WE RIDE THE LAST CARBURETED 450 WORKS BIKE EVER: MIKE ALESSI’S KTM 450SXF

Mike Alessi’s KTM 450SXF was the last of the carbureted Mohicans. The petcock will become a thing of the past on the National circuit and KTM SXFs.  

When KTM asked MXA if we’d like to test the last carbureted 450cc works bike they would ever race, Mike Alessi’s KTM 450SXF, we got a little teary-eyed. We felt like we were about to throw roses on the grave of a favorite uncle. Make no mistake about it, we understand the limitations of a Keihin FCR carb better than almost anyone because we have tested every motocross bike made since 1973. We know that fuel injection will eventually rise above the organic power output of a carbureted bike, but we also know that if Kawasaki and Honda had been able to put the correct jets in the CRF250 and KX250F, we probably wouldn’t be talking about EFI today. Those two bikes were so poorly jetted that they turned the world against carbs, even though it was working well on other brands (and making more power).

Enough weeping. If there is one thing that the KTM race team has, it is options. There is no such thing as a perfect bike?just the perfect bike for one particular rider. KTM factory riders can choose between double overhead cams, finger-followers, rocker arms and single overhead cams. They can put electric starter on their race bikes and they can take it off. There are no-link PDS chassis and the Yamaha-clone rising-rate linkage frames. WP forks come in a wide variety of models, including the 52mm all-aluminum Cone Valve forks. KTM factory riders can choose between four-speed, five-speed and six-speed trannies. There are also Magura and Brembo hydraulic clutch options and several different clutches. Every factory team has options, but KTM takes it a step further by offering their riders a choice between the 350SXF and the 450SXF (and if the team really wanted, they could race the 250SX two-stroke). The fun is in seeing what combination a KTM factory rider puts together. 

Alessi’s AMA National bike was about to be chopped into pieces, parted out and discarded (kind of like they did with Mike when his contracted expired after the Nationals were over). Fortunately, someone yelled, “Stop!” Alessi’s bike, which is a bike that represents the end of an era, was spared the dumpster thanks to MXA‘s insistence on testing it

Mike Alessi is one rider who didn’t jump on the 350 bandwagon for last year’s AMA National Motocross Championships. Instead, he jumped off of the 350SXF train after the 2010 season. “During the very first day of testing, I realized that the 450 was going to be the bike for me. Honestly, I never really gelled with the 350SXF. I felt really good on the 450SXF immediately, and I was happy with my decision. On that bike, I could run up at the front of the pack and get good starts, regardless of the track conditions,” said Mike.

According to KTM technician Ian Harrison, Alessi wasn’t a rider who worried about power placement as much as the quantity of power. “Mike liked a lot of power. The more the better.” That should come as no surprise, because from the moment that Mike made his debut in the AMA 450 class, he turned heads with his amazing speed and numerous holeshots. In his second-ever 450 Pro race, Mike finished third overall behind Ricky Carmichael and Kevin Windham. In fact, unlike many quarter-liter riders, Mike elected to move to the 450 class way before he pointed-out, and he did so despite criticism from many who thought it was his year to win the 250cc Championship.

The abundant torque of Alessi’s 450SXF made the bike very stable over bumps and off jump faces. Once into the midrange, hang on!

Mike wasn’t a stranger to KTM when he signed his two-year KTM contract for 2010 and 2011. Mike began his AMA Pro career with KTM way back in 2004. He switched to Team Suzuki in 2008 and 2009, but wisely, Mike didn’t burn any bridges. He returned to KTM for the 2010, 2011 season (and ironically, will is back on a Suzuki, albeit on a privateer effort, for 2012). 

MXA isn’t a stranger to Mike Alessi’s KTM, either. We tested his works KTM 450SXF in 2007. Mike’s 2007 bike was unbelievably fast, and we still mention it today whenever the question “How much power can a bike make?” arises. Surprisingly, we almost didn’t get to test Mike’s National KTM 450SXF. Due to a communications mixup between MXA, KTM, Roger DeCoster and the team mechanics, Alessi’s AMA National bike was about to be chopped into pieces, parted out and discarded (kind of like they did with Mike when his contracted expired after the Nationals were over). Fortunately, someone yelled, “Stop!” Alessi’s bike, which is a bike that represents the end of an era, was spared the dumpster thanks to MXA‘s insistence on testing it, giving us the honor of testing both Andrew Short’s works KTM 350SXF and Mike Alessi’s KTM 450SXF in the same season, which is also the last season either rider was on the team. We wanted to be the last people to ride a 450cc works bike with the Keihin FCR (and we are already angling to be the last people to ride the carbureted YZ250F when its National days are over).

Mike Alessi’s engine used a surprising number of stock components, but on the track it doesn’t run like a stocker.

Alessi chose the front caliper available from KTM Power Parts for its firmer feel at the lever over a works Brembo unit.

Alessi’s outdoor forks are valved in the realm of motal man, but the 4mm larger works WP units are far from ordinary.

The WP SXS Trax shock is all about keeping the rear wheel on the ground and the engine hooked up.

SHOP TALK: WHAT MAKES IT TICK?

Factory race bikes have access to the trickest parts in the world, which is why the MXA wrecking crew is attracted to the stock parts more than the trick parts. The number of stock parts is proof of how good the production bike really is. Alessi’s bike was loaded with stock items?here is rundown of works, aftermarket and production gizmos. 

Engine: Of course, KTM started with the stock engine. The stock cases and cylinder head are mandated by the AMA production rule. We were surprised to find stock cams (even though they had been retimed). The piston and connecting rod were made by Pankl, an Austrian aerospace and Formula One firm. Exotic, yes, but they also supply CP and Carillo with parts.

The engine was bolted to stock KTM motor mounts (supplemented by a carbon fiber head stay). The 41mm Keihin FCR came right off the production line. The ignition was highly modified, but wasn’t as complex as the maps found on fmost uel-injected bikes.

Transmission/clutch: Having tested Max Nagl’s 450 Grand Prix 450SXF after its last season as a GP bike, we expected to find a similar four-speed works transmission?not so. Alessi ran a stock five-speed production gearbox. The KTM 450SXF clutch was replaced with a full-Hinson six-spring unit (similar to the highly rated 2008 CRF450 clutch). Alessi preferred the feel of the conventional design over the Hinson SS (single spring) clutch, but had Mike stayed at KTM for 2012, he would have been racing with KTM’s in-house, single-spring, Belleville washer clutch. Alessi chose the Brembo master cylinder and hydraulic actuator over the Magura that comes stock on the 450SXF. Brembo units come on the 250SXF.

Brakes: Compared to the production brakes on most Japanese bikes, the stock 260mm KTM front brake is a works brake right off the showroom floor. As a bonus, Team KTM riders can choose between three different front brake calipers. The most potent choice is a works Brembo caliper with a big 28mm piston. The team claims that this caliper has increased pucker power, but a more progressive feel. The second option was the one that Mike Alessi prefers. It is the aftermarket front caliper available through the KTM Power Parts catalog. This caliper delivers firmer feedback through the brake lever. The third option is the stock Brembo caliper. Alessi’s final brake choices were the stock-size 260mm front rotor with the Power Parts front caliper mated to the stock 2012 rear master cylinder, which wasn’t stock when Alessi was using it. 

Suspension: There was nothing stock about Mike Alessi’s 52mm WP monster forks. They are visibly larger than the stock 48mm WP legs. X-Trig makes special triple clamps to hold these forks. Alessi runs the old-school 20mm offset (Ryan Dungey runs the stock 22mm offset on his fuel-injected 450SXF). The trickest thing about the 52mm WP forks is that every part is made from aluminum (stanchion, fork legs, cartridge rods, pistons) except the fork springs.

For the outdoor Nationals, Alessi ran a WP SXS Trax shock, also known as a “drop-out” shock. The Trax has a special rebound circuit that senses a decrease in pressure when the rear wheel is leaving the ground and ramps up to try to push it back into contact. Alessi also ran a titanium shock spring, while his teammate Andrew Short ran a steel spring. Both bikes run shorter-than-stock shocks to help with the chassis setup. As trick as the shock was, the rising-rate linkage was right off the OEM shelf.

Wheels: Alessi’s wheels were made with Italian-built Kite hubs and D.I.D. Dirt Star LT-X rims. The works Dunlop rear tire had wide-spaced knobs and looked similar to the soft-terrain Geomax MX31, but it was an unobtainable factory tire. The front was a more accessible MX51F (although not necessarily the MX51 rubber compound that Dunlop sells to the public). Both were protected from flats by foam mousse-style inserts instead of inner tubes.

Controls: Alessi chose Renthal 608 Fatbars with medium-compound, half-waffle Renthal grips and grip donuts. Mike, like many factory riders, had his subframe cut down 5mm to lower the seat and balance out the bike’s stance. Because the subframe is cut down, the Akrapovic exhaust system had to be modified to fit. Alessi uses the same Selle Dalla Valle pleated seat cover that replacement rider Ryan Dungey now uses help keep him from sliding off the back.

Electric starter: The battery that powers the electric starter is an easy place to shed weight. The race team uses a very light Full Spectrum Genesis unit. It saves almost 3 pounds over the stock Yuasa battery. Other cool little items include a carbon fiber gas petcock cover from KTM Power Parts and a Kite holeshot device. Alessi ran the standard rear brake pedal with mud foam and a tether. Flu Designs made the Red Bull KTM graphics for Alessi’s bike, but N-Style handles the graphics on Dungey’s bike.

TEST RIDE: MORE LAPS, PLEASE

Race teams are very protective of their prized race bikes. They typically treat them like babies and hover around them whenever an MXA test rider steps off. But, since we saved Mike Alessi’s bike from the scrap heap (for a little while, at least), there were no hovering helicopter mechanics. We rode the bike until we couldn’t ride anymore.

What did it feel like? When the first MXA test rider sat on Alessi’s KTM 450SXF, the bike was noticeably lower and flatter than the stocker. Some test riders loved the flat feel, but taller test riders weren’t impressed. It should be noted that the flatter saddle meant that you had to be ready for the power to hit; otherwise, you could slide right off the back?pleated saddle or not.

Rolling on the throttle, Alessi’s bike had tons of grunt. It would pull hard out of turns, even if it was short-shifted and lugged. The torquey bottom end quickly transitioned into a meaty midrange where the bike did its best work. As with all KTM 450SXFs, the engine revved, but we had our best luck shifting up and staying in the midrange.

Even though Alessi’s bike was very powerful, the power wasn’t concentrated in one spot on the curve. Instead, the power was spread out for usability. Alessi’s powerband allowed the rider to be a little lazy. It didn’t punish ham-fisted riding as much as the typical fire-breathing works engine. The abundant torque was so smooth and easy to use that test riders could choose to use it to its fullest or short-shift to ride the torque curve or depend on the Keihin FCR to keep pumping juice into the top end. Most of the MXA test riders preferred Alessi’s stock five-speed transmission to Max Nagl’s works four-speeder (although we did have a handful of lazy test riders who thought that the powerband would be even easier to use if you never had to shift).

As for the question that everyone wants the answer to (although with both riders gone from KTM for the 2012 season, it becomes more of a trivia question)?which bike is better, Alessi’s 450 or Short’s 350? Comparing Alessi’s 450SXF to Andrew Short’s 350SXF is like comparing a tractor to a weed whacker. The 450SXF was a torque monster, while the 350 revved to the moon and then some. In the end, we favor cubic centimeters. 

The most distinctive part of Alessi’s 450SXF was the WP Trax shock. It took a long time to get used to it. The Trax is designed to follow the ground over small bumps and chop, and in those areas it was great. But, when leaving the ground over jumps and mid-sized humps, there was sometimes an odd double-kiss sensation in the rear. Back in 2007, the dropout shock also made an annoying clanking sound in these situations. Thankfully, there was no clank on Alessi’s bike. The sensation wasn’t necessarily bad, just different. Otherwise, Alessi’s suspension setup was balanced. He definitely doesn’t run an overly stiff, slam-bang, Supercross-style setup.

CONCLUSION: WHAT’S THE FINAL WORD?

When the MXA wrecking crew was forced to give Mike Alessi’s 450SXF works bike back to KTM, we got that same sick feeling you get when you have to take Rover to the vet to be put to sleep. We couldn’t bear to think about what would happen to the bike once it left our protective custody. Sadly, that is the way of life. Alessi isn’te on KTMs for 2012. His AMA National bike didn’tt live to see another day. And, we will never see another carbureted 450cc works bike again.

But, hope springs eternal. We’ll get a new puppy?and are making plans to test Ryan Dungey’s all-new, fuel-injected, single-cam KTM 450SXF. Still, we would be remiss if we didn’t applaud Mike Alessi for resisting KTM’s 350SXF push. In our eyes, he made a good choice and while he isn’t at KTM to enjoy the new 450?he did lay the ground work of the switch from 360 to 450 by sticking to his guns.