Yamaha have pulled off a minor miracle with the new R1 by creating a modern superbike that meets the stringent Euro5 emissions regs, remains reliable and does not lose a drop of power.
Here we take a look at how they did it.
Sum of its parts
Yamaha haven’t made huge headline-grabbing changes, instead they have focused on making lots of little bits of the engine run more efficiently. The top end, in particular, has received a deal of attention.
Prior to the big 2015 model update, the R1 ran a bucket and shim set-up with the cams acting directly on the valves. But since 2015, the R1 has used the increasingly popular finger follower arrangement.
Bucket set-ups are very reliable but they’re heavy, which can cause issues at high revs. By using finger follower rocker arms, the lighter weight valve action results in more stable opening and closing of the valve. And now Yamaha have improved the design to make it more efficient.
Finger followers also allow for more space in the head, which has allowed Yamaha to fit cams with new profiles. This extra space in the head also offers more opportunities to race teams, which will have WSB bosses rubbing their hands.
Paul Denning, Yamaha WSB Team Principal, said: "The new configuration internally gives us more scope to create more horsepower and more durability with more horsepower, so for a race team, or a trackday guy, the base is a step better."
The biggest change has come in fuel delivery, which required a completely new cylinder head. On the new machine the throttle valves have been moved closer to the combustion chamber, which has reduced the intake volume.
This results in more stable combustion and greater efficiency for reduced fuel consumption. The new fuel injectors are positioned on top of the throttle bodies, rather than beneath, and the new injectors give a wider spray into the combustion chambers, again increasing combustion efficiency.
In addition to this the exhaust ports have been redesigned for improved cooling, which helps maintain consistent combustion chamber temperatures. Yamaha have combined this with a new exhaust that has four catalysers to meet tougher Euro5 emissions regs.
For increased running efficiency the crossplane crank now spins on larger journal bearings, with larger diameter oil ways, while the oil pump itself is actually more compact. Elsewhere there’s a wider second gear pinion for increased transmission efficiency and thicker plates on the final drive chain; it all adds up!
Yamaha R1 in detail
- Wide open New 10-hole Bosch fuel injectors open up the fuel spray to 21.5 degrees for a more efficient burn
- Lead not follow Finger followers are roughly 30% lighter than a bucket and shim set-up, so valve train mass is greatly reduced
- Price Despite all these changes Yamaha have managed to keep the standard R1 down to a very competitive £16,799 when it hits dealers in September
- Slip 'n' slide Bigger oilways have enabled Yamaha to reduce the oil pump rotor by 10% and reduce drains on power
- Clean running The exhaust now has four catalysers in two pairs of two that help get the bike through Euro5 emissions tests
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