Some guys kick around the idea of building a dirt bike as if it was as simple as building a flower box or a shelf for their books. It’s not. It takes a lot of determination, knowledge, common sense, mechanical wherewithal, patience, persistence and the ability to not get too impressed with yourself. After all, just because it looks good doesn’t mean it will run. And just because it runs doesn’t mean it won’t fall apart the first time you hit a rock on the trail.
Now that we know we should pay attention while building our dirt bike and not be distracted by the newest “Shadow of the Colossus” release it’s important to mention that there are actually 2 ways to build your own dirt bike. The first entails finding an old dirt bike that has been moldering away in the junk yard, stripping it of anything that’s no longer useful (which should be just about everything) and then pimping out the frame with new components until you have the dirt bike of your dreams.
The second way to build your own dirt bike is to create it from scratch. That is, start with nothing and build it from the floor up. With this method you have absolute control over the build from day one and can make sure you select only the best parts. That way you minimize the possibility of equipment error and can just focus on putting everything together properly and fine tuning it prior to taking it out on the track. Be warned that it will cost a pretty penny to do it this way however.
Before we get into the nuts and bolts of how to build a homemade dirt bike though it’s important to know the different types of dirt bikes out there along with when and why they are typically used. After that we’re going to look at the various components that make up a dirt bike. Then we’ll dive into the process of putting it all together and tripping it out with your own custom dirt bike graphics.
The Different Types of Dirt Bikes
People unfamiliar with the common dirt bike tend to think there is only 1 kind: the kind with those high-strung engines and fenders like woa! The fact is however there are a number of different kinds of dirt bikes and if you try to win a motocross with an endurance bike you’re going to be in for a very long, unsuccessful day. So choosing the right type of dirt bike for your intended use is critical if you are going to build one you can actually use. With that in mind here are the different types of dirt bikes.
- Motocross Bikes – Commonly referred to as “MX bikes” motocross bikes are built for one thing: racing. The typical motocross course involves lots of loose dirt, mud, jumps, tight corners and straightaways. Sometimes these are very tightly controlled courses built temporarily inside arenas and sometimes they’re long established outdoor tracks like Unadilla. Motocross bikes typically have tough suspension systems and tires with deep, hungry treads.
- Desert Bikes – Desert bikes are also referred to as “sand bikes” and their designed specifically to be used on large expanses of sandy terrain whether that’s in the actual desert or on a beach. Because sand is such a corrosive element the drivetrain and transmission of the desert bike needs to be sealed tight. Tires are also specifically designed to avoid sinking into the sand and to grab as firm a hold as possible in the loose surface.
- Trail Bikes – Trail bikes are commonly mistaken for motocross bikes. But while there are many similarities there are also differences between the 2 that are driven by the differences in the terrain they have to navigate. While MX courses can be extremely challenging they are relatively well-groomed compared to some of the trails out there. And even though trail riding is mostly an enthusiast sport rather than a profession the bike is still going to take an extreme pounding. So heavy duty suspension and special off-road tires are the order of the day.
- Endurance Bikes – Enduro races test the strength and endurance (and so the name) of both the bike and the rider. It’s a lot like trail riding only far more grueling and a single race can last up to 3 hours. That’s a lot of time to be battling tree roots, creek beds and woodland trails. Because of the length of the race an endurance bike will need a larger than average gas tank and a suspension system that’s tuned to the particulars of the course since every course is a bit different.
- Street Bikes – A street bike can be taken off road or down the highway (although you won’t want to take them on the Interstate). As such they’ll need to pass standard road-worthiness requirements which usually means tires that are better suited to flat, hard road surfaces and mufflers that bring noise levels into line with local ordinances, along with a full complement of lights.
Now that we know what the different types of dirt bike are let’s take a look at the various components that go into building one.
Major Parts of a Dirt Bike
We’re going to assume for the purposes of this article that you have decided you want to build a standard MX bike. There are still a few more things you should probably know about dirt bikes before you start procuring parts. Your dirt bike won’t have a faring to break the wind, won’t have a big comfy seat for 2 people, won’t have the kind of top-end speed a standard street bike will and won’t be very heavy or very aerodynamic. Got all that? Great. Let’s look at the main components you’ll be needing to build your own dirt bike.
- The Frame – The frame provides structural support for all elements of the chassis which in turn determine the relationship of the vehicle to the course. The frame is typically built of aluminum or steel and is responsible for carrying the weight of all the other parts, so it needs to be tough. The suspension is an integral part of the chassis and includes the rear shocks which attach to the frame at one end and the swing arm at the other and the front forks which have built in shocks that can be adjusted as you see fit.
- Engine – Almost all dirt bikes will have a 2-stroke engine. These engines fire on every revolution of the crankshaft as opposed to firing on every other revolution, which is what a 4-stroke engine does. Because of this the 2-stroke gets off the line much faster than the 4-stroke. The 4-stroke is also heavier which impacts its ability to get up to speed. Most MX bikes will have an engine displacement under 450cc (with most being considerably smaller than that). They are also single cylinder engines which again cuts down on weight and means fewer moving parts (so fewer potential problems).
- Wheels, Tires and Seat – Tires made for use on hard terrain would be made of relatively soft rubber with tread blocks that are pretty close together. Tires built for sand or desert bikes typically have what’s called a ‘paddle tread’. As for your standard MX bike you’re going to want tires specifically designed to navigate the terrain of the MX course. And that means tread. And lots of it. Typically widely spaced lugs that have the effect of paddling through the soft dirt and mud. You also owe it to yourself to get a top notch seat. You’ll have pretty wide leeway regarding styles, just make sure to keep the weight down.
- Brakes – A lot of times on the motocross track you’ll be landing after a big jump and then smashing straight into a hard turn. Your brakes better be able to hand it. Whether they’re drum brakes (whose stopping mechanism is internal) or disc brakes (whose stopping mechanism is external) they’ll need to withstand enormous stress and strain.
- Drive Mechanism – Most dirt bikes use a chain drive although an increasing number use belt or shaft drive systems. Chain or belt drive systems are lighter and when something goes wrong they’re typically easier to fix. While shaft drives are efficient but heavier and a pain in the you know what to repair if something goes wrong on the course.
It’s a given at this point that you’ll need an array of nuts and bolts, screw, wires, pins and clips to assemble a complete MX bike but we’re not going to get into that kind of excruciating minutia here. Instead, let’s have a look at what goes into building your new dirt bike using reclaimed/reused parts.
How to Build Your Own Dirt Bike: The Reclamation Method
A lot of MX enthusiasts want to find a way to enjoy their favorite sport without going broke. Certainly building your own motocross bike is one way to save money; as long as you can find the necessary parts and do it right. The alternative is to build your dirt bike using all brand new parts. Which is not only impractical but can get expensive as we’ll talk about below. The preferred way for most builders then is to start with a junker and rebuild/refurbish. Here’s how to do that.
- Visit the junkyard – Take a Saturday and go to the junkyard. Sift through the various dirt bikes they have on hand and look for one whose frame seems structurally intact without a lot of rust. The less rust the better, but as long as the frame isn’t rusted through anywhere it’s likely salvageable. Plunk down a few bucks and take it home. Alternately you can search online for a junker someone is trying to get rid of and as long as the frame meets the above requirements, pick it up.
- Assess the engine – Clean the bike up when you get it home enough so that you can get a good look at the engine and tell if it’s worth saving. If you’re unsure ask someone with mechanical abilities to take a look at it for you. A good mechanic should be able to tell you in short order if the engine can be salvaged. Just to be clear, most engines can be.
- Disassemble the engine – Drain all fluids from the engine and then take it completely apart. It’s important that you catalog and clean each part thoroughly. Keep everything organized so you know where each nut and each bolt came from and the sequence you used to take it apart.
- Assess body parts – Take a good close look at the gas tank, airbox and other parts to determine if they’re salvageable or need to be scrapped. You may want to just scrap them regardless and replace them with new customized parts that will allow you to retain the performance profile of the bike but give it a unique look and feel. If you want to stick with the original look of the bike and need to buy any parts look online for refurbished parts. The Internet is teeming with them.
- Paint the frame – Here’s your chance to add a custom touch by giving the frame a nonstandard paint job. Just make sure you keep in mind the motorcycle decals you’re going to add later so that everything works well together.
- Rebuild the engine – Put the engine back together carefully. Again, if you know someone with mechanical acumen it’s a good idea to have them on hand during this process to ensure it all goes smoothly.
- Buy new rims, tires and seat – Chances are good that the tires, rims and seat suffered the brunt of the years of neglect the bike went through before you claimed it from the scrap heap. As such they should be completely replaced. Make sure to pick a seat that is light, firm and reasonably comfortable.
- Finishing touches – If you were building a street bike you’d need to worry about the headlight, tail light and blinkers. But you’re not so you can skip that step. Your final touch should be to build your own dirt bike graphics. These motorcycle decals will be the cherry on the cake of your new bike (we’ll get into them more below).
- Test the bike – Have your mechanically inclined friend around when you test the bike. In case anything goes wrong they’ll be able to point you in the right direction to fix it. Once everything is working properly take it out for a test ride but keep the speed down and your eyes and ear open.
- Begin working on your legend – No one else will do it for you.
How to Build Your Own Dirt Bike: The OEM Method
The second way to build your own bike is to start with nothing more than a place to work and build from the floor up using OEM (Original Equipment Manufacturer) parts. While there’s no precise answer to the question “how much does it cost to build your own dirt bike?” it has to be said that this method is probably going to cost you more than if you just went out and bought a brand new bike. However, if it’s something you’re determined to do and you have the financial wherewithal then more power to you. We’re not going to go through all the steps in painstaking detail because they’re basically the same as described above:
- Start with a good frame. Give it a nice paint job.
- Add the engine.
- Add the tank and other parts. Give them a nice paint job.
- Add the wheels, tires and seat.
- Add custom decals from OMX.
- Rock the course!
The most important thing we can do here is provide you a checklist of things to keep in mind when building your own custom dirt bike from the ground up. Print this list out and tape it up on the wall of your workshop to always have at the ready.
Note that if you are unable to find new OEM parts reconditioned parts will usually do. Just be sure to procure them from a reliable seller.
- Tip 1: Consider a steering stabilizer – While these aren’t widely used by MX riders it just could save your bacon some day when landing hard (and maybe help you win in the process).
- Tip 2: Use a high-quality chain – Bars are full of old MX riders with stories to tell about how they had the race in their hands when their chain broke. Make sure you use a high quality chain and you won’t have any excuses for not winning.
- Tip 3: Be real with the power – A 250 2-stroke should be all the MX bike engine you need unless you have some compelling reason to have more power than that. With 450s you’re talking 4-strokes and extra weight and that would need to be justified.
- Tip 4: Rugged suspension is vital – You’ll want to work with someone who knows what they’re doing when it comes to selecting and tuning your suspension. But the bottom line is that it will need to be a robust system if you’re serious about motocross.
- Tip 5: Get the handlebars right – If you’re of average height you’ll probably want to go with low bars, maybe rotated forward a little until you find your comfort zone. Anyone over 6 feet is going to want taller bars or they’ll be unbalanced to the fore all the time.
- Tip 6: Don’t forget the skid plate – One unlucky encounter with a rock or tree branch or piece of gravel could end your day in a hurry and send you to the parts store for a new oil filter, shifter or brake pedal. Not having a skid plate increases your chance of not finishing. Why would you want to do that?
Building a dirt bike from the ground up using OEM parts will be expensive but it may well provide you with a hybrid MX bike others will be drooling over. As long as performance matches the looks you’re golden.
Decal Works: Build Your Own Dirt Bike Kits
Whether your new custom dirt bike is based on a salvaged frame and motor or is something you built from scratch using off the shelf OEM parts the custom decals you apply as your final step will make all the difference in the way your bike, and you, are perceived. OMX graphics offers a dizzying array of semi-custom dirt bike graphics along with the ability to design your own fully custom dirt bike graphics with the help of our world class designers.
When you choose to build your own dirt bike you’re making a statement about your brains and determination and you’re telling the world you will not be denied no matter what. Your new bike deserves custom graphics that are as bold and original as your new bike. No matter what path you chose when it came to the matter of how to build your own dirt bike it’s here now. Make sure it’s one to be reckoned with by installing incredible custom graphics from OMX. They’re a tremendous value, provide you with a wealth of options regarding how much or how little coverage you want and they’ll be in your hands in a flash so that once you build your own bike you can get it on the course in a hurry.
Here’s one final tip: make sure you document the process every step of the way. Not only will it be priceless record of your effort that you’ll refer to for years to come but it will help you immeasurably when it comes to things like putting the engine back together.
Whether you start from scratch using off the shelf parts or rescue a vintage bike from the junk yard you’ll always have a special connection to your new bike regardless of whether it enjoys a legendary career or not. Make sure you pay homage to the effort that went into its creation by decking it out with custom graphics from OMX.