Cycle News

VOL. 52 ISSUE 25 JUNE 23, 2015 P119 reliable and friendly liquid-cooled V-Twin with shaft drive. While the performance of the normally as- pirated CX was nothing to write home about, the bike generally earned the respect of riders who wanted a lightweight tourer and it was the courier motorcycle of choice of that era. Honda decided to spice things up by turbocharging the CX and giving it a serious bodywork upgrade as well as other components like suspension and brakes. The CX was indeed speedy once on boost, but the turbo-lag presented problems when riding ag- gressively in the twisties. That transition between being off-to-on boost was not a place you wanted to be when leaned over. Honda remedied many of those issues with the CX650 Turbo the next year, an excellent shaft-driven sport tourer that has become somewhat of a collector's item. Yamaha then released the XJ650 Turbo, an- other shaft-driven model that favored the touring side of sport touring. A favorite performance trick of the XJ was for riders to weld shut the waste gate to have constant turbo boost, but accord- ing to former pro road racer Troy Sorensen, who had that modification done to his Yamaha, "It had much more power, but went through turbos like Bic lighters!" In 1983 Suzuki released the fascinating XN85 Turbo. The XN85 was perhaps the most sport-ori- ented of the turbo bikes. It was the first production sport bike to feature a 16-inch front wheel, all the rage at the time as a carryover from GP racing. The Suzuki was lauded for its excellent handling, but the power from the mildly boosted 650cc mill barely put it on par with the 750s of the day, much less 1000s. The last of the production turbos of the 1980s was Kawasaki's GPz750 Turbo. It was perhaps appropriate that the maker of the original turbo - Kawasaki - became the king of the 1980s turbo- charged bikes thanks to its larger displacement. It was claimed to be the fastest production bike in the world in the mid-1980s. In addition to having the best performance figures, it was generally regarded as the best example of a turbo mo- torcycle. Lag was down and the turbocharger actually did what it was intended for – to make it quicker than a comparable normally aspirated machine. It did well in the showroom as well – being sold for two years in comparison to the other makers one year stints. A few of the Kawasaki turbos actually made it onto a few club racing grids across the country. I had the chance to personally test the GPz on the road course at the Indianapolis Raceway Park in 1984. And on my first hot lap I almost ended up on my ear when the thing came on boost through IRP's carousel, but once I got the feel for when the boost came on the bike was a stable handling machine that provided a nice kick in the pants down IRP's long front straight- away. Ultimately the promise of the turbo age never quite came to pass. The bikes were generally heavier than other middleweights, way more expensive, dealt with troublesome turbo lag and in the end rarely matched the performance of liter bikes. They also happened to be released in the middle of a recession, which temporarily put a major damper on motorcycle sales. By the middle of the 1980s we witnessed the sunset of the short-lived turbo age. With the excitement generated by Kawasaki's new H2R, some in the industry think the timing may be right to revisit turbocharging. Technol- ogy and computer-controlled engine manage- ment seems tailor made for dealing with the complexity of turbocharging. Perhaps the turbo age was 30 years before its time and the prom- ise of smaller, lighter bikes with the power of bigger displacement machines could still be realized.CN Subscribe to nearly 50 years of Cycle News Archive issues: www.CycleNews.com/Archives

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