Here’s a bit of an odd duck: a cherished Honda CX500 Turbo! For a period in the early to mid-1980s, all of the major Japanese motorcycle manufacturers flirted with forced-induction, although it seems to have been a bit of a fad. The main advantage of a turbocharged motor is efficiency: some wasted exhaust energy is scavenged and repurposed to the production of more power, and obviously you can get much more volumetric efficiency with a turbo than you can with normal aspiration. But the benefits of forced-induction in a motorcycle are outweighed by the additional complexity they bring to the table, especially when a simple bump in displacement or revs might, at least in a motorcycle, provide the same power increase.
But in the automotive world, the word “turbo” was all the rage, and bike manufacturers didn’t want to be left behind. Many of these early attempts were fairly crude, and while turbo lag and a big hit of power can be a rush in a car, they’re especially dangerous qualities for a bike. Porsche’s early 911 Turbo developed a reputation for lethality because mid-corner boost from the primitive turbocharging combined with tricky lift-throttle handling to surprise more than a few owners, testing their cars’ build-quality and crash durability as they headed off the road backwards.
Now imagine that same dynamic, on a bike leaned over at 45° on 130-section tires…
When Honda joined in on the craze, they did it with typical refinement, although their choice of a platform might seem odd at first. Instead of a signature sophisticated and smooth four-cylinder, they chose their almost retro-tech, slightly ungainly CX500 v-twin. But while the spec sheet for the CX500 looks low-tech, it was actually a very sophisticated design, with many thoughtfully designed aspects designed in: the pushrods were required by a slight twist to the angle of the heads so the carburetors didn’t try to occupy the same space as a rider’s knees, and the transmission spun counter to the longitudinal crankshaft to minimize torque-reaction to the shaft-drive rear.
Most importantly, the engine was liquid-cooled and could easily handle the additional heat and pressure that the turbo would add, and the simplicity of the 80° twin left plenty of space for intake and exhaust plumbing. The resulting package was far from pretty, but with 19psi, the little 487cc motor put out 82hp and could push the bike north of 120mph. The bike also featured modular ComStar wheels and tubeless tires, a relative rarity at the time.
From the original eBay listing: 1982 Honda CX500 Turbo for Sale
Well, you found it! My pride and joy. And if you are looking at this listing I can pretty much guarantee you already know alot about this motorcycle. Its super rare and hard to find. It has been in my possession since around August 2005. It appears by paperwork I have in the shop manual that I am the third owner and that it was originally purchased in CT.
This bike is in original condition with a few exceptions. I replaced the front brake lines with Galfer SS lines just this past weekend. Along with the new lines I did a complete rebuild of the front calipers, polished caliper pistons, new piston seals and dust caps, new pads, master cylinder rebuild, and of course new fluid. Also shortly after I got it the paint on the exhaust was chipping off on the “TURBO” shields. I removed the paint with intentions of painting it back black and never got around to it. Besides that this bike is stock and unmolested. Adult active duty military owned, kept in a climate controlled garage and was the Queen of all the bikes, always covered up and sheltered from the elements.
However, this bike is not perfect. It does have imperfections and most of them common to this model. A paint chip in the front fender, a scratch here and there, the crack in the right side fairing that is common due to the heat off the exhaust, a small crack in right front turn signal (cant see it unless your looking for it), Small imperfection in the windscreen, etc. Remember this bike is 32 years old!!! Also the bike was laid over in the garage by previous owner and probably contributed to the crack in the fairing. The left side battery compartment cover was cracked real bad when I bought her. I replaced it with an original equipment one soon after I bought it. There is a piece of gauge cluster foam gasket material that has slid down on the tachometer. It does not affect the function of the tach and I was going to replace but am scared to take it apart that far. I’ve tried to take pictures of all her imperfections and am representing the bike to the best of my ability.
Thats the bad, now the good. Bike has a new battery, original owners manual, shop manual (which I used to rebuild brakes), and runs like a top! I just rode this bike this past weekend with my dad and it still makes me grin ear to ear when the boost kicks in and the turbo gauge ramps up to max psi! It is definitely like no other bike I have ever had and I hate to see her go and hope the next person will appreciate her and take care of her as well as I have.
The CX500 was produced for only one year, and was followed by the more refined, slightly bigger CX650 Turbo. While ultimately a technological dead-end for motorcycles, the flirtation with turbocharging has led to a few very funky, affordable collector bikes, and many can be found in very nice condition if you poke around.
There are still a couple days left on the auction, although the reserve has not been met at about $3,000. It looks to be in very nice, original shape: the cracks are unfortunate, but speak to the originality of this machine and the bike is in otherwise very nice shape. The stainless front brake lines are a welcome touch and the bike appears to have had very careful maintenance.
Turbocharged bikes were a bit of a gimmick at the time, but can be a real blast on the road: that lag and boost can be a bit of a pain if you’re looking at lap times. But on a back road, that rush of power can be a whole lot of fun! And modern technology that smooths power delivery, reduces lag, and improves safety might see the return of forced-induction to motorcycle manufacturing… Fun, collectible, reliable, and affordable, snap one of these up before prices shoot up: 80’s bikes are still a bit uncool, but these things tend to be cyclical [pun!] and interest is on the upswing.