Custom Yamaha YZF R1 - Semi Serious Business

It all seemed so natural and simple in the beginning. The time had clearly come for our local expert roadracer/test-pilot Curtis Adams to upgrade from his slightly used GSX-R1100 if he intended to ever again beat long-time Willow Springs Motorcycle Club nemesis Chuck Graves. And semi-retired technical consultant Kaz Yoshima, of Ontario Moto Tech fame (e-mail yagyu1@pacbell.net), wanted to see what he could do with an R1 and a rider capable of shoving it to the front.

Willow's Toyota Gold Cup Formula One race is the money event every third Sunday of the month, with run-whut-ya-brung rules just like the ones in the AMA's Formula Xtreme class. Heh heh.

Our boy Curtis fell off an Attack Performance bike at the last AMA Xtreme race held at Willow, in 1998, but is game to try again. After that last one, some unkind things were said on the podium by a young Erion Honda rider, to the effect that some of the locals had been riding over their heads. Yes, Curtis said, and I can do it for 25 laps (most of the time anyway). Our Curtis does have an assertive style, all legs and elbows and alpha-male ego. I wanted to call us Curtis Interruptus Racing, but got voted down again.

A plan evolved: to beat the factory teams at the next Xtreme race. Why not? Kaz builds the bike, Curtis brings home the trophy, I show up in time for the champagne and laurel wreaths. So far it's not working out that way.

PACE screwed up everything by starting up its new race series, and offering enough prize money to render Curtis unable to just say no. In PACE's mislabeled "Unlimited Superbike" class, though, you can only have 145 rear-wheel horsepower, have to use the stock fork, stock gas tank, etc.-which means our all-out R1 needs to be two bikes in one, and therefore twice the work.

Bike
We chose the R1 because it's the lightest package 130 horsepower comes in. Yamaha gave us the customary industry-guy discount and we paid for the bike. OK, our man Brad Bannister at Yamaha also hooks us up with the occasional wheel bearing and brake pad (OK, spare wheels, some levers, oil filters, 10 head gaskets, two cases of oil, etc.), but there's no factory stuff on this bike. Everything was bought or built by Yoshima or obtained from one of the following sponsors.

Tires
At this level it's all about tires, and to do well you need more of them than any magazine should ask for. We're using Dunlops because Curtis has raced on them for years, and because Curtis earned the tire deal his own damn self. Dunlop, in fact, uses C.A. as a regular tester; if a tire lives at Willow in the summer under C.A., it's a pretty good tire. Long-time proprietor of Dunlop's West-Coast-based Sport Tire Services (805/226-9410) Dennis Smith sponsored Curtis to a pair of 16.5-inch Marchesini wheels. The 16.5 rear's been in use for several years; the 16.5-inch front is a recent innovation. It puts down a bigger contact patch.

The Marchesinis are lighter than the stock wheels. You already know that less unsprung and rotating weight aids acceleration, deceleration and suspension action. Did you know lighter wheels make a bike much easier to turn at 150 mph due to less gyroscopic force? Curtis tells us the real advantage comes when muscling the bike into Willow's fastest turns.