At the Track
WHAT A DIFFERENCE A DAY MAKES! Cycle World's program to see if a private team can be competitive in the AMA Pro American SuperBike class had a great day at Spring Mountain Motorsports Ranch near Pahrump, Nevada, but ran afoul of several realities in its second test, a two-day outing at Barber Motorsports Park near Birmingham, Alabama.
After that first outing, experienced national rider Eric Bostrom says that the bike “had precision” (meaning it was stable, a good platform from which to launch maneuvers) and seemed really good. But at Barber, with 16 other bikes on the track, he needs more rear grip, increased front suppleness to deal with small bumps and relief from upsetting engine braking.
Barber is tight—the classic modern “bull-ring” racetrack, designed to let spectators see several turns at once and lots of action. Part of “precision” is a stiff chassis, which late-model bikes now have. Another part is harder damping and springing, but that and a rough surface destroy grip.
“It’s a compromise, like everything else,” says Richard Stanboli, crew chief for the project and owner of Attack Performance.
A test is endless work. The rider comes in, there’s a conference and changes are made. Big right now is engine braking. Off come the clutch cover and the clutch, revealing that the “slipper” unit (intended to prevent engine braking from dragging the back tire into turns) is completely stock. When the back tire drives the engine during braking and comer entry, a set of ramps reduce clutch grip, allowing it to slip. The crew removes one of the three slipper springs and reassembles the clutch.
Bostrom goes out, does a lap or four laps, or whatever it takes to evaluate the last change, and comes in. The clutch is apart several more times. Tires are changed. The spring and damping on the Öhlins shock is changed. Front springs. Ride height is adjusted. More laps, more conferences.
“We’re losing time here,” says Bostrom. “We’re playing catch-up as it is. We asked for base settings from Yoshimura, and this is clearly not what they are running.”
Yes, but times are hard. Some teams may not be here in a year. Promises made in the sun may become awkward when the sky darkens. We started the day with “Mladin gearing”—a setup that lets the rider use just second and third gears but which requires a lot of corner speed to work. With less-thanhoped-for side grip, that’s not possible. More changes are made, searching for a useful direction. On the timing monitor, Bostrom is at the bottom of the SuperBikes, with only 600s behind him. Discouraging.
Al Ludington of AMA Pro Racing comes by the pit. His choppy, assertive speech reminds me of the old TV show “Kojak.” He delivers the message that the AMA is on its way, on track for a brighter tomorrow. I certainly hope so. He strides off.
Bostrom is in again. “There’s front chatter.”
“Mid-corner?” asks Stanboli.
With a metal syringe, Stanboli takes oil from each fork leg. By reducing the “compression ratio” of the fork’s internal air volume, he makes the front end less progressive—one standard remedy for chatter. Bostrom goes out and does 1:28s. We need to drop 2 seconds to get in the game. But the chatter has receded. Lunch break.
The day continues inconclusively. A race setup takes time to achieve, and there’s usually no way to “get lucky.” It’s work, trying A, trying B.
At a point, Stanboli says, “This new form of racing (AMA/DMG’s closerto-stock SuperBike rules) makes my brain numb. Back in the 1990s, I’d be driving home from a race and I’d say, T can beat these guys. I can build a bike that will beat these guys.’ But all these bikes make so much power now that racing’s about everybody pushing to the limit all the time. So the work is all about ‘keeping your guy happy’ [so he has the confidence to go to the limit].”
Next morning, Stanboli and Bostrom agree to call today “Day One” to put yesterday behind them.
“We found something in the ‘decel’ program,” Stanboli says. “The subthrottle mechanicals and its software were in conflict.”
The sub-throttle is normally an idle throttle positioner. But in racing, it becomes a “throttle kicker,” putting the idle up when the throttle closes to help the slipper clutch handle engine braking. With the gas tank propped up, Stanboli makes an adjustment.
In a couple of short sessions, it works well; they’ve straddled the problem and can zero in on a best setting. Back to the other issues. Another shock arrives, along with a box of bright yellow springs. New choices! Mechanic Jim Matter uses the rear stand as a lever to lift the wheel while Dan Schwartz, one hand invisible, to insert or remove the bolts the shock. Shock in, shock out, shock in again—they march through changes. Stanboli backs off the compression and rebound adjusters, then counts clicks to the desired settings. The bike goes out again, sometimes for as little as a lap if the answer is negative.
At about 9 a.m., a crash. As Bostrom approached the left hairpin in front of us, the chain “derailed.” The instant required to gather up from that big yank put him in too hot and into the gravel.
“He’s up,” calls Matter. “It rolls and has two handlebars.”
Upon returning, Bostrom says breathing is painful. This is not one of the three times I’ve seen a racebike fly into three large cartwheeling parts. It’s a semi-mild crash—a quart of gravel in the belly pan and a cup up the pipes.
The crew gets busy. Making the front end straight again requires replacing everything but the steering stem and the axle. Racing eats parts—all the fiberglass, plus a rear wheel and seat frame. The mounting points on the back of the gas tank are pulled out 10 millimeters by the impact, so the tank no longer fits. Stanboli, with his flat, slightly amused affect, puts it right with well-judged blows of a soft hammer. The tank fits again. By 2:37 p.m., it’s time to start up and go again. Stanboli knows that endoed engines often fail early; their oil pumps have sent air to the crank bearings. But it starts right up and runs.
“It’s not stepping out with this shock,” says Bostrom. “It’s really inspiring; I’m having a ball. But it’s too bad I can’t ride it.” He was looking pretty stiff when getting on and off the bike now. Most importantly, he gets down to a better time than his morning’s best.
I left at 4 p.m., in the midst of more suspension and tire changes, and before another crash, a lowside. Work continues.