Unlike automobiles in the USA market, Honda motorcycle models were not designated strictly by calendar year. Honda distinguished models by affixing a K-number suffix to the model, typically beginning with K0 at the model's introduction, sometimes with K1. Individual K models were offered for one or more years, depending upon sales rates and remaining inventory. For example, the initial CB450 (the 4-speed Black Bomber, shown below on the cover of Cycle World, September 1965) is designated CB450K0. It remained in Honda sales literature through 1968, alongside the next model, the CB450K1.
The 5-speed CB450K1 (below) was sold in the US in 1968 and into 1969, when the CB450K2 was introduced. Most CB450K1 machines in the USA were fitted with a seat with white piping and rough alligator-like textured black vinyl. The restyled tank was introduced in response to initial negative public reception of the "bomber" tank. The K1's new styling was also intended help publicize the fact that this was truly a new machine, with many engineering improvements as well as cosmetic updates. Click here or the image below to see the single-page 1968 brochure in high resolution. Click here to see high resolution images of the USA-model CB450K1.
CB450K1 USA 1968
MODEL as shown in original Honda brochure.
The CB450K2 (below - click here or on image for additional high-res images of the K2) was the first CB450 without chrome tank panels, and was sold through 1969 and into 1970. The new tank, reminiscent of the then-popular Triumphs, had a screw-type gas cap but was otherwise identical to the tank on the CB450K3, introduced in 1970. The CB450K2 kept the 18" front wheel and drum brake of earlier models, and the fork shrouds were all metal. Air cleaner covers were changed on the CB450K2, with a new shape and a new cast metal emblem reading 450 DOHC. The covers were unchanged through the CB450K3 model. Beginning with the CB450K2, a new pleated seat with black piping was fitted. This seat was used almost entirely through the CB450K3 model run for the USA market. The exhaust system on the CB450K1 and CB450K2 is identical, with tapered mufflers. Megaphone-styled mufflers were introduced on the CB450K3.
Japanese domestic models and European export models often varied considerably from USA models. The European brochure circa 1969 (two images below) shows the CB450 with extended fenders and rubber fork gaitors. Rubber gaitors were not introduced on the USA-market CB450 until the CB450K3 in 1970.
CB450 1969 EUROPEAN MODEL
as shown in original European Honda brochure (cover)
CB450 1969 EUROPEAN MODEL
as shown in original European Honda brochure (interior photo)
The CB450K3 was the first USA model with a front disc brake and 19" front wheel (shown below in red and gold from the 1970 Honda USA brochure). Other new features included a larger tail light, hinged gas cap, black-finished handlebar switches, fully -rubber cushioned instruments, and restyled mufflers. The headlight shell and upper fork brackets were painted to match the tank and sidecover color. In 1970 Honda color choices on various models also began to expand, moving beyond the traditional black, silver, candy red, or candy blue to include candy gold. Unfortunately, the original candy red and candy gold finishes are extremely vulnerable to sun fade. The candy blue Honda used is remarkably stable. The CB450K3 was the last model to incude significant engineering as well as styling changes. Most modifications through the CB450K7 were minor and cosmetic only.
CB450K3 USA 1970
MODEL