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We ride the TRX450R

Honda's made for racing TRX450R
By Jorge Cuartas

Few phone calls in my life have managed to get me more excited than the one I received from John Pellan last Wednesday night asking me to attend the press intro of the 2004 Honda TRX450R down in sunny Texas. As you can imagine, after taking a few deep breaths and pinching myself to make sure I wasn't just fantasizing I took off running West towards Lake Whitney, Texas (after all I only had six days to get there). Luckily for me, John called back and explained that I would be traveling by the far superior form of transportation known as the airplane. For the next five days I scrambled, buying film, packing shorts and sunscreen, and putting in as many laps as I could aboard a couple of borrowed Yamaha YFZ450s (thanks David & Leland), after all what better way to judge the Honda than by riding its main competition. By the time my travel day caught up with me I was informed, rested, and ready.

Upon arriving at Dallas Fort Worth Airport, I was pleasantly surprised to find Kory Ellis waiting for me in the baggage claim area, I now had a partner in crime. We wasted no time loading up and heading down to Lake Whitney where we were greeted by the Honda press staff, and the Red Rider hero himself, Mr. Tim Farr. Prior to dinner, we were given a guided tour of the all-new race quad by the R&D guys who helped design it. At first glance, the absence of an oil pump concerned me, apparently the oil pump is built into the left-side crankcase instead of using a separate pump housing. Honda guys explained this reduces weight. On top of that, the five-speed gearbox incorporates its own separate lube system (just like a two-stroke engine), so the oil-bath surrounding the eight-disc clutch will be subjected to a lower heat load. Also, the TRX engine case incorporates a twin wet-sump design like that in the CRF dirtbike, but the four-wheeler features an increased oil capacity to accommodate one inherent difference in an ATV's nature that most riders would of never thought of. Unlike our two wheeled counterparts, ATVs lean considerably when running on cambered terrain, so Honda deepened the sump to help ensure a good flow of engine oil under normal race conditions.

ATV Scene's Kory Ellis powers through a sweeping turn at high speed. Ellis said the Honda handles well.

Other interesting features include a lightweight cast piston which features a very short, 28.4mm piston skirt length, and three piston rings. The Nikasil® cylinder saves weight while running cooler for lengthened engine life and consistent power output (Nikasil® has been used forever in dirtbike motors). The techs kind of lost me when they began to rant and rave about the double-carburized connecting rod and its needle bearing on the big end (which apparently maximizes high-rpm performance while also boosting durability). First impressions led me to believe that the pre-release hype was well deserved, but I wouldn't get to confirm that until the next day when I could ride it.

To everyone's dismay, Thursday morning started out badly as the temperature dropped into the lower forties and the rain started coming down (so much for sunny Texas). As we loaded our gear bags the excitement of riding was replaced with the fear of Pneumonia. The excitement quickly found its way back, as we pulled into the track and up to the Honda semi with the eight identical TRX450s waiting for us under the awning. Suddenly Pneumonia didn't seem so bad. Tim was the first to wrestle himself into some riding gear and proceeded to take off, I grabbed the camera, a Recon, and gave chase. Within a lap, Kory was also on track and the potential of the new machine made its way to center stage. By lap two, Kory and Tim were flying around the track at GNC speeds, these two put on a show that grabbed everyone's attention, even Mother Nature noticed as she rewarded them with a break in the rain. From what I could see through the camera lens, the TRX450 was impressive, but it was time to judge for myself and ride the red beast.

Ergonomics

You'll want to get familiar with the bar mounted hot start button. Since the Honda is kick started only, starting the mighty 450 without it can be difficult.

As I made my way towards my designated machine (#000022), I began to feel the anxiety of trying to start the big thumper, after all the last four stroke I had to kick was a YZ426 hybrid and it was no where near easy or fun to start. To my utter joy I was able to start the Honda on the first kick while sitting down. If you're at all worried about the lack of an electric start, forget about it, with the engine cold this thing can be started with little to no effort with the choke on (once it's warm just hit the hot start button and it's just as easy). As I sat there waiting for the motor to warm up I realized that the ergonomics were exactly what you would expect from a Honda with a little bit of Cannondale comfort thrown in for good measure. The seat height is a little taller than say a 250R or 400EX, and the gas tank has that nice wide crotch-rocket feel to it. The stock bars felt pretty good too, just wide enough with a bend that doesn't have that stock "bo-bo" feel to it.

 

Engine & Tranny

As I let the clutch out it was textbook Honda smooth, so far so good. The rain had stopped and the Lake Whitney track was absolutely perfect, the TRX was hooking up perfectly. As I put in some laps I realized a couple of things; The TRX is surprisingly easy to ride, and this certainly wasn't a CRF motor thrown into a 400EX chassis like some people rumored. The motor is strong in stock form; it has a nice even pull through the gears and when ridden properly, rarely reaches the rev limiter (by properly I mean as you would typically do on a MX track). The TRX doesn't have the de-tuned feeling that I somewhat expected and it was a nice surprise. A big, 42mm Keihin carburetor has been fitted to provide plenty of wide-open fuel mixture flow, and a throttle position sensor helps maintain accurate and linear response throughout the rpm range. The TRX's transmission has been strengthened for added durability in its ATV racing role, and the five-speed gear span was selected specifically for ATV use.

Chassis, Brakes, & Suspension

The 450R's brakes are second to none.

In all honesty I can't see what the big deal is that everyone is making out of the rear linkage. No it's not a CR500 linkage, but it's not exactly a 250R linkage either (which in my opinion, wasn't all that bad). I repeatedly, intentionally came up short on a small step up and a medium sized double, and even with the stock bouncy tires the ATV reacted exactly as I thought it would, there are few surprises in this department, typical Honda. The frame seemed to flex just enough when going into whooped out turns and over small whoop sections to keep the bars from being jerked out of my hands. The steering is spot on; at no point did I feel I should have a steering stabilizer. The Brakes are awesome, the front brakes will get you stopped in no time, and the rear (from what I could tell with my limited rear brake knowledge) seemed pretty effective as well. The fact that the hybrid brake system is comprised of flexible CR-style hoses with zero-expansion steel lines plus durable ATV-style lines ends up providing you with awesome feel as well as stopping power.


HRC Hop up kit

Honda suggests their HRC Hop Kit for additional power.

After spending the better part of three hours aboard the stock TRX we were called in for lunch, during which the Honda guys listened to our feedback while looking for signs of abuse on the machines. After lunch we were set loose on the HRC kit equipped 450s. The HRC kit consists of a cam, jetting, new air box lid, larger air intake snorkels, & a much less restrictive exhaust tip (still quiet enough to ride the EPA areas). For a measly $299.00 the kit delivers a whopping 13% horsepower increase. Once again Kory was fastest to climb aboard, and within seconds he was gone (13% faster than last time out). From what I could make out trackside, the kit makes a huge difference. Upon climbing aboard the HRC TRX, I was able to confirm that the difference is indeed significant enough to warrant spending $300-, this quad really came to life.

The Verdict

Farr is getting very familiar with his new factory ride. He's already done several photo and video shoots on Honda's new 450R.

I learned a lot in the few days I spent with the mighty Honda TRX450R, for starters it's everything that the racing community has been wishing for since 1990 It is a far cry from the joke that was the 400EX, it's not your typical OEM solution of stuffing a ten year old motor in a mediocre chassis, it's a well thought out, solid ATV.

How does it compare to the YFZ? In my honest opinion, I think it's a little stronger in stock vs. stock form, (without bolting up Yamaha's GYTR package on the YFZ or Honda's HRC kit on the TRX). Stock vs. stock, I also think it handles a little more predictably. Would I go so far as to say that riders would have any sort of advantage on one machine over the other? If so, it wouldn't be by much, a competent rider could win a championship in any class aboard either machine. As for me, I'm a little less than competent, I need all the help I can get, so I'll be riding Red.

 

Specifications

Engine
Engine Type:	450cc liquid-cooled single-cylinder four-stroke
Bore and Stroke:	94.0mm x 64.8mm
Compression Ratio:	10.5:1
Valve Train:	Unicam; four-valve
Carburetion:	Keihin 42.0mm with throttle position sensor (TPS)
Ignition:	CD with electronic advance
Starter:	Forward kick
Drive Train
Transmission:	Five-speed
Driveline:	O-ring-sealed chain
Chassis/Suspension/Brakes
Front Suspension:	Independent double-wishbone with Showa shocks, featuring adjustable spring preload, rebound and compression damping; 8.4-inch travel
Rear Suspension:	Pro-Link with single Showa shock featuring adjustable spring preload, rebound and compression damping; 9.0-inch travel
Front Brakes:	Dual hydraulic 174.0mm discs with twin-piston calipers
Rear Brake:	Single hydraulic 190.0mm disc with single-piston caliper
Front Tires:	22 x 7-10 knobby radial
Rear Tires:	20 x 10-9 knobby radial
Dimensions
Length	72.6 inches
Width	46.3 inches
Height	43.6 inches
Wheelbase	49.2 inches
Seat Height	32.6 inches
Dry Weight	350.0 pounds
Fuel Capacity	3.2 gallons
Other
Model ID:	TRX450R
Colors:	Red
Options:	Consult your owner's manual for optional HRC Racing kit parts

Additional Features

o Engine design meets California Air Resources Board (CARB) off-road emissions standards.

o Convenient oil-level window allows for at-a-glance oil check.

o Long, narrow seat is designed for superior comfort and performance in all operating conditions. Saddle is also easy to remove for convenient access to the air filter.

o Adjustable dual headlights with 30-watt bulbs and improved reflectors for excellent visibility and distinctive appearance.

o Pivot-access brake calipers for easy pad replacement.

o Engine cases protected by high-impact plastic skidplate.

o LED tail/brake light for light weight and aggressive appearance.

o New, shorter CRF-style adjustable clutch and front brake lever.

o New wider footpegs for improved rider control.

o Aluminum shift and brake pedals.

o New CRF-type handlebar grips.

o Honda Racing-inspired colors and graphics.

o Optional HRC® Racing Kit available.

o Transferable six-month limited warranty; extended coverage available with a Honda Protection Plan.

o Ownership includes one-year complimentary Membership in the Honda Rider's Club of America™. Benefits include discounts, travel benefits, roadside assistance and much more. For HRCA® details, call 1-800-847-HRCA.

Engine/Drivetrain

o All-new powerful purpose-built ATV four-stroke 450cc liquid-cooled four-valve Unicam™ engine is based on the award-winning CRF™450R motocrosser's.

o Compact, lightweight engine designed specifically for ATV usage is worthy of its CRF heritage.

o Unicam valve train provides the light weight of a compact single-cam drive and the optimum combustion chamber shape for maximum power at all engine rpm.

o Unicam valve train features a carburized single camshaft that directly actuates two 36mm steel intake valves. The camshaft exhaust lobe actuates two 30mm steel exhaust valves via a forked, low-friction roller rocker-arm.

o Lightweight, compact, internal auto decompressor provides superb cold-starting and hot-starting operation.

o Engine incorporates ATV-type forward kickstarting for ease of starting and light weight.

o Crankshaft is made of high-strength, low-carbon steel with carburized main journals for maximum durability at sustained high-rpm operation.

o Cylinder head cover is made of magnesium to reduce engine weight.

o Cast 10.5:1 compression piston features 28.4mm piston skirt length, with three piston rings for added durability.

o Double-carburized connecting rod utilizes a big-end needle bearing for maximum high-rpm performance and durability.

o Nikasil® cylinder lining is lightweight and provides cooler and quieter operation for extended engine life.

o Press-fitted steel spark plug pipe fits between forked exhaust rocker arms, further contributing to compact cylinder head design.

o 42mm Keihin butterfly-type carburetor features light throttle effort, smooth operation and excellent rideability.

o Carburetor features a throttle position sensor (TPS) that helps maintain linear response throughout the rpm range.

o Twin-sump lubrication system separates the oil supply for the crankshaft, piston and valve train from the clutch and transmission. This ensures a cool supply of oil to the clutch, eliminates clutch and transmission material contamination to the engine oil, and reduces the amount of circulating oil and the required size of the oil pump. This design allows for an oil cooler and no external oil tank is needed.

o Aluminum oil cooler ensures a cool supply of oil.

o Vertically split crankcases feature a built-in oil pump, reducing weight compared to a conventional design.

o Left side countershaft bearing and axle carrier feature double-row bearings for added durability.

o Exhaust system uses a lightweight stainless steel header and muffler.

o High-capacity radiator is rated at 17.2Kw for efficient engine cooling in extreme operating conditions.

o Compact, flat radiator fan is lightweight and provides efficient cooling.

o Gear-driven balancer reduces vibration and drives the water pump. Eight clutch plates provide the surface area necessary to handle the engine's massive torque.

o Durable five-speed transmission with all-new ratios designed for ATV application.

Chassis/Suspension

o Round-tube steel frame with removable aluminum subframe is lightweight and durable.

o One-piece cast aluminum swingarm for light weight, maximum strength and durability.

o Independent double-wishbone front suspension with fully adjustable Showa® shocks provides 8.4 inches of travel, and features rear-facing reservoirs for increased durability.

o Pro-Link® rear suspension with fully adjustable Showa piggyback shock provides 9 inches of travel.

o Dual 174mm front disc brakes with twin-piston calipers and new high-pressure front brake lines provide excellent stopping power.

o New 190mm rear disc and beefy single-piston caliper provide improved stopping power and increased ground clearance.

o Aluminum brake calipers and brackets front and rear reduce weight.

o Removable aluminum rear grabrail and front bumper for reduced weight.

o Lightweight aluminum wheels reduce unsprung weight for outstanding handling.

o Dunlop radial tires provide superb traction and cornering ability.

o Durable and lightweight O-ring-sealed drive chain.

2004 Honda TRX450R powersports.honda.com