It comes as no surprise that Honda ATVs high-end TRX700XX model incorporates some dazzling technological innovations that not only set it apart from other manufacturer's four-wheeled offerings, but will help shape the future of sporting ATVs.
Powering the Honda TRX700XX is a liquid-cooled 686cc Single that was modeled after Honda's ultra-reliable XR650R off-road motorcycle powerplant. Like its XR650R brethren, the compact engine is a SOHC design and utilizes a four-valve cylinder head, with 37mm valves on the intake side and 32mm on the exhaust. Beneath, the cylinder boasts 102 x 82mm bore/stroke dimensions and a 10:1 compression ratio. A gear-driven counterbalance helps quell the tremors pumped out by the 4-inch-wide piston. A dry sump lubrication system eliminates the need for an oil pan and within the external oil hose a wire mesh filter prevents oil slosh and aeration. The clever setup thereby reduces the engines height and helps to lower the machine's center of gravity. Making sure that the engine is always operating at the correct temperature, a thick 28mm aluminum radiator is mounted beneath the handlebars - protecting it from any potential trail hazards.
Both fuel injection and electric start grace the Honda ATVs TRX700XX and allow the rider to fire up the engine with the turn of a key and simple push of a button. The huge, almost two-gallon airbox supplies the air while a single Denso fuel injector squirts fuel from the three-gallon fuel tank through a 44mm throttle body. Exhaust is purged via a quiet, spark arrester-equipped stainless-steel muffler.
Power is transmitted to the Dunlop-shod 11-inch rear aluminum wheels via a five-speed transmission (with reverse) and an innovative centered chain final drive. In fact, the unique chain drive is a key design component Honda specifically engineered in order to meet the 700's design goals. Not only is the setup much lighter than a shaft drive found on other big-bore quads, its also more efficient. However, chain final drives do have some inherent problems when applied to an Independent Rear Suspension (IRS). Typically, the chain and rear sprocket get in the way of the rear suspension components, thereby sacrificing handling. Engineers solved this dilemma by fitting a pair of gears around the countershaft sprocket which position the rear sprocket exactly 33mm left of the machine's centerline.
This design feature facilitates the use of optimum equal length A-arms and drive shafts. The upper steel and lower aluminum pieces attach to the steel frame, which features a removable subframe component. Rear damping is courtesy of dual preload adjustable coil-over shocks with piggy-back reservoirs. The gas-charged units make use of 9.3 inches of travel before hitting the stop. A rear sway bar attaches to the frame and lower A-arm helping to prevent excessive body roll.
Up front, the independent double-wishbone suspension consists of long travel steel A-arms damped via unique dual-stage shock absorbers - the first of its kind for Honda ATVs. Both the short top spring and the larger main spring are single rate but when used together they perform much like a progressive rate spring - allowing for superior bottoming resistance, yet response reaction over small bumps and chop. Front suspension travel measures 10.5 inches.
Braking is courtesy of dual hydraulic disc brakes recessed within the 10-inch aluminum front wheels. Out back, a single hydraulic disc brake spaced 66mm opposite the rear sprocket facilitates the IRS and aids in machine balance. All four wheels also incorporate nifty removable metal wheel scrapers to help prevent mud build up.