The long mystery sales hold on the 2011 Kawasaki ZX-10R is scheduled to end in late January, and the company has given an explanation for the holdup: the possibility of intake-valve spring surge (coil vibration) under what Kawasaki calls “unique riding conditions, such as on a racetrack.”

The intake camshaft, valve springs and spring retainers of new ZX-10Rs will be replaced to eliminate this possibility, “without affecting engine performance.”

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Scrutineering: Standing in line and doing what you’re told. Here, master mechanic Niles Follin waits to get his papers checked.

Day Two of Jonah Street’s Dakar Rally adventure is in the books, so he called with an update and then e-mailed a few photos to us. This was a pretty hectic day for the Yamaha rider as he spent most of it chasing his tire supply. Meanwhile, master mechanic Niles Follin has been putting the finishing touches on Street’s JVO Racing-equipped WR450F.

Here’s what Street had to say today:

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Bike prep is almost done. Yep, that’s a Porsche in the background. We’re at a dealership here in Buenos Aires.

American Dakar Rally racer Jonah Street just called from a Buenos Aires, Argentina, Porsche dealership where he’s assembling his Yamaha WR450F. This is his first live update from the 2011 Dakar Rally. Besides buttoning up his race bike, Street is tracking down a large stack of tires with borrowed passports and cold, hard cash!

Here’s the latest straight from Street:

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Cycle World.com will be hosting daily blog updates from American rally ace Jonah Street as he competes in the 2011 Dakar Rally in Argentina and Chile this January. Street, a Dakar stage-winner and contender for overall victory at this year’s event, will be checking in daily via satellite phone from the remote South American race.

“Rally fans in the United States have been dying for live coverage from this amazing race,” said Street. “Since I rely on fan and sponsor support to get me to and through these races, I want to bring as many people as possible along with me for the adventure. So, I’ll be calling in daily with race reports, uploading behind-the-scenes photos and video and giving Dakar Rally fans a unique view into the most amazing race in the world.”

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An important point can be easily forgotten in high-flown discussions of technology: cost. Each time the state of the motorcycle art is advanced, this point is central—but invisible. Through most of the 1960s, Honda produced its reliable electric-start motorbikes using traditional (and expensive) rolling-element bearings. Meanwhile, in winning many world championships, its Grand Prix racebikes created a new “brand” with the words “Honda Four.”

In 1969, Honda was ready to release a production Honda Four that the public could buy. Doing so required designing unnecessary expense out of the machine at every possible point. This took the form of adopting economical automotive technologies, such as plain bearings for crankshaft and connecting rods, and Hi-Vo chain between engine and gearbox. The resultant machine was the CB750, which led the motorcycle market in a whole new direction.

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When you make a sporty start on a motorcycle, you bring engine revs up smoothly as you begin feeding the clutch. The motorcycle isn’t moving at first, so all the engine’s power initially goes into heating the clutch; none is actually turning the rear wheel. As the rear wheel does begin to turn, some power is going to the wheel but most is still heating the clutch. As the slip rate drops and the rear-wheel rpm rises, less power goes to the clutch and more to the rear wheel until full engagement is achieved.

This is pretty routine stuff on the street, for as you ease away from a green traffic light, your engine is making maybe 20 horsepower and the clutch just gets warm—not really hot. Once you are underway, the oil splashing around in the primary case carries away the clutch’s heat and everything goes back to normal.

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After I low-sided at Laurel Bank on the TT Mountain Course on the first day of practice for the Junior Manx Grand Prix in August, 1970, my 348cc Shepherd-Kawasaki GP bike needed extensive, though mostly cosmetic, repairs. There happened to be a doctor at the site who gave me a quick check and said I was okay, though bruised. Even so, the next day, the Clerk of the Course on the Isle of Man would not allow me back on the track until I showed up in my leathers and demonstrated by doing pushups that I wasn’t actually injured and trying to fake my way back onto the track. He knew the doc on the scene had done a preliminary check and cleared me then, but some injuries take longer to show up, as he told me sternly. Hence, the precautions. I grimaced as I did the pushups, but I didn’t begrudge their demands, because I knew all too well how racers like me tended to dive into the river in Egypt (“Denial”) following a crash. (Roadracer’s famous last words, cont’d: “Nah, it doesn’t hurt. Just wire me to the bike, doc.”)

Falling into denial doesn’t only happen to racers; it can happen to any of us, including people who might be riding with us when we hit the pavement or dirt. For example, recently, I happened to be at a rural restaurant where a bunch of riders had just arrived. One of them—an older rider, like me—had suffered a get-off but was apparently okay enough to ride from his crash site to the group’s gathering place. Seated on a picnic table nearby, he looked very pale and was clearly in pain. A couple of folks asked how he was feeling, but mostly, people just left him alone, presumably because everybody thought he was not seriously injured.

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Kawasaki issues "Technical Hold" on ZX-10R

Last week, while trying to arrange a test of the Kawasaki ZX-10R, Cycle World’s access to the bike in Europe was suddenly revoked. All we were told by our Continental sources was that the “stop” order came from Japan. Today, Kawasaki Motors Corp., U.S.A., issued the release below. A representative stated that he did not know the cause of the technical hold, but did say he was told it was “not performance oriented.” There were no issues at the recent U.S. press introduction for the all-new liter-class Ninja. “We’ve built so much momentum as a company over the last few years with great products and we don’t want anything to harm that, so we are are taking the necessary steps to ensure the bike is up to our standards,” said the spokesman. Approximately 20 units were delivered to customers. More as the story develops.

From Kawasaki:

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Recovery from injury is a battle. It beats you down both mentally and physically. In my case, there was little I could do to take the edge off the stress while I was lying around trying to keep my rump above my heart in an attempt to defuse the swelling on my inner thigh. Even finding a comfortable position to read a book was a challenge, so I ended up wastefully witnessing one Hollywood failure after another on television.

After spending a week entrenched in this dilemma, I felt it was time to stimulate my mind with the aid of a laptop computer. Eight hours later, I looked up to take inventory of my wound. All was well with the skin flap and sutures, but I was mortified to feel something roughly the size of a grapefruit hanging off the back side of my leg.

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2010 125cc World Champion Marc Marquez/Photo by Gold & Goose

We have known for some time that 2010 was to be the last year of the 125cc Grand Prix roadracing class, but until the new Moto3 regulations were published this past November, all we knew about its replacement was that it is to be 250cc four-stroke Singles of some kind.

Salient features of the new class are that its engines are to be for sale to bona-fide competitors at a price of no more than 12,000 Euros—about $15K. Engines will have only one cylinder of no more than 250cc. The maximum permitted bore (no oval cylinders) is 81mm, and rpm is to be limited to 14,000. Engines must be atmospheric; no supercharging allowed. No more than four valves can be used, none of which may employ pneumatic or hydraulic operation. Variable valve timing is prohibited, and camshafts can be driven only by chain. Fuel injection—only upstream of the intake valves—is assumed as the fuel system.

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Cycle World Managing Editor Matthew Miles told me the other day that he never expected his work in motorcycle magazines to include embedding video in a road test. Nevertheless, he, like everyone at the magazine, knows the importance of trying to capture more and more of the motorcycle experience in images. Sometimes, a picture really is worth a thousand words.

That’s why, back in June of ’79, when I was at Cycle Guide, the staff and I cobbled together an angle-iron frame to bolt onto the BMW R100T we had for a couple of weeks as part of a comparison test with a Honda Gold Wing. Dave Clark, our art director, and I saw the potential of getting a dynamic still photo of the BMW’s cylinder head and crashbar virtually on the ground in a turn with the road rushing under the footpeg and rider’s boot, and the horizon tilted crazily ahead in the picture, drawing the viewer’s eye into it and creating the impression of speed and the unique kinesthetics of riding.

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Photo by Fran Kuhn

Did somebody say track day? As it happened, the Yamaha Champions School invited us out for a day at the Streets of Willow Springs not long ago. Hah! We’re ready! For once, I get to ride something expendable—my cheapie Craigslist 2000 R1!  http://www.cycleworld.com/first_motorcycle_ride/special_features_articles/10q4/millennium_r1_-_special_feature

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CW Associate Editor Mark Cernicky (50e) Photos by Jamie Blunt

We members of the Southern California Flat Track Association were pleased, but not surprised, when our season-ending doubleheader’s Pro-class entries included Josh Hayes, newly crowned AMA Pro American SuperBike champion, and John Hopkins, lately of MotoGP. Their seasons were history, and they like keeping in shape and practice and, well, racing. (Hayes and wife Melissa, also a Pro roadracer, are graduates of American Supercamp, same class as yer reporter, and she was on the program, too, in the Open class.)

Also entered was CW’s own Mark Cernicky. This was a logical surprise, in that Mark’s experience has been in roadracing and supermoto. But then, early in this season, he showed up at the club track (in Perris, California) with his Honda XR100 just to have something to do that day.

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When a new machine comes along and information is scarce, I begin exploring possibilities. Recently, MV Agusta revealed that it had developed a three-cylinder 675cc machine with 138 horsepower. Poking around the Internet suggests this bike has been in development for at least two years, delayed by uncertainty over the company’s future. Now that Harley has sold the MV operation back to the Castiglionis, that is resolved—at least for the moment.

The new Triple is said to have a backward-rotating crankshaft, along with what have become standard sporting Euro-bike features (ride-by-wire with multiple maps and traction control) and be radically small and light.

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Freddie Spencer, on the Honda RS1000, leads Dan Chivington (90) and the rest of the field heading into Road America’s turn five early in the road race national at Elkhart Lake, Wis., in May of 1981. Spencer won that day giving the RS its first victory in America. (Photo by Tom Riles)

In the late 1970s roadrace nationals in America were largely a procession of Yamaha TZ750s and the AMA was looking to spice things up. Fortunately there was a roadracing class already out there called TT Formula 1, devised by the Isle of Man organizers in the mid-1970s to replace the 500cc Grand Prix World Championship, which abandoned the dangerous island circuit after the 1976 event.

In 1980 the AMA announced its AMA Formula One class would allow restricted 750cc two-strokes like the Yamaha TZ750 as well as unrestricted 500cc two-strokes and 1025cc four-strokes.

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