2015 Yamaha YZF-R1 Unveiled

andrew Bike Reviews 1 Comment

2015 R1

Well, it seems Yamaha engineers have been busy behind the scenes, and their next-gen R1 looks like it is going to be a tough one to beat. Yamaha have thrown the kitchen sink at the R1, and on paper at least, we have a considerable proposition: a 200 horsepower, 200kg (oiled and fuelled) bike with a clever 6-axis computer to keep an eye on things. Traction Control, Slide Control, ABS (with linked brakes), anti wheelie system, quick shifter, titanium alloy con-rods, magnesium alloy subframe and wheels, TFT LCD clocks, and the gnarliest rear end seen for quite some time.

Engine Modifications

Yamaha has kept the Crossplane crankshaft, but upped the power significantly, through the usual engine mods to lighten inertia, reduce internal friction, increase strength and reduce the weight of the reciprocating component to improve the maximum engine speed as well as how fast it can spin up. The R1 uses fractured titanium alloy con rods for lighter weight components for the same given strength, a lighter crankshaft which allow the engine to spin up faster, and a shorter stroke for a higher rev-ceiling, to wring more power out of that 1 litre engine.

Bore and Stroke are 79.0mm x 50.9mm, unsurprisingly more over-square than the previous model’s 78.0 mm × 52.2 mm. The reduced stroke combined with the lighter pistons and lighter con rods means a higher rev ceiling is possible before the limiter cuts in. The use of diamond like coatings within the engine reduces friction and increases the useful power available at the output shaft.

The oil pan is recessed, and the lubrication system doesn’t bathe the crankshaft, rather oil is delivered to the main points required. This helps to reduce the engine losses further and achieve a higher engine output.

Yamaha has used the fractured con-rod method to fabricate its R1 con rods for some years now. The benefits of a fractured con rod is strength, having been cast as a single piece and then deliberately fractured it makes aligning the big end bearings easier, as the two faces match each other more accurately. It also brings about benefits in reduced manufacturing costs. Read about it here.
The variable length inlet trumpets remain, and the engine has larger valves and a narrower valve angle to improve airflow and mixing. The R1 gets two 12 hole injectors per cylinder, one operating at low revs and both kicking in when the going gets tough.[/text_output]