Latest 2011 Yamaha YZF-R1 Review

The key components of this cutting edge engine design are the “crossplane” crankshaft and an uneven firing order. Both of these features are used on Yamaha’s championship winning M1 MotoGP racer. Please note … this is not a “big bang” engine. The R1 departs from the norm for in-line 4 cylinder engines and the 180 degree alignment of the crank pins (where the connecting rods attach to the crankshaft), and locates the center two rods at a 90 degree plane from the outer cylinders. This means instead of the crank pins aligned on the same plane (a straight line drawn through the center of the crankshaft), they align on 2 planes in the form of a cross … or “crossplane”. Working in conjunction with the crossplane crank is an uneven firing order. A traditional in-line 4 cylinder’s firing order is normally 1,2,4,3 with a 180 degree interval. This R1 engine fires 1,3,2,4 cylinders and the firing intervals are uneven at 270 / 180/ 90 /180 degrees. What all this means to the rider is the most linear torque possible and amazing throttle control. This engine design allows a whole new level of rider – machine communication. One of the most important benefits is the outstanding cornering performance that increased engine control allows. Mikuni fuel injection system features twin injectors (one set of primary & one set of secondary injectors). This type of twin injector system is also used on our M1 MotoGP race bike and the R6. One set of injectors (primary) are located in the 45mm throttle bodies while the secondary injectors are located in the air box very near the computer controlled intake funnels. The primary injectors utilize 12 spray holes to maximize the fuel atomization process. The secondary injectors, located inside the air box, begin to function at mid rpms onwards to supply more fuel as required.
Yamaha D-Mode variable throttle control enables the rider to adjust the performance characteristics of the engine based on riding preferences or conditions. Standard mode emphasises the very linear throttle and torque feel of the engine. The A mode allows the rider to enjoy sportier engine performance in the low to mid rpms. While the B Mode reduces the power response for riding situations that require softer power characteristics. The switch mechanism is located on the RHS handle bar switch gear.

CHASSIS/SUSPENSION

Aluminium Deltabox frame has been designed to offer an optimized rigidity balance to maximize handling performance. This frame is very rigid or stiff at the head pipe, engine mounts and swingarm pivot point. In other areas, material has been carefully removed to allow “tuned flex”. Finished in black, this frame boasts a compact 1415mm (55.7″) wheelbase. The swingarm pivot location has been optimized to minimize the chain tension effect under hard acceleration, providing more stable handling. The engine is a fully stressed chassis member to maximize handling. Stability, a key to great handling, is unsurpassed while the ability to hold a line under hard acceleration is excellent. This frame features a mix of gravity cast (head stock & front engine mounts & swingarm pivot area), CF (controlled filling) die cast (outer tank rails) and aluminium panels (inner tank rails). Each of these aluminium parts has different flex characteristics in order to provide the rigidity balance the engineers desired.

Fully adjustable 43mm inverted fork features independent left and right damping system. The compression damping is adjusted via the left fork leg, while rebound damping is adjusted on the right fork leg. This system simplifies the flow of oil through the fork and minimizes oil cavitation (aeration of the oil) for more stable suspension performance. Adjustments include 5-way spring preload, 25-way rebound and 25-way compression damping. Front wheel travel is 120mm (4.7″). The thickness of the inner fork tubes and the shape of the outer tubes have been optimized. The adjustable design allows the rider to tailor suspension settings to match rider weight and road /track conditions to maximize handling and suspension performance.

Bottom link Motocross rear suspension utilizes a fully adjustable piggyback-style rear shock. Adjustments include 16-way spring preload, 18-way rebound and 20-way hi speed compression damping and 4-way low speed compression damping. The bottom link design lowers the centre of gravity for excellent handling. This shock features 2-way (hi speed & low speed) compression adjustment plus rebound and spring preload adjustability too. This is a rising rate or progressive system. The adjustable design allows the rider to tailor suspension settings to match rider weight and road /track conditions to maximize handling and suspension performance. Rear wheel travel is 120mm (4.7″).

Race inspired lightweight instrumentation includes an analog tach plus digital speedo, dual tripmeters, clock, coolant temperature and fuel trip meter. This console also features adjustable back lighting, adjustable shift light and a low fuel warning light. Other key features include a gear position indicator, accelerator opening angle indicator, engine mode indicator integrated stop watch, lap timer with split time mode and an air intake temperature display. The lap timer is controlled by the starter switch button for added convenience and ease of use.