berms than loamy and sandy soils.
Use the bucket to roughly put the dirt in place for the jump, then open the bucket and use the blade to shape it.
BUILDING THE TRACK
Mark out the track where the berms and jumps will go using spray marker paint. Get the kids to go for a test ride around the marked out area to see if it feels right. Check that corners are not too tight and that there is adequate distance to brake into a corner after a jump.
Then it is really a case of getting the dirt where you want it using the front end loader. A 4-in-1 bucket is very handy as you can use the bucket in the closed position for scooping and dumping dirt. Then opening up the bucket exposes the blade for grading the jumps into shape.
Keep in mind to make the jump wide at the base as it will get narrower at the top. Also shape the jumps at angles the riders can handle. It is pretty easy to make adjustments after a test ride.
This will take care of 99% of the back breaking work. After all the dirt has been pushed and shaped it will need to be compacted. Simply riding around the track will help this. A little a bit of old fashioned manual labour will be needed to put the final touches on the contouring.
Over time riding around will cut grooves into the track. These can be filled and graded with the loader.
99% tractor. 1% good old fashioned labour to get the finishing touches.
Safety is always the highest priority. Always use a tractor that complies with Australian Standards, including Roll Over Protective Structure, seat belt and protective covers. Only take on tasks within the capability of the machine and operator. Follow all relevant safety warnings, instructions and regulations. Wear appropriate safety equipment and use common sense.
* This article is a general guide only. Conditions vary from site to site. Judgement relating to your individual conditions must be exercised.