Correlation betwwem rim and tire size

Trying to understand the relationship between tire size and rim size. If you go up in rim size and reduce sidewall mass of the tire, does your rolling resistance decrease? I would think the larger wheel would weigh less than the increased weight of the tire you have with a smaller rim. Input would be much appreciated.

 

Really it would depend on the wheel. Some wheels are very heavy.

The smaller the sidewall, the harsher the ride will be.

 

I would think an aluminum wheel would weigh less that a 8 to 10 ply rubber sidewall on a tire...

 

I thinks a margainal difference. 1” of rubber vs 1” of aluminum. Probably the difference of a couple lbs.

 

Spent a couple minutes on tirerack and looked up OE sized tires and rims (same model in both sizes). the 20" tire was 4lbs lighter but the rim was 4lbs heavier. You would have to pick a rim and tire you want and compare the two sizes to see if one is lighter