The Honda CX platform was around for a while.
We had a standard CX500 platform bike at the house when I was growing up. I got to ride it a handful of times, and I’ve got to say, it’s extremely difficult to believe anything derived from that powerplant could ever be described as “high performance.”
It was an infomercial on wheels. A two-wheeled lecture on fiscal responsibility. A soft rock radio station with dual carburetors.
Small displacement *pushrod* twin, heavy steel frame, closed shaft final drive… We put some serious thought into swapping the engine for foot pedals or a hamster wheel to improve off-the-line performance.
The CX platform’s top speed was somewhere just over 100mph according to Honda, but hitting triple digits was a feat accomplished through patience and persistence rather than forced induction.
But turbochargers (especially early 80’s turbos) are nothing if not surprising, and the Honda CX500 Turbo delivered on the surprises in more ways than one.
History of the Honda CX500 Turbo
The Honda CX platform was introduced back in 1978 as a replacement for the much-loved CB550.
It was an oddball in the Honda lineup at the time, but received a standing ovation from the press thanks to an assortment of uncommon features for the time like liquid cooling, a longitudinally mounted engine, and tubeless tires, which had never been equipped on a motorcycle from the factory before.
The platform continued to grow and expand, receiving refinements each year to handling, braking, and design.
The little 500 twin was a popular ride, but it didn’t quite capture the imagination of the horsepower-hungry public who were easily distracted by big unruly sporting machines like the Suzuki GS750.
In fact, sportbikes were getting so popular by the early 80’s, manufactures were beginning to shoehorn the largest motors they could into poorly designed frames, just to stay on top of the raging horsepower wars.
The Kawasaki Z1R was arguably the best example of this, with a KZ1000 motor just barely contained inside a wildly flexing frame and useless suspension. The press didn’t have many nice things to say about it, but the public, once again, couldn’t get enough displacement.
And just when the world of motorcycling thought it couldn’t get any crazier, Kawasaki decided to up the ante, and in 1978 they launched a limited production Z1R… with a turbocharger.
The Z1R-TC was a terrible motorcycle. It required a liability waiver to be signed at the time of purchase from the dealership, and was infamously prone to catastrophic failure thanks to the high-revving nature of turbocharging and no rev limiter to control it.
Not surprisingly, the new Z1R-TC was sold without a powertrain warranty of any kind, but that didn’t stop people from buying them either.
For all its faults, the Z1R-TC did two things very well: It piqued the interest of the public, and it scared the competition enough to kickstart an arms-race that we now know as the “turbo-era” of motorcycle history.
Japanese manufacturers saw the Z1R-TC and immediately ran to the drawing boards to draft their own plans to cash in on the new mystique of turbo-powered street bikes.
The motorcycles that followed all went on to live in infamy for better or worse, but none would be quite so advanced as the first mass-production turbo motorcycle in the world: The Honda CX500 Turbo.
Honda CX500 Turbo Performance
The CX500 Turbo wasn’t just the first turbo-charged motorcycle put into mass production.
It was also the first computer-controlled production motorcycle, and the first to come from the factory with electronic fuel injection too.
The mild 497cc engine seemed like an unlikely candidate for a cutting-edge performance bike at first glance, but Honda chose to double down on the little twin due to its abundant low-end torque and bulletproof reliability, two features that help make turbocharged induction a more reasonable proposition.
Lucky for the motorcycling public, the CX500 Turbo’s engine was given some serious R&D and a complete technological overhaul before being fitted back into the familiar frame. In addition to the digitally controlled fuel injection system, the engine received a redesigned heavy-duty crankshaft and a modified engine case to house larger crank bearings.
And then, of course, there’s the whole turbocharger thing.
Although the turbo itself was only a tiny 51mm unit, Honda delivered the CX500 Turbo tuned from the factory to push a full 19psi of boost, which nearly doubled the mediocre 48 horsepower of the standard twin to an impressive 82 ponies.
This pushed the top speed up to 130mph, which was more than respectable for the early 80s (especially for a 500cc twin). The little turbo could run a quarter-mile in a just over 12 seconds.
Unlike the Kawasaki Z1R-TC, Honda didn’t skimp on the CX500 Turbo suspension or brakes to keep everything under control either.
37mm Showa forks were fitted up front with Honda’s TRAC anti-dive control, and an adjustable Showa shock smoothed things out in the rear. Double 280mm disks handled stopping duties for the front wheel while the rear drum brakes were replaced with a large 300mm single disk out back.
Buying An Original Honda CX500 Turbo
Approximately 5,000 CX500 Turbos were produced in 1982 before Honda upped the ante to their larger displacement CX650 Turbo just a year later in 1983.
Nostalgia for the age of turbos appears to be in full swing, especially for the original 1982 model, which ranges in price anywhere from “not cheap” to “prohibitively expensive” depending on their condition. To illustrate:
A clean but less-than-perfect CX500 Turbo with just over six-thousand miles recently sold for $8,100 on BringATrailer.com in June of 2020.
Then, just weeks later, an absolutely flawless example with just 520 miles on the clock sold for a whopping $19,000.
Six months after that, a slightly-blemished third CX was sold at the same auction for $7,600.
The only bike I was able to find online for sale anywhere was pretty clean, but the dealership was asking a hefty $9,999 for it.
So finding a CX500 Turbo can clearly be an undertaking, and finding a nice one will cost you both time and money.
The silver lining here is that the CX500 was engineered with reliability as a consideration, and is probably tied with the Yamaha SECA 650 based turbo in that regard, so if you do happen to find one, chances are it will be running just fine.
Restoring A Honda CX500 Turbo
Since the CX500 Turbo had an extremely limited run, high-quality replacement parts can be tough to come by, especially those unique to the model like the bodywork and original exhausts.
Expect to pay a premium for those, and to have some paintwork in your future as well if your goal is a full restoration.
That being said, since the CX platform remained so consistent throughout its five-year production, there’s a considerable amount of parts interchangeability for the odds and ends, especially from the CX500EC sports model, which will make the job much easier.
My recommendation for anyone interested in adding a Honda turbo to their collection would be to make sure that the motor is sound first and foremost, as parts for the induction assembly are going to be expensive and difficult to source.
Is the Honda CX500 Turbo a Good Investment?
Interest in the turbo-era of motorcycles seems to be at an all-time high.
The Honda CX500 Turbo seems destined to be the most collectible of the factory turbos thanks to its historical significance, refined styling, and extremely limited twelve-month production run.
I don’t see them getting any cheaper, or any easier to find in the future. Many have already found their homes in museums, and that’s always a good indicator of a wise investment.
Just how high their value will go in the coming years is tough to say, but if I could find a clean example today for around the $7,000 mark, I would jump on it without hesitation.
The Honda CX500 Turbo is one of the most important collector Honda’s to date.
In addition to its impressive list of technological firsts and retro-cool features (like having the word “TURBO” printed in big bold letters on both exhaust pipes), the CX500 Turbo is yet another reminder of what Honda’s engineers can accomplish when their reputation is on the line.