Hard-core ATV nuts have been waiting patiently for the new Sportrax 450R ever since the venerable FourTrax 250R disappeared from Honda's lineup in 1989. For 15 years we've been waiting for this day to come. From the looks of it, Honda's new "sport" quad won't disappoint! Here's the info we have so far - stay tuned for our next issue, when we actually get a chance to ride the machine ourselves!
Engine
Before we start, here are the answers to your most-pressing questions! No, Honda is not using a pumped-up 400EX motor. Yes, the 450R does come with a derivative of the ultrapowerful CRF450R dirt-bike engine. With that out of the way, let's take a closer look at the 450R powerplant.
Nestled inside the chassis is a potent, liquid-cooled, four-valve, Unicam engine. As previously mentioned, the engine found in the 450R is not identical to the one used in the dirt bike - certain items have been specifically modified and, obviously, beefed-up for four-wheel use. Interestingly enough - though the two engines share many similar items - the bore and stroke on the 450R is set to 94mm x 64.8mm. This yields an exact 450cc displacement (the dirt bike's is 449 - hey, we'll take that extra 1cc!). In addition, we get the same proven Unicam design (a compact single-cam drive), the short-skirt slipper-type piston and the nikasil cylinder liner found on the dirt bike. Even the cool-looking magnesium cylinder-head cover makes its way onto the 450R engine. This is all good stuff!
Other features to look forward to are a five-speed gearbox; a gear-driven counterbalancer to smooth engine vibrations; a 42mm Keihin butterfly-type carburetor; and a twin-sump lubrication system that separates the oil supply for the crankshaft, piston and valve train from the clutch and transmission. The twin-sump lubrication system is unique in the fact that it helps ensure that the engine and transmission oil supplies do not contaminate one another. It also reduces the amount of circulating oil needed and the size of the oil pump. Ultimately, you end up with just an oil cooler - no external oil tank is needed.
Chassis/Suspension
Honda has always set the benchmark for handling, so we expected to see more of the same with the 450R. While we didn't receive the trick aluminum box-style section frame treatment found on the dirt bike (the 450R comes with a tubular-steel main frame), lightweight aluminum is used throughout to help save weight. Items such as a removable subframe, rear sprocket hub and shift and brake pedals are all made from aluminum alloy.
The 450R holds the distinction of being the first Honda ATV to feature fully adjustable suspension front and rear (get the feeling that big red is serious about this model?). Up front you'll find independent double-wishbone suspension married to fully adjustable Showa shocks with rear-facing reservoirs. The front shocks sport 8.4 inches of travel. In the rear, the 450R is set up with a cast-aluminum swingarm and Honda's Pro-Link rear suspension. The rear shock features a fully adjustable piggyback reservoir and enjoys 9 inches of travel.
Racer Features
While Honda will certainly be quick to point out that the 450R is not a "racing" ATV (remember, it's called the Sportrax 450R, not the Racetrax 450R), there's little doubt in our minds this is a race-oriented vehicle. It is being touted as a "high-performance sport ATV featuring a race-bred chassis ..." Well, to help cement the fact that the 450R is more "racer" than "sportster" is one key characteristic that makes it stand out from the rest of the sport crowd. No electric start! That's right - if you want to fire up this bad boy, you'd better begin kickin'! Look closely at the left handlebar. What you'll see is a "hot-start" button rather than an electric-start button. By not including an electric starter, Honda has all but confirmed that the 450R is meant for the true speed-oriented enthusiast.
Other cool "raceworthy" features include high-performance brakes (Honda wanted to give the 450R the stopping power and feel of its CRF450R motocross bike). The front brakes consist of dual 174mm discs and dual-piston calipers, while the back comes with a 190mm disc and single-piston caliper. The front and rear calipers as well as the brake brackets are made from aluminum to help reduce unsprung weight.
As for tires and wheels, the 450R rolls on Dunlop-shod 10-inch aluminum wheels up front and 9-inchers out back.
Last, but not least, Honda announced that an optional HRC racing kit will be offered concurrently with the 450R's release. What that entails, we don't yet know. Honda is keeping the details pretty close to the vest.
Based on what we've seen, we have every reason to believe Honda has a winner on its hands. We can't wait to throw a leg over this machine. Honda has a proven track record of producing awe-inspiring, superb-handling sport quads. How its new offspring stacks up against the competition remains to be seen, but one thing is certain - it looks as if the battle for the top sport ATV is about to be turned up a notch!
How Potent is the 450 Engine?
With the preliminary information we've received from Honda, it's hard to say exactly how closely its engineers matched the internal specs of the 450R engine with its powerhouse CRF450R dirt-bike counterpart. As we mentioned, the two engines share quite a few common elements but are not identical. Will the quad engine be as powerful as the one found in the dirt bike? If it's close, we have a lot to be happy about.
The CRF450R engine puts out some pretty impressive specs. It herds a whopping 55 horsepower at 9000 rpm and 36.5 foot-pounds of torque at 7000 rpm - yikes! The only major difference we're aware of between the two engines is the dirt bike comes with a more-impressive carb (a 40mm FCR downdraft type versus the quad's 42mm Keihin butterfly-style unit) and a more-free-flowing exhaust system in stock trim. Will the quad engine come with all the trick titanium internals and the same high-compression (12.0:1) piston? As of this writing, we could not get solid confirmation on all the 450R's internal engine details. When we get the final word, we'll pass it along!