Watch the video above for all the juicy details.
When looking at the forks on a vintage Honda motorcycle it is not always clear what you have. On one hand, Honda redesigned their forks several times even within the same families of motorcycles. On the other, these motorcycles are 40+ years old so it is entirely possible that what is on your motorcycle might not be what should be on your motorcycle. When examining the forks over here at CMC, we decided to give each architecture of fork a unique name so you can better identify what is on your motorcycle and what parts you need to rebuild it. Keep in mind, each fork architecture was made in several different sizes so check out the full rebuild article below for your specific motorcycle for links to the exact seals, springs, fork oil, and specifications.
These architectures were used on these families of Honda motorcycles
CB175 / CL175 / SL175
CB200 / CL200
CB350 / CL350 / SL350
CB360 / CL360 / CJ360
CB450 / CL450 / CB500T
CB500K / CB550
External Spring Fork
The first architecture of fork is defined by its most obvious feature, the external spring. This was used on the early models of CB350, CL350, CB450, and CL450 families of motorcycles. The upper triple tree used with these motorcycles was a clamp-through design in that it sat onto the fork tube and the fork top cap went through the triple tree and screwed into the fork tube to hold it together. These are often found with rusty springs that can be either cleaned up or replaced with our replacement Ikon external fork spring upgrade.
Internal Spring Fork With Dampening Rod
The second architecture is defined by the unique dampening rod that runs through the spring the entire length of the fork body. The top cap of this fork is actually screwed directly to this fork and the spring cannot be removed until the top cap and lock nut are both untied from the internal dampening rod. This can be found in the later models of the CB350, CL350, CB450, and CL450 families of motorcycles. The upper triple tree used with these forks is a clamp-around design in that it clamped around the upped of the fork tube and pinched it. These triple trees are prone to cracking because of the inferior metal used back in the day and the tendency to overtighten them. Replacements for the later CB350's and CL350's are available right here.
Internal Spring Fork Without Dampening Rod
The third architecture is by far the most commonly used design in this era of Honda motorcycles and can be found on the CB360, CL360, CJ360, CB200, CL200, Later CB175, Later CL175, CB500K, CB550, and CB750 families of motorcycles. It lacks the full-length internal dampening rod but in all other regardless looks almost identical, so the top cap needs to be removed to tell the difference. The top cap on this fork is not attached to anything inside the fork so be aware it can shoot off the fork slightly when removing it. Once the top cap is removed, the internal fork spring can be slide right out and changed. The upper triple tree used on these forks is also a clamp-around design with the CB360, CL360, and CJ360 versions being prone to the same cracking issue. You can find the replacement for that right here.
Sealed Spring Fork
The fourth architecture of fork is defined by its most annoying feature, the sealed spring. This fork uses a clamp-through triple tree design like the external spring fork where the fork attaches to the upper triple tree via the fork sliding into the cast triple tree and top cap screwing into the fork tube. Because of this, the top of the fork tube is reduced in size, and the internal spring is trapped inside. To replace the spring you need to completely disassemble the fork to access it. The fork is found on the early CB175 and CL175 families of motorcycles, as well as many other small cc Honda's of the '60s and '70s.
Fork Rebuild Guides:
Early CB175 / CL175
Late CB175 / CL175 / CB200 / CL200
Late CB350 / CL350 / SL350
CB360 / CL360 / CJ360
Late CB450 / CL450 / CB500T
CB500K / CB550 / CB750