How to Build a New or Old School BMX Bike

Installing Profile Racing Cranks

You will need a cup pressing tool with a threaded rod with nuts and washers to press the Profile Cups into your frame. Use some grease to allow the cups to press in smoothly. Make sure the center bearing spacer is in place between the bearings and use the one that best fits your frame. The Profile crank tool will pull the arms onto your axle most of the way. The rest is done by tightening your crank axle bolts. Be sure to use the spacers to get a nice chain alignments and so that your left crank clears the frame sufficiently. Grease the 48 spline axle with the included anti seize grease and make sure the right arm goes on right side of bike as you look down when riding. Some cranks have a sprocket bolt on both arms so it can cause you to make a mistake.

Inner Tube Installation:

There are two valve types, Presta or Schrader. The Schrader valve is standard like on a car and the most common. The presta is a metal skinny valve that requires a smaller hole on your rim. Presta is sometimes called a French Valve. Presta Valves can be inflated using a Presta Valve pump or an adaptor that converts the tube valve to Schrader. Check your inner tire for sharp objects before installing your tube. Inflate tube slightly before installing so it keeps its round form. When the tire is ready for air push the valve up and down to seed the tire to the rim. Slowly inflate the tire while checking that the tire is equally seeded on the rim. If it is not seeded and you inflate it,  you could have a blow out and ruin your tire and tube. Don't bother patching tubes, just buy a new one unless you have had good luck with patching.

Do not drive around with a high pressure tire next to you especially in hot weather. If your tire blows out you could damage your ears or the girls ears next to you. Try a little baby powder between tire and tube to prevent sticking. A 20 x1.75 tube will inflate up to a 20 x 2.125 tire or even larger. The inner tubes will fit a range of sizes since they stretch. If you have a 20 x 2.3 or 2.5 you may want to use a wider tube to the tube does not have to stretch out so much and become thin making it easier to get a flat. However, using thinner tubes is lighter weight which is a advantage rolling resistance wise.

Chains Install:

Chains are sold in a standard length that will need to be cut to fit your bike. Chains are 3/32" narrow for race bikes and 1/8" for Freestyle Bikes. If you front sprocket is a 3/32" you can use either a 1/8" chain or 3/32" chain. If you sprocket is 1/8" you can not use a 3/32" chain. Chains are cut to length with the proper chain tool. Choose a tool for the width of your chain. For 1/8" chain the Shadow Interlock chain breaker tool is nice. If you have a multi speed bike then you buy the chain that says it works for your number of speeds. For example, if you have a 3 x 8 drive train then you get a 8 speed compatible chain. When using your chain tool, make sure the pin you pushed in is exactly the same as the other pins and the links are not damaged in the process. Most chains break because they are not installed properly. If you are replacing your old chain simply cut your new chain to the same length and install.

Custom Wheel Building

When some wheels are hand built there is a break in period where the spokes may loosen up.
Often you can tighten up the spokes by tightening each spoke by a half turn or full turn, until tight. This loosening of spokes occurs because all hubs, rims, spokes and nipples have different machining. For example, one hub may not be as compatible with the rim and spoke you choose. Buying prebuild factory wheels can often prevent this wheel break in period. A spoke wrench and a truing stand would be helpful in maintaining your wheels. Click wheel building rates for more info. Check this bmx bike wheel building video

If you can find your hub and or Rim on the BMX spoke calculators you will need to get the specifications from the manufacturer website and plug them into a spoke calculator like this one we link to.

Headsets

Bearings, cups and other parts needed hold your fork to the frame. Old school frames take 1" threaded headsets. If you fork has threads on it it is threaded and not threadless. Then the industry when from 1" threaded to 1 1/8" threadless we had a change in the standard. 1" headsets would tend to loosen up so the new design took over. This collaborative industry change marks the new standard size. It just may just go down in history as the time when old school became new school. The forks became 1 1/8" threadless and the steerer tub became longer so the threadless new style stem would slide on to it. The old style stem (gooseneck) was called 1" shafted and always had that long expander bolt to hold it in place.

Traditional Threadless Headsets:

Traditional threadless headsets are headsets that use a cup and bearing system. These headsets use cups that must be pressed into the frame and by force of compression via a star nut can be tightened down. These headsets were most popular on all frames from 1994-2001. Set your 1 1/8" Aheadset spacers below your stem so that your ahead cap never touches the top of the fork. Usually a 1/8" gap is nice. If it touches your headset will not pull together to snug the bearings up. Use a Phil Wood or Park grease or any white Lithium. Even automotive axle grease is better than no grease on unsealed cartridge bearing headsets. 

Internal Headsets:

Internal Headsets are the newest headset design for modern Aluminum Race Frames. These headsets are commonly mistaken for Integrated Headsets (which are headsets that are made with no cups so that the bearing is sitting inside the frame). The Internal headset is a headset that still has a steel cup that sits in the frame, but rather than a traditional 1-1/8" Threadless Headset the cups are hidden inside the frame. Since Aluminum frames are pitted easily, bearings cannot be run on the metal with a steel divider so the cup must be used. Generally, you can tell an internal frame from a traditional frame by the width of the headtube and the hourglass design that they use to make the headtube wide enough to hold an entire headset inside. This style headset has only been used on frames for around five years.

Integrated Headsets:

Integrated Headsets are the most widely used headsets on newer style chromoly frames. Integrated Headsets utilized semi sealed or sealed bearings that rest inside the frame on a cup that has been bored out of the headtube. This makes easy assembly and disassembly. These headsets come in two sizes for different types of frames. One size is a 45 x 45 Campagnolo Style Headset. This would include the FSA Impact, FBM, Eastern and Campagnolo Hiddenset Integrated Headsets. This is the general size for integrated headsets and there are few exceptions to the rule. This would include all chromoly frames with the exception of Sputnic, Volume, Stolen and a few others denoted throughout the website. These frames use a slightly larger Cane Creek IS-2 integrated style headset. These headsets are the same design as the Impact Headset with a different sized bearing that will only fit those rare frames. You can tell an integrated frame by a coke can size or hourglass headtube that looks to have cups built in.