Improper inflation of your bike’s tires could lead to excess flats and big drop-offs in performance and comfort. So, how much tire pressure should you maintain? There is no straight answer, but your tires, the type of riding you’ll be doing, your weight, and your preferences will result in the optimal PSI for you. Here are tips on how to start riding with your ideal tire pressure.
1. Check your tire pressure regularly.
Tires leak air over time, from as little as a few PSI in a week to drastic drops overnight. Outside factors, like lower temperatures, can increase the rate of loss. Developing and sticking to a habit of regularly checking your tire pressure and topping-off their levels before you ride will do your ride wonders.
2. Start with the range on your tire.
Begin to find your ideal air pressure by starting with the manufacturer's recommended pressure range you'll find printed on the tire's sidewall. If it's a wide range, like 40 to 70 PS, start in the middle of these ranges, then factor in your body weight. The more you weigh, the higher your tire pressure needs to be. For example, a person weighing 130 lbs may use 80 PSI on a while a 200-pound rider could run closer to 120 PSI on the same tire.
People often make the mistake of riding with too little pressure in road tires and too much pressure in off-road, knobby tires. Narrow tires need more air pressure than wide ones. And while it may seem natural to inflate front and rear tires identically, your weight balance isn’t 50-50 front to rear. Since you ride with more weight in the back, you’ll want higher air pressure in the back and less in the front.
3. Don't overinflate.
More isn't always better, and the maximum pressure listed on the sidewall is generally too high. It does not take into account any factors that influence your tire pressure such as rider size and terrain. The bone-shaking effect of over-inflated tires on bumpy surfaces steals your energy and is jarring at best. On ultra-smooth roads when rolling resistance is critical, like in a time-trial, go as to the high-point of your tire's rating. Stay at the lower end of the range for comfort and rough roads.
4. Adjust for your ride.
Tire pressure isn't a set-it-and-forget-it thing. Your perfect pressure may change according to conditions, terrain, weather, or if you switch brands. On new pavement, your tires might feel great at 100 PSI. On a rough road, however, they might roll faster at 90 PSI since your tires have more room to roll over bumps without transferring the impact to you. In wet conditions, you may want to run 10 PSI less than usual for improved traction. If you're a mountain biker who rides to the trailhead, keep in mind that while your bike rolls smoothly on the road with 40 PSI, it will probably feel better on the single-track at 30 PSI.
5. Find the sweet spot.
Experiment with tire pressure by deflating front and rear, roughly 5% (not PSI) each. Go ride and take note of how it feels and don’t be afraid to drop a little more pressure. Ideal tire pressure gives you a comfortable ride with a confident feeling in corners. Once the front wheel starts to feel the least bit squirrely in hard cornering, add a few PSI back in.
If you’re swapping from a traditional 23mm road clincher to 25- or 28-mm tires, or from a 2.1-inch mountain bike tire to a meatier 2.3, you’re increasing tire volume significantly, so you’ll need to adjust air pressure downward. If you run tubeless you can scale down even further, about 10-20%.