Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127583
o States, and will not be as easily ob tained as the TY350 was. Yamaha Motor Corporation, U.S.A . (YMUS) brought only a single uni t into the U.S. for testing. The Tryals Shop, a multi-line dealership in Florida, imported five of the TYZs, but at time "Of this writing had sold all five bikes for a whopping $6500 each and didn't expect to recieve any additional units . But why import only one? "Trials is a very specialized sport and there isn't a huge following in the U.S.," explained Yamaha's Mike Wilkinson. "We wanted to test the TYZ out and allow a few publications to do so as well, then see what kind of response we got before even considered importing them." For a few weeks, we became the envy of every trials rider in the nation (except for the five Tryals Shop customers), as we were able to spend considerable saddie tim e aboard th e TYZ. And during that period, we came away with a few las ting impressions of Yama ha's mostexclusive motorcycle. The first thing about the TY250Z that catches your eye is the alumi n um Deltabox frame. Though the design has been featured for years on Yamaha's street motorcycle lineup and seen on various Yamaha works motocross bikes, the TYZ is the first production Yamaha offroad machine to feature such a frame design. The Deltabox frame provides a compact, mass-centralized design that is claimed to be extremely rigid and strong in comparison to the traditional singlebackbone and d ouble-cradle style. A three-liter (.08 gallon) fuel tank sits deep inside the frame, rather than on top of it, making the entire bike quite compact. The dista nce from the bottom of the skidplate to the top of the fuel tan k is very short, and allows plenty of room for rider maneuverability. . There are qu ite a few interesting features to be found up on close insp ection of the frame . The frame's main beams are mad e of one-piece extrusions, rather than multiple pressings that have been welded together. A remo vable alumin um subfram e allows for easy access to the airbox, ca rburetor and s hoc k, and th e frame' s front downtubes detach as well. Why ha ve deta chable front do wntubes, yo u as k? Ju s t like th e s u bfra rne, th e d e tach ab le fro n t tu bes provid e ea sy access to the motor and the small, single radiator, wh ich is mounted between the front tubes and well-p rotected aga inst crash damage. But wh at abo ut the motor? The watercooled e ngine doesn't ha ve tricky exhaust va lves like its motocross and road race cousins, instead it features a standard, reed -valved short-stroke design with a seemingly endless list of small details designed to make it trialsuser friendly. The combination of light weight crankshaft flywheels and a heavy magneto flywheel is designed to provide smooth, yet tractable power, while precise crankshaft balancing and a lightweight piston are claimed to reduce vibration. When the motor heats up and there is n 't sufficien t natural airflow through the radiator, a small, thermostatactivated cooling fan handles the airflow chores. The Yamaha TYZ features a conventional Kayaba cartridge-type fork instead of the u p sid e- d o w n units that h a ve beco me th e norm on the curren t Euro pean mod els. Yamaha 's ans wer to the flex com monly associated with a conven tional-type fork are a pair of la rge 41rnm tub es th at taper to 37mm a t the top . The la rge tubes, p aired with a heavy-duty aluminum brace, are claimed to eliminate flex. Fron t wheel travel is a claimed 180rnm (72 inches). Out back, the Monocross rear suspen- A T-type rim allows for the use of tubeless rear tires. Th anks to the unusual-looking hub, the stra ightpull spokes may be rep laced wi th out the removal of th e wheel. The extra- long rear fende r provides pl enty of sp lash protection. Yamah a added the spark arr estor for Californi a use. The TY Z looks quite n a rro w, b ut ac tuall y requires a rath er wi de ri ding st ance. No thi ng snags the rider 's boots. The frame's front downtubes are removable for easy access to the radiator and motor and the pipe is tucked up and away from potential rock damage. The kick starter is a bit awkward. The radiator cap is located in front of the small .8 gallon fuel tank. Both are seated inside of the pe rimiter frame. 11