How to Assemble a Complete BMX

Purchasing a complete BMX bike means most components are pre-assembled. However, to fit the bike into a suitably sized box, the handlebars, pedals, and front wheel are not fitted.

If you carefully follow the video instructions and the steps outlined below, putting together your BMX bicycle will be straightforward, and you'll have your complete BMX ready quickly!

Assembling your bike provides an opportunity to familiarise yourself with it thoroughly. For an enthusiastic BMX rider, there’s nothing more satisfying than giving your new bike some tender loving care before embarking on your first ride.

Essential Tools for Assembling a Complete BMX Bicycle

Just a few tools are needed to begin.

Allen keys
Spanners
Open ended 15 mm spanner for pedals
Air pump

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

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

Begin by removing all plastic and foam, and ensure everything is unpacked, checking nothing is missing from the box.

Initial part of the assembly process

Apply grease to the pedal bolts.
Identify which pedals are left and right.
Screw in the right pedal clockwise - use a spanner to secure tightly.
Screw in the left pedal counterclockwise - ensure it is completely tight with a spanner.
Loosen the stem bolts.
Detach the stem faceplate.
Grease the stem bolts.
Fit the handlebar.
Position the faceplate over the stem, ensuring the knurled section of the handlebar is centred within the stem.
Tighten the stem bolts in a cross pattern – do not fully secure the faceplate at this point.
Use an Allen key to loosen the top cap/compression bolt.
Align the handlebars with the fork.

Now, you’re set to attach the front wheel:

Nearly unscrew the front axle nuts to provide clearance for the fork dropouts.
Tighten the nuts using your fingers initially.
Finish tightening the nuts using a spanner.
Insert the BMX seat into the seat tube, considering greasing the clamping area’s interior for easier removal of the seat post in the future.
Secure the seat clamp with an Allen key.

With the seat installed, aligning the handlebars and fork becomes easier while sitting on the bike, allowing for precise adjustments:

Align the handlebar with the fork – use the front wheel for guidance.
With an Allen key, tighten the top cap/compression bolt.
Complete the tightening of the stem in a cross pattern, always tightening the bolt diagonally opposed to the one just tightened.
Ensure there's a uniform gap between the stem faceplate and the stem itself - it's crucial that the faceplate is evenly secured.

Before you embark on your adventure, check these final elements:

Inspect the chain - if it moves more than 2 centimetres, it is too loose – solve this by loosening the wheel and pulling it back until the chain is appropriately taut.
Ensure every nut and bolt is securely tightened.
Inflate the tyres to the advised pressure (noted in PSI on the tyre's side).
Remove the valve cap and attach the pump.
Inflate the tyre and replace the valve cap.
Repeat the process on the opposite wheel.
Now you’re ready to set off!

Browse our extensive selection of complete BMX Bikes.

For more comprehensive guidance on brake mounting, refer to: How to Mount a BMX Brake.