Originally Posted by
merlinextraligh
roller size affects resistance.
2.25" rollers are likely enough resistance without a seperate resistance unit.
Kreitler Rollers UK
This one is actually built into one of the rollers.
You can buy the rollers then add the drum , or buy it all at once
SportCrafters RD110 OverDrive Replacement Drum - Spin Zone Cycling in Granger, IN