Honda’s immense manufacturing facilities in Japan allowed them to make almost anything they desired and in a hurry, if there was a need. Previous to 1961, the front forks of Honda motorcycles were of the leading-link style, consisting of a pressed-steel fork housing, a couple of coil-over shock assemblies, a U-shaped link all put together with a handful of bolts, bushings and other fasteners. These fork assemblies were rugged, easy to service, but had crude damping characteristics, creating a pogo-stick ride quality, especially when the roads got rough.
With the release of the 1961 CB72 and CB77 Super Hawks, true hydraulic forks came into being and they greatly enhanced the road stability of their Super Sport models. Unfortunately, the damping qualities still left a lot to be desired, but at least they were headed in the right direction, finally. Their choice for the hydraulic fork design was to use a thin steel piece of tubing, welding some axle holders to the bottoms and threading the top portion for a screw-on fork seal holder. The Type 1 “steel fork” slider designs were the main features of several models, through about 1966. The new Type 2 “alloy fork” slider types were faster to machine and of lighter weight, which is always a good thing for a front fork assembly.
Many vintage Honda enthusiasts know about Type 1 and Type 2 forks, featured on both the CB72-77 Super Hawks and the CL72-77 Scramblers. On the CB models, the forks and the steering stem/fork bridges were all re-engineered because of the change on the geometry for the front axle. Steel forks held the axles in a “leading axle” position, ahead of the centerline of the fork sliders, gripping the axle with a pinch bolt on one side and a large axle nut on the opposite end, to cinch everything tightly together. Steel forks are very vulnerable to denting from a crash and particularly if the inside fender bolts holding the fender and brake stay were excessive in length. When the bolts bottomed out in the welded on brackets, the tubing deformed beneath the bolt ends causing the bushing surfaces to go out of round. When this happened, the fork bushing would jam inside the fork slider, preventing removal of the fork tube/bushing assembly from the fork housing. Brute force will usually allow the fork tube and bushing to be removed, however the slider is no longer usable and the fork bushing will require replacement as well. The fork’s fender mounting bolts have different lengths for each location, which must be carefully observed; otherwise this kind of damage occurs.
The move to the Type 2 fork designs eliminated the fender mounting bolt issues, by locating the mounting bosses rearwards, off-center of the fork housing. The axle retention system changed to double studs and a clamping cap, centered upon the bottom of the fork housing. Relocating the axle right beneath the fork housing changed the fork geometry, so the fork bridge and steering stem’s mounting holes were pushed out to recover the lost wheelbase dimensions. The front fender mount locations changed, as well, so there is almost nothing interchangeable between the Type 1 and Type 2 front fork types. Additionally, the Type 2 forks on the CBs had outside springs vs. the internal fork springs of the Type 1 versions. The fork tubes, themselves changed their outer diameters several times, so that various types of fork covers are required to match all the components up correctly. It is VERY important to note the serial numbers and fork types before tracking down fork seals (different for each slider type) and the upper and lower fork cover sets. Relocation of the fork springs from inside to outside created more space for fluids inside the fork assemblies, too. The fork seals installed in the upper inside edges of the alloy fork housings, eliminating the labor intensive screw-on fork seal holders. Chrome sleeves mounted on the upper outside edges of the fork sliders to cover up the outside fork springs. The fork springs have small spring retainer cups which nestle inside the lower fork covers. A special threaded tool is required to reach down from the top of the fork bridge and screw into the top end of the fork tube, allowing the tube to be drawn upwards into the fork bridge mounting holes. With no internal fork spring tension in the new designs, the fork tubes sag down when they are inserted into the steering stem, leaving a large distance gap between the tops of the tubes and the bridge.
Generally, it just takes a second to confirm which type of fork is being used on the Super Hawks and Scramblers. Steel fork sliders were always painted the same color as the frame. All the alloy fork slider designs were painted silver. Checking the axle retention designs will also verify which type of fork is in use.
The change in forks affected the CL72-77s in a slightly different way. While the CBs went from internal to external fork springs, the change for the Type 2 forks on the Scramblers kept the fork springs inside the fork tubes/sliders. Otherwise, the bulk of the changes were similar to those of the CBs. The axle was relocated to beneath the center of the sliders, the fender mounts moved back on the alloy housings and the screw-on fork seal holders were eliminated, as they were on the Super Hawks. While the newer CB fork seals just install in the top of the sliders, the CLs have a special threaded ring, which keeps the seals firmly in place, but adds a bit of frustration to the servicing of those parts. While the CBs always had the large 8” DLS brakes, no matter which style forks were used, the CLs began with the steel sliders and small SLS 6.25” brake assemblies. In early 1966, Honda did a wholesale change on the 305 Scramblers, though, in that they changed the forks, rear swing arm and added the 8” wheel/brake assemblies, all at once. Scramblers suffered from seriously dangerous braking until the upgrade was completed and all the changes helped the overall enjoyment of the machine for most owners.
Scrambler forks use a rubber, accordion-style fork boot, which covers the fork tubes, in lieu of the metal fork covers used on the CBs. It is interesting that neither the fork bridge nor steering stem was changed when the fork types were redesigned on the Scramblers. There were three different fork boot part numbers, however, to address the fork changes. The last one included a change to the fork covers, which like many other parts were rubber-mounted to help increase durability. Vibration levels on the Scramblers are much more apparent on these models vs. the Super Hawks, thus numerous chassis parts on the CLs were cushioned, including the seat, battery, rear fender, muffler, driver footpegs and fork covers.
The 1965-66 time-periods seems to be the engineering transition era for many of the Honda fork designs. Similarly affected models included the Super 90, CB160 and CB450K0 “Black Bombers,” which all began production with steel fork sliders and ended up with alloy fork slider designs well before the end of their runs.
So, now you have the lowdown on the steel vs. alloy fork designs for the mid-1960s Hondas. I know that now you can pass the final exam at Fork University with flying colors!
Bill “MrHonda” Silver