Interview Assistance: Motorcycle King Tsukuba Out of Print Museum
The RZ250R was a long-selling full-spec 2-stroke 250cc racer replica with an aluminum frame, full cowling, and 45PS engine. The R1-Z took over the position of the RZ and was a rare motorcycle that made its presence felt even amid the newly emerging naked motorcycle boom.
The R1-Z was born from Yamaha's determination to make two-strokes
More than 20 years have passed since the two-stroke engine disappeared from the public eye, but Yamaha Motor was originally a manufacturer that specialized in two-stroke sports motorcycles. The beginning of the legend can be said to be the RZ250 released in 1980, which is said to be the origin of the racer replicas that would later become a boom.
When racer replicas entered the era of aluminum frames and full cowls, the RZ surrendered its leading role to the TZR and continued to evolve as a standard sports motorcycle. Then, with the 3HM model equipped with 17-inch wheels released in 1988, the RZ's history came to an end.
When Kawasaki released the Zephyr in 1989, the racer replica boom, which had been getting increasingly high performance and extreme up until then, rapidly faded away, and the naked boom began. While each manufacturer released 400cc and 250cc four-stroke naked models one after another, Yamaha, which specializes in two-stroke engines, released the R1-Z in 1990, which took over the stance of the RZ.
The 4L3 RZ250, equipped with a liquid-cooled 2-stroke engine having the same bore x stroke as the production racer TZ, was the first true racer replica.
The 29L RZ250R, which underwent a full model change in 1983, found itself in a difficult position with the arrival of the RG250γ, which featured an aluminum frame and a 45PS engine.
The 1AR RZ250R was released as a cowl-less version of the RZ250RR, equipped with a frame-mounted cowl and a 45PS engine.
The 1XG-type Rz250R appeared in 1988. The TZR250 with its deltabox frame was introduced to the racer replica scene, and the RZ250R became the standard sports bike.
The 3HM model, which was equipped with 17-inch wheels and single disc brakes with large diameter rotors, passed the baton to the R1-Z, becoming the last RZ250R.
A unique sports motorcycle that stands out from replicas
The word "naked" had not yet been used when the RZ was released, but the RZ was originally based on a cowl-less design. The RZ250RR was equipped with a frame-mounted cowl, but only cowl-less models were produced from the 1XG model onwards. And until the end, the 1AR model, which was released in 1983, was used as its base model, with some improvements added to the steel frame and engine. The R1-Z, which could be said to be a full model change version of that, was one of Yamaha's answers to the naked boom.
Looking at the design of the R1-Z again, the truss-structured steel frame and the dual right-side exhaust silencer make for a striking presence.
Functional beauty is the word that comes to mind for this rear view. It proposes a new naked bike design without resorting to classic design.
The position is compact, but more forward leaning than the RZ250R. However, it is more relaxed than the 3MA and 3XG TZRs of the same era.
The foot placement is very good, and when a rider who is 171 cm tall and weighs 65 kg sits on it, both feet feel like they are firmly on the ground.
The name R1-Z is a combination of the 1 (National Route 1) and RZ, and it can be said that it was clearly positioned as the successor to the RZ. However, although the engine is the same parallel twin-cylinder, it is based on the 1KT TZR250 series. By the way, the 29L RZ250R engine is a piston reed valve type, with a bore x stroke of 54 x 54 mm and a capacity of 247 cc. In contrast, the 1KT TZR250 is a crankcase reed valve type, with a short stroke of 56.4 x 50 mm and a capacity of 249 cc. The R1-Z is equipped with a specification closer to the TDR250, which places more emphasis on the mid-low speed range.
This engine is mounted on a newly designed steel truss structure frame, and the swingarm is also of the truss type. The front suspension is a 38mm upright type front fork, and the rear suspension is a Monocross suspension with a shock unit with a reservoir tank. The front brakes are dual discs with opposed 4-pot calipers, and the rear is a single disc with opposed 2-pot calipers.
The front face has a sharp impression with its simple round headlights and integrated meter case.
The same-sized speedometer and tachometer and neatly arranged indicator lamps create a cohesive cockpit.
The handle is a separate type that can be mounted on top of the top bridge. A switch box of simple design is combined.
The step holder, which integrates a small heel plate, is made of aluminum. The lightweight design is full of functional beauty.
The tank is designed to match the frame shape and has a capacity of 16 L. Underneath the tank is a reservoir tank for the rear shock.
The seat has an unusual gray upholstery. The front and rear seats are integrated, and the tandem side is also thicker.
The tail cowl, which has a sharp design as if the rear end had been cut off, is combined with a simply designed taillight.
It is powered by a 1KT TZR-type engine with crankcase reed valves. Naturally, it is also equipped with YPVS and has an easy-to-handle character.
The truss structure frame, in which pipes enter to surround the engine, is the core of the R1-Z's design.
The right side two-piece silencer gives the R1-Z's design a more distinctive look. The carbon fiber silencer also adds a sporty look.
The front end of the car is a combination of a 38mm-diameter upright-type front fork and 17-inch wheels.
The brakes are double-mounted with opposed 4-pot calipers and 282mm-diameter rotors for powerful stopping power.
The rear brake is a combination of opposed 2-pot calipers and 210mm disc rotors.
The swingarm is a steel truss structure type like the frame, and attention to detail is apparent in the aluminum chain cover.
With repeated improvements, it became a long-life model, lasting about 10 years.
The R1-Z became a long-selling model manufactured for about 10 years, undergoing repeated minor changes such as increasing the rigidity of the frame, changing the suspension settings, adopting radial tires, and changing the CDI to comply with horsepower regulations.
Although the engine and frame are different from the RZ, the R1-Z is a clear successor that inherited the soul of the RZ, and many Yamaha fans accepted it. And, compared to the high prices of racer replicas, it was also very well received by young riders as an affordable and fast 250cc sports motorcycle.
In the 1991 model change, the frame was made stiffer, the suspension settings were changed, and the seat thickness was modified.
In the 1992 model change, it was made 40 PS to comply with horsepower regulations and fitted with radial tires.
R1-Z Major Specifications (1990)
Overall Length x Width x Height: 2005 x 700 x 1040 mm
Wheelbase: 1380mm
Seat Height: 775mm
Dry Weight: 133kg
Engine: Liquid-cooled 2-stroke crankcase reed valve parallel 2-cylinder 249cc
Maximum Output: 45 PS/9500 rpm
Max. Ttorque: 3.7kgm/8500rpm
Fuel Tank Capacity: 16L
Transmission: 6-speed return
Brakes: F=disc, R=disc
Tire: F=110/70-17, R=140/70-17
Price: $3306.23 (price at that time)
Filming Support: Motorcycle King Tsukuba Out of Print Museum
Rare out-of-print motorcycles are displayed in the showroom. A wide range of color variations and years are also available.
Address (e.g. of house): 120 Kokinuki, Tsukubamirai City, Ibaraki Prefecture, Japan Phone:0297-21-8190 Business Hours:10:00-19:00
Closed: Thursday
