Tag Archives: Kenny Roberts

Kenny Roberts Yamaha OW60 GP Racer

1982 Kenny Roberts Yamaha OW60 GP Racer

With Phil Aynsley


Yamaha’s first foray into the 500cc GP class came in 1973 with the piston-port, in-line four-cylinder OW19. The company stuck with this basic design up until 1980 (although the final version, the OW48R, had the outside two cylinders reversed) when they decided that to stay competitive, a new, rotary-valve engine design would be required.

OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

The new motor was a square-four very much like Suzuki’s RG500, but with the cylinders inclined at 45-degrees. The OW54 subsequently won three races in 1981, two for Roberts, one for Sheene.

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OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

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OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

For 1982 the bike was heavily revised with an upgraded motor and a completely new chassis. The frame featured square section alloy tubing (with additional reinforcing bottom rails welded in place. Likewise on the bottom of the swing arm. Plates also boxed in the steering head tubes. A new progressive-rate bell crack rear suspension was used.

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OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

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Eight bikes were constructed, with two each for Roberts, Sheene, Graeme Crosby and Marc Fontan (Sonauto Yamaha). However Roberts only rode the OW60 twice, firstly in the ’82 Daytona 200 (DNF – motor), then in the GP season opener in Argentina, which he won (with Sheene second), before switching to the completely new OW61 V4. Crosby finished second in the Championship on the OW60 however.

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OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

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OW Yamaha PA YamahaOW

The OW60 featured four seperate crankshafts contra rotating in opposed pairs, Teflon coated steel rotary discs and housings. YPVS power valves were also fitted. Output was 156 hp at 10,600 rpm. Wet weight (half a tank of fuel) was 121 kg with a top speed of 290 km/h. For comparison the OW48R made 102 hp and weighed 135 kg.

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OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

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OW Yamaha PA YamahaOW

A bored and stroked version, the 695cc OW69, was used at Daytona in ’83 and ’84 with Roberts winning both events.

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OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

The bike seen here is fitted with the ’82 Daytona bodywork , although the “European” bodywork is also owned.

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OW Yamaha PA YamahaOW

1982 Kenny Roberts Yamaha OW60 GP Racer

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OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

OW Yamaha PA YamahaOW

Source: MCNews.com.au

The History Of Motorcycle Racing Knee Sliders

Roadracers have been scraping tarmac with their knees since the 1970s. American racing legend Kenny Roberts Sr. popularized a new style of riding introduced by Finnish rider Jarno Saarinen, which saw riders lowering their body position and regularly skimming their knees on the ground—on purpose. The result? Faster lap times, bloody limbs, and torn leathers.

In those days, most riders layered the knees of their suits with duct tape, adding extra protection and helping their knees glide along the asphalt. Others were more creative, carefully dissecting plastic milk cartons. It wasn’t until the ’80s that leather manufacturers adopted dedicated knee sliders mounted to the suit via Velcro, like the ones we still see today. Some wood, others leather, and most plastic, these were the first means of purpose-built pucks, and the end of non-incidental road rash.

Steeper lean angles and evolution in riding technique have since added purpose to the role of knee sliders, with racers using the pucks as a feeler gauge on the track. Touching sliders to the asphalt comes with a boost of confidence, providing riders exactness in their perception of lean angles, especially on a wet racetrack. Like tires, knee pucks require a break-in process before they’re optimal. The asphalt carves into the slider, precisely matching the rider’s angle of attack, perfecting the feel as they drag their bodies through corners.

Sliders can also prove vital in saving racers from hitting the deck. Ask MotoGP rider Marc Marquez—a man known for saving crashes on his knee. The seven-time world champion chews through tens of Alpinestars proprietary plastic sliders each year, replacing them nearly every time he exits the pit lane. Imagine how his knees would look in the ­duct-tape days.

Source: MotorCyclistOnline.com