THIS WEEK AT DIRT BIKE

 

Doug Dubach rides the DB KX450 testing his own pipe and helping with suspension set up.
 
Let me apologize up front. If you called the Dirt Bike office this week you ended up lost in phone mail. We were spread pretty thin. Adam was at Budd’s Creek, Maryland, riding the 2010 Yamaha YZ450F. This is the most exciting bike of the year and he was pumped to be the first to ride it. But at the same time, he wanted to be cautious. Last year Honda invited Adam and me to ride the new 2009 Honda CRF450R at Lake Whitney  in Texas. It was a great day of riding on a great track and we had a blast. But once we got back to California and rode the same bike a few weeks later,  the magic was gone. The bike that seemed so good on Honda’s terms wasn’t nearly as wonderful once we had it here.
      So Adam didn’t want to be sucked into the same trap again. Yes, he liked the Yamaha. Yes, it might well be the best 450 of the year. Throttle response is instant, the bike feels light and turns well, power was good and so on. But he won’t proclaim it the bike of the year just yet, at least not on the record. Privately he’s pretty excited about it.
      Tom had another tough assignment. He went to Michigan to ride the Parts Unlimited U.P. 300. This is an annual event that might be the best ride in America. Parts Unlimited invites its very best dealers to come ride with Dick Burleson, Alan Randt and other notable personalities on 25,000 acres of private property. The trails range from double-A ugly to scenic and mellow. But all of it is fun. Tom was working on several stories for future issues, so if  you see cool photos that look like Michigan, you’ll know where they came from.
      I was here in good, old 106-degree Southern California. After shooting photos of the WORCS race at Glen Helen over the weekend, I returned to test suspension with Enzo on Thursday. I was also curious to see how some of the trails near the track looked after the WORCS Pros rode them. I was surprised; they  held up pretty well.
      Enzo sent out Will Decker to help us figure out  our 2010 Kawasaki KX450. Right off the bat, he came up with an excellent fork set-up. We felt the stocker was too stiff and had gone to lighter springs with decent results. Will put the heavy springs back, but altered the valving. It felt softer than the light springs that we installed.
      We struggled with the rear suspension.  I tried a few different settings, then Will tore apart the shock in his truck and revalved it. I was having a hard time with what I thought was bottoming. It turned out that I was just in a stiff part of the stroke that felt like a bottom-out situation. As the track got rought, it became more difficult o know if we were going in the right direction. Luckily, Kory Ellis was there testing a 2010 KX450 for Yoshimura. It had stock suspension, so I was able to ride his bike between settings. We definitely made progress, but Will is going to have another set up to try next week. Hopefully it won’t be 106 degrees again.
      Kory’s bike had a closed-loop Yoshimura ignition that was recording all kinds of data, including exhaust burn percentage. He said the black box was measuring output as he rode so that they could come up with a better ignition map for the PIM2, which is Yosh’s programmable ignition. It’s all way over my head, but Yoshimura has the background from road racing to deal with this new world.
      Doug Dubach was testing as well. He has a new pipe for the KX450 that tucks in tighter. He saw a number of smashed head pipes last year. The new KX pipe will have the same dimensions as last year.
      And testing in plain sight was the Suzuki R&D team. Chris Wheeler and Chris Johnson were enjoying the hot weather as they turned lap after lap on the new fuel-injected RMZ250. Suzuki also had a 2009 Yamaha YZ250, a 2009 Honda CRF250R and a 2009 Kawasaki KX250F for comparison. Wheeler and Johnson are professional test riders and they know how to play the game. They aren’t allowed to talk to anyone while they test–especially not me. But afterward they came by and talked about everything except the test.
      Suzuki is officially saying that the new 250 will be available in November or December. It should be interesting.
 
 
Glen Helen hit the 106-degree mark. It was a perfect day for suspension testing.
 
 
Will Decker of Enzo revalves the KX shock while we wait. He could have done it slower and we wouldn’t have minded.
 
 
One of the cool products that Enzo offers is this ring that allows you to do away with the preload locking ring on your shock body. 
 
 
Chris Wheeler was spotted testing the new fuel injected Suzuki 250.
 
 
Ron Lawson was almost knocked of his bike by Tim Hoover’s roost. Tim was proud of the damage to Ron’s nose.

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