Sneak Peek - Transworld KX500AF vs. KXF450

[JohnN]

This is a little sneak preview for the readers of the forum. I'm typing up this article that was in Transworld motocross a few months back. The test was a Service Kawasaki KX500Af vs. a KXF450.

The interesting part is that the test rider owns and races a KXF450 but posted lap times that were 2 to 3 seconds a lap faster on the unfamiliar two-stroke.

The part that confuses and confounds is why did he pick the four-stroke over the two? Read this little "sidebar" to find out why.

"There's No Replacement For Displacement

By Brendan Lutes

Up until the time when the Service Kawaski KX500AF arrived at our offices, I had only swung a leg over a 500cc two-stroke once in my life. I always thought that the fabled bikes of yesteryear would be way too much to handle for anyone, and that for me, I wouldn't be able to ride to my full potential. I couldn't have been more wrong.

After getting used to the KX500AF and pounding out a few motos, I became aware that although the big bike commanded a lot of respect, it was a bike that was very fun to ride. The instant power allowed me to ride around the track and be lazy-I'm not sure if that's a good thing or not-and the lightweight chassis that the motor was placed into gave the bike a feeling reminiscent of the modern four-strokes I have become accustomed to. While I did get tired much quicker, it wasn't something that I couldn't overcome with a little more seat time aboard the big bike, or a little more time at the gym rather than my favorite watering hole. In fact, since taking delivery of the KX500AF, I've even raced it and had a blast. But riding motos on it is one thing; where the test really got interesting for me was when we broke out the stopwatch.

After being timed aboard the big KX500AF at Racetown 395, I hoped on my more familiar KX450F and immediately felt right at home. While pounding out timed laps, I clearly remember thinking to myself, "Man, I'm killing the lap times I set on the 500!. Upon pulling back into the pits, however, I found that I couldn't have been further from the truth. While I felt faster and more at home on the 450, my lap times on the 500 were consistently two to three seconds a lap faster. In the end, the truth of the matter was that the brute power of the 500 undoubtedly allowed me to carry more speed down the straights and through the corners-even if it didn't feel like it-giving the big bike that little edge over the 450. Even though the lap times speak for themselves, under race conditions, and on a rough track, I would probably pick the 450 over the 500. I'm more comfortable on the 450, and I can ride it at a consistent pace for a longer period of time. Nonetheless, I still had a blast during my time testing the 500. It's definitely something different and fun."

[Alec S]

....... I'm more comfortable on the 450, and I can ride it at  and find out.a consistent pace for a longer period of time..........

Which of course begs the question: How long has he been riding 4T?  I'm more 'comfortable' shooting an over/under in sporting clay competition but but I shoot a semi pretty durn well when I do. If I leave my "comfort zone" and get 'comfortable' with the semi would I be better off overall?

Would the racer be better off overall if he spent a couple months on the 2T?

I guess the only way to know is to make the plunge and find out.......but boy, it's hard to leave that comfort zone....

I think all comparisons [where someone had a solid foundation on either side of the coin] should always be viewed with a full understanding of just that.

[dogger315]

This test rider experienced the same thing I did (only in reverse), when I switched from
two strokes to four.  I didn't feel comfortable on a CRF, it was heavier, had a strange
(for me) power delivery, if you chopped the throttle too soon on a jump - watch out!
and what's up with all this braking compression.  In addition to spending a lot of time
adapting to all the changes, I spent an equal amount of time modifying my CRFs to
behave more like a two stroke with items like slipper clutches.  In spite of everything
I did, I could never lap faster on a CRF than a CR, but I was stronger (less tired) at the
end of the moto.

Soon, there will be a generation of racers that have known nothing but four strokes and
wouldn't switch to a two stroke due to familiarity and comfort unless they were forced to.

dogger

 

[2smoker]

TransworldMX is by the far the worst Motocross magazine when it comes to shoo-outs!  Half of their magazine are ads and females in bikinis...I also think that Lutes and Donn Maeda are both clowns and done nothing positive to the sport.Their DVD movies are among the best but filled up of 4 strokes...It just hurt to watch this!

[Recovered]

So much for not being able to a 500 2T to it's potential.

[JETZcorp]

I say we invent a time machine and send one of these guys back to have a little chat with Heikki Mikkola, Brad Lackey, Danny Chandler, Andre Malherbe, and all those guys when they were in their prime.  It's easy to look at some 50-something guy and conclude that his stories are all just fanciful tales of yore.  If they could see the mastery these men commanded over their 500s, they'd find themselves constantly in their garage, staring at their 450F and wondering, "What happened to us?"