Wheel/Tire Combo Weight and Performance Question

[Burdy]

I am sure one of you physics majors can answer this:
When it comes to rotational mass and energy used to spin a wheel/tire combo, does it matter if greater weight is on the inside or outside of the wheel?

For example, all things being equal (Circumference, width, offset etc) is there a difference in the amount of power needed to spin a 10lb wheel with a 20lb tire vs a 20lb wheel with a 10 lb tire? My feeble brain tells me it's harder to spin the 20 lb tire with the 10 lb wheel since the weight is furthest from the power source but I am not sure.

Sponsored

 

[pdydm]

Your intuition is correct. Moment of inertia (effectively, mass in a rotating frame of reference) scales with radius^2. How much that actually affects the performance of a vehicle is going to be dependent on the vehicle and the exact geometry of the wheel/tire, but relative to each other the 20 lb tire/10 lb wheel will need more power than the 10 lb tire/20 lb wheel.

 

[Burdy]

Your intuition is correct. Moment of inertia (effectively, mass in a rotating frame of reference) scales with radius^2. How much that actually affects the performance of a vehicle is going to be dependent on the vehicle and the exact geometry of the wheel/tire, but relative to each other the 20 lb tire/10 lb wheel will need more power than the 10 lb tire/20 lb wheel.

Thank you for answering this question. Would be cool if there was a calculator somewhere where you could plug in a wheel diameter and weight, tire size and weight see how much energy is required to move a particular combo.

Sponsored