Initially I was surprised with the feedback of the 600. Once the tires were warm, my first impression from the R6 was a warning from the front tire and it was loud and clear… It would hurt me if I tried pushing. 

Immediately I was into the pits asking for screwdrivers and a 17mm T handle. It was obvious that the attitude of the bike was, on average, front high. This condition is even more apparent under acceleration when weight was transferred rearward. In an effort to place more weight on the front, my first changes had me removing front spring preload and compression damping. I went back out and came straight back in again. The change had helped with the geometry but the actual front suspension rates had been compromised. 

Since the rear needed no adjustment, a change was made placing more weight on the front tire by pulling the fork tubes up in the clamps. Yamaha's technical guys responded by changing the fork height seven millimeters. Even before returning, spring and compression damping settings were returned to their original positions. 

Out again and this time the change was an obvious improvement. Although the results were good, I felt it was still not perfect and would have liked to try another three-millimeter change, testing again. For various reasons I did not, instead concentrating on other things. Measurements later would point out an interesting fact. Replacing the front 120/60 OEM tire with the 120/70 GP Star resulted in a large change in front tire diameters. The actual difference between the two tires measured half an inch. (Herman Munster would feel this) 

When things are in the ballpark, a chassis that has a high front-end setting will yield both advantages and disadvantages, depending on the racetrack and other variables like rider position. Increased rear tire traction could be one advantage, but in this case the R6 was very sensitive to attitude. Willow Springs has several areas where front wheel traction and stability are at a premium. The first indication that Yamaha had inadvertently sabotaged (at least) me was while exiting Turn Two, a fast right hand corner which crests into an almost off-camber straight. It was here on the R6 that I first sensed the need for weight on her nose. Your lean angle and acceleration are constant while the track crests, emptying into a short straight. The change in track elevation caused borderline instability here. Further supporting my theory was a similar head-shake while cresting turn Six and again, when accelerating through a series of bumps entering turn Eight. 

Since all the misbehavior I had experienced had been under acceleration, I determined that more front weight was necessary. Following the first session, I had heard some of the journo's mumbling something about the need for more trail and steering dampers. Again, this whole issue stemmed from the fitment of a taller tire without compensating or making other adjustments. Once the correction was made in fork height, all was stable. With this tire, I would start with a change of 10 millimeters.

The R6 has impressive geometry figures. A steep steering head angle combined with small trail numbers (82mm) and a short wheelbase definitely have the 600's chassis tuned on a fine edge. For this reason alone, even small changes in suspension and geometry will be discernable. Perhaps this is where Yamaha draws their parallels with the TZ. Once adjusted, I was impressed with the steering feedback, entry speeds, mid-corner speed and overall stability of the R6. Although Willow is not known as a serious braking racetrack, the brake components (identical in size to the TZ) were ample and provided good feel. With braking, their remains vast differences between 250's and 600cc four strokes as the latter will always carry more mass. The R6 offers more engine braking, but again, the 250 sports another advantage, a close ratio transmission.

In the quest for competitive top speed equality between the different supersport manufactures, the race for rational street going top gear ratios has been left far behind. Because the machines seemingly arrived ready for Bonneville, the overall gearing suffered. Although Willow is one of the faster racetracks, I doubt the R6 ever saw Sixth gear. Another impression found gaps in transmission ratios for various corners. One gear was too short and the next choice too tall. Even Mr. Oliver was in agreement that a change with final drive change was the solution. Perhaps riding a 600 at a relaxed pace, either gear would do. The solution on the 250 would have found the cassette gearbox removed and the gear chart open.

2001 Yamaha YZF R6 Specs Specs MSRP $7,999  Champions Limited Edition $8,499 (800 Units Available) Engine : DOHC, 16 Valve Liquid Cooled, 4 Cylinder  Displacement: 599cc Torque 50.2 ft lbs. @ 11,500 Bore & Stroke 65.5mm x 44.5mm Compression Ratio 12.4:1 Fuel System Keihin CVRD37 with TPS & Ram Air Induction Valves 4 Valves per Cylinder  Ignition System Digital TCI, Electric Start, 12V/10AH Battery Clutch Wet-Type, Multiple Disk Transmission Constant Mesh, 6 Speed Chassis Aluminum Deltabox II Overall Length 79.72" Overall Width 27.16" Overall Height 43.5" Seat Height 32.2" Wheelbase 54.33" Ground Clearance 5.31" Dry Weight 365 Lbs. Front Suspension Telescopic Fork, 5.12" Travel Front Brake Dual Disk, 295mm Diameter Rotors Rear Brake Single Disk Front Wheel Cast Aluminum, 17 x MT 3.50  Front Tire 120/60 ZR17 (55W)  Rear Wheel Cast Aluminum, 17 x MT 5.50 Rear Tire 180/55 ZR17

In the RPM category the R6 wins. Spinning easily past 14,000, never once did I encounter the rev limiter. An occasional straightaway glance at the tachometer had my shift point indicating 13,500. The meat of power seemed available from 10,000 on, and although there was no point in really spinning her further, she was willing and able to ascend past 15,000. Peak torque was @ 11,500. Yamaha had pointed out during their tech brief that changes were made to improve shifting feel. My impression here was that under load, a conscious effort was still required, and although I have experienced lighter shifting machines, this is in no way a complaint. Nor did I take sides with any other of the controls as I found the riding position compact and comfortable, almost familiar.

It has always amazed me how competitive the current 250's and 600's are in AMA racing. Lap times between the two classes are sometimes identical, especially at the high-speed tracks. High top speeds are a direct result of horsepower and streamlining. All of the current 600's have both. 250's generate fewer horsepower over a narrow rev range but obviously benefit from a greater power-to-weight ratio and excellent streamlining. In comparing the two Yamaha's, the difference would be approximately 150 pounds. Simple math would place many advantages squarely in the 250's corner, but with few exceptions, this is not the case. Perhaps the greatest difference is in their applications. Although finesse, sensitivity and control are always the key, you will never see 250 guys entering corners with the rear tire hung-out and smoking. Likewise, the 250's lack of available torque and over-rev limit the amount of rear wheel spin exiting corners, hence no black strips either. Not so simply put, they cannot be ridden the same. 

As previously mentioned, the R6 has the same size brake rotors and calipers as the TZ but has a bigger job pulling down the weight. Sprung and un-sprung weight differ. Here the GP equipment is true magnesium wheels shod with slicks. 

I still have trouble rationalizing how the two machines could be so different yet the end result, at least in this country is almost the same.

It is obvious that Yamaha's R6 is an excellent motorcycle. Even in stock trim with competitive rubber, its limits extend virtually well beyond all those beneath "Mr. Fast" or his peers. Truly a comforting fact should one be destined for your garage.

For me, it was nice to be back.

Ends

Dan Coe is a former writer at Cycle, and was a very competitive 250 rider in the late 1980s. His most memorable finish was third place at Daytona in 1988. John Kocinski and Alan Carter beat him to the podium.