Reviving an Old Neglected 6 Speed Classic "421 6SP Proj"

At Benjie’s Cafe Racer, they love working on bikes -- both modern & old!
However, old bikes that have been neglected & have stopped running will always have a special place both in our hearts as well as our garage. We find an insurmountable joy in taking a bike that has long since past its last mile & reviving it to a version of itself that leaves its original life roosted in dust. When a client approached us to build a custom old school style cafe racer out of a 1976 CB400F, we were eager to accept the project even before seeing the donor bike.

When we received the dried-up, neglected CB400F, it had a long front end from the ‘80s, chunky bubblegum grips, & antiquated gold 16 mag wheels with dry, cracked tires. The motor had burnt loose pistons, the loosely hanging timing chain had worn-out guides, & the stock carburetors were heavily oxidized inside. To be honest, the only thing the donor bike really had going for when we first got it was that it was a 6-speed -- a rarity for bikes from the ‘70s/’80s.

Immediately after receiving the donor, we stripped it down to its bare bones rolling chassis. Since the client requested an old school style, we kept the stock frame, but changed the end frame to an up swept frame loop. As with any of our vintage cafe racer builds, we started our design process with the gas tank -- guided by the philosophy that the gas tank will dictate the attitude of the rest of the build & the bike itself.

Our vision was to create a tank that was handmade with big curves -- like something you’d see back in the ‘60s -- so we made ours out of aluminum with a polished finish & with extra width to accommodate the wide stance of an in-line 4 motor. We also elevated the tank higher than we usually would in allusion to the design of old ‘60s race bikes. Continuing the retro design, we went with a Monza gas cap & made a stainless steel tank strap with an exposed air vent.

The seat was next & was made with an aluminum tail, derivative in style of the gas tank. We dropped the sides of the tank to provide the number plate look, & we exposed the tail frame for additional detail -- showing the simple modification added to the frame. We topped the seat off with black suede cowhide leather upholstery with silver/gray stitching to tighten up the shape of the seat.

After the tank & seat had been made, we decided to lower the front end by an inch & a half, leveling the stance of the bike. We scrapped the disc brakes that came with the bike & installed a reproduction 4 leading brake drum with side air vents on a shouldered aluminum wheel. From stainless steel, we made fork shrouds with headlight ears & blended the low bar clip ons to flush the design into seemingly one piece. We shaved & cleaned the upper tree, making sure to remove any inessential tabs. The front fender was made out of aluminum with stainless steel brackets, & to top off the front end with peak nostalgia, we made an aluminum euro-style headlight bucket with a more modernized custom gauge from speedhut.com.

At BCR, we believe the exhaust should be designed in a way that speaks in conjunction with the seat & the gas tank. This usually means building exhausts specifically for their respective projects, & this project was no different. For this bike, we made our exhaust out of stainless steel with a 4 into 2 into 1 setup. We hammered the body of the muffler to have a curved, tapered shape -- complementary to the shape of the tank & seat.

For this build (like many before it), we wanted to make as many of the parts as we could. The handlebar switch boxes & rear sets were made in-house out of stainless steel with aluminum knurled pegs & lever ends. Then, cone LED tail lights were hand hammered -- also out of stainless steel. The turn signal lights (front & rear) were housed in a combination of stainless & aluminum, much like the stainless steel electronic ignition points cover with an exposed center rotor.

The engine of the bike was shot when it arrived. The engine case had completely oxidized, & most of the internals were worn out, so we took the motor apart for a complete rebuild. Since the the stock pistons were burnt & loose, we had the cylinders bored for bigger 54.5mm pistons -- increasing the motor displacement to 466cc. We then replaced the old mechanical points with more reliable electronic magnetic pick up ignition points.

We at Benjie’s Cafe Racer are big fans of anything classic & old school -- not just in appearance, but also in the sound & the visceral feeling you get when you ride one. They may lack the bells & whistles of modern bikes that come with riding aids (that are generally great in regards to safety), but they come roaring out of the gate with soul. We jumped as quickly as we could at the opportunity to breathe new life into a long defunct 1976 Honda CB400F. Most might be deterred by a non-operational donor bike, but we welcomed the extra work with open arms, & we are all pleased with how it turned out.

Photos By; Ben Chan and Dante Dizon

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