Again in early 2001, the YZ250F had not but gained in Nationwide Competitors, however Roger DeCoster, amongst others, knew it could, and he knew it could change motocross ceaselessly. Within the March, 2001 subject of Filth Bike he made it clear that he was no fan of the foundations that allowed a 250cc four-stroke to race within the 125 class. Right here’s what he needed to say.
In any type of racing, it’s laborious for a group supervisor to publicly focus on guidelines. In spite of everything, we have now a vested curiosity. You don’t count on a Democratic choose to rule for a Republican president and also you don’t count on a race group supervisor to favor a rule change that provides his group an obstacle. Besides, I believe any goal particular person would agree it’s time to rethink the AMA guidelines that permit four-strokes and two-stroke engines of various sizes in the identical class. When Yamaha got here out with the 426, it was awkward. However, after Doug Henry retired, it grew to become a moot level on the nationwide degree. The bike was no nice benefit as a result of few riders would make the most of the additional energy. Yamaha’s race group had a tough time discovering riders who needed to race it. Now that Yamaha is benefiting from the rule that permits a 250cc four-stroke to race in opposition to 125cc two strokes, it’s develop into a sizzling subject once more. If four-strokes actually do want greater engines to compete with two-strokes, shouldn’t there be a components to reach on the correct quantity? That’s what car sanctioning our bodies got here up with when the Wankel rotary engine began to show extra highly effective than typical engines of equal displacement. Proper now there isn’t a components in MX, simply numbers seemingly pulled out of a hat.
Within the case of the four-stroke versus the two-stroke, the FIM did nothing for years; two-strokes and four-strokes of the identical capability had been lumped collectively. It was solely on the U.S. aspect that the AMA allowed four-strokes extra capability. This was in all probability a remnant of the ‘60s and the period of British bikes. Bear in mind, although, that at one time the state of affairs was reversed. 4-strokes had been dominant. It wasn till Paul Fredrichs gained the 500cc world Championship in 1966 that anybody took two strokes severely. Till then, individuals thought “Yeah, two-strokes can win in small-bore lessons, however not in the primary class,” Quickly two-strokes dominated so simply that even the FIM had a rule permitting four-strokes extra displacement.
Via the ‘70s and ‘80s, bike producers ignored four-stroke motocross bikes regardless that four-stroke know-how was advancing. F1 auto racing pushed the envelope farther and farther, and a few of that know-how discovered its means into superbike racing.

It wasn’t till the Japanese producers bought out of the five hundred GP class in motocross that some Europeans gave four-strokes one other look. At first, it wasn’t even a manufacturing unit, just a few former Husqvarna workers who began constructing Husabergs in a barn. Then others adopted, however nobody actually took benefit of the foundations till Yamaha entered the image with the YZ400F.
The state of affairs just isn’t in contrast to what occurred at Indianapolis a couple of years in the past. At Indy, they raced underneath a mix of CART and USAC guidelines. In addition they had an outdated provision the place aspect valve engines had been allowed greater capability and extra turbo enhance than the newer engines. Roger Penski seen and satisfied Mercedes and Illmore to construct such an engine. They cruised to a simple win. It solely took one race for Indy to vary the foundations and throw that provision away.
One of many greatest gripes I’ve with immediately’s rule is that the allowance is totally arbitrary and freed from any logic. The AMA has simply decreased the restrict within the 250 class from 550cc to 450cc (for 2002), however nonetheless that’s an 80 % benefit. Within the 125 class, the 250cc four-stroke is a one hundred pc distinction. Within the 80 class (the place a 125 four-stroke is authorized), it really works out to a 47 % benefit. There’s no rhyme or motive.
If a constant share had been utilized in each class, at the least there can be some logic concerned. However even that might ignore the truth that small engines are extra environment friendly than massive ones. Doubling the dimensions of a 125 engine leads to a a lot larger real-world benefit than doubling the dimensions of a 250 engine–nobody may successfully use that a lot energy anyway.
One other subject is weight. Within the 125 class, the minimal weight is 194 kilos for each four-strokes and two-strokes. So if Yamaha is profitable in decreasing the burden of the YZ250F to that degree (tough, however doable in concept), then the bike can have a much bigger benefit in energy to weight. If the bike is allowed the displacement of a 250-class bike, shouldn’t it even be held to the burden of a 250cc bike?
Clearly, the foundations must be thought out and have constant logic utilized. This 12 months it is going to be fascinating to see if the YZ250F actually is an enormous benefit. In that case, then we shouldn’t be afraid to handle the problem. Yamaha will nonetheless scream that they developed the bike particularly to make the most of the foundations, however I‘m positive that the YZ250F’s first-year gross sales figures will greater than justify the bike’s improvement. Likewise, I’m positive that Honda doesn’t wish to see the 450cc restrict lowered within the premier class now that they’ve a four-stroke within the works. However, by the identical token, I’m positive that Roger Penske didn’t wish to see his benefit in Indy racing go away. The choice is that we are going to finally see the 125 two-stroke go away. Authorities rules may do this sooner or later, however let’s not hurry the method alongside. Within the lengthy historical past of racing, guidelines have come and gone with a purpose to take care of altering know-how and altering instances. Let’s not get caught prior to now now.