The other advantage of light wheels that is touched on in that GRM blurb is lower unsprung weight . . .

Less mass that the spring & shock need to control means better handling & improved ride quality (increased sprung/unspring weight ratio).

 

Who the hell drives around without their gas or brake using the weight of their wheels ? Obviously the bigger and heavier the wheel, the harder for the motor and gears have to work. The lighter and smaller dimension of a wheel, less stress. I'm not Bill Nye the goddamn science guy here, but i've never heard of anyone buying huge *** heavy wheels to add to the acceleration of their car. just my 58 cents.

 

heavier and larger rims will cause u to stop slower as well as accelerate slower..acceleration is slower because its harder to move because of center rotational mass (u can look at it this way: hold a sledge hammer with a short grip and mak a circulur motion above your head...now use one with a longer grip and try doing the same thing...it'll be harder to "spin" the one with the longer grip)...to explain how it stops slower think of a lightened flywheel..lightened flywheels rev up and down faster..it revs down faster because it doesn't have any momentum to keep spinning..heavier wheels have more momentum and will want to keep spinning

keep in mind that u measure the diameter of the rim + tire...so u can't really compare a 14' rim with a 17' rim unless u add how big ur tires are..my 17's have a smaller diameter overall than my stock wheels because my tires are low profile

smaller and lighter rims will make acceleration and deceleration better than having larger rims

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NonovUrbizniz &raquo;</TD></TR><TR><TD CLASS="quote">well my car defies physics then because my heavy wheels used to slow me down and my light ones roll for MUCH longer with hardly any slow down...
</TD></TR></TABLE>


Not only does your car defy physics... it probably is defying a good allignment then. A bad allignment will slow a car down faster than your heavy wheel theory...

I believe your toe or camber will be the one to blame for the slow down...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NonovUrbizniz &raquo;</TD></TR><TR><TD CLASS="quote">Heavier wheels WILL slow you down faster... they will also be harder for the brakes to stop...</TD></TR></TABLE>

You've made a contradiction in a single sentence. You are correct about it requiring more energy for the brakes to stop, but you are incorrect about heavier wheels slowing you down faster. Ask yourself, why is it harder for the brakes to stop a heavier wheel? A heavier wheel has more inertia and thus more kinetic energy, which the brakes must overcome.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">they will also make it harder to accelerate... they are bad on ALL counts...</TD></TR></TABLE>

Yes. Do you know why? Have you taken physics? You have 7 people screaming "you are wrong" yet you are still arguing me? Heavy wheel resist all acceleration in every direction compared to a light wheel.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">your logic and response is flawed because:
A: The heavier wheels where NO bigger... IDENTICAL tire sizes and wheel dimensions...</TD></TR></TABLE>

That's fine. For rotational inertia -&gt; I = 1/2MR^2, where M is the mass. So if the dimensions are the same, I still increases with mass (aka weight for the physics impaired).

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">B: the new wheels have no less "expensive" tires on them.</TD></TR></TABLE>

I was attempting to help you out here. So the new wheels have grippier tires? If so, then there is probably more rotational friction causing the wheels to slow quicker. I'm just trying to figure out why you are insisting on this.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">C: A dumptruck is hard to stop because of the weight riding on the wheels not the weight of the wheels...</TD></TR></TABLE>

There are many forms of inertia. Rotational inertia is just one, linear inertia is another. The entire dump truck has more inertia than the entire Civic because it weighs more. It's the same rules.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">heavy wheels slow you down in everyway imaginable... they DO slow you down at a roll MUCH faster than light wheels would... they rob power be it from the engine or your momentum.</TD></TR></TABLE>

From http://dictionary.reference.com/search?q=inertia
Inertia
-Physics. The tendency of a body to resist acceleration; the tendency of a body at rest to remain at rest or of a body in straight line motion to stay in motion in a straight line unless acted on by an outside force.
-Resistance or disinclination to motion, action, or change: the inertia of an entrenched bureaucracy.

This is the simplest form you can see it. Give me any evidence that proves it wrong, besides what you "feel". I can get much more complicated if you want me to. This is elementary physics. If you can't get this, then I'm not going to even try talking to you about momentum.

 

Maybe I'm wrong then.... but I really don't think so.