Learn You: Honda CX500

Do you know the Honda CX500?  It is an important bike, and the reason the Civic Type R is with us today.  A stretch?  Let me explain.

The CX500 came out in 1978 and per Wikipedia, "included innovative features and technologies that were uncommon or unused at the time such as liquid cooling, electric-only starting, low-maintenance shaft drive, modular wheels, and dual CV-type carburetors that were tuned for reduced emissions. The electronic ignition system was separate from the rest of the electrical system, but the motorcycle could only be started via the start button." Heady stuff for the late 1970's and they positioned the CX500 as Honda's top bike and the very first V-Twin they ever made. From an engineering standpoint, it was a hit and the CX500 quickly became synonymous with reliability, durability, ruggedness and a steadfast refusal to break down or suffer issues.

From a styling perspective, well, I will let Bike EXIF take that one: "With a short wheelbase, high front end, awkward looking subframe and unflattering plastics, it earned nicknames such as ‘plastic maggot’ and güllepumpe (the German word for a pump used to shift liquid manure) when the Standard model was first released in 1978." OK, it was not a stunner and its use by couriers across Europe did not help that reputation. The later CX500 Custom - full disclosure, my first bike - gave it a cruiser style and helped a bit. A bit.

 But the bike was still the subject of Honda's top engineering minds, and variants began to roll out. After the custom came the deluxe:

 Then came the CX500EC Sport, moving the CX platform firmly into the sporting-bike realm:

You would rather tour you say? How about adding a fairing, saddlebags, and a unique passenger seat/storage box option?

Honda also punched out the motor for a 650cc version of the Silverwing (baby Goldwing) along with a 400cc version for Japan to comply with regulations there.

But this wasn't good enough for the minds at Honda so they went ahead and added a turbo: 

BAM! The CX500 Turbo, and later the 650 Turbo. A race bike for the street, kinda. It looked good, it had lots of 80's turbo lag, and obligatory TURBO stickers. It convinced Honda that turbochargers were cool and made power and could transform their more pedestrian offerings into fast sexy beasts. Fast-forward a few years, and Honda comes out with this:

Coincidence? No. A Direct descendant? Oh yeah, for sure. You can see the DNA all through it, down to the extra plastic that makes it look ugly. Without the CX500, there would be no CTR. Full stop.

And you can still enjoy the CX500, it has become a popular platform for customizing:

Who's ugly now?

Editor's Note: The views presented here are only loosely based in fact and are often opinion or total fantasy. If you enjoyed it, share the history of something you know about, it is December and we are all bored.

I believe you 100%. Honda was crazy about motorcycles during this era. For a span of roughly 8 years, they had roughly 8 completely unique engine architectures at any given time, with almost no common parts between them. Compare that to today, where they use the 300 in literally everything.

I almost posted this exact thread.  I have frequently questioned why the CTR is the way it is but after long periods of reflection it became obvious.  The lineage is undeniable.  At this point since the world has been informed of the reasons for the Turbo, and aggressive plastics on the CTR I would like to discuss another pair of prominent features of the CTR that where clearly foretold by early Honda Designs.

I present to you the Honda HR21 Lawn Mower.

In 1978 Honda blessed the world with the results of years of research in excellence in small scale agrarian service.   Numerous design details were perfected for future use on this brilliant machine.  It's obvious that the CTR application of 4 wheels pushed to the corners of the vehicle chassis offered increased stability, dynamically adjustable chassis settings allow for machine response to the operating environment, and Red items in the middle of the vehicle distinctly identify it as a Honda.  But these features are not the most noteworthy features the HR21 identified.  

Determined to provide a place to store all the detritus that is generated by the operation of the device, Honda pioneered the use of a Rear Bagging device to store the sheared biomass.  The use of a rear bag to provide large carying capacity was widely known but the brilliant decision was made to have the ability to access the bag through the vehicle chassis.  This combines the volume of the bag directly with the cutting volume of the vehicle.  No extra apertures are required streamlining the vehicles appearance and integrating the storage.

Additionally the benefits of use of a high mounted handle at the rear of the vehicle was identified.  By locating this handle high and rearward the handle has sufficient leverage to excerpt large pressures on the vehicle chassis and effect the weight distribution.  A lower/shorter handle would not have as great of forces.  By providing adjustability of this handle the machine operator would be able to tailor the vehicle response characteristics to their desires.  Honda also realized that by using a multi-element design on this handle additional command over the machine could be realized.  

These elements are clearly baked into, no make up the DNA of the CTR.  Observe Hondas steadfast dedication to the rear bagging design by utilization of the now popular "Hatchback" pioneered by the HR21 mower cargo area.  And finally the prominent, elevated multi element handle is preserved on the CTR.  Here constructed instead of chrome steel out of a modern Carbon Fiber but clearly a derivative in function and form of the original HR21 Handle.  

Thank you Honda CX500 and HR21.  Without you the CTR would not be the car it is.

I'm firmly convinced that the Turbo was a case of "You're saying you can't turbo a twin[1]? Hold my sake and watch this..."

[1] All the other factory turbo bikes out of Japan were inline fours.

I had a buddy who had aCX500 TURBO. I was young, and it felt like being strapped to a rocket. The bar graph on the digital dash marked TURBO told you exactly how much fun you were having. Another buddy had the 650 SECA TURBO. Much the same can be said if it.

This is how those bikes made a much younger version of me feel:

Had a CX500D, a CX650 Eurosport and a  GL650 Silverwing.

Great bikes, I'd have another.

They're what got me into 'Guzzis. As much as I love my Moto Guzzis, I believe the Honda twin was a better design.

I don't know what episode numbers they are but The Motorcycles and Misfits podcast one of their members bought a decent CX500 Turbo recently and they talk about it extensively for several podcasts. Really interesting bikes.

ShawnG said:

Had a CX500D, a CX650 Eurosport and a  GL650 Silverwing.

Great bikes, I'd have another.

They're what got me into 'Guzzis. As much as I love my Moto Guzzis, I believe the Honda twin was a better design.

We must be brothers with a different mother!  I too had a '79 CX500D and an '81 Silver Wing Interstate.  I bought the D new, trading in a '75 CB400F that I wish I still had, and put around 80,000 miles on it.  It was my only mode of transportation, luckily I was in Florida and don't melt in the rain.  I bought the Silver Wing on a whim around 2004 with 24K miles on it and rode it for about 20K miles.  Great bikes if you maintained them, both the engine and the frame/suspension demanded attention.  Ignore maintenance at your own risk!  Really interesting and historic bikes.  While they had a following in the US, my understanding is that they were hugely successful in the UK.

I swear, the pictures of the Deluxe and the Silver Wing in the original post look EXACTLY like the bikes I owned.  Same colors, same everything.  Serious trip down memory lane.  Damn...

The turbos are really interesting to me. I've owned a turbo car and it had turbo lag. That sounds terrifying on a bike doing anything but going straight. 

I feel like Honda put the nail in the coffin of turbo bikes with their CX twins.

Everyone else was turbocharging their already fast bikes and going really fast.

Honda walks in, swinging Honda money around and turbocharges one of their more pedestrian offerings. They built the fastest turbo motorcycle and pretty much said to everyone "Look what we can do with a CX650, do you really want to go down this road?"

Even the mighty Kawasaki had to farm theirs out to a subcontractor and it came without a warranty.

I would totally rock a near stock one today. Swap the buckhorns for a super bike bar. Otherwise (near) stock, not bobbed. 
 

This boutique dealer my dad worked at on weekends had a turbo for sale back around 2000. It was cool. 

In reply to stukndapast :

I had the exact same silverwing too. I learned to ride on that bike.

CX500s really are great, and I'm a big fan of the engine. Smooth, predictable, enough power to be plenty of fun, sound good, and gearing short enough that you can blast through the first 4 on most interstate onramps. Seem to be surprisingly durable, too.

I have a thing for V twins, and I race dirt bikes, so this is what mine has become:

The engine is shockingly well-suited to dirt bike duty.

Ha, I knew when I sw the title that I'd see Dave's build (second from the last with the tan seat).

When he built that there were literally only a couple CX customs and his CX made a name for himself. I told him he should make copycat kits and sell them to fund his fledgling bike building business—he disagreed, and since, he's been copied about as much as any one designer can be. I have a theory that bike of his is what helped people(stateside at least) see the promise of the platform, and subsequently drive prices up from borderline "free" to "I know what I have."

They're reliable, but slow, and unless you're WELL under 6' (Dave nor I are) you'll look like an absolute goon riding one. He does not agree. 

He sold it last year but DOES have a CX Turbo waiting to be built up...

Selling my CX500 is the biggest mistake I did.

In reply to gearheadE30 :

What fork are you using? Asking because I have a 79D in my back shed and it would make a pretty awesome scrambler me thinks.

In reply to akamcfly :

The forks are off of a 1996-1998 RM125 or RM250 - 49mm Showa closed chamber forks. They are awesome for ripping off road, but for typical scrambler stuff a cheaper and easier option would be DRZ400 open chamber forks. They are much more common and are externally the same. I shortened them quite a bit internally so they have ~7.5" of travel to match the rear. I couldn't go taller because the driveshaft angle gets pretty extreme. Regardless of which one you use, you'll probably need stiffer springs. I have 0.58s and it seems about right.

All Balls Racing has conversion bearings that more or less work, but I had to cut down the races a bit because the RM250 stem was just a hair too short otherwise. Honda uses a goofy bearing diameter (28.5mm or something) so conversion bearings are about your only option.

In reply to gearheadE30 : Thanks! I added this info to my CX500 list