Originally Posted by kittycactus
It's interesting that engine displacement seems to be all over the place with the older bikes. Any particular reason for that or was it just a period of trial and error and growth? How did they lump bikes together for races?
I think it might be a little misleading. things were either 125-250, or open class, sometimes referred to as the 500 class.
but anything bigger than a 250 went there and they all knew the deal. there were few real 500's except the thumpers, BSA's etc, but then again it all depends when you were talking about. For me, starting point of reference 1970, the 500 class was an endless procession of 350's, 360's, 370's 380's 390's, 400's galore, 420's, 440's, 450's, 480's, 490's the legendary 501 Maico, and then the big boys on the BSA's and even Triumphs.
You run what you brought in the 500 class. too bad they killed it.
and we're talking more MX here. In scrambles there would be also a 200 class chock full of Bultaco's with a few stragglers thrown in on Pentons or hotted up Jap.
and of course lets not forget the 100 class chock full of Hodaka's and more hotted up Jap with the Kawasaki Centurion as a bonafide race bike circa 1970. the 100 class made the 125's sound like thumpers in comparision.
then of course in enduro's there would be a 175 class....
and of course todays 250 class where you can run a 450.
and the 125 class where you can run a 250
but they've finally changed it to legitamize the cheaters.