Monday, June 1

TECH: YAMAHA’S TWISTED FOUR



With Ben Spies dominance of the Utah Superbike Round it's worth reprising this article that first appeared in May Kiwi Rider.
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We had such good feedback about our recent in-depth looks at a number of new road and dirt models we asked office font-of-all-knowledge Michael Esdaile to cast his eye over some race bikes.

In this, the first in a series on bikes competing in the Superbike World Championships, the all-knowing one backgrounds Yamaha’s radical new YZF-R1.


WORDS: Michael Esdaile PICS: Todd Sutherland & Peter Geran

In 2005, in its search for a better tool for Valentino Rossi to battle the previously all-conquering Honda RCV211Vs, Yamaha adopted a completely different crankshaft layout for its 990cc in-line four.
Rossi had been pushing for a V4 engine, but what Yamaha came up with was an even better solution: it re-phased the big-end journals on the crankshaft of its in-line four to make it fire exactly the same as a 90 V4 but without the extra bulk a V4 layout entails.
To do this, it phased the big-ends at even 90 intervals something legendary German engineer Helmut Fath pioneered with the 500cc four cylinder URS engine he developed in the mid-1960s.
Fath used his URS engine to end BMWs 15 year long reign in the World Sidecar Championship when he took the title in 1968. He had adopted the even 90 phasing of the crank pins because he did not like the vibration inherent in a normal inline four with two cran kpins set at 0 and two at 180. Yamaha chose the 90 route to make life easier for a rear tyre trying to cope with 230 bhp.
After proving the re-ordered crank pins worked in its 990cc MotoGP engines, Yamaha continued using it for the subsequent 800cc engines that followed, capturing the world championship again last year. Having proved the layout worked, Yamaha decided to use it in the all-new YZF-R1 for 2009, no doubt hoping it would yield similar results in Superbike racing to what it has enjoyed in MotoGP.
The other bonus is that the two plane crankshaft provides the revised in-line four with a guttural, off-beat exhaust note that really stands out. Readers who remember when Honda could actually build a serious race bike will recall the sound of the fabulous RVF750 V4s, and the later RC30 and RC45s.

SERIOUS INTENT
Proof of Yamahas intent to finally win the Superbike World Championship came when it re-named its world championship squad Yamaha World Superbike Team and moved it under the umbrella of its Amsterdam Yamaha Motor Europe operation, with the bikes resplendent in new blue livery with fl ashes of white.
Previously the team was Yamaha Motor Italia.
The operation is still managed by Massimo Meregalli with technical direction remaining the responsibility of Silvano Galbusera. However with Troy Corser jumping ship to lead development of the new BMW Superbike and Noriyuki Haga taking Troy Bayliss place at Ducati, Yamaha needed riders.
Rather than drawing on old SWC hands, or MotoGP refugees, the team signed three times AMA Superbike Champion Ben Spies and British Superbike man Tom Sykes to head its 2009 campaign, with Spies bringing Tom Houseworth, his crew chief from the American Yoshimura Suzuki team, with him. Neither Spies (pronounced Speees) nor Sykes had raced in the Superbike World Championship before, or raced a Yamaha Superbike for that matter and in Spies case he had never raced on Pirelli slicks before.
None of this bothered the Yamaha team. It wanted two young riders who were keen to go hard out with the new bike.
It hasn’t been disappointed. After four races in the opening two rounds of this years Superbike World Championship, Spies has scored two pole positions, three wins and a 16th place finish the latter the result of being bumped off the track on the first lap of the opening race at Phillip Island in Australia. Sykes has had a quieter start to the championship.
At Phillip Island he qualified 11th fastest before scoring a pair of tenth place finishes while at Qatar he qualified sixth fastest then took 7-5 placings in the two races.
It is a credit to the entire team that they have produced such strong results so early in the new YZF-R1s development but like all success in racing, it is the result of a good basic design and lots of hard work in pre-season testing.

TESTING
In order to take part in the revamped Yamaha teams first test at Portugals new Portimao circuit in November 2008, Spies had to get a release from his American Suzuki contract. For the first day the team put both riders on the 2008 bikes with the conventional 180 crankshaft to get a base line, something to compare with the lap times achieved by Corser and Haga in the final races of the 2008 season only a few days earlier.
For the second day, Spies and Sykes tested the new bike for the first time, with Spies ending up just a few tenths of a second slower than the best lap 2008 World Champion Troy Bayliss recorded on the works Ducati a few days earlier. Jumping from any standard in-line four to the new firing order R1 feels strange initially, Sykes explains.
The way the power is delivered lets you roll through the corner a little hotter but also it sucks you in a bit. On a Superbike there are some corners you need to be getting it stopped and turned rather than rolling through fast.
I think on an overall level its just an easy bike to ride, quite consistent, and not as aggressive as a normal in-line four. Texan Ben Spies agrees. The engine characteristic is definitely different and definitely smoother and better for me, he says. With a lot of bikes, when you are in the middle of a corner you have to find the right time to open it (throttle) up and get out because once you initiate opening the throttle you have got to go with it. But with the new R1, in the real long corners its more a case that you can open the throttle but if you have to get back out of it you can and it doesn’t upset the chassis so much.
On a normal in-line four, say in the last corner (at Phillip Island) when you start to open the throttle, you’ve got to keep going with it, you cant back off because that upsets the front-end and then you teeter-totter all the way around the corner.
With the new R1, its a lot more user-friendly in the long sweeping corners and hopefully better on the tyre come the end of the race.
Spies added that he could get on the throttle earlier while Sykes view was that the power delivery was also deceptive.
A lot of that comes from the engine noise and you certainly do get an impression of it not being as quick but you look at your lap times and the other data and you’re actually going quicker, the British rider said. So it is very deceptive, which is good.
It’s always nice to feel you’re not having to push. Ducati riders Michele Fabrizio and Haga. The three of them were the only ones to get under 1m 40s.
One of the things that may have helped speed development of the new R1 Superbike is that while the two riders have different riding styles, they adopt a chassis set-up that is very similar. Team manager Meregalli said the team had tested tyres, different suspension set ups, different engine mappings and some other things at Kyalami.
We are very satisfied, we know what our potential is and we are very happy, he reported. A month later the Yamaha team was back in Portugal for the three day test, and it discovered the new motor worked very well in the wet too as the test was blighted by inclement weather. Despite that, both riders were on the pace, always in the leading group and although the rain meant they did not get to try some new ideas, they discovered they had good traction in the slippery conditions, which no doubt will come in handy at some point during the season.
The bike is incredibly confidence inspiring.
The way it lays down the power so smoothly, especially through the corners in both the wet and the dry is incredible, Spies said while Sykes added that the chassis feels really planted and poised. No doubt part of this is due to the team having plenty of experience with chassis set-up and electronic engine management, but there seems little doubt the new Yamaha is a significant step forward.

BUILDING A RACE BIKE
To turn a showroom stock R1 into a Superbike capable of running at the front of the world championship takes an enormous amount of work.
The technical rules require the standard chassis and engine to form the base for the race bike.
The crankshaft, crankcase castings, cylinder and cylinder head castings must be based on the showroom model, although engine side covers may be replaced. The frame must retain the standard geometry but it may be strengthened.
As the Superbike class is a silhouette category, the fuel tank and bodywork must retain the original shape of the street bike the racer is based on. Wheels and suspension are free and while there is freedom of choice in brake calipers and rotors, carbon discs are not allowed.
Although the bike is all-new, the Yamaha team is using the same wheels, brakes and suspension it had on its 2008 bikes: magnesium alloy Marchessini wheels, radially-mounted Brembo brake calipers, with 320mm floating stainless steel discs up front and a 240mm disc at the back while Ohlins provides the front and rear suspension.
With higher compression pistons and camshafts with more lift and duration, the Superbike engine makes more heat than a stock bike, which is why there is a bigger radiator fitted, along with an oil cooling radiator.
Exhaust pipe maker Akrapovic has collaborated closely in the design of the new titanium race pipe and using lessons learned in 2008, the team has a new, wider and stronger swing-arm. But the biggest change from the stock R1 to the Superbike racer is the fuel tank.
Look carefully at the tank on the race bike and you will see slots in the sides of it.
Clearly that would not be much use for holding petrol, so where is the fuel?
The answer came when one of the mechanics was spotted refueling the bike through a filler at the rear of the seat pad. What the team has done is build an alloy fuel tank that mounts behind the motor under the rider, doubling as the seat support.
Along the top of the frame spars an alloy plate has been welded in to stiffen the chassis and inside this sits the airbox, fed from new carbon-fibre intake snorkels from the nose of the fairing. With the fuel removed from the area behind the airbox, there's room for the maze of electronics which no modern fuel injected racing motorcycle can do without.



EARLY DAYS
At this stage, the Yamaha team has barely scratched the surface in finding the full potential of the new YZF-R1 and yet it is already highly competitive.
In the view of Ben Spies, if the bike is not running up front and winning its because were not getting the job done. Its a great bike, he enthuses.
I think at most of these tracks (2009 Superbike World Championship) there’s going to be seven or eight guys who can run at the front and then the real race will start over the last eight laps. I think that if we have the speed to run with those first ten guys for half the race I think we will be fine in the end.
The bike seems to really work well and if we do run into any problems I think everybody else will have the same problem. Its going to come down to how that bikes going to work on worn tyres when its moving around: I think its going to be pretty good. Its our first year and Tom and I, neither of us has seen half the tracks, were both on factory bikes and (the English) fans are looking to him to go well and America is expecting me to go well so well have to try and run up front and I think the bikes going to be great and the team is just working fl at out to get us what we need.
I have never been with a team where you ask for something and three weeks later at a test you’ve got something major, I mean a big change, and they are wanting to win. I keep telling them its our first year but they are pushing so we are gonna try to go for it!