There are tons of ideas on Harbor Freight bead roller mods on this site and u tube.
Some have replaced the crank with a wheel. The HF crank is approx 13" long. I have not seen a single site that talks about the diameter wheel used. To get the same mechanical advantage as the crank, it seems you need a 26" diameter wheel. If you used a wheel, what did you use? What diameter is it? And how did it perform?