From fiery basket case to The One Moto…
The Honda CB360, a four-stroke twin, debuted in the mid-70s as an alternative to Honda’s more expensive and complex lightweight fours. The 34-hp engine was tuned for a broader torque curve and light maintenance. While the CB360 may not have been the lithest or most powerful of the CB series in stock trim, for some builders, this only adds to the challenge and satisfaction of drawing the most from the platform.
Enter Xavier and David from NorCal’s Moth Vintage (@mothcustoms), who are fans of all things old and vintage, from pre-war race cars to 70s dirt bikes to BMW airheads. We saw their latest build at the 2019 One Moto Show and had to learn more. They picked up this ’75 CB360 as a fire-damaged basket case and decided showcase the potential buried in the 356cc twin CB. Says Xavier:
“I wanted to show what a CB360 could really be. While keeping it a CB360. So no modern front USD forks, monoshock, or anything that would take away that it’s still a CB360.”
The bike was stripped down and lightened, with a detabbed frame, aluminum wheels, and carbon fiber rear cowl, seatpan, battery tray, and other accessories. We especially love the work the guys did on the engine, which has been punched out to 378cc with Suzuki GS850 pistons, oversize valves, titanium springs, ported head, road race cam, and more. The motor is now good for 42 wheel horsepower at 9,500 rpm!
When Xavier first brought home the bike, a crow landed on it, so they named the bike “Yatagarasu,” or “Three-legged Crow” — a creature found in East Asian mythologies. Below, we get the full story on this little beast.
Honda CB360 Cafe Racer: Builder Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
My name is Xavier and I’m 37 years old. I’ve always been into old cars and only a few years ago started customizing motorcycles. My friend David and I call ourselves “Moth Vintage” and we are fans of all things old. Pre-war race cars, Airhead BMWs and 70’s dirtbikes.
• What’s the make, model, and year of the bike?
This is Honda CB360, 1975.
• Why was this bike built?
This is my personal project and I wanted to show off everything we could do in our shop.
• What was the design concept and what influenced the build?
The bike was purchased as a basket case, had recently caught fire and was heavily damaged. I wanted to show what a CB360 could really be. While keeping it a CB360. So no modern front USD forks, monoshock, or anything that would take away that it’s still a CB360.
• What custom work was done to the bike?
The most obvious is the paint – which was done in house. The bike has just about everything else done to it. Starting at the front with progressive springs, lowered slightly and clip-ons, and an aluminum-housed headlight. Switch housings were thrown out and a simple mini pushbutton switch for the still intact starter sits on the right bar.
Carbon fiber was used for the rear cowl/seatpan and battery tray which is under the cowl. Aluminum rims round out the footprint, and a slightly longer swingarm.
Frame has every tab removed, and every seam welded for rigidity, and mounts added for the high output canister coils. A 520 chain conversion with aluminum sprockets, carbon fiber and billet aluminium brake stays, license plate brackets, and exhaust collars keep the weigh low on a “barely legal” street bike (been pulled over six too many times for lack of turn signals).
Onto the engine: Lightened and rebalanced the crank, punched the cylinders out using pistons from a GS850 (as they have the right wrist pin diameter and high, but are lighter than stock and about 2mm larger in diameter) to a displacement of 378cc.
Custom laser cut copper gaskets were needed to get the clearances right. KibbleWhite oversized valves, titanium springs, and bronze guides were used, while the head was ported to allow the MegaCycles Road Race cam to breathe deeply.
Pamco electronic ignition with its own digital advance allows the motor to top 12k RPM, making peak power at about 9,500.
The top oiling system was modified to allow better flow, cutting a new passageway to the center cam journal, allowing higher pressures to the top end and also cooling the clutch basket. Work on the carburetor internals was needed to get them to work properly with velocity stacks or pod filters: secrets that go beyond simple jet changes.
• Does the bike have a nickname?
We call it “Yatagarasu.” Yatagarasu is a mythical creature of Japanese culture, it’s an omen…sometimes good and sometimes bad. The day I brought the bike home a crow landed on it, outside. It was really freaky and I had to look up mythical crows.
• How would you classify this bike?
I would call it a cafe racer.
• Was there anything done during this build that you are particularly proud of?
Keeping it as much a CB360 as possible, while doing every last bit of work ourselves in our garage is satisfying!