Upper Triple Tree | Honda CB350 / CL350 / CB360 / CL360
The upper triple tree on your late CB350, CL350, CB360, or CL360 is one of the most failure-prone parts on the bike. The original Honda casting was a poor-quality aluminum alloy that cracked under load, and finding a clean used one is nearly impossible. Our reproduction is built from a modern alloy with a denser, beefier casting in the areas that failed first.
Why You Need This
The original Honda upper triple tree was made from a brittle aluminum casting that cracked at the fork tube clamps under normal riding stress. For years everyone (including Honda) thought the cause was over-tightening — Honda even shipped little D-shaped washers to limit the clamp force. The real problem was the casting quality, not the install procedure.
We worked with a Brazilian OEM manufacturer that builds triple trees for the major Japanese motorcycle brands. The reproduction casting is meatier and denser than the factory part, with a more flexible modern aluminum alloy that won't crack under load. All the factory mount points and dimensions are preserved, so it bolts up exactly like the original.
Specifications
| Spec | Detail |
|---|
| Replaces OEM Part Numbers | 53230-369-305, 53231-369-000, 53231-317-701, 53231-317-702, 53231-388-000 |
| Fits Models | CB350K4 (1972), CB350K5 (1973), CB350G (1973), CL350K4 (1972), CL350K5 (1973), CB360G (1974), CB360T (1975–1976), CL360K0 (1974), CL360K1 (1975), CJ360T (1976–1977) |
| Material | Modern aluminum alloy, denser casting than original |
| Manufacturing | Made in Brazil by an OEM triple tree producer |
| Sold As | Complete kit with triple tree, Space Capsule handlebar dampers, and stainless mounting hardware |
Model-Specific Notes
- CJ360: The Honda OEM part numbers vary slightly for CJ360 models. The fork setup is similar but we have not personally tested this triple tree on a CJ360. We believe it fits just fine and want feedback from CJ360 owners.
- CB350F (four-cylinder): Not a direct fit. Our triple tree will mount to a CB350F's forks and steering stem, but the gauge mount spacing is different and you will need additional parts for a clean conversion. Contact us first if you ride a CB350F.
What's in the Kit
- Upper triple tree (1) — Brazilian-made reproduction
- "Space Capsule" polyurethane handlebar dampers (4) — made in USA, replaces the original rubber bushings
- Stainless steel mounting hardware (full set)
Installation
Difficulty: Intermediate
Installation tip: Clean the top of the fork tubes thoroughly and remove all dirt, rust, and corrosion before installing the new triple tree. You may need to loosen the fork tubes in the lower triple clamp to help everything line up properly during install.
Once all the parts align, torque the fasteners as follows:
- Upper triple tree fork tube clamp bolts: 12 ft-lbs
- Lower triple tree fork tube clamp bolts: 18 ft-lbs
- Center steering nut: 60 ft-lbs
While you're already in here, this is the perfect time to upgrade the loose ball steering bearings to a tapered roller kit (links below).
The video above is our overview of why the factory triple trees fail, what makes our reproduction better, and what comes in the kit. For the actual hands-on removal procedure, the steering bearing upgrade video on our channel covers it as part of the bearing job.
Frequently Asked Questions
How do I know if my triple tree is cracked?
Cracks usually appear at the fork tube clamp areas, where the casting pinches the fork tubes. Look for hairline cracks running away from the clamp bolts toward the body of the casting. On many CB350, CB360, and CB450 bikes the original castings cracked even when the bolts were torqued correctly — so don't assume yours is fine just because nothing has come loose yet.
Will this fit my 1973 CB350G?
Yes. The disc-brake CB350G uses the same upper triple tree as the CB350K4 and K5 standard models. The reproduction is a direct fit.
Do I need any other parts to install this?
No extra parts are required for a basic install. The kit includes the triple tree, the Space Capsule handlebar dampers, and the stainless mounting hardware. Most riders use the job as an opportunity to also upgrade the steering bearings (links below).
Will this work on a CB350F (the four-cylinder)?
Not as a direct fit. The triple tree will mount to a CB350F's forks and steering stem, but the gauge mount spacing is different and you will need additional parts for a clean conversion. If you ride a CB350F, contact us first.
Why did the original Honda triple trees crack?
The factory casting was a brittle aluminum alloy that would crack under normal riding load even when the clamp bolts were torqued correctly. Honda originally thought over-tightening was the cause and shipped little D-shaped washers to limit clamp force, but the real problem was the casting quality. Our reproduction uses a denser, more flexible modern aluminum alloy.
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Last updated: April 2026
