Those tests came from various
Cycle World Road Test Annuals, which compiled motorcycle tests during each year. I have British motorcycle road tests that go back to the 1930's and
Cycle World road tests that start in 1962, when I first started riding. Since no dealer ever gave a possible customer a chance to ride a new motorcycle before purchase, if you wanted to know anything about a motorcycle before buying one you had to get your information from either the manufacturer's advertising or brochures, or magazine road tests. What I did was to subscribe to every motorcycle magazine on sale at the time and either buy the
CW test annual each year or rip out the new motorcycle tests from other magazines and pour over them to make a decision on which motorcycle to buy next. During the 1960's I tended to purchase a new motorcycle every year as they were improving a lot all the time, plus the Japanese ones could usually be purchased for just a few hundred dollars after trading in last year's bike.
I have collected many hundreds (if not thousands) of motorcycle road tests and brochures over the past 56 years. One that I really like is a British test of the 1961 RE 250 Bullet, that managed a top speed of 88 mph. Likely another "ringer". I posted that article several years ago in the Vintage sub-forum. I could do it again upon request.