2010 Factory Race Bikes - Dirt Rider Magazine

Andrew Short

When the average motohead cruises the pits at a Supercross, he or she sees a sweet works bike constrained by a so-called production rule. A mechanic might see cubic hours of labor, but an accountant would see a huge pile of money. And since there is both time and money in a works bike, you might wonder if the poorly-tuned economy has eroded the quality of these finest examples of moto machinery. We'll be honest: A few of the impressive rigs, some faces we've come to expect and long-time supporting sponsors were missing. But at the pointy end of racing, when it comes to the machinery intended for guys with an honest shot at a win, the bikes are still glorious examples of moto excess. But you can bet that performance spending is carefully scrutinized to ensure bang for the buck. Of the three podium finishers in the 450 class at Anaheim 1, the most obvious example was Kevin Windham and Factory Connection racing with "production" suspension. Trust us, when FC finishes with it, you wouldn't tell it from "works" by riding it. Ryan Dungey's Suzuki RM-Z450 looked as trick as ever, but Suzuki started with essentially the same bike as Reed's '09, and Mike Gosselaar is still working on it-talk about efficient R&D.; James Stewart's 2010 YZ450F was looking a little more stock than we expected his bikes to look, but there aren't many aftermarket parts ready for that bike, and Yamaha-whether it has an in-house factory team or not-likes its number one bikes to look pretty stock. As you might expect, we took a very close look at the bikes, and we are passing along the goods. Check out the top SX machinery in the world right here, right now.Honda reportedly had the trickest ignition in 2008. Riders pushed a button on the start line, and a specialized power setting was engaged for the start. As soon as the rider down-shifted, the map reverted to race mode. In race mode the ignition changed radically to kill engine braking and make the specific power each rider preferred. In '09 these electronics weren't ready to be combined with the EFI, but now Honda has the '08 features plus two map choices on the fly.Honda was running these wild-looking fork caps. The team has been mute about what the additional adjusters are, and claims that two are air bleed screws. The odd shape looks like a weight-reducing move to us. Notice the slot and pinch bolt in the steering stem portion of the top triple clamp? That is for Davi Millsaps only. With his size and aggressive style he twists the front end without the additional safeguards.Millsaps and Andrew Short run engines with approximately the same internal specs, but with very different exhaust pipes. Milsaps runs this short pipe with a chamber on the header for more hit. Short, ironically, runs a longer pipe for smoother, longer power delivery. Naturally they do run different ergonomic set-ups to accommodate their differing heights.New for 2010 was a hydraulic clutch system. The rules allow this on a modified stock case. You can see the welds where the slave portion was added. Having the juice clutch must be for consistent, automatic adjustment, since the pull doesn't seem a lot easier than a stock cable-operated unit.

Ryan Dungey

Chad Reed's KX450F had this tiny pressure switch touching the clutch actuating arm. The switch will engage any time the clutch lever is pulled in. Kawasaki wouldn't confirm what the switch did, but Villopoto's bike did not have it. Some tuners speculated that the switch could maintain a set RPM at the start for a perfect launch every time.There is more hand work in the radiator cap than most riders spend on their entire bike. The cap is polished (which looks cool, is easy to clean and obscures what cap the team is using), and it is safety-wired to keep it tight and in place. Note the detailing on the radiator overflow hose and the welded radiator seams as well.Kawasaki has used these ultra light and cool-looking magnesium brake calipers for several years, but this is the first time we remember seeing them on the Pro Circuit KXs. These brakes are used on dry SX rounds only. The pads are too light and thin for mud or outdoor races.The factory team runs these Pro Circuit pipes with a chamber on the header. The company can't sell these due to patent issues, but PC does use them to help the bike pass sound. As always, the attention to detail on the factory KX450F is incredible. Despite every precaution against mechanical failure, Reed DNFed the opening round when another rider's footpeg tore a few dollars worth of spokes from his front wheel.This intricate clutch cable holding bracket appears to be machined from billet magnesium! It not only ties into the engine is several places, the edges seem matched to the cases to add further support. This bracket gives the cable a perfect shot at the actuating arm. This is to prevent flex in the perch, cable and cable mount which can all add a vague feel to the clutch engagement that makes consistent starts difficult.It seems that most of the teams are interested in a long wheelbase setting in 2010, but few are as extreme as Suzuki. The axle could not be much further back in the swingarm. It doesn't look like the stock chain adjuster marks could be used, and perhaps not even if the stock (heaven forbid) axle blocks were used.No doubt this billet water pump and corresponding magnesium cover are carry-over parts from the outdoor series. Heat isn't usually that big of an issue for SX. How long do you think it took to drill that carbon fiber skidplate out that carefully? Mike Gosselaar's bikes are always rolling works of art.Suzuki does a lot of testing with triple clamps to make sure the clamp is maintaining the correct feel: A compromise between ultimate control and harshness to the rider. Reportedly, the chamfered edges make a big difference to the riders. This fork top looks the same as in '09, but the white color is new and unexplained, though white generally means a magnesium part.With front ends going wide for strength, many teams are making efforts to prevent the fork from snagging and catching the side of ruts. For Suzuki that means this superbly fitted carbon-fiber slider and the billet aluminum bracket that locates it. Definitely amazing attention to the smallest detail.

Ryan Dungey

Early testing revealed that the 2010 YZ450F likes more air intake area when you have a rider who runs the engine hard and you have tuned the engine for more high RPM boost. For now the solution is to cut away large parts of the filter cover to allow the engine to breathe a little easier. As you would expect, the cuts are intricate, but very cleanly done with smooth, rounded edges.Yamaha has the '10 radiators hanging out a little farther than the '09's so the coolers are corner-gusseted from the factory. That did not prevent the team from welding the seams as a precaution. The belief is that a welded seam won't burst open if hit like the stock seam can, so most teams weld up the radiator seams that they can get to, especially those that are exposed.This is Josh Grant's Muscle Milk JGR Yamaha, but all of the top privateer teams with ties to Yamaha run these works hubs. The wheels are among the few 2009 parts that can be used on a 2010 race bike. Even though these bikes see a lot of exotic materials, the actual overall weights are not much-if any-lighter than stock. Graphics, skidplates, heavy tubes and other parts make up most of the difference that all that magnesium and titanium makes. Instead, race teams concentrate on reducing unsprung mass: weight directly attached to the wheels and not supported by the suspension.In the past, the second San Manuel team bike was a couple of steps below the level of first Reed's and now Stewart's bikes. That trend doesn't seem to have extended to Josh Hill's bike. Externally, at least, it was a copy of Stewart's. One difference is in the handlebar clamps. Hill runs a much taller bar mount to account for his height.

Davi Millsaps\' Honda CRF450R
Andrew Short
Ryan Villopoto\'s Kawasaki KX450F
Ryan Villopoto
Davi Millsaps\' Honda CRF450R
Andrew Short
Ryan Dungey\'s Suzuki RM-Z450
Ryan Dungey
James Stewart\'s Yamaha YZ450F
James Stewart
Davi Millsaps\' Honda CRF450R
Andrew Short
Ryan Dungey\'s Suzuki RM-Z450
Ryan Dungey