Betty Blog #2

So CMRC announces the much debated (and yes I was in those debates) 250cc two-stroke rule.

For the Amateur MX2 classes only, the maximum displacement for two-strokes will be increased to 250cc. The two-stroke displacement rule for the MX1 class will not change, therefore Amateurs may compete in both the MX2 and MX1 classes with a 250 two-stroke motorcycle. Intermediate ranked riders will be permitted to compete in the MX2 Pro/Am class at CMRC Nationals with a 250cc motorcycle. The maximum displacement for two-strokes in the Pro class will not increase, and will remain at 153cc.

For many this rule speaks to the past, and those critics point out the fact that two-stroke bikes are old technology. It is highlighted by the fact only two major manufacturers even distribute competitive two-strokes (Yamaha and KTM).

The KTM 250cc --Two Stroke

There is an opposing group who suggest that two-strokes are more affordable, cost prohibitive and a competitive option. They like to point out not only do two major manufacturers make excellent bikes, other smaller niche manufacturers make lots of incredible options as well.

On the competition side of the argument, there are those that say in the hands of the right rider this bike offers a big advantage, and by the way the rules are laid out by CMRC that rider could be an ultra-competitive US B rider or top Canadian Intermediate.

Personally, I don’t feel compelled either way on the cost issues of four-strokes vs. two-strokes. In fact on a year to year basis I don’t feel it is that much more money to improve or maintain a two-stroke compared to a four-stroke that is so good out of the box. I do believe two-strokes are better entry level bikes for people learning about motorcycles and maintaining them. That is an advantage that has little relevance at the Pro level.

The advantages sited for two-strokes, if they were allowed to compete on a level displacement field in the US, aren’t, in my opinion, as strong here in Canada. I believe on Canadian tracks the advantages that exist perhaps south of the border won’t be as prevalent here in Canada.

In the US, many, if not all, tracks have brought sand into their tracks to change the soil base with a few exceptions. US national tracks are now a sandy loam. Most are fast, long tracks that let even the frightening fast 450F open up and breath. The way lines develop, thanks to the deep tilling and deep loam, means momentum is still king.

In Canada most tracks are clay based with a few exceptions. One of those exceptions being the gruelling Gopher Dunes track that forces riders to search for smooth lines or pay for it in a whooped out body pounding. In all cases the tracks are tighter than the US, and very few have high speed sections. Guys with strong throttle control and the ability to spot creative lines that link the track together find the most success. This changes the game for two-strokes. Four-strokes are great at grunting through corners and using torque to get through the tight stuff, where a two-stroke is the bike to use in momentum sections, for riders who let lines drift and simply let it hang out.

Need proof? Look to the final round National at Walton. The track in the late ‘90s and early 2000s had often been described as more flowing and the lines drifted more. The track was prepped with a very deep till plus heavy watering. The bikes and riders would push the lines wide, and by day’s end the berms would be pushing out off the track. As four-strokes crept in, especially in the mid-2000s, the track became rutty…really rutty! Long slot car ruts. The track preparation had not changed, but bikes and riders were able to hook into inside lines and torque the inside of the wide corners. As the races wore on more and more ruts formed until it was often described as slot car racing. Then three years ago the team moved away from simply leaving the track after a deep till, and used a power harrow to tighten the soil to prolong the formation of ruts. It worked however the track hasn’t gotten as rough as many would like. They suggest there isn’t enough to separate riders (although results are comparable to the roughest tracks).

The starting lines are another place there is an advantage for the two-stroke. Most say in a straight line drag a two-stroke can out gun the four. Once again Canadian start straights are shorter, tighter and there is more emphasis placed on the jump from the gate; a jump from which three starts are concrete (Walton and Riverglade might as well be), which is also an advantage to the four-stroke. Nanaimo, with the concrete start, is perhaps the shortest and many riders do not shift the entire straight. This seems like an advantage to the four-stroke.

The final argument in the two-stroke and four-stroke debate (that I have) is most riders under 25 (which represent most competitive Pros) have never ridden two-stroke bikes. All their skills and technique have been built on the four-stroke engine and racing a four-stroke. The idea of hanging off the back of a pinned 125cc is just something they have seen on YouTube. As foreign as it was for riders 10 years ago to start moving over to four-strokes, it is the very same mindset to go back to a two-stroke for many Pros. In many minds, two-strokes are fun but maybe not competitive, regardless of what anyone says.

In the end, nobody really knows what advantage either bike type will have. It has created some debate and topical discussion but like most things in racing we won’t know until the gate drops and the checker flag is thrown. Will we see a return to dominance of two-strokes in Pro racing here in Canada or will this be just on more blip in the slow extinction of two-strokes in Pro motocross? I really do not know. Perhaps the interest and conversation from all sides is all we get from this rule, and if that is so, a little hype isn’t a bad thing either.