Increasing force script, physics and a special 2 wheel Bike setting

I have a special issue ... please help me on this! hm

i have a future bike.

  • It starts with a empty, which has a simple custom mesh collider on it.
  • This empty/mesh collider has a rigid body on it.
  • The empty holds the whole bike!
  • Under this empty are two meshes (the front & the back tail)
  • There are 2 wheels as another subobjects under the front & back tail meshes attached
  • Those wheels have no rigidbody. ... hm
  • The wheels have a mesh collider, cause i want excact collision behavior.

now what i need is a script, which i dont have (cause i am a pure grafic artist xD), that gives the empty (not the wheels) exponentially a increasing force/actuator/gear forwardly, by holding a mouse button, so that the bike moves forward and that the wheels are rotating by the friction of the ground and not by the force itself. imagine a jet engine that boosts the bike forward and the wheels are freewheeling rotating by the friction of the ground. The ground physic material is set to rubber too.

could & would someone please help me on this?

  • what script do i need?
  • what did i maybe wrong in my settings, by my special requirement?
  • i know that my requirement takes a lot of performance. but it should be more a simulation, than a faked bike physic game.

Please help me on this! :(

btw.. the steerment could be managed by another point at the back tail of the bike. which can be animated and simply assigned to a keyboard controller. so that's not the problem ... atm -.-

well i would try using a wheelCollider.

but if you set on the physics engine then you could try using a hingeJoint for the wheels.