Avon tire questions

[atlm]

The two most important traits of all tires are grip and mileage. All tires are a compromise of the two. Costs and tire design being equal, a softer rubber compound will give better grip at the expense of mileage, and visa versa, a harder compound will give higher mileage at the expense of grip. Race tires have softer rubber compounds for high grip, but give very low mileage. Touring tires have harder rubber compounds for higher mileage, but have less grip.

 

Tires are designed to run at a specific temperature. That temperature gives the optimal grip and mileage for that specific tire, as determined by the tire manufacturer.

 

When you drive on a tire, it flexes. That flex causes heat, which brings the tire up to its running temperature. The amount of flex determines the amount of heat. A properly inflated tire, per the manufacturer's specs, will flex the proper amount to bring the tire to the designed running temperature. That temperature will give you a certain level of grip and a certain amount of mileage.

 

The more load you put on the tire, the more it will compress, or flex.

The more air pressure you put in the tire, the less it will flex.

Since temperature is based on how much the tire flexes, to get the correct running temperature, you need the correct amount of flex.

 

Since the amount of flex is based BOTH on load and on pressure, as the load in the tire goes up, so must the air pressure.

 

The max tire pressure on the sidewall is for the max load on the sidewall. Anything less than the maximum load, as listed on the sidewall, requires less air pressure than the maximum listed on the sidewall.

 

That's why the tire pressures given by manufacturers for a given tire for a given bike are based on the running weight of the bike (with driver, passenger, etc.). The higher the weight, the more air pressure.

 

Can you run tires at the maximum pressure listed on the sidewall with lower than maximum tire load? Yes, absolutely. However, the tires won't come up to their designed running temperature, which sacrifices grip. Since the tires are colder/harder, your mileage will increase. For highway riding, or for riders who take twisties at a very moderate pace, higher pressures can work fine and provide higher mileage. However, for riders who are aggressive in the twisties, exit ramps, etc., higher than designed air pressures could prove disastrous.

 

Can you run tires at lower than optimal pressures? Yes, absolutely. However, the tires will run at higher than designed temperatures, which could give you slightly better grip, but will also lower your mileage. Too low can result in tire breakdown and failure. Many stunt riders will run their tires at very low pressures to get them up to temperature at low speeds.

 

Hope this helps clear things up.

Edited January 13, 2010 by atlm