Does the weight of the rim or size affect the performance?

Rotational mass does play a pretty big role in the ability to spin the rim, but its the placement of the mass that is the key. Rather extreme circumstance here, but just using as an example: If your rim had 95% of the mass on the outermost inch of the wheel, you would have a loss of power as compared to a rim with the exact same weight, but the 95% concentration of the mass in the centermost inch of the rim. This happens because the engine requires more power to turn more mass when it is having to complete a longer radius of a circle. I'm sure you guys have heard of a centerforce flywheel. Same concept.
 
MarvinMyCat said:
I'm going to chime in here and say that a lot of the handling does depend on the tire manufacturer as well as the proper size tire for the application. I'm sure a top of the line 16" tire would out perform the 17" Sears special of the week tire.

But using identical tires on different sized rims would make a difference (properly sized).

That's just my two cents.

That is true to a point. I was agreeing till you said 17" tire special of the week at Sears. Sears has no specials on 17's because they are considered a special sizing. I'm sure as they become more popular the prices will go down, but as of know, you can't get special pricing on a tire that'll fit a 17" rim. Oh, and there's no such thing as a 17" tire unless your thinking of a go cart or geo metro tire. Try 265/45/17's maybe? :shrug: Just thought I'd do a little correcting on bad jargon that leaves novices confused. I work part time as a sales rep for sears tires. :nonono:
 
I'd love to explain everything to ya'll, but I'd feel my physics teacher patting me on shoulder and telling me that I'm a nerd, lol. so much mechanical engineering butt is going to shut up before i talk to much and end up writing a book on torque, mass, wheel mass, wheel diameter, wheel strength, wheel, bla bhla bla bla, ok, i'll shut up.