(Above) Testing at the Salinas, CA quarter-mile oval track. (Below) Renthal 47-tooth rear sprocket with a 15-tooth countershaft sprocket delivers smooth power to the rear.
We took our 2011 Kawasaki KX450F Dirt Track machine out to Round 1 of legendary dirt track racer Eddie Mulder’s West Coast Dirt Track Series at Willow Springs International Raceway. The track layout included a 3/8-mile oval on some very slippery decomposed granite dirt. The roost from other bikes is almost like a sandblaster so before we hit the track we covered up our beautiful machine with some duct and masking tape to keep it from getting that pitted look.
Luckily for us we were able to get in a day of testing during the week prior to the event. We tested at a quarter-mile oval track in Salinas, CA. When we set up the bike to test we mounted a Renthal 47-tooth rear sprocket and a 15-tooth countershaft sprocket. Come to find out, our sprocket size would be just the ticket, running in second gear on the quarter-mile track and third gear on the 3/8-mile race track. As far as suspension went test day, we made some adjustments to the rebound of the shock, slowing it down three clicks in to stop the bucking on corner exit.
The Saturday of the two-day weekend event included a full day of practice which helped me, an ex-pro dirt track racer before I began road racing, get back into the thick of things since I had not been on a dirt track bike since ‘05. At first I was struggling a bit trying to figure out the lines. Willow Springs is a tricky track as the lines are always changing depending on where the traction is. I remember racing there when I was younger on 85s and 250s and nothing had changed. You run the bike into the corner and pitch the thing sideways completely wide open, letting off for a split second to get the bike turned in the apex of the corner before it’s back to wide open again searching for any traction you can get on the corner exit and straights. The track is all about momentum. Once I figured out how to get the bike around the track we started working on bike set-up. We took a turn and a half of spring out of the rear shock to lower the rear end of the bike making it more stable and giving it more traction. We also took out two clicks of compression on the shock which would allow the bike to squat more in the corners. The fork of our dirt track machine appeared to be working great all weekend with no adjustments. Looking for traction, we took a tire groover to the rear Dunlop of the bike to give it some more bite. By the end of the day we had gotten up some good speed and were talked into signing up for the events’ Pro Class featuring some of the top AMA Pros including AMA Expert class points leader Sammy Halbert, reigning Twins Champion Jared Mees, Jimmy Wood, and 2010 Amateur flat track Horizon Award winner Briar Bauman. Once the practice day was over it was time to clean the dirt off of the new Bell full face helmet and apply some tear offs for Sundays race day.
As Sunday morning came we added some fresh fuel to the green machine, bled the Race Tech re-valved fork and checked tire pressure running 15 psi in the front and 12 in the rear. As practice was underway, we heard track conditions for race day were much more slippery than that of Saturday’s practice so we prepared for the worst. Boy that was a good thing. Just before the heat races started we removed the rear Excel wheel from our bike and flipped the rear tire and grooved the new side for maximum traction. The conditions were much more slippery and it made the track very difficult to ride. Once the heat races began the track started to get worked in and get better and better. I ended up in Pro heat three of four. I ended up with the jump off the line but the DTX machine was no match for the framers as Sammy Halbert and another rider got around me exiting Turn 2 and another framer got by coming out of Turn 4 on the first lap. This placed me in fourth with another DTX machine just behind. After holding onto fourth the whole race I ran wide in the last corner and was beat to the finish. I would end up with a fifth place and a third row start in the main event. One thing that caught my attention in the heat race was the fact that my bar stops were preventing me from sliding the bike as much as I needed to and wanted to throw me over the high side, so before the main event we took a grinder to the right side stop and ground it down a bit to allow the bars to turn further. We also took out a turn of compression on the shock for added squat on exit. We also added two turns of rebound as the track had gotten pretty rough throughout the day. As the Pro main event approached we had one final go-through of our Kawasaki KX450F, checking air pressure, adding fuel and making sure everything was set for the 20-lap race before we headed out.
After a couple of sight laps we were lined up by Eddie Mulder himself. When the green flag was thrown I immediately dropped the clutch and headed for the inside of the turn hoping to get by a few guys. Everyone ran a bit wider and I was about mid-pack until coming out of the corner I hit a dry spot on the track and lost all my traction. It took a while for everyone to get settled in after passing back and forth. It was just about impossible to keep up with the front runners on their framers but after the halfway point I found an edge riding higher on the banking which would be enough to help me quickly catch the group ahead. The white flag came out and I made a last ditch effort to make a couple passes but it was just too late. I ended up 14th on the day.
Overall, I am very pleased with the way the Kawasaki worked. The bike had come a long way from our first ride on the dirt tracker with the adjustments we made. I believe the bike has even more potential to get even better with some more seat time and testing. What’s next? Engine work and mapping? Ride height adjuster? I guess you’ll have to stay tuned to find out!