When Yamaha first launch its radical R1 in the late 1990s, it was explained asâ€no cooperation”, high-performance sport bike. Yamaha has tried hard to stay ahead of the rivalry ever since. For 2007, Yamaha has yet another cohort of R1 to introduce to sport bike fans.
At first glance, the method appears to be a mild evolution over last year’s popular machine, but Yamaha had more than a new look in mind with the new R1’s bodywork. Yamaha claims that the new R1 will have better aerodynamics and intake flow into the ram-air system. In addition, a layered cowling is designed to draw hot air away from the engine compartment to help preserve maximum horsepower.
The main changes lie beneath the surface of the new R1. The new engine switches to four-valve heads (from Yamaha’s trademark five-valve design), features a higher density ratio (12.7 to 1), and titanium intake valves. The trickiest part of the new engine is in the intake, however.
The new fuel injection system features what Yamaha calls “YCC-I” (Yamaha Chip Controlled-Intake). The intake runner measure 140mm at lower rpm levels — switching to 65mm at higher rpm levels. This spreads torque and horsepower in excess of a broader range than fixed-length runners.
For 2007, the R1 also gets throttle-by-wire similar to the system found on the R6 last year. The powerful chip reads throttle position changes every 1000th of a second. The new R1 will also come with a stock ramp-type slipper clutch for smoother downshifts and corner entry. Radiator capacity is up by 13%, and the exhaust system (titanium, except for a stainless mid-pipe and catalyst) is redesigned for 2007.
Net effect of these engine changes (and others we will discuss after we test the bike) is a claimed increase in power across the board (low-end, mid-range and top-end power). Peak power is said to increase by 5hp to 178hp at the crank.
Consistent with the “all-new” theme is a new frame (flex-tuned for better handling and traction). The rigidity of the all-new swing arm is also tuned (30% stiffer torsion ally and slightly less stiff laterally). With a swing arm pivot position 3mm higher than last year’s model, Yamaha claims improved turn-in, together with better grip for corner exits. New 43mm fork feature larger pistons (up from 20mm to 24) and slightly reduced weight. Yamaha claims their rigidity is matched to the new frame for improved performance.
The rear upset features new linkage to change the progressive nature of the damping (again, to aid traction while exiting corners on the throttle). The front brakes are new, 6-piston calipers using smaller (310mm) rotors. Yamaha claims the new calipers grip the disc closer to its circumference — effectively making the braking surface as large as the old arrangement, which featured larger, heavier rotors.
Specification
Engine
Type 998cc, liquid-cooled, 16-valve, DOHC, inline four-cylinder
Bore x Stroke 77 x 53.6mm
Carburetion Fuel Injection with YCC-T and YCC-I
Ignition TCI
Transmission 6-speed w/multi-plate slipper clutch
Final Drive #530 O-ring chain
Chassis
Suspension/Front 43mm inverted telescopic fork w/adjustable preload, compression damping, rebound damping; 4.7″ travel
Suspension/Rear SSingle shock w/piggyback reservoir; adjustable for hi-/lo-speed compression damping, rebound damping, spring preload
Brakes/Front Dual 310mm discs; radial-mount forged 6-piston calipers
Brakes/Rear 220mm disc w/single-piston caliper
Tires/Front 120/70-ZR17
Tires/Rear 190/50-ZR17
Dimensions
Length 81.1″
Width 28.3″
Height 43.7″
Seat Height 32.9â€
Wheelbase 55.7â€
Rake (Caster Angle) 24.0°
Trail 4.0â€
Fuel Capacity 4.75 gal.
Dry Weight 381 lbs.
Other
Primary Reduction Ratio 65/43 (1.512)
Secondary Reduction Ratio 45/17 (2.647)
Gear Ratio - 1st Gear 38/15 (2.533)
Gear Ratio - 2nd Gear 33/16 (2.063)
Gear Ratio - 3rd Gear 37/21 (1.762)
Gear Ratio - 4th Gear 35/23 (1.522)
Gear Ratio - 5th Gear 30/22 (1.364)
Gear Ratio - 6th Gear 33/26 (1.269)
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