http://www.quadbikeworld.com en-us Wed, 07 Jan 2009 04:06:45 -0600 http://www.quadbikeworld.com/honda-trx450r/ Actually the first powerful sport quad bike to feature a V-twin design, the TRX450R is a high performance ATV (All-Terrain Vehicle) manufactured by Honda powersports. The ATV is also known as a Quad Bike in such countries as Australia, New Zealand, South Africa, the United Kingdom and parts of Canada. They are used extensively in agriculture, because of their speed and light footprint on the soil. Honda TRX450R initially was presented in late 2003 for the 2004 model year. Its only other competitor at the time of its introduction was the Yamaha YFZ450.

The Honda TRX250R, the predecessor to the TRX450R, was considered by many to be the best sport ATV on the market. Although Honda stopped producing the TRX250R in1989, it continued to see plenty of racing action. Towards the late ninety's and early 2000's, many racing sactioning bodies started to phase out two-strokes, eliminating the TRX250R from the racing scene. In 1999, Honda introduced the TRX400EX. This bike was considered to be the next great successor to the TRX250R. With a similar suspension setup to the TRX250R and a engine derived from the popular XR400 motorcycle, the TRX400EX became the new industry standard. Many racing sanctions had a displacement limit of 440 cubic centimeters, 400s were often bored and stroked to get their displacement closer to the 440 cc limit.

As motocross racing sanctions were doing the same thing to phase out the two stroke racing bike, this left a large gap in the four-stroke market between the heavy, big-bore 650 cc bikes and the lighter, underpowered 250 and 400 cc bikes. Both Honda and Yamaha went to work on developing a high compression, racing four-stroke engine. In 2002, Honda released the CRF450R. Immediately after its release, rumors spread of CRF450R derived engine to be in an ATV, just as Honda had done earlier with putting an XR400 derived engine in the TRX400EX. Rumors also hinted of an all aluminum chassis and a wide number of transmissions. On September 10th, 2004 in the Mandalay Bay Casino in Las Vegas, Nevada at the annual Dealer Meeting, Honda announced the introduction of the TRX 450R.

While both the CRF450R and the TRX450R both share the same displacement number, there are very few of the same components between the two engines. Initially, many people were disappointed because the first TRX450R was very weak compared to the CRF450R. Honda claims that it designed the TRX450R engine to produce more torque so that the engine was more suited for ATV purposes. In 2004 and 2005, the only interchangeable part between the ATV and motorcycle engines was the camshaft. In 2006, Honda overhauled the TRX450R engine to make it more similar to its motorcycle variant. This included a more aggressive cam profile, a larger bore with a shortened stroke, a new, short skirt piston and titanium rather than steel valves. In addition, Honda changed the carburetor from a 40mm Keihin to a 42mm Keihin . This increased the power from about 33 horsepower in the first generation to over 40 horsepower in the second. The first generation engine had a 10.5:1 compression ratio while the second generation had a 12:1 compression ratio.

Identical to the CRF450R, both ATV engine variants use a 5-speed transmission with a chain final drive. In addition, the both use a twin-sump oil system that separates the oil supply for the crankshaft, piston and valve train from the clutch and transmission. This allows 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. The first generation engine had a oil cooler, but changes in the engine in 2006 allow the engine to run cooler, so the oil cooler was eliminated. A forward style kick-start lever is used to start the atv. Electric start versions would become available in 2006 and later years.

In view of the fact that for many years the four-stroke class displacement limit was 440 cubic centimeters, many racing sanctions bumped this number up to allow the new 450 cc bikes and ATVs to compete. Along with the introduction of the TRX 450R, Honda announced, after 17 years, it would once again support factory sponsored racing. The 450R would be the first factory sponsored bike out of any of the other atv manufacturers. Honda's first sponsored rider on the new 450r would be Tim Farr. The sponsored Honda team would compete in the ATVA MX and TT Nationals in the Pro-Production class. The 450r's first national race would be the 2003 Baja 1000. The 450R was off to a good start even before it's public launch. The 450r was first across the line in the ATV class with a total time of 181 hours, 27 minutes, and 24 seconds. With an average speed of 43.78mph. In the 2004 National MX races, the 450r would place 3rd overall. Desert racing, and track racing would not be the only events the 450r would race in. The 450r would also compete in the Grand National Cross Country series although Honda would not sponsor any riders. Following the first year of racing the 450R, riders knew what where the ATV would use improvement on the race level. Communicating their needs and wants to aftermarket manufactures. By the start of the 2005 racing season most 450Rs' that were being raced looked nothing like the ATV that was in Honda showrooms. Custom made suspension, different color plastic, exhaust systems, bumpers, skid plates, and even engine enhancements. With so many options available to owners and racers of the 450R, it became difficult to get one that didn't have some sort of aftermarket accessory on it. ]]> Tue, 28 Oct 2008 09:55:26 -0500 http://www.quadbikeworld.com/honda-trx450r/ http://www.quadbikeworld.com/2008-honda-trx700xx/ 2008 Sportrax TRX700XX: Extreme engine performance, combined with a chassis that lets you put all that power to use. The stunning new TRX700XX brings the stable, confident handling that Honda ATVs are famous for to the big-bore IRS class. The engine is a high-tech marvel, boasting 686 cc of fuel-injected, liquid-cooled power and torque. And the chassis is even more advanced, with innovative features such as a central chain drive to the rear wheels that allows perfectly symmetrical rear A-arms and driveshafts, plus numerous other benefits. The result? Reduced wheel scrub, improved rigidity, and a much more planted feel in all conditions. One ride, and you'll feel the difference. Its electric-start, fuel-injected 686cc four-stroke engine traces its heritage to the Baja-dominating XR650R and delivers class-leading power. Just as significant, the drivetrain and suspension of the TRX700XX are state-of-the-art and then some. Specifically, Honda has engineered a brilliant centered chain drive system that permits the use of fully Independent Rear Suspension (IRS) with more advantages than traditional IRS designs.

The essential of the 700XX is its 686cc dry-sump, liquid-cooled SOHC four-valve single-cylinder four-stroke engine. With a bore and stroke of 102mm x 84mm, it boasts the largest diameter single-cylinder that Honda has ever mass-produced. Although it is infused with the heart of the potent XR650R mill, the 700XX engine has been purpose-designed and built for the rigors of ATV duty. Given the higher weight of ATVs (compared to off-road motorcycles), torque—and lots of it—was a priority. A longer (plus 2.0mm) stroke and slightly larger (plus 1.4mm) bore accomplish this. But in keeping with Honda’s philosophy of mass-centralization and a low Cg (center of gravity) to achieve optimal handling, engineers concluded that a taller cylinder and engine would not do. So they shortened the overall height of the engine by creating a longer-throw crankpin and a correspondingly shorter, carburized connecting rod to shorten cylinder height. The connecting rod is affixed to a ball-bearing crankshaft. Smooth, all-day riding comfort was assured with the fitment of a gear-driven counterbalancer to counterbalance engine vibration.

Like Honda’s renowned CRF motocrossers, the XX piston features a slipper skirt design and it strokes through a centrifugally forged, 3.5mm-thick steel sleeve. A forged piston was used to handle the increased mechanical and thermal loads, and it also benefits from an underside shower of cooling oil shot from a jet that protrudes into the center of the engine case. Compression is 10:1 and the high-tech slug is fitted with a larger 24mm piston pin. The combustion chamber utilizes a pentroof shape and is fired by a single, centered spark plug.

The engine inhales through a foam air filter fitted in a 7.6-liter airbox. Intake valve size is 1mm smaller than those used in the XR (36 vs 37) for better low-rpm flow—and therefore torque—while the exhaust valve diameter remains unchanged at 32mm. The Programmed Fuel Injection (PGM-FI) system draws fuel from a 3.6-gallon blow-molded, multi-layer fuel tank and delivers it via a single Denso injector through a 44mm throttle body. A Keihin Engine Control Module (ECM) manages both the fuel injection and the transistorized ignition. The engine exhales through a single long-tube header tuned for excellent low-end and mid-range torque without sacrificing top-end power. Gases are expelled through a muffler constructed of 128-grade stainless steel.

Several improvements are made to the engine to simplify its operation and enhance durability. An automatic decompression system is activated whenever the electric starter is engaged. The starter-motor housing is incorporated into the engine crankcase casting and a disc-type torque limiter minimizes shock to the starter mechanism.

The frame of the TRX700XX is constructed of steel with a removable sub-frame; each is extremely durable and strong. Independent double-wishbone front suspension uses steel A-arms and premium shock absorbers featuring two single-rate springs per side. This application of dual springs, a first for Honda, separates the function of each. Both the main spring and the short top spring (second spring) are single rate. Bottoming resistance is provided by the heavier main spring and the top spring adds compliance over small bumps. Together, they achieve what a progressive-rate single spring could have accomplished, but in a lighter, more compact package that takes full advantage of the 10.5 inches of useable suspension travel. Front preload is adjusted with screw-type adjusters. The A-arms are attached to aluminum steering knuckles, which in turn bolt up to aluminum hubs and 10-inch diameter aluminum wheels fitted with 21x7R-10 Dunlop radials.

The TRX700XX shows off its high-performance capabilities with aggressive sports styling. A polyethylene push bar, polypropylene rear A-arm protectors and high-impact urethane frame and engine-case protectors are tough, lightweight and replaceable. A cowl-inte-grated headlight with dual 30-watt bulbs provides superb lighting and a highly visible LED brakelight is the most common view competitive riders will have of the new TRX700XX.

The TRX700XX redefines the Sport category of ATVs with a whole new level of confidence, comfort and high performance. With double-wishbone Independent Rear Suspension (IRS), a unique centered chain drive system, and a fuel-injected 686cc engine making monster torque, the TRX700XX is Best of the Best Sport ATV. ]]> Mon, 21 Apr 2008 08:27:05 -0500 http://www.quadbikeworld.com/2008-honda-trx700xx/ http://www.quadbikeworld.com/suzuki-quadsport-z400/ The Suzuki QuadSport Z400 continues to be a dominant force in the sport ATV category, both in the showroom and on the track. The Z400 features an advanced four-stroke powerplant, state-of-the-art chassis and suspension components and a slick-shifting five-speed transmission all combined in a powerful, nimble and lightweight package.

Powering the QuadSport Z400 is a high-performance 398cc liquid-cooled, DOHC, single cylinder four-stroke engine with a 37mm Mikuni carburetor with TPS. Its bore and stroke measure 90.0mm x 62.6mm. Four valves are actuated by cam lobes riding directly on bucket tappets. The cylinder head features a narrow 28-degree included valve angle for a compact, efficient combustion chamber with an 11.2:1 compression ratio. Fuel is fed through 36mm intake valves, with exhaust leaving through 29mm valves. A dry sump lubrication system contributes to the more compact engine package.

The aluminum-alloy cylinder is plated with Suzuki’s own race-proven nickel phosphorus-silicon-carbide coating, known as SCEM (Suzuki Composite Electrochemical Material), for reduced weight and improved heat transfer, allowing for tighter and more efficient piston-to-cylinder clearance. Additionally, the piston is forged aluminum-alloy for even more weight savings. A counter-balancer shaft reduces vibration, while an automatic cam chain tensioner and an electronic CDI ignition simplify maintenance duties. A manual fivespeed transmission (with reverse gear) transmits horsepower to the wheels. A handy knob on the front left fender releases the reverse interlock to select reverse gear with final drive transmitted through an O-ring sealed roller chain. Suzuki’s own Start-In-Gear System allows the engine to be started in any gear when the left brake lever is applied.

The QuadSport Z400 starts with a lightweight, rigid, high-tensile-steel-alloy tube frame and sub-frame. An independent double-wishbone front suspension system with piggyback reservoir shocks provides 8.5 inches (21mm) of travel. Out back, an aluminum-alloy swingarm utilizes a fully adjustable piggyback reservoir shock with 9.1 inches (230mm) of wheel travel. A high-impact skid plate is standard equipment as are durable, serrated-steel footpegs. Wheelbase measures 49 inches (1245mm) with a full 10.4 inches (265mm) of ground clearance. Rolling stock consists of aluminum alloy wheels shod with Dunlop radial tires for maximum traction and performance. The Z400's T-shaped seat is narrow at the front and flares out over the rear fenders, allowing the rider to comfortably shift weight back and forth and side to side.

Seat height is set at 31.9 inches (810mm) and smoothly transitions to the bodywork and lightweight 2.65-gallon (10-liter) fuel tank. A multi-reflector taillight mounted at the rear completes the QuadSport Z400. The Z400 has a sharply angled nose with stacked dual headlights, twin air intakes and high-mounted, deeply flared front and rear fenders.

One ride on a QuadSport Z400 and you'll understand what heart-pounding performance is all about. The QuadSport Z400 is engineered to be the best all-around sport machine for any terrain - from woods to sand to the track. Boasting industry-leading technology, the QuadSport Z400 sets the standard for high-performance sport four-wheelers.

Go ahead - take aim and turn it loose. The QuadSport Z400's hard-hitting and high-revving powerplant lets you blast out of corners and rewards you with awesome acceleration on the straight-aways. And talk about maneuverability! Its lightweight design makes it incredibly agile, while its state-of-the-art chassis and long-travel suspension smooth out the gnarliest terrain.

The QuadSport Z400 - pure sport performance! ]]> Tue, 19 Feb 2008 14:22:20 -0600 http://www.quadbikeworld.com/suzuki-quadsport-z400/