All that information about the various gearing for these bikes must have taken many a year to learn all of that.
Many years ago, at the John Deere dealership, also sold a huge variety of equipment, had taken on a trade a 125cc BSA, .aybe it was called a Bantam, too much bridge under the water so I dont remember the model name.
I was in grade school and wanted to buy that motorcycle, scrounged every piece of scrap metal I could find and came up with enough for the down payment, then the dealer hit me with the title and registration fees and being it was going to be financed, had to have insurance too.
I took my money and opened a savings account, $79.95. Kept that money in there for a good long while unti one day I seen this 1957 Dodge Coronet at the GMC dealer. Polyhead 318 Super Red Ram engine, four barrel carb. That old car would scoot pretty good for a 16 year old.