Overview
Assembling a BMX bike from the ground up may seem at first like a daunting task. But when the process is broken down into a few manageable procedures, it gets a lot easier. You’ll put together the front fork and steering first, then the crank and seat. Next will be the wheels, and finally you’ll install brakes. With the right tools, a BMX bike can be assembled in less than day.
Step 1
Place the bottom bearing race onto the steering tube on the bike’s fork. Place the wood block on the inside edge of the race and carefully hammer it in place, working around the race as you go. Grease the race and slide the bearings onto the tube. Insert the steering tube into the head tube in the bike frame. Slide the top bearings, top cap and spacers for the brakes on the head tube.
Step 2
Unscrew the bolts of the steering stem and attach the handlebars to the stem. Tighten the Allen bolts. Place the stem on the steering tube and push down. Grease the steering bolt, insert it into the stem and tighten it.
Step 3
Grease the inside of the seat tube in the frame. Place the seat clamp onto the seat tube. Insert the seat post and tighten the seat clamp. Attach the seat to the post. Flip the bike over to stand on the handlebars and seat.
Step 4
Grease the crank tube. Install the crank bearings into the crank tube using a bearing press. Attach the sprocket to the right crank arm. Insert the crank axle through the right crank arm and place the crank spacer onto the crank axle. Hammer the crank axle in place in the right crank arm. Place any crank spacers onto the other side of the crank axle. Place the left crank arm onto the end of the crank axle. Thread the crank arm bolt into the crank axle and tighten it.
Step 5
Grease the threaded holes at the end of each crank arm. Insert the threaded pedal axles into the holes. Tighten the pedals with an Allen or adjustable wrench.
Step 6
Place the front wheel on the front forks. Place a washer and axle nut into one of the front foot pegs and thread the nut onto the axle using a socket wrench and extender. Repeat this step on the other side for the remaining front foot peg.
Step 7
Place the rear wheel into the dropouts in the frame. Place the chain over the gears. Install and adjust the chain tensioners on each side of the dropouts. Place a washer and axle nut into each of the back foot pegs, thread the nuts onto the axle and tighten the nuts with the socket wrench.
Step 8
Attach the brake levers to the handlebars. Grease the front brake arm mounts. Slide each brake arm onto the brake arm mounts. Insert the brake spring bolts into the brake arm mounts and tighten them finger tight. Insert the metal tip of the inner brake cable into the front brake lever. Run the brake cable along or through the frame to the brake arms. Measure the brake cable and cut the outer housing to length. Attach the cable to the brake arms and tighten the spring bolts. Trim the inner cable and crimp a cable tip on. Repeat this procedure for the back brakes.
