Motocross teams constantly tweak, test and tweak some more to gain the slightest edge over competitors.
From chain tension to a small adjustment on the clickers it can all add up to a smoother, faster Moto that keeps the rider at the front of the pack. One of the most common adjustments team mechanics make that the weekend rider often forgets is tire pressure, known as psi, or pounds per square inch.
Yes, you can ride your dirt bike on tires that feel "good enough." But you can't really ride unless you've got proper inflation for the type of terrain you're about to tackle. You'd be amazed at how much your riding can change depending on proper tire inflation. Think of it this way: Unlike a car where a pound or two doesn't make a huge difference in the 30 to 40 psi range adding 1 psi to 10 lbs. of tire pressure is a 10 percent difference.
So while your buds are out hot dogging on the triples follow the tips below and smoke them on the way to the finish line.
Some of the confusion around proper dirt bike tire pressure is because in many respects it is confusing. Most riders tend to throw their hands up and just go with the common 12 psi up front and maybe the same in back or an extra half pound. But riding on hard pack or off-road requires higher pressure than riding on soft and sandy conditions. Dune riders get even lower.
Plus you need to account for the pressure increase once the tire heats up. Generally, on a fair weather day you won't see a significant rise in tire pressure from riding but a 100 degree day could impact the pressure by several pounds. The tire heats up quickly so you'll know after a few laps how the weather and riding affects the overall tire pressure.
Top Motocross teams make half pound and even quarter pound psi adjustments between Motos if that's any proof of how important tire pressure is. So...
the best tire pressure for your dirt bike?
Before we get started - check the pressure at your destination not the night before at home. Changes in elevation can change the pressure in your tire.
Check the tire pressure where you're riding, not at home
Track or Trail Conditions
Start with 12 in the front and 12.5 to 13 in the rear whether you're riding track or off-road.
In off-road, the higher pressure is less about the speed factor and more about preventing flats. A harder tire is one defense against a flat. The softer the tire the easier the tire is to puncture. Now you can prevent all this guess work by using a Bib-Mousse which eliminates the need for air and also eliminates the chance of a flat. It provides a constant 13 psi. The downside is the expense, installing them (not easy) and only Michelin tires use them. If you're riding another brand then stick in a heavy duty tube.
In Moto, 12 psi is a starting point until you get the lay of the land. Often however you'll know whether you're riding in sand or blue groove and can adjust accordingly prior to riding. That's what a walk through is for, so is the practice ride. In fact, most popular motocross tracks publicize the typical riding conditions and if you ask around you can learn pretty quick the ideal tire pressure settings.
If you're on a sandy track lower the front to 11 and the rear to 11.5 but if you're on hard pack try 13 front, 13.5 in the rear. Keep in mind though, if it is 100 degrees out you'll have higher pressure once the tires heat up.
As with all things dirt bike no rider is the same. Ricky Carmichael famously rode with his bars practically in his lap but most riders prefer the more upright position. We don't know anyone who wins Motos riding on 7 psi tires but hey if that's working then that's what you ride. You get the point.
Therefore, when riding, if you're doing everything correctly but that squirrely rear tire keeps breaking loose or your front tire won't stay planted in the corners you just might have a tire pressure issue. (Of course we're assuming you're a skilled rider and have the basic mechanics down, If not read 5 Mistakes Dirt Bike Beginners Make.) Add or subtract air as necessary. If you're still having issues then you might have the wrong tires. Check out Dirt Bike Tires & Wheels Explained.
Take note of the tire pressure prior to riding and then in between Motos make the change. Yes, you'll need to let the tires "cool off" so if there's not enough time just let all the air out and start over. It's pretty quick to get the tire pumped up to 12 psi especially if you have a tire compressor. Check the tire pressure right up until the gate call and make any changes. One rule of thumb is to add extra air since it's easier to let it out in a time crunch then adding more air in.
Don't forget your pressure gauge, preferably one that measures in quarter pound increments, and tire pump every time you ride.
For the ideal Dunlop tire pressure at the the best motocross tracks in the country check out Dunlop Tire Setup at the Top Motocross Tracks.