Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Should the rear wheel be larger

  1. Jun 20, 2012 #1
    Generally all cars have equal sized wheels but few like batmobile (the tumbler from dark knight) have larger rear wheel. What is the advantage of larger rear wheel.
  2. jcsd
  3. Jun 20, 2012 #2


    User Avatar
    Science Advisor

    In the case of a drag racer you want your rear wheels to have the maximum possible surface area touching the ground.

    [The more surface area, the less force per unit area. The less force per unit area the softer the compound you can use. The softer the compound you use, the stickier you can make it]

    On the other hand if you are building a dragster, you want your front wheels to have low aerodynamic drag and to be as light as possible.

    In the case of a Batmobile, the overriding motivation is almost certainly to look cool and to give an impression of "there must be some physical principle that they're taking advantage of".
  4. Jun 20, 2012 #3


    User Avatar
    Science Advisor

    If the rear wheels are larger, then you're always rolling downhill and don't need any power! ;)
  5. Jun 20, 2012 #4
    Didn't really get you! Do you mean that a car with larger rear wheel will start moving on its own!
  6. Jun 20, 2012 #5
    can't get you. I am unfamiliar to many words you are saying. It will b a great help if you please explain yourself.
  7. Jun 20, 2012 #6


    User Avatar
    Science Advisor

    I guess that's why those high wheelers came out of style. Going uphill all the time was annoying.

  8. Jun 20, 2012 #7


    User Avatar
    Science Advisor

    It was a joke.
  9. Jun 20, 2012 #8


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    Why not? :confused:
    Gimee one good reason. haha
  10. Jun 20, 2012 #9


    User Avatar
    Science Advisor
    Homework Helper

    An obvious DISadvantage is that you need two spare wheels and two spare tires. But I guess Batman has some special powers to fix that problem :smile:
  11. Jun 20, 2012 #10


    User Avatar
    Homework Helper

    Some rear wheel drive sport cars (Corvette Z06, Ford GT, Viper), and almost all street motorcycles (rear wheel drive) have larger rear tires. Part of the reason could the rear tire is providing force to overcome drag when ever the vehicle is moving, so it's a wear issue. Otherwise the forces are related to acceleration and braking.

    Formula 1 rules regulate tire size and front tire is smaller. The possible factors include aerodynamic drag since it's an open wheel car and more slippage at the rear tires in racing conditions, plus the constant force on the rears to overcome drag.

    http://www.formula1.com/inside_f1/rules_and_regulations/technical_regulations/5277/fia.html [Broken]

    On the other hand, Lemans Prototype race cars have large front tires and they appear to be about the same size as the rear tires. Audi's R18 e-tron quattro is a diesel + electric hybrid, and uses electric motors at the front for all wheel drive.

    wiki audi r18 e-tron quattro.htm
    Last edited by a moderator: May 6, 2017
  12. Jun 20, 2012 #11
    Weight distribution is also a factor. In a street car you want the front and rear tyres to stick equally.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook