Listing and Links to Old Honda CT90 Patents

I was working in my shop the other day prepping some side cases for paint from one of my CT90's and noticed the "PAT. APPLN. PEND" that is cast into the side of one of the cases just above the high/low range gearbox and selector and I started wondering what if anything, Honda had actually patented on the CT90.

I've noticed this text on the side of the case a number of times before, but I had a some free time available, so I decided to dig a little deeper at the Google Patent web page to see what I could find out.

I ended up finding a number of patents for several features that exist on the CT90 that I have shared below along with links to the actual patent at the Google Patent web page.  In addition, I've shared two additional Honda patents for removable front forks that I found interesting and that look like they were targeted for the CT90 & CT70, but never made it into production.

At the end of this post I've gone out on a limb and included one additional Honda patent for an easy kick starting device that I found entertaining due to the abstract description within the patent that probably wouldn't be considered politically correct now days by most people. It's gives an interesting glimpse of what was considered acceptable wording by the US Patent Office back in 1978.

Here are the five Honda patents of features that actually exist on most CT90's.

Two speed Transmission

Patent: 3,438,277 -  Driving apparatus for a motorized two-wheel vehicle
Granted back in 1969 - Link to this patent

The Air Cleaner Attachment to the Rear Rack

Patent: 3,698,503 - Support of an air hose of an air cleaner of a motorcycle at its inlet opening
Granted in 1972 - Link to Patent

Handle Bar Release

Patent: 3,705,733 Steering handle attaching apparatus in a two-wheeled vehicle
Granted in 1972 - Link to Patent

Rear Brake Light Switch 

Patent: 3,521,233 Brake indicating apparatus for a motorized two wheel vehicle
Granted in 1970 - Link to Patent

Shift Drum Stopper and Related Linkage

Patent: 3,421,384 Change speed apparatus for a vehicle
Granted in 1969 - Link to Patent

Removable Front Forks

The following are the two patents Honda was granted that involved removable front forks.  To my knowledge neither of these two designs were ever implemented on a Honda motorcycle, but by the pictures in the patents they look like they were designed for the CT90 and CT70.

Patent: 3,675,944 Apparatus for attaching a front-wheel fork to a head pipe in a two-wheeled vehicle or the like
Granted in 1972 - Link to the Patent

Patent: 3,757,882 Motorcycle which can be disassembled into front and rear subassemblies

Granted in 1973 - Link to Patent

Politically Incorrect Honda Motorcycle Patent
As I shared above, as I was looking for CT90 patents I came across this patent and decided to included it due to the slightly politically incorrect language used in the first sentence of the abstract for the patent. Give the link below a click and read the abstract and it should be pretty clear.  Enjoy.

Patent: 4,067,243  Engine starting device for a motorcycle
Granted in 1978 - Link to Patent

I hope you found this post interesting.

Helpful Links (Shop Manuals, Wire Diagram, Model Information, etc.)

Link to page with listing of CT90 parts available on Amazon