How to Build BMX Ramps
The first step in building a BMX Bike Ramp is to decide what type of type of BMX ramp or ramps you are interested in trying. Take some time on planning because it's going to take some time and materials to build it and if you have it all done and then find you don't like it well, that will suck! Get out a pad of paper and a pencil and create a sketch or two of what you want the ramp to look like. be sure to put in dimensions as that's how you're going to know what materials to buy. Of course the easiest way to do this is to just surf around and find some good ramp plans that people have already done. You can find free ones or ones which may cost you just a few bucks online and really, unless you're an artist or an engineer or really want to create something no one has ever done before, it's a lot faster and easier just to use a prefab plan.
Once you know what you want you are going to need to do a little shopping or scrounging depending on how much cash you have. One thing for sure is you are going to want to obtain as much wood as you possibly can. Here's a minimum list of things you are going to need: 3/8 X 4 X 8 sheets of plywood (lots of them); 8 2x4's; Skill saw; handsaw; hammer; nails; sander and sandpaper; drafting compass; string; chalk (chalk line); garden hose; a couple of sawhorses; nail-punch; a pen; wood screws; drill with bits and driver heads; 3/8" PVC pipe
Now you need to get a good big space to work (driveway, backyard, garage) and to sort out all of the materials. If the plan is to build a big ramp or series of ramps then you are best to do it right where it's going to be used. BMX Ramps can get pretty heavy once they are built and it can be a hassle moving them. That said if the weather is bad or you have another reason you can still build your ramps in modules and then move them to your site to be attached together.
For ramps that are going to have curved transitions you need to use the string and compass method:
Determine the transition curve and height. Tack one end of the string around a strong steel push pin and tack it into the sheet. Now pull the string tight and measure exactly the transition. Mark the string with a pen. Attach a drafting compass to the other end of the string and tighten it on top of the pen mark you just made. Hold the string tight and swing the compass from the edge of the sheet in a 1/4 circle, marking this with your chalk. You will probably need to play around and try moving it different ways to get the curve you want. Finally put the sheet on your sawhorses and carefully cut out the templates.
Now that you have drawn and cut your templates you need to build the bracing.
With the bracing and framework complete you will most need to prep the top pieces of the plywood. Bend the sheet to fit the transition, carefully - without breaking it. You can achieve this by propping up the sheet which is cut to size at an angle, sloping it with a slight bend. Then use your garden hose to soak it. Keep apply water so it doesn't dry out while also apply slight pressure or weights in the centre - you can use bricks or something with decent weight. In about an hour you will find it contours to the curve nicely and you will be able to nail it in place.
Tip: always cut and place wood aligned with the grain. It won't curve and will probably break if you try and bend against the grain.
You could stop here but then you will likely end up with a bumpy transition, which sucks and can cause you to wipe out. To get a smooth transition sand the bottom edge of the sheet so it is flush with the ground. Check it over for splinters. Sand it and paint it if want but know that paint will make your BMX ramp a lot faster. Use can also use duct tape or even aluminum strips to make certain your transition is nice a smooth.
To see all of this in action I have put some excellent videos below this - check 'em out.
BMX Dirt Ramps
Build your own BMX Ramps from wood, from scratch is a lot of work. It takes time, space and money and some level of skill. Many BMXr's choose to go natural by just pulling out a shovel and heading out to the closest quarry or back field where they can create some really cool BMX Dirt Ramps. There's another vid below which gives you the quick and easy steps to building your own.
Join a Bike Club
Of course videos and articles and even books can give you all you need to know about building your own BMX Ramps but it's a lot more fun when you have someone to do it with. If you bike with other BMXr's get your group together and create a project you can all work on. If you don't know any one who is into it then surf around and find a good bike club that has a BMX chapter. There's lots of sites around online like http://bikeclubinfo.com/ which can direct you to a Bike Club in your area.