Thanks for the link, I hadn't seen but one of those pictures before.
And for those thinking a 900lb. Honda Goldwing is required for cross-country travel, Pirsig's bike was Honda Hawk 305, as in 305cc. It put out 28 horsepower. I'll bet there are scooters today that put out more power. And Pirsig loaded it with two people and camping gear and rode it cross-country.