custom bmx bike

Custom BMX Bike – Build Your Own Bike from Scratch

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Not everyone’s demand, requirement match to what the bike manufacturing companies offer to the customers. For example, a person who is tall requires a longer tube for him. If you do not get what you want, then why not make it the way you like?

Building A Custom BMX Bike

When it comes to building a custom BMX bike, it is not that difficult how it seems to build one. Almost everyone with a little knowledge of assembling parts can make their own.

In this article, I will show how you can make your own BMX bike.

1. Choosing the Frame

Want to make a good quality bike? Make sure you choose the right frame.

Your most desired bike will be constructed on this frame. In this case, you can weld tubes or get a frame set from the professional bike frame makers.

I would suggest you to buy a frame that checks all your needs. It will ensure better durability and add a professional touch for your bike. A frame consists of a top tube, angular head tube and seat tube, and a stand over.

Now, what would be the measurement?

It depends on your height. As it is a custom made bike, everything here will be according to your requirements. However, there is some standard measurement that you can choose. If your height is between 4'9"-5'.2", then go for tube frames of 18-19.5".

You need to use 20-20.5” tube frame if your height is between 5’2” and 5’5”. Use 20.5-21” frame tube if your height is 5’6”-6’. Furthermore, if your height is above, then go for the one that meets your comfort.

When you choose the components, it is important for you to have proper knowledge about it. The best recommendation would be, search on google and check YouTube videos to make sure what you are purchasing is made of good quality.

The front end consists of forks, bars, and stem. You can purchase these parts from just one company. But if you have personal preferences and decide to mix brands, make sure you choose brands that only sell good quality parts for bikes. 

2. Installing The Headset, Stem And Fork

You will find frames with an integrated head tube. What you need to buy is an integrated headset. Now, check if your fork has an integrated headset race.

Most of the BMX bike fork includes a race. And if your fork does not have one, do not panic; your headset packages your back.

Inside the headset box, you will find few races. Here you need the lower race. It would be better if you apply a thin layer of grease to the headset surface. Now, install the lower headset bearing. Make sure the rubber that seals the bearing is faced downward.

Next, apply a thin layer of grease to the bearing surface of the head tube. Once you have done this, then slide the fork up to the bottom of the head tube. Then install the upper headset bearing. At this point, the rubber seal should be facing upward.

Now, it is time for installing the space ring. This bearing is also known as the compression ring. Apply a thin layer of grease here as well. The compression ring is for tightening the headset. Then, install the dust cover over the bearing and compression ring.

Depending on your height requirement, you might need to add a couple of races on top of it to raise the handlebar. Now, install the stem and handlebar to the fork. Make sure the stem is not standing too high that the fork takes the majority inside the stem.

Now, tighten the fork with fork compression bolt. Then tighten all the pinch balls for keeping the handlebar straight. You are done with the fork.

3. Installing Bottom Bracket, Crankset And Peddles

It is time to install the crankset and peddles. Flip the bike and let it rest on its handlebars and seat. To step further, you need to take care of the bottom bracket first. Bottom bracket consists of two bearings and an internal spacer that holds the crankset.

Your seat tube and down tube is attached to a short tube that referred to as bracket shell. Install the spacer through it. Keep holding one side of spacer until you install the bearing on the other side. A rubber mallet will hold it firmly.

Now, install the other bearing to the opposite side.

As you might already know, a crankset is the thing that attaches both the chain and pedals. And it spins the wheels by pedaling. The entire crankset consists of a spindle and a sprocket.

The spindle is a rod that attaches both the crank arms and sprocket is a wheel of cogs for the chain.

Now, you need to insert the spindle into the right side of the crank arm. Make sure it matches with the splines and pushes the spindle in. Tighten the bolt. Slide the sprocket down to the spindle. Attach it to the crank arm with a bolt.

When it comes to the installation process of cranks, bear in mind that you need to install them separately. The right crank should get attached to the bottom bracket. Do not forget to slide a crank spacer ring over the spindle.

At this point, the spindle will find its way to home.

Insert it into the bottom bracket, make sure it gets all the way to the end. A rubber mallet will make the placement of the crank firm. The crank should be in a vertical position facing downwards.

Now, it is time for the second crank to install. Like before, you need to slide a spacer into the left crank and insert into the bottom bracket. This crank needs to face upwards vertically. If the installation is correct, it will form a straight line.

Now, check whether both the crank arms have the same amount of clearance within them and the frame. If not, then you will need to add or remove spacers to adjust them. Finally, lock them up by tightening the bolts.

4. Pedals

Before starting the installation, apply grease to the threads of each pedal. Then with the help of a pedal wrench, attach both of them to each side of the crank arm.

On your pedals, you will find L and R indicator showing which one will attach to the left and right side of the crank. Wrench clockwise to tighten the right one, and do the same meaning counterclockwise for the left one.

5. Wheels

The front wheel will be mounted on the fork. Make sure, the safety washers are fully engaged in their holes. Then tighten the lock nuts on both sides.

To avoid crooking the wheels, you need to tighten each nut a little at a time. It will keep the wheel centered. If you plan to install pegs, it needs to do before tapping on the axle nuts. It will make the wheel installation a lot easier and keep the bike balanced.

For installing the back wheel, slide into the frame. Now, the rest of the work will be done after installing the chain.

6. Chain

First, wrap the chain around the back sprocket. After that, wrap it around the front sprocket. Join both the ends of the chain together. Make sure every master link is connected with each end of the chain. Every two pins of the master link need to be connected with a plate.

Slide the clip over the plate and snap it into the place. If you find any difficulty, you always have the option to use a flat-head screwdriver to get the thing done for you.

Install your pegs but keep it loose. Pull the back wheel and tighten the chain and tighten the pegs a little. Make sure you tighten up each side until the pegs are tight enough.

7. Breaks And Levers

You need to slide the levers onto the handlebars. But you can orient them whatever position you like. Take your time and try sliding it on different positions and choose a comfortable position. Then, tighten the levers with appropriate wrench.

Now, you can install the brake arms. Apply grease to the brake mounts. Then, slide the brake arms and spring onto the brake mount. Tighten the spring bolt.

Insert the cable into the lever and leave the barrel adjuster on the lever. Run the cable all the way to the brake arm through the top of the crossbar, down the fork to the wheel and in front of the fork. The cable should not be tight, and neither it should be loose.

Pull out the cable and cut the extended part of it by a wire cutter. Through housing, make sure the inner cable is put back. Now, connect it to the brake arm. Tighten the bolts.

You need to adjust the spring tension. It needs to tighten one by one side. To make things easy, loosen the spring bolt and adjust tension.

Once you are done, tighten the bolts again. You must test the brakes to ensure that they are applying pressure correctly.

You are almost there, the last thing that you need to do is to adjust the brake pads. Loosen it while holding the brake pad steady. Make it parallel with the rim by lining up the pad. When you are done, tighten the bolt.

The brake pad should not touch the rim. Keep minimum 0.04-inch distance from the rim.

To Conclude,

Do not be afraid just by reading the entire procedure. Once you start assembling your BMX bike, things will get a lot easier than how it seems now.

If you follow our instructions, you will not only be able to create your BMX bike, but also you can remove and re-install any parts of your bike whenever you want. In fact, you will gain the reputation among your riding circle as an expert BMX bike builder.

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