Correlation between Tire Pressure and Acceleration of a Motorbike

In summary, there is a discussion on Stack Exchange about the correlation between tire pressure, loadout (such as riders), and acceleration of a motorbike. The conversation mentions that tire pressure can affect load sensitivity and that total rider mass is important for power-limited acceleration. The addition of a passenger can potentially increase rear wheel loading and improve traction on certain surfaces. However, for most motorcycles, acceleration is not grip limited and is instead limited by other factors such as rear swingarm geometry and center of gravity.
  • #1
bagasme
79
9
I have asked this question on Stack Exchange: SE question.

I often encountered this sticker on most motorbikes (especially matic ones) [credit: cintamobil.com]:
245804


There, when the tire pressure was measured from cold condition, the tire pressure are same regardless of loadout (29 psi and 33 psi for front and rear tire respectively).

According to SE:
The acceleration of the bike is given by the torque of the engine and the mass of the bike plus passengers - so when you have a passenger, there is greater inertia to overcome and your acceleration will be less
The force of friction is typically (naively) modeled by Ff∝μN
, whether static or kinetic (while both of these forces are vectors, the normal force acts perpendicular to the surface while friction acts in some direction parallel to the surface). If engine/gearbox can put enough torque on the axle to spin the wheels out, then the acceleration is capped not by the drive-train, but by the friction between the drive wheel(s) and the road.

Most tire manufacturers recommend a tire pressure which balances the durability of the tire's sidewall and the increased gas mileage of an over-inflated tire with the added comfort, acceleration and braking of a slightly less inflated tire (see rolling resistance). Obviously, tires either too flat or too full are a safety hazard.
If the engine/gearbox are powerful enough, the center mass hasn't moved too high and the connection between the road and the wheels exceptionally tight, one could see greater acceleration with a passenger.

Is it true that tire pressure and loadout (e.g. riders) correlate with acceleration of motorbike? Are there any papers that explain about it?

Regards, Bagas
 
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  • #2
bagasme said:
Is it true that tire pressure and loadout (e.g. riders) correlate with acceleration of motorbike? Are there any papers that explain about it?
Tire pressure will figure into load sensitivity.

As indicated above, for power-limited acceleration, total rider mass is crucially important.

The passenger will be toward the rear of the bike. Adding the passenger could thereby increase rear wheel loading proportionally more than front wheel loading, gaining more through traction than is lost due to the extra mass. On some surfaces, (snow, slush, water sufficient to hydroplane), the weight of the passenger could help the wheels "cut through" and get some purchase on the road beneath.
 
  • #3
For most motorcycles, acceleration isn't grip limited anyways, so all of those factors are irrelevant. Acceleration is limited by rear swingarm geometry, suspension, and CG location, since the limiting factor is the acceleration at which the bike will wheelie and flip over backwards.
 
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FAQ: Correlation between Tire Pressure and Acceleration of a Motorbike

1. What is the correlation between tire pressure and acceleration of a motorbike?

The correlation between tire pressure and acceleration of a motorbike is a positive one. This means that as tire pressure increases, acceleration also increases. Conversely, as tire pressure decreases, acceleration decreases.

2. How does tire pressure affect the acceleration of a motorbike?

Tire pressure plays a crucial role in the acceleration of a motorbike. When tire pressure is too low, the tire flattens out, resulting in a larger surface area in contact with the ground. This creates more friction, making it harder for the motorbike to accelerate. On the other hand, when tire pressure is too high, the tire becomes more rigid, reducing the surface area in contact with the ground and allowing for easier acceleration.

3. Is there an ideal tire pressure for optimal acceleration of a motorbike?

Yes, there is an ideal tire pressure for optimal acceleration of a motorbike. This ideal pressure varies depending on the type of motorbike and the surface being ridden on. Generally, it is recommended to follow the manufacturer's recommended tire pressure for the best performance.

4. Can changing tire pressure improve the acceleration of a motorbike?

Yes, changing tire pressure can improve the acceleration of a motorbike. As mentioned earlier, the right tire pressure can help reduce friction and improve the motorbike's overall performance. However, it is essential to maintain the recommended tire pressure to ensure safety and prevent potential tire damage.

5. Are there any other factors that can affect the correlation between tire pressure and acceleration of a motorbike?

Yes, there are other factors that can affect the correlation between tire pressure and acceleration of a motorbike. Some of these factors include the weight of the rider, the condition of the tires, and the road surface. It is essential to regularly check and maintain these factors to ensure the best possible performance of a motorbike.

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