Clark Stiles' YZ450F
Bike: Yamaha YZ450F
Rider: Clark Stiles, #61
Mechanic: Todd Thompson
Sponsors: SoCal Racing, P-LoK, Lucas Oil Products, Yamaha, Interlakes Sport Center, Enzo Racing, Dubach Racing Development, Barnett Performance Products, Shoei, Glaceau Vitamin Water, Polisport Plastics, Synergy Racing Technologies, Sidi Boots, SDG USA, Vortex Racing, RK Racing Chain, Pro-Wheel Racing Components, TriStar Racing, DeCal Works, Dragon Optical, TekBolt, Hot Rods, Hot Cams, Pivot Works, Stomp Design, Engine Ice, ProClean 1000, Michelin, ICW Bike Stands, IMS Products, K&N Filters, Vertex Pistons, Renthal, Park Tool USA, Kicker Car Audio, RB Components, Galfer Brakes USA, SFB Racing, Wonder Warthog Racing, Krause Construction, Images In Motion, EVS Sports, ASV Inventions, Tune Products, Evol Nutrition
When we first got a look at Clark Stiles' bike, we were wondering who was going to be big enough to ride it? All of the DR guys at Southwick were in the 5-foot 10-inch range and this YZ had the skyscraper seat and tall bar and clamp set up for its 6-foot-tall rider. It was literally at the other end of the size scale from Jason Thomas' CRF450 we rode last year. But the minute I sat on the bike, all my fears turned to curiosity, as the seat foam was essentially mush and the bar was not really that high in its TriStar clamps. The next in a series of agreeable realizations came within the first minutes on the bike. The motor was extremely tame and ridable. It was jetted spot-on and started pulling from the basement. It was also smoother than the stock YZ, building as progressively as possible while still packing a huge whale of a smooth top-end surge, running deep into the rev limiter, pulling all the way. And the suspension was really plush and soft-feeling, a striking contrast to most pro setups.
When I took it out for a few laps on the track, the setup began to come to life. First was the motor. I know the game a lot of these pros are playing. It's all about taming the 450s to make them as ridable as possible while still retaining the engine's gusto to get the start you'll need to be up front. And in both motos on Sunday, Stiles was pretty far up there, so I wouldn't doubt the overall pull of the bike one bit. It ripped and gripped with the Michelin sand tires, easily lofting the front wheel without my leaning back or hanging off the back too far. While observing morning practice, I even saw this YZ pull Carmichael's RM-Z, when the two were close together. A lot of that involves laying the power down to the ground; the P-Lok guys are surely onto something.
The suspension might just play into that as well. The soft feeling was what caught us off-guard, but the way it stayed stiff, not bottoming or wallowing in the monster sand whoops that would crush and pummel a stock setup, was amazing. Whether it was some fancy midstroke valving, a high-speed setting or a combo of lighter springs and stiff valving or stiff springs and light valving, I couldn't tell, but this was by far the most forgiving bump absorbers I've ever ridden on a race bike, but it never came close to bottoming. And did I say it hooked up?!
All those fancy stepped seats have nothing on Stiles' mushy tall seat. What this thing does is multitask. It may be responsible for some of the suspension's pleasant feel, at least through my butt receptors (don't think about that too much). It also lets you smash into it and get low in the turns. And when you whack the throttle open, you literally get stuck in the pocket, like a cut seat, which helps keep you forward on the bike. The little things like the bar position and lever setup would be considered normal by us older guys and "old-school" by the younger kids, meaning his bar was a little high and his levers were a little low, but I liked it just fine.
P-Lok isn't the biggest nor best-funded team on the circuit, but it was made up of nice guys who know to make things work without too much fuss. "It isn't really that special," mechanic Todd Thompson says. "It's just how Clark likes it." Which is just how a race bike should be.
Opinions
I was pretty much beaten down by the 'Wick when I saddled up to this bike for my final ride of the day. The power was promising. And it gave me reason not to shift as it pulled strong, smooth and long out of each corner. The suspension was soothing. Progressively smooth doesn't even begin to describe how well it worked as I kept pushing it farther into the stroke. And the ergos and ride comfort were surprisingly compliant even though it looked like a loaf of bread was accidentally left under the seat cover. I suppose this is why I could ride this bike longer than any other privateer weapon that day at Southwick. -Jesse Ziegler
For what I expected, this bike was pretty tame, with a mellow, detuned feeling in the motor. But that is not to say that it wasn't fast! Given the engine characteristics, this bike had a lot of useful power. The suspension was solid. The rear rebound felt like it was was dialed in to be on the slow side, probably to minimize kicking, but it held a balanced platform all the way around. This bike is proof that you don't have to go all-out to make a great race bike. -Chris Denison
I thought there would be no way I could ride Clark Stiles' bike with his tall seat/handlebar setup. I also expected an arm-ripping motor that would have me flapping like a flag. Instead, this was probably the most ridable of the five bikes I tested that day. The motor was incredibly controllable, and it seemed as if I could do whatever I wanted with the throttle-wheelie over bumps, slide the back around in a corner-anything I asked of it. This bike is not slow as I saw Stiles pull a top-10 start in moto two just hours before we got to ride his Yamie. The suspension worked surprisingly well for me in spite of the large weight difference between Stiles and me. It was very balanced and controllable, which gave me plenty of confidence to ride the bike hard. -Sean Finley
This bike was the tractor of the 450s. You could leave it in third gear and never touch the clutch, never shift and never lose any power. The suspension was real plush on the initial and held up real well in the bigger stuff. -Ryan Orr