Yamaha's Smokin' 6!
YAMAHA'S SMOKIN' 6!
ROUNDUP
WHY DOES A RIDER buy this 600cc sportbike rather than that one? A few people read the specs and decide that way, but many more assume all the specs are pretty much the same and go for the raddest and baddest look. Yamaha is covering both bets with the 2006 YZF-R6, which looks like a sinister cross between Samurai armor and 21 st-century motorcycle tech.
Specs first: All YamaSgjÚ ha would say at this WW early date is that “redr lineis 17,500 rpm.” If we subtract 2000 revs to estimated peak-power rpm, we get 15,500. Take that number, the displacement and current-level combustion pressure and crank it through the fonnula and we get just under 140 crankshaft horsepower. Oh, one other loose fact: the induction system has a “computermanaged throttle butterfly.” This tells us that the new R6 probably has a dual butterfly system. One in each intake pipe is controlled by the rider, while the computer modulates the opening of the second one just enough to let the fuel keep up with the air. This is useful when the intake tract is so huge (as probably is the case in a 17,500-rpm engine) that it won’t work any other way.
Enough facts-let’s judge
the book by its cover, because that's all they'd show us. "Barge boards. MotoGP-inspired. Banana-style con trolled-fihl swingarm. Weight forward. Formula One influence." What is this-code? Well, yes, in a way. Appearance is a coded visual mes sage to the buyer. See the semi detached piece on the side of the fairing? That's a "barge board." In F-i car racing that's a splitter that separates turbulent, low-energy air coming off the front tires, then a turning vane diverts it outward so that only higher-energy air from its other side enters the oil and water radiators in the side-pods. A barge board on a motorcycle is mysterious, magic stuff.
Banana controlled-fill? A banana swingarm arches up for exhaust pipe clearance, and controlled-fill refers to the Yamaha-Hitachi thinwall aluminum casting process that makes these bikes so light. Weight forward is just common sense-every time you add more power, a bike tries harder to wheelie, and that makes it harder to steer out
of turns. So you shift weight forward to re-balance the forces in play.
Don’t fret about styling conflicting with aerodynamics. Motorcycle seatbacks are in fully separated airflow anyway, so nothing the stylist does there can hurt anything (gargoyles, maybe?). I’ve seen motorcycles go faster at Daytona after their lower fairings were entirely removed, so not all mysteries have been revealed. As long as the frontal area is small, there is room to play. Therefore, let’s have some fun and make things look interesting.
We see four-piston brake calipers at the front, and each lower fork leg carries a little bottle. This fork raises the
ante with adjustments for both highand low-speed compression damping. Maybe something does leak into the production department from racing. Good.
Now look at the machine’s outline: it’s slightly irregular, not abstractly smooth. I like this for it suggests the skin gets this shape from important stuff undemeath-just as it is with us humans. “Organic” used to mean smooth (plump?), but in this case the opposite works even more powerfully. Racebikes look this way because they are bulging with important stuff. MotoGP inspired.
One more detail: “Titanium EXUP valve.” Use of EXUP on this model’s “midships” exhaust suggests that longer cam timing is definitely in use, and you’d expect that also from the very high redline rpm. When you raise the revs, you also raise valve-train peak accelerations-unless you also extend the cam timing, thereby giving more crank degrees in which to get valves from here to there.
Yamaha tells us this bike is a “crouching cat, ready to spring.” Sure, why not. If it really makes 140 hp at the crank, they can say anything they want about how it looks.
Kevin Cameron
