January 1st, 2006 by admin
Honda invited us down to the Lake Whitney MX track in Whitney, Texas to see and ride the new TRX450R everyone has been waiting on. It was worth the wait! Yes, it is everything you could expect from Honda. To answer a couple of rumors first, NO it is not a 450 size engine in a 400EX frame, the frame is totally new. Second, it is not the 450 dirt bike engine adapted to the quad frame, its new from the Valve Cover (only interchangeable part) down. Honda put a lot of time and effort to make this a great quad!
The heart of the 450R is an ATV specific built high-tech, liquid-cooled four-stroke single-cylinder engine with a bore and stroke of 94mm x 64.8mm creating a displacement of 450cc’s. Cooling the big engine is accomplished with a big aluminum radiator with thermostatic controlled electric fan. The TRX engine uses the same type of “Unicam” as the CRF engine. A single camshaft activates the intake valves while a forked roller rocker arm operates the exhaust valves. Eliminating an exhaust camshaft and gear, and the added chain to drive those, cuts down on the weight on the upper end of the engine. Keeping the weight down as low as possible is a high priority on ATV racing quad. The cast piston has a short skirt at 28.4mm, but has 3 rings for added longevity. The piston sleeve is a Nikasil© liner which saves weight and permits closer piston-to-cylinder clearance for cooler operation for better engine life and consistent power output. You will find a needle bearing on the big end of the connecting rod, for maximum rpm and durability.
One of the interesting features of the 450R engine is the vertically split crankcase. The TRX engine uses a twin wet-sump design to separate the transmission/clutch oil from the crankcase oil. This allows the owner to use two separate kinds of oils in the same engine. Now your clutch oil will not contaminate the crankshaft/camshaft oil with burnt friction material. Added baffles in the cast design of the engine keeps everything lubed up even when riding on uneven terrain.
Forget about electric start, this is a performance quad! The forward rotating kick starter makes for easy starting of the big bore quad. With a built in auto compression release, one smooth forward kick is all that’s need to fire it up. A “hot start” lever is conveniently mounted on the left handlebar to assist in starting the engine after its warmed up. A 42mm Keihin Carburetor will provide plenty of wide-open power and a throttle position sensor will help maintain accurate response throughout the rpm range. Honda made the clutch easy to service by using a removable clutch cover. We can easily see aftermarket billet anodized covers coming
On the front end of the double wishbone style a-arms are 174mm disk brakes with twin piston calipers. An innovative hybrid brake line system combines flexible CR style hoses with zero expansion steel lines to produce stopping power. The new brake lines and adjustable reach lever make the braking feel excellent. At the rear is a 190mm disc with oversize single piston caliper. All calipers are constucted with aluminum for reduced weight.
After many hours of testing tires, Honda decided Dunlop’s were the best all around tire for the rear, but the front tires are an all new design, specifically for the 450R.
The shiny plastic is all new for the 450R. Up front you will find dual 35watt headlights for excellent night time viability. Rubber grommets holding the nose section on allows for easy removal and access to the major electronic components. On the rear is a trick looking LED tail light/brake light. We can imagine how many of these tail lights will find there way to other quads.
When you finally get to ride the 450R you are going to realize the wait has been well worth it. Honda has put a lot of R&D into this quad in an effort to make it the best. The ride and handling are second to none. We rode the 450R on the track, some trails and also some nice tall hill climbs. It never let us down. In the air the R is very predictable and we noticed no bad habits, it’s a good jumper. The shocks are easily adjusted for rider preference and unlike some adjustable shocks, these adjustments do work. The front tires keep the R headed right were you point it and the rears have just the right amount of traction to power slide you through the turns or propel you off the jumps. The frame and suspension geometry are based on the legendary 250R with new refinements and improvements. Handling is spot on, just like you would expect from Honda. The quick revving 450cc engine has plenty of power and we are sure the aftermarket companies are hard at work to make it even better. The front end seems light and nimble and the “wheelie” riders will have no problems getting the front end airborne.
HRC (Honda Racing Corporation) is going to market a “hop-up” kit for the 450R. This will include a more open air box lid, differnet jetting, camshaft, air box snorkel and removal of the muffler baffle. After riding the hopped up version, we think it will be definitly worth the roughly 0.00 list cost. There was a noticeable difference in the power of the two quads, and it adds a deep throaty sound to the quad.
|Engine Type||450cc liquid-cooled single-cylinder four-stroke|
|Bore and Stroke||94mm x 64.8mm|
|Valve Train||Unicam; four valve|
|Carburetion||Keihin 42mm with throttle position sensor (TPS)|
|Ignition||CD with electronic advance|
|Final Drive||O-ring sealed chain|
|Suspension-Front||Independent double-wishbone with Showa shocks, featuring adjustable spring preload, rebound and compression damping; 8.4 inches travel|
|Suspension-Rear||Pro-Link with single Showa shock featuring adjustable spring preload, rebound and compression damping; 9 inches of travel|
|Brakes-Front||Dual hydraulic 174mm discs with twin-piston calipers|
|Brakes-Rear||Single hydraulic 190mm disc with single-piston caliper|
|Tires-Front||22X7-10 knobby radial|
|Tires-Rear||20X10-9 knobby radial|
|Seat Height||32.6 inches|
|Ground Clearance||4.2 inches|
|Dry Weight||350 pounds|
|Fuel Capacity||3.2 gallons|