Gravity car wheel radius selection

Click For Summary
SUMMARY

The selection of wheel radius for a gravity-powered car significantly impacts speed and stability. Smaller wheels, such as 20 inches, offer better acceleration but may compromise stability, while larger wheels, like 26 inches, enhance top speed and reduce axle friction due to lower rotational speed at equivalent forward velocities. The optimal choice depends on the race distance and the balance between acceleration and stability. Narrow and hard wheels are recommended to minimize rolling resistance.

PREREQUISITES
  • Basic understanding of physics principles related to motion
  • Knowledge of rolling resistance and its impact on speed
  • Familiarity with gravity-powered vehicle design
  • Experience with race course dynamics and distance considerations
NEXT STEPS
  • Research the physics of rolling resistance and its effects on vehicle performance
  • Explore formulas for calculating speed and acceleration based on wheel size
  • Investigate the impact of wheel width and hardness on rolling resistance
  • Analyze case studies of successful gravity-powered car designs
USEFUL FOR

Amateur engineers, physics enthusiasts, and participants in gravity racing events looking to optimize their vehicle's performance through informed wheel radius selection.

paulnist
Messages
2
Reaction score
0
As someone who regretfully has never studied physics, I am at a loss as to how to begin to evaluate the choice of wheel radius for a gravity powered car I am building for a local gravity race. How would one go about picking a wheel radius that would maximize the speed of the vehicle?
 
Physics news on Phys.org
I imagine smaller wheels would be faster and yet less stable.
 
Top speed will probably be highest with larger wheels, while acceleration would be higher with smaller wheels. A lot depends on the distance of the race I would guess.
 
I suspect that there would be less axle friction with the bigger wheels because they won't be rotating as fast as small ones at the same forward speed. Mostly, keep them narrow and hard for less rolling resistance.
 
update

Is there anyone that could provide a formula to help decide whether to use 20" vs 26" wheels? I have a set figure for the course distance.
 

Similar threads

High School Calculating Stress on Car Motors with 4 Wheels
  • · Replies 1 ·
Replies
1
Views
1K
High School Rotational Dynamics: Confused about the tension in this string pulling a mass up an incline
  • · Replies 2 ·
Replies
2
Views
2K
High School Centrifugal Force on Rotating 4" tire / wheel @ 100mph
  • · Replies 15 ·
Replies
15
Views
3K
Undergrad How to transfer angular momentum between two flywheels?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad How find moment of inertia for car in turn?
  • · Replies 49 ·
2
Replies
49
Views
5K
Graduate Can Weight Transfer Cause a Car to Stay in a Stuck Position?
  • · Replies 14 ·
Replies
14
Views
3K
Undergrad Can Adding Alternators to Car Wheels Save Energy?
  • · Replies 10 ·
Replies
10
Views
2K
High School Physics Egg Car Project Tips: How to Safely Transport an Egg from a 1m Ramp
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Battery re-powered from wheels of a car?
  • · Replies 11 ·
Replies
11
Views
3K
Graduate Momentum and energy equations for a car rolling over a step
  • · Replies 1 ·
Replies
1
Views
3K