TIP ONE: CHECK THE PRESSURE EVERY DAY
Tire pressure constantly changes. It increases as the tire gets warm during use. It decreases as the tire cools. It changes with altitude, air temperature and humidity. Checking it often will save you from going to the line with an under- or over-inflated tire.
TIP TWO: BUY A REAL TIRE GAUGE
Motocross success depends on getting the tire pressure spot on. You can't afford to be off by a pound or two. There is a big difference between 16 psi and 14 psi. Tire technicians always use the best air pressure gauge they can afford. A pencil gauge is the minimum for any racer. They are normally accurate within one pound, durable and small enough to fit in your tool box.
TIP THREE: HOTTER EQUALS HIGHER
As we said, weather affects your tire pressure. If the temperature drops significantly, it will lower your tire pressure. If the temperature rises, your tire pressure rises. Direct sunlight on a tire will increase tire pressure by several pounds. If you adjust your tire pressure in the cool morning air, don't expect it to be the same when the afternoon temps hit 90 degrees. Also, in the course of a moto, tires heat up and the air pressure increases. You can gain as much as 4 pounds during a long moto. Makes some calculations about this as you bcome more experienced.
TIP FOUR: DIRT IN EQUALS AIR OUT
Dirt on your valve stem can cause air leakage. Always run valve caps on your Schrader valves. Make sure the cap is tightened all the way down. Valve caps with rubber seals are best.
TIP FIVE: HARD TRACKS REQUIRE HARD TIRES
The rule of thumb for motorcycle racing is that hard dirt requires hard tires. If you normally run 13 pounds of air on loamy dirt, you may want to increase that to 15 pounds on rock-hard dirt. Low tire pressure squiggles on hard dirt, and even worse, rock-hard square-edge bumps can pinch flat a tube if you run low pressure. If you track has square-edge bumps, rocky ledges or other hard obstacles consider a pound more to help lessen the chance of flats. Pee-Wees should always run high tire pressure (soft tires just rob power from the little engines).
TIP SIX: SOFT DIRT SPELLS SOFT TIRES
The softer the dirt the lower the tire pressure you should run. On a really muddy day, you can lower your tire pressure to as little as eight pounds to help the tire squish down and search for traction. The only exception to this rule is when the mud is very clingy and clogs up the knobs. In clinging mud, increase the tire pressure so that the fully inflated tire will fling the mud off to help clean the tire out.
TIP SEVEN: PRESSURE CAN AID YOUR SUSPENSION
Your bike's handling and suspension can be helped by the proper tire pressure. Too much air pressure will create understeer in the front end and midstroke harshness in the rear. Too little air will cause oversteer in the front and wallowing in the back.
TIP EIGHT: HOW TO BREAK THE BEAD
The best way to break a tire's bead is with two tire irons. Use one iron to pry down on the tire's bead while inserting the second tire iron close to the first one. Use the second tire iron to get between the rim and the bead. Push down until the bead drops into the hump of the rim. If this fails, you can always use the old standby–standing on the sidewall.
TIP NINE: GET YOURSELF A SPOON
Spoon-style tire irons are the best. The spoon end helps you get between the bead and the rim easily. Additionally, the spoon lessens the chance of pinching a tube. The longer the tire iron, the more leverage you have. As a rule of thumb, tire irons should be at least 10 inches long.
TIP TEN: GET IT HOT BEFORE YOU START
A warm tire is easier to mount than a cold one. Before you even consider mounting a new tire, try to get it warm. The easiest way is to put it in direct sunlight. On a cloudy day, you can put it under the hood of your car with the engine running.
TIP 11: STAND UP LIKE A MAN
Your rim needs to be free of dirt, tape and chemical residue. When changing a tire, it's best to get it up off the ground. Water buckets, bike stands, pickup truck beds or garbage cans make excellent tire changing stations.
TIP 12: LUBE IT UP
A slippery bead goes on smoother than a dry one. You can lubricate the bead with a wide variety of solutions. There are very good commercial tire lubes (like 1.7's Tire Mounting Lube), but a 50/50 mix of soap and water also works very well.
TIP 13: PREP THE RIM LOCK BEFORE IT'S TOO LATE
Check the rim lock before you put the tire on the rim. Mount the rim lock in the rim and snug it up. Once you have it tightened down, check it carefully to make sure it fits properly. Look for bare metal, exposed edges or a bad fit against the rim. If the rim lock doesn't fit evenly, get a new one.
TIP 14: EASE UP ON THE RIM LOCK
Don't over-tighten the rim lock. A rim lock is designed to trap the bead of the tire against the rim. It doesn't have to be super tight. It only needs to be snug.
TIP 15: PUT AIR IN BEFORE YOU PUT THE TUBE IN
Put air in the tube before inserting the tube into the tire. This takes the creases out of the tube. Only inflate the tube enough to give it a saggy shape. Putting air in the tube lessens the risk of pinching it with a tire iron (because the tube doesn't lay flat against the bead).
TIP 16: SMOOTH AS A BABY
Before you put the tube in the tire, sprinkle baby powder on the tube and inside the tire carcass. This minimizes chafing (just like on a baby).
TIP 17: WATCH IT CLOSELY AT FIRST
A new tire needs special attention. Place a mark on the tire directly in line with the valve stem. After your first ride, check to insure that the mark on the tire is still lined up with the valve stem. If it isn't, the tire has spun on the rim. Tighten the rim lock if you note any slippage. You should also check the tire pressure after your first ride. It could change as the tire and tube expand under pressure.
TIP 18: EXTEND THE LIFE OF YOUR TIRE
You can extend the life of your tires by 25 percent if you flip them over once they start to wear out. The knobs almost always wear out in the direction of rotation, while the trailing (braking) edge wears less. By turning the tire around, you can get a sharper edge without spending any money.
TIP 19: HACK AWAY AT THEM
Tire manufacturers don't recommend cutting knobs on used tires, but they are in the business of selling new tires. To tell the truth, sharpening up the edges of an old tire (with a razor blade or tire groover) doesn't turn an old tire into a new one and can cause the tire to wiggle because it narrows the knob and encourages knob flex, but it does give the tire a new edge (if only for a short time). It is best to groove the top of the knob to get new edges to grip with.
TIP 20: TIRE TIPS FOR CONCRETE
Don't do smoky burn-outs on concrete starting pads. It doesn't do squat. Just spin the tire a few times to make sure that it is clear of dirt and debris. Excessive spinning doesn't give you any advantage, but it does wear out your tire faster. You want clean rubber - not hot rubber.