With a new year comes a new supercross season and new bikes to dial in. We toured the pits at the early rounds of the SX series and grabbed one of each color to tell you what’s on the factory supercross machines of 2017 and what performance traits some of the top racers are striving to get out of their machines. It’s interesting that all four of the bikes here that come with air forks have converted to coil spring forks, and both of the bikes that come stock with coil spring forks are running air forks. Also, the bikes that come stock with traction control are the two bikes here with the least amount of electronic componentry. All of the information in this story is based on what we could squeeze out of these top mechanics (and maybe a few things we saw but couldn’t get a comment on) on a race weekend.
Ryan Dungey’s Red Bull KTM 450 SX-F Factory Edition
Mechanic: Carlos Rivera
Ryan doesn’t want any play in this throttle and wants it to feel light and friction-free. “The less resistance, the better.”
The front brake perch is positioned closer to the center of the bike than normal, away from the end of the handlebar, and the lever is shorter than stock. In addition to all that, the reach of the lever is set in close to the grip. This gives Ryan the leverage feel he wants by contacting the lever further out, and the “inboard” position is so Ryan can cut closer and closer to Tuff blocks; when he bumps a block with this setup, it only bumps the bar rather than touching the front brake lever and likely causing a crash.
The works Brembo front caliper has an oversize piston and grabs a Moto-Master rotor. Ryan sets it up to be powerful with a firm feel at the lever with no mushiness.
Carlos worked with Mettec to design some of the different titanium bolts; some are available to the public.
The bike is light. It’s just a little more than the AMA 220-pound weight limit, just enough to be safe of not breaking that rule.
Roger DeCoster helped develop the team bikes’ triple clamps. Neken makes them for the team. Carlos says the clamps are “pretty much” in the stock offset position after the team tested a couple of different options.
The WP 52mm works Cone Valve fork is a coil spring fork. The team tests different setting mid-week, always looking for a way to improve the firm/plush balance. The forks look beefy, but according to Carlos they are lightweight.
The left front axle nut is replaced with a cool cap that takes a 3/8-inch ratchet or impact wrench directly, so there’s no need to find the right socket during quick front wheel changes. It also helps prevent the fork from catching in ruts.
The skid plate is designed by KTM and Akrapovic. It wraps around the frame rails, which makes it more durable since it doesn’t bridge across the rails. Carlos half joked that he also appreciates that he can power-wash it without taking the bike off the stand.
The engine mounts are right off the stock bike…from 2015. Dungey prefers the feel of the older steel mounts compared to the new aluminum ones. The engine is built by KTM’s in-house factory engine services. Dungey’s supercross engine package is tuned for stronger low-end power.
The race engines are inspected after every race, but the practice bike engines go 25 to 30 hours with only basic maintenance before they are opened up.
The muffler is close to stock but is actually a little quieter because of the sound rule regulations.
The team doesn’t use a traction control map, even though the stock bike has one available. As Carlos tells us, “His traction control is his hand.” Ryan also doesn’t use a starting map or any type of rpm indicator.
The titanium billet pegs are one piece—no welds.
The transmission keeps “pretty much” the stock ratios but with slightly more durable materials used.
Ryan uses a WP Trax shock. It employs a WP titanium spring and a KTM Power Parts quick adjuster. Carlos and Dungey will sometimes make sag adjustments during practice to suit the track.
The team covers up the engine case’s oil sight glass with an aluminum plug that is pressed in and has a clip that holds it in place. Carlos appreciates the trick look of it.
Ryan likes his “5” so the team got clearance to “ghost” it into the number one that he is required to run. Carlos prefers the “1” to the “5,” “…number one, of course we like it. It looks nice too. It looks lighter.”
Ken Roczen’s Honda HRC CRF450R
Mechanic: Oscar Wirdeman
The team never tested a kickstart bike. They had the electric start-only version from day one of testing. The kickstarter and its internal pieces were never on the bike as a weight-savings measure. The team added a second starter button just under a frame rail on the right side as a button backup in case the button on the handlebar got damaged.
The exhaust has an oxygen sensor so the team can gather data on the air-fuel mixture. They use this mainly in the beginning of the season, especially on an all-new bike like this to make sure the settings are as good as they can be.
Roczen uses different silencers than teammate Cole Seely for a difference in power preferences. Roczen likes his power smooth and down low in the rpm since he isn’t a revver.
The engines are built in-house, and the plan for 2017 is to do a complete teardown after each of the early races just to double-check all is good since the bike has an all-new engine. Later in the season the engines will go more than one race before a teardown.
Roczen’s front brake lever uses an ARC lever, roughed up for extra traction, and he runs the lever very close to the bar. He likes a progressive feel. Roczen runs his brake lever a little higher than his clutch lever.
The triple clamps are HRC factory triple clamps with stock geometry. In fact, all the geometry on the bike is extremely close to the production bike. The team did minimal testing with geometry changes in preseason testing.
The fork is a KYB air fork, even though the production bike uses coil springs. The riders had the option, and Roczen picked the factory air fork for its plushness and hold-up. Oscar says Roczen runs his fork a little softer than most supercross riders.
Honda’s pegs and mounts are titanium. They are extremely sharp and hold their edge for a long time.
The linkage is a works part, but Oscar claims it’s close to the stock linkage’s ratio and would not elaborate on how it differs, just that, “It’s just a little bit better for supercross for us.”
KYB gave the team two red color choices for the shock spring, and the team chose the brighter Candy Apple Red.
Roczen is hard on the bike’s left side panel and swingarm with his boots when he’s scrubbing, but otherwise is very easy on the bike. He’s more comfortable scrubbing to the left, and the left side always gets more abuse.
The brake rotors are production units. The front brake uses a Nissin works caliper. On the rear brake, the master cylinder has the sight window removed, welded over, and then ground smooth.
The team uses rubber straps rather than bolts to secure the gas tank. Like different engine mounts this is likely done to affect the feel of the chassis.
Testing was quick and the team found a base setting Roczen liked fairly easily. In years past, when Roczen gets a setting he likes he generally sticks with it, without changes, throughout the supercross season. Roczen wants predictability in his bike and is willing to give up a possible improvement to keep a familiar feeling.
Eli Tomac’s Monster Energy Kawasaki KX450F
Mechanic: Brian Krantz
Tomac runs KYB suspension, while his teammate Josh Grant runs Showa. Tomac switched to KYB in his final year on Honda two seasons ago and carried that over on his Kawasaki.
The works Kawasaki has sensors on the fork, but Brian wouldn’t comment on them other than to say they run all the data acquisition sensors they can to help interpret what’s happening with the bike versus what Tomac is feeling. This includes a sensor on the clutch arm so the team can see exactly what he’s doing with it.
Eli’s bike had the factory triple clamp on it for Anaheim 1 but later switched to an Xtrig clamp like teammate Josh Grant. The Xtrig clamps are more forgiving and give a little more feel, which Krantz says can help when initiating turns. The advantage to the factory clamps is the potential for a little more stability.
Eli runs a Renthal Fatbar while teammate Grant runs the Twinwall, which seems odd since Eli was running stiff clamps and bar with more flex while Grant started the season with more forgiving triple clamps yet a stiffer handlebar.
Brian puts a lot of effort into keeping all the controls smooth and buttery by keeping the cables clean and everything properly lubricated.
The team has different brake options, and, again, the teammates split on their choices. Eli’s bike runs the billet caliper while Josh’s bike has the magnesium caliper on it. The billet caliper has a firmer feel at the lever that Eli prefers.
The factory water pump cover and magnesium water pipe going into the top of the engine don’t really change coolant flow, according to Krantz.
Eli runs a very progressive rear suspension linkage so the rear-end stiffness ramps up a lot as the swingarm gets further up in the stroke.
The airbox is built to stock dimensions, just made in green plastic. The team tries to run all green plastic, including the rear mud flap.
Jason Anderson’s Rockstar Energy Husqvarna FC 450
Mechanic: Chris Laredo
Jason’s bar is a ProTaper Fusion with a custom bend made just for him. Laredo will use the flex lock on the crossbar to tune more flex into the bar if the track is rough or has a lot of sharp edges.
The bar is connected with a solid bar mount. Jason has used air-suspension bar mounts in the past but felt the solid mounts were better for him since he’s been on the 450.
The fork is a WP Cone Valve 52mm coil spring fork. “We’re always trying to achieve maximum hold-up, maximum stiffness for those big hits and big G-outs... as well keeping plushness in the top part of the stroke to allow for maximum traction and turning ability. Too stiff then you tend to lose traction; too soft you kinda get a little bit of a low feel in the rhythm section. It’s a give and take.”
The team will test in both California and Florida in the preseason to get base suspension settings that work best in both hard and soft dirt conditions. Then after the series moves east they shift most testing to the softer test tracks in Florida that are more similar to the softer, ruttier dirt of the East Coast racetracks.
There was no official comment from the team, but we spotted what looks like a Honda steering stabilizer on the front end.
Jason does not like an aggressive or hard-feeling front brake lever; he likes a progressive feel. The master cylinder and lever are stock; to this Chris adds a factory Brembo brake line, which is a little longer than the stock line, that pushes fluid into a Brembo Husqvarna Accessories caliper. The caliper has a 24mm piston (same as stock) but with different coatings that give it a “slicker” movement. Jason prefers stock brake pads but wants them broken in to the rotor. Laredo says if you see him riding the bike slowly through the supercross pits, you’ll probably notice he’s dragging the brakes to get them hot and make sure they’re broken in.
The FMF exhaust is not an off-the-shelf unit. Jason likes his power linear and smooth. “Depending on how the characteristic is, more is not always better.”
The clutch is made up of Hinson pieces internally but with stock clutch plates, though they are measured to a certain stack height and surfaced to make sure everything is perfectly flat.
Laredo believes in brake snakes to prevent the brake pedal from being ripped off, but there is not one on Jason’s bike because every time he’s put one on, the cable is broken when Jason brings the bike back. Laredo even had other mechanics put one on to make sure he wasn’t doing something wrong—but the cables came back broken. “I don’t know if it’s the way he hits corners or digs it into ruts or what. But I can’t keep it on there, he breaks the cable. The pedal is okay but it comes back and the cable’s just dangling.”
Jason has “factory” Dunlop tires that are not available to the public. At Anaheim 2 he had 783A on the rear and a 768 on front.
Even though Jason’s style has him back over the bike more, Laredo says Jason’s WP Trax shock’s setup is very normal and balanced, in line with what other racers would use.
Jason is particular about his shock sag and just a couple of millimeters make a big difference for him. Laredo says they seldom change it for track condition, but if they do it’s a change of 1 or 2mm of ride height.
The engine is fed through a stock throttle body that’s had the mounts and guards trimmed off to save weight.
The bike has a hold-down device on the fork but no special start map.
Cooper Webb’s Monster Energy/Yamalube/chaparral Yamaha YZ450F
Mechanic: Eric Gass
Eric removes some of the protective sheathing from the brake hose just to try to lighten up the bike as much as possible.
The hydraulic clutch is from Rinaldi Yamaha of Europe. Eric says it gives Cooper a more consistent feel at the lever and is more consistent for the launch off the starting line.
The GET display on the front fender can light up like a tachometer. It helps Cooper keep the rpm in the correct range even with 21 other bikes on the line with him. Eric would not tell us what rpm Cooper launches at.
Cooper runs a factory air fork and has for most of his pro career. He tested with coil springs when he moved to the 450 but went with the air fork because even deep down in the stroke it can have a more “pillowy” feel.
The factory hubs are similar to the stock hubs in shape, pattern, and material (aluminum), but Cooper’s hubs are machined, not cast.
The factory footpegs look like cast units but are not. They are titanium units, and sandblasting creates their cool look.
Next to the throttle, Cooper has a map switch and a start program button. A cowling over it protects an accidental engagement. Cooper will often test between two different maps during practice but usually picks one and sticks with it through the night’s racing.
Cooper likes to pick a base suspension setting and stick pretty closely to it; he picks predictability and familiarity over what might be a slightly better setting for each track. “He really prefers to get to know what the bike is going to do and ride around that.”
Pro Circuit builds an exhaust tuned to work with Cooper’s engine package and pass sound.
The team slightly detuned the 450 when Cooper moved to the bigger bike full-time starting with the Motocross des Nations and then brought up the power slowly during preseason as he asked for more.
Cooper is hard on the clutch when he’s in a battle on the track, but other than that he’s very easy on the bike, “…brakes, grips, the graphics, it’s like he just floats around on that thing.”
Both the front and rear brake are completely stock other than mods to the rear brake pedal, an ARC lever, and removal and welding over of the sight window on the rear master cylinder.
After testing different shock linkages and swingarm setups, Cooper felt most comfortable with the swingarm and shock linkage right off the stock bike.
On top of the top triple clamp is a GPS antenna to match the bike’s data acquisition info with the exact spot on the track to better compare data with what Webb is reporting about the bike.
Weston Peick’s Autotrader/Suzuki/JGRMX RM-Z450
Mechanic: Glen Hobson
Peick uses ProTaper 1/3 waffle grips but rotated a little forward so he doesn’t grip on the waffle. This helps prevent him twisting the grip out of place.
Weston’s front brake uses a Galfer 280mm front rotor and an ARC lever with adjustable ratios but stock master cylinder and caliper.
The ARC brake banjo bolt guard, a new product from ARC, endures a lot of abuse when coming through the pack.
Weston runs a conventional spring fork, not air. As Glen reports, “We found in a lot of our testing that with his, we’ll call it less-than-fluid style, the progressiveness of the air fork was tricky to get right.”
The team uses stock 2017 triple clamps but had to bore them out to hold the factory fork tubes. The top looks shaved to tune flex, but the team told us that was really a result of needing to mod the lower camp so the JGR machine shop could fit them into the jig. The team did try some other triple clamp options, but the stock setup gave the more forgiving feel Peick was chasing.
One quirk the team carried over from the blue bike is the Yamaha production gas cap hose grommet that keeps the breather hose tucked into the steering stem.
Most of the titanium is from RaceTech/RaceTrader titanium. Regarding the quest to save weight, “As much as they can dish out, drill out, modify, shorten, cut, that’s what we’re going to do.”
Weston is a big believer of the GET’s LCGPA launch control device and rpm indicator as an additional indicator of his bike’s rpm (other that vibration and noise) on the gate.
The team uses GET data acquisition and runs it full time.
Weston runs his kill switch beyond straight up and down to avoid accidentally hitting it.
“If he’s off, or having a bad day, or around mixed company on the track, the clutch wear increases exponentially.” Peick might go through three clutches in one race day, yet in practice one clutch can last up to two weeks.
Glen revealed that the bike had a high-compression piston, a higher lift cam, mods for better flow, and different timing. Weston likes power smooth, but snappy, and lower in rpm range, while his teammate Justin Barcia never met a rev limiter he didn’t bump into.
The shifter is a JGRMX piece. It’s a stronger aluminum, the splines fit tighter to the shift shaft for a more precise feel, and the tip never exposes the pivot and spring to mud even at full lock.
The pegs are done completely in house and fit the stock mounts. They are likely available for sale by the time you read this.
The axle and swingarm pivot boltholes are plugged with Delron to keep mud out.
The bike runs a factory Showa shock with a Ti spring. “As long as bike is stiff enough to forgive all of his errors on track and allows him to bank off of berms and riders, he’s pretty happy.”
The water pump is stock inside and out but the team changed the hose routing to equalize the flow to both radiators better.
The team liked the stock linkage ratio but designed custom pullrods that use interchangeable pills to fine-tune pullrod length for progressiveness and rear-end height. Peick wanted it close to the stock ratio but did want a lower rear ride height.