Speaking of the AMA trying to do a good thing and mucking it up...is the rule that allows 4$ to be double displacement (which by the way is an FIM rule and being subordinate to them, was adopted by the AMA). It really was a good idea at the time. It kept the doors open for many manufacturers in Europe for many years. It was rare to see the VOR, CCM, and Rickman machines in America but in Europe and England especially, there were hundreds of builders using big bore 4$ engines. These bikes could be competitive, but not dominant, in motocross in their day. The problem came in the '90's when metalurgical advancements allowed them to build a better 4$ and the rules were not adjusted to keep it balanced.
If you are going to write something, make sure you know what you're writing about.
The AMA had long standing 'over capacity' rules - rules that were used initially by KTM with their 540cc LC4 based bike? Rules that a lot of companies did not take advantage of, for a Long time. Anyone else here remember Rex Staten on the Works Honda 4t - it being only 410cc - at least that is what they said it was. Based on the XL350 - it probably was far from 500cc - it blew up enough as it was. It was Trick though!
Now, I'm not exactly sure of the capacity max allowed - I do think 540cc was the max allowed in 250 (2t) class racing, I never really knew what was allowed in 125(2t) racing, perhaps it was 170cc? (I'm Australian, we, like the Europeans, and other countries that held to FIM rules, had the same class maximum as 2ts), but I do know that 125cc 4ts were the capacity allowed against 85cc 2ts - before Honda brought out the 150. Honda, worked out that an affordable 125 4t would never stack up against an 85cc 2t, so made the 150. Most associations throughout the world, proceeded to 'bend' over for Honda, but, in a rare show of having a spine, the AMA did not allow it to compete against 85s. That may have changed now - the irony is, quite a few countries have now stopped the 150 from going up against 85s, after initially allowing it - citing the cost it brought to minicycle racing. I think the FIM, have taken that stance, along with introducing EMX125 racing - for a cheaper, entry level class to GPs.
I can't recall exactly if Jacky Martens Husky, the first modern era 4t 500 World MX Champion, was 500 cc - I'm fairly sure it was. The Bartolini Bros, raced Husabergs in 500GPs that were definitely just below 500cc. I'm pretty sure all Joel Smets Husaberg wins were on sub 500s - quite often, he raced a 470 capacity 'Berg. I know this, because I worked at OZs biggest 'Berg dealer for many years, and the owner, travelled with his Kiwi Mechanic for a few weeks during the GPs, after topping a sales contest. I just cant recall when the FIM allowed bigger 4ts - I think it was 630 /650?cc. Perhaps it was the year Smets went to / was transferred to, KTM? That eventually became the MX3 category - 500cc max 2ts, 650cc max 4ts.
All the '500cc' 4ts till the last year 4ts won (late 60s?), through to the last days of the BSA team, thence to the years of CCM 'tilting at windmills' with their magnificent BSA based engines, as well as Bengt Aberg on the Hallman / Enquvist (sp?) Yamaha, were limited to a 500cc Maximum. In 1977, there was much controversy, at the British GP, as the CCM riders, John Banks, and Bob Wright, had been doing well in earlier GPs, thus upsetting Hondas Steve Whitlock. You blokes might remember him - mainly from his tenure of being a 'boss' in AMAs MX structure - he very much presided over the 125 2t /250 4t and 250 2t/450 4t current set up, though he later shed crocodile tears over it, admitting it was a mistake. The CCM riders, were doing so well, there became some grumbles (Honda / Whitlock) about them being oversized. Well, Banks got second in the second moto (Wright and Banks were going 1-2, for the first 25 minutes of the first moto), behind Mikkola, ending up 4th overall.
Banks' bike was measured. It was officially found to be 401cc - BS - it was 498cc, 'on ya!' tech inspectors!, as were the others (2ts, of course) in 1st, 2nd and 3rd. Bob Wright had finished 6th . Whitlock was still pissed off, so found a loop hole in that the official fifth place finisher, was registered as a 250GP rider, so Wright was '5th 500 rider'. CCMs Jeff Clews, was incensed by this, feeling his team had gone through enough BS orchestrated by Whitelock, and took Wrights bike from the Parc Ferme. Hence, some people thought, to this day, Wrights bike " must of been a 580", a size offered by CCM - a size, that Wright disliked. He was a revver.
CCMs are something I know quite a deal about - having grown up with BSAs, then CCMs around me, as both my Dad and Uncle rode / raced them, right through to the last year the BSA based CCMs were made - including a couple of 630cc 3 speeders. They owned a variety of Rickmans as well - Rickman - made chassis only - any 4t Rickmans raced in the 500cc World Championships (in the 60s), was a 500cc.
VOR, grew from Vertemati, who came from Husaberg - the Vertemati brothers so modifying the 'Berg, that it became another bike - Smets rode for them, before being picked up by Husaberg proper.
Enough history - it's just to emphasise FIM World Championship racing Was 500cc - bigger sizing, later, was influenced by AMA Rules.
As I said, get it right. Get it wrong, you leave yourself / this site / 2t fans, open to being described as a bunch of BS artists, by the 4t crowd.
I like all sorts of Motorcycles / Engine types. And I've probably had / ridden more 4ts than 2ts - making 'specials' for many years, 'tilting at windmills' myself. But I love 2ts - cripes, I pretty much put endless crap on my dad and uncle on their exotic 4ts, whilst I hammered around on a succession of CR , RM and YZ 125s. Since the 'modern 4t era' began, I've ridden big capacity 2ts. I wanted simple, grunty bikes, that I could work on with half of one eye open..............and work on, rarely.
All I hate, are the p**s poor rules, and the idiots, who just don't seem to understand that 4ts, got to domination, through those rules - rules, that Should Have been rescinded about 10 years ago.
The sport, would be in a Lot better shape now, if equivalency was back - just as equivalency was in force, right up to the AMA Rules influenced the rest of the worlds rules.
