Jeff Allen

Attack Performance Yamaha YZF-R1 MotoAmerica Superbike Exposed

Behind the bodywork of Richard Stanboli’s race-winning R1

February 4, 2019

Richard Stanboli is the privateer builder who can challenge the factories in US roadracing. In 2018, on the machine you see here, rider Josh Herrin won two MotoAmerica Superbike races. As these photos clearly show, this is a professionally prepared bike. Its swingarm was CNC-milled from solid, and its fuel tank could be designed and shaped only as items on order arrived from suppliers. And Stanboli is not just one of the small elite of CNC shops that can turn out parts such as these: He has also made himself master of the new electronic rider-aid technologies that have become full partners with hardware in modern racing. With the help of throttle by wire, engines can be tuned to levels that would be unrideable without the torque-civilizing power of electronics.

Stanboli has been building Superbikes for decades. In 1994, he built a very ambitious Yamaha YZF750 for the Cycle World Daytona 200 Superbike project with rider Don Canet. His business, Attack Performance, makes aftermarket racing and high-performance parts and has provided contract racing teams and services. In 2007 and '08, Attack Performance AMA Formula Xtreme 600 entries won the Daytona 200. In 2012, Stanboli decided to build a bike to race in MotoGP's CRT class (which permitted use of non-prototype engines in special prototype chassis). Material for the chassis was delivered to the Attack Performance loading dock as hundreds of pounds of aluminum alloy billets on a pallet. A chassis was milled from these solid pieces and welded together to fit a Kawasaki ZX-10RR engine like a sweater.

Why isn't Richard Stanboli a part of a top-level factory team in MotoGP or World Superbike? Surely for the very same reason that the late John Britten did not choose that direction. Stanboli is not part of an organization. He is the organization. Why does he build these beautiful racing machines? Because he has made himself able to do it.

The first thing you notice is the complete density of a modern superbike; you can’t see through it from side to side at all. The second point is mass centralization. The closer a motorcycle can approach the ideal of a cannon ball, the easier it will be for the rider to maneuver it. The third striking point is this machine’s substantial structure—the chassis beam, the forward engine hanger attaching at cylinder level, the rugged uprights carrying the swingarm pivot, and the vertically deep and therefore twist-resistant swingarm.Jeff Allen

The obvious alternative to the Grand Prix-style “banana” swingarm of old: Just cut a clearance notch for the exhaust pipe. Because this YZF-R1 was originally a streetbike, the rear suspension unit has to be left in the stock location. Even so, a lot of space is available above the swingarm for a rearward and downward extension of the fuel tank. All details—footpeg plates, carbon-fiber heel guards, etc.—are executed at a high level. You can see the rear wheel’s speed sensor just above the axle end, reading the rotation of the black, toothed wheel.Jeff Allen

Everything is packed in tight. Note the close proximity of the number-one exhaust header pipe (with oxygen sensor), water and oil hoses, and electronic cable routing and connectors. That’s because, if you go to the wind tunnel, the crew will emphasize the value of minimizing frontal area. Twenty years ago, Ducatis were 19 inches wide and the Big Four Superbikes were 21 inches wide, a 10 percent difference. This photo and the previous one show the pipe to be a 4-into-2-into-1, which uses acoustic trickery to “gentle” the slopes of the torque curve. Electronics can’t turn a light-switch engine into a tractor; smooth torque delivery is still founded on the engine’s natural powerband.Jeff Allen

The model for rider aids, both conceptually and in hardware, is the digital flight controls for aircraft, developed from the late 1960s onward and originating in the Apollo program. Why such expensive connectors? Ever had a flaky computer connector? Ever got salty water in electronics? It costs complexity and therefore money to keep everything reliably connected, despite vibration, rain, and misadventure. But some things don’t change: That rubber retaining strap on the ECU looks a lot like the one that held the lead-acid battery on my 1970 Kawasaki H1-R. Get that mighty cast cross-member: Yamaha a few years ago found suspension forces were pinching the chassis uprights together, creating stick-slip movement. Lessons learned.Jeff Allen

All the good stuff. Let’s start with the rock screens on the coolers. They keep stones from letting vital fluids escape. T-slot floating brake discs. Radial-mount brake calipers allow easy relocation for different-size discs (see the cylindrical spacers between caliper and fork bottom). Because brake torque can lift the rear wheel off the ground, there’s very large stress on the fork bottoms. That’s why they have smooth, organic, fatigue-resisting shape free of notches, angles, or other stress raisers.Jeff Allen

The forward part of what we used to call the fuel tank is actually the engine’s intake airbox. The need for it (which can boost torque by 10 percent in a limited range) has forced the fuel to move aft and down, into the space under the seat and above the swingarm. Only two chassis welds are visible, the result of modern casting methods’ ability to produce complex shapes with high strength and fatigue resistance. A few cast pieces, a limited number of welds, and you have a chassis as sophisticated as any painstaking hand fabrication from the wild two-stroke 500cc GP years. Lots of wires are probably just the beginning, as motorcycles grow nervous systems of their own.Jeff Allen

The part with weld on it is the actual fuel tank. To the left is just a cover over the intake airbox, inside of which are the four engine intake throttle bodies and the fuel injectors. The fabric-patterned black material to the right is for looks. As classic GM stylist Harley Earl said, “Design must lead the public. But not by too much.” Futuristic-looking bikes have never won wide approval.Jeff Allen

Both the main sump cover and the “dagger sump” are machined from solid, as the tool traces covering their surfaces attest. The deep sump keeps the oil pump pickup submerged at all times; if the pump “gets air,” it is death on engine bearings. Those swivel-hook exhaust pipe springs are the real thing, products of long experience. The year Honda showed up at Daytona with pipe springs made in a simpler different way, they broke and were strewn all over the track.Jeff Allen

That web joining the front engine bearer at the left to the chassis beam comes straight from MotoGP, where it was developed to improve the compromise between some lateral flexibility (to keep the front tire hooked up on rough pavement) and the need to prevent the steering head from being flexed by braking force. The little wire, discreetly tie-wrapped to the right-hand brake hose, is making its way to the front wheel’s speed sensor unseen below the fork bottom.Jeff Allen

The little red guy to the right of the yellow suspension spring reports rear suspension movement. The pistol grip on the damper is the gas accumulator that maintains enough pressure on the damping fluid inside to keep it from cavitating. Lying on the swingarm to the right of the suspension sensor appears to be an electrical connector that will be attached to the fuel tank when it is installed.Jeff Allen