Some of our readers may remember an article I wrote in July 2004 asking the question "Why Don't We See Factory Turbocharged Motorcycles?". While in that article I focused on the likelihood of a production turbocharged sportbike (which I still believe will happen), it seems that the first turbocharged production bike of the new millenium may be a cruiser.
Yesterday we reported on rumors that Honda may manufacture a limited-production cruiser powered by a turbocharged version of the VTX1800 motor. Although I hadn't given it much thought before, hearing about a turbocharged cruiser made me wonder why it hasn't happened already.
Turbocharging seems a good match for typical cruiser engines. These engines usually have fairly low compression (at least relative to that of a sportbike) and large displacement. Relatively low compression is necessary for a turbocharged engine, in order to keep cylinder pressures at a reasonable level and avoid detonation. Larger displacement is also a big advantage, as the higher volume of exhaust gas produced by a larger motor will spool the turbo up quicker (at a lower RPM).
The combination of low compression and large displacement that exists in most cruiser motors would seem to make a turbo system more of a "bolt-on" affair, rather than requiring re-engineering of the powerplant as it would with most sportbike motors. This means that a turbocharged cruiser would likely carry a smaller price premium than a turbocharged sportbike.
Considering the weight of most modern cruisers, it seems unlikely that many buyers would be put off by the extra heft of a turbo system. Certainly weight is a less important factor than it is in sportbike design.
All-in-all, turbocharging seems like an extremely intelligent solution to increasing the power output of a modern cruiser. If other manufacturers can recognize this (perhaps, inspired by Honda's example), we may see a sudden surge in the power output of top-of-the-line cruisers. Considering the poor (by motorcycle standards, at least) power-to-weight ratio of most modern cruisers, we can see no market segment where it might be better appreciated.
