The following suggestions (with some minor edits) are excerpts from an eHow.com article called How to Set Up Your Bike for Flatland Freestyle, contributed by an unnamed author. These tips are very general, but there is some valuable basic info here for beginners. Read on:
BMX flatland freestyle is probably one of the most difficult sports on the planet, but it is also one of the most rewarding. It takes years of practice and dedication, and it helps to have a bike that is set up for flatland. Follow these tips to get started.
• Start with a good flatland-specific frame. These usually have a short top tube, a short rear end, and steep angles.
• Do a quick check of the frame and everything else on the bike, to be sure nothing is cracked, bent or broken.
• Remove any pads, reflectors, chain guards or kickstands.
• Put axle pegs on the front and rear wheels, and install a cable detangler for the brake cables.
• Position your handlebars so that they are straight up and down, or parallel with the fork. You may be more comfortable with your bars a little further forward or back, but don't stray too far in either direction.
• Remove old grips if they're torn, or if the handlebar is showing through. Bar end caps will help protect you from the ends of the handlebar.
• If possible, choose a wheelset that has a rear hub specifically designed for flatland, usually called a freecoaster. Freecoaster hubs allow you to set your pedals at one position, and they will stay at that position when rolling backward. Conversely, hubs with a regular freewheel allow the pedals to travel backward when the rear wheel is rolling backward, and coaster brake hubs don't let you set the pedals easily because of the brake built into the hub.
• Use tires that have a smooth tread, and inflate them to the maximum air pressure. Most flatlanders run at least 100 pounds of pressure in their tires, even though it is usually well above the recommended pressure on the tires. When doing so, take care to use tires which are rated to near that pressure range.
• Tighten all nuts and bolts to their specifications, including axle nuts, stem bolts, pedals, cranks, seat and seat post nuts, brakes, and headset.
• Lubricate all moving parts, such as brake cables, brake pivot bolts, and your chain.
• Put a sufficient amount of tension on the chain, so that it doesn't fall off or have excessive slack when you're riding.
• Choose platform pedals over caged pedals or clip-in pedals.
• File down, cover, or otherwise protect yourself from any sharp edges on the bike, such as the edges of the stem or handlebars.
• Many riders are learning to ride flatland with only one brake, or even with no brakes. It's all a matter of your personal preference and style.
• When you're setting up your brake cables, make them as short as possible without sacrificing effective braking. Long cables tend to get in the way.
• Always make sure your spokes are tight and the wheels are straight.
• When choosing pegs, find some that are knurled or grooved for traction, or consider adding grip tape. Smooth pegs are great for street and ramp riding, but you'll want foot traction for flatland.
• If you can get pedals that have removable pins or pins which are not too sharp, use those. You're more likely to tear your legs up on sharp pedals than you are to slip off from smooth pedals.
• Always use pegs on the wheel axles, rather than on the fork or frame. The further from the axles you are, the harder the tricks are.
• Short crank arms - 165mm or 170mm - are less likely to get in the way than are longer ones, although for many cranks, 175mm is the shortest version you'll be able to find.
• If any part of the bike is creaking, check it out. It probably needs to be greased or tightened, or it may be cracked. A good bike is solid and silent.