I have a set of chains made for the A.Each wheel uses three,and the part that goes between the spokes over the rim is contoured to fir the rim.They look they will only fit the 19 inch,not the 21's.They were under the seat of a Tudor I bought that spent it's life in hilly country.I'm not sure if they were ever used,they still have red paint on them,but they spent their life in a canvas bag riding around in that Tudor.I've used rope on motorcycles before,you tie one end to a spoke and lace it around until you get back to where you started.If you try to lace another rope around in the opposite direction,the bike will hop up and down like a MR Joggy.Old Harley 45's will plow through 6 inches of snow like a tractor.