Guide to Assembling a Complete BMX

When you purchase a complete BMX bike, most components come pre-assembled. Nevertheless, to ensure the bike fits into a reasonably sized package, the handlebars, pedals, and front wheel are not attached.

Putting together a complete BMX bike is straightforward if you follow the video instructions and the steps outlined below. Your new BMX will be ready in no time!

Building the bike offers a great opportunity to become acquainted with it. As an enthusiastic BMX biker, there's nothing more satisfying than giving your new bike some care before heading out for your inaugural session.

If you feel uncertain about assembling it on your own or lack previous experience with bikes, we strongly suggest seeking assistance from a specialised shop.

Tools Required for Assembling a Complete BMX Bike

You will only need a few tools to get started.

Allen keys
Spanners
15 mm open-ended spanner for pedals
Air pump

Explore our range of BMX Tools - We've got what you need!

Unboxing and Assembling a Complete BMX - Step-by-Step

Begin by removing all plastic and foam, and unpack everything, ensuring that nothing is missing from the package.

Initial Assembly Steps

Apply grease to the pedal bolts.
Distinguish the left and right pedals.
Turn the right pedal clockwise and secure it with a spanner.
Turn the left pedal anti-clockwise and tighten it completely with a spanner.
Loosen the stem bolts.
Detach the stem faceplate.
Grease the stem bolts.
Attach the handlebar.
Position the faceplate over the stem, ensuring the knurled section of the handlebar is centred in the stem.
Tighten the stem bolts in a cross pattern; you don't need to fully secure the faceplate at this point.
Loosen the top cap/compression bolt using an Allen key.
Align the handlebars with the fork.

Now, you're ready to install the front wheel:

Almost completely unscrew the front axle nuts to make space for the fork dropouts.
Tighten the nuts by hand.
Using a spanner, ensure the nuts are fully tightened.
Insert the BMX seat into the seat tube. Consider greasing the clamping area internally to facilitate easier removal of the seat post later on.
Secure the seat clamp with an Allen key.

Once the seat is in place, you can adjust the handlebars and fork alignment while seated on the bike. This greatly enhances precision:

Align the handlebar with the fork, using the front wheel as a guide.
Tighten the top cap/compression bolt using an Allen key.
Complete the tightening of the stem in a cross pattern, ensuring the bolt is tightened diagonally across from the previously tightened one.
Ensure there's an even gap between the stem faceplate and the stem itself—uniform tightening of the faceplate is crucial.

Before riding off, inspect a few final points:

Examine the chain—if it moves more than 2 centimetres, it's too loose. You can resolve this by loosening the wheel and pulling it backwards until the chain is correctly tight.
Verify that all nuts and bolts are adequately tightened.
Inflate the tyres to the specified pressure (marked in PSI on the tyre's side).
Remove the valve cap and attach the pump.
Inflate the tyre and reattach the valve cap.
Repeat for the other wheel.
Now you're set to ride!

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For more exhaustive instructions on brake installation, refer to: How to Mount a BMX Brake.