’40s Inspired: Honda CB350K by Black Bean Motorcycles

Honda CB350K Custom

Introduced in 1968, the Honda CB350K Twin was not a technological marvel like the soon-to-arrive CB750 Four, but the 36-bhp parallel-twin was the perfect bike for the time — punchy, reliable, affordable, and fun. Said Cycle World‘s Kevin Cameron of the 350 twin in a 2017 retrospective:

“Fifty years ago the loudmouths were all in bars, there were no S1000RRs or Panigales, and young people were employed, not carrying a hundred grand in college debt. Just about anybody could walk into a bike shop and roll out on gleaming factory-fresh new wheels for way under a grand. Sit someone behind you and set off for the Cape or the cabin at the lake. Living large for little! Honda’s CB350K parallel-twin was just the bike for this, so in its five years on the market 300,000 were sold.”

CB350K Custom

Decades later, an army of CB350s would be rolled out of sheds and barns and dusty garage corners, rebuilt, modified, and turned into mainstays of the vintage racing community.

“The emotional satisfaction of building and developing these bikes was that they responded so well to modern tuning ideas—making everyone into a ‘wizard of tune.’ A lot of really good affordable racing took place.” —Cycle World

Honda CB350K Custom

It still does, in fact. Walk through the paddock of any AHRMA or VRRA race, and CB350 twins might be the most common bikes you see. In some ways, they seem a throwback to simpler, friendlier times, when you could buy, build, and race on a (somewhat) reasonable budget. The CB350K has also been rediscovered by custom builders the world over, who’ve found the small twin to be a perfect platform for customization.

Enter Axel, the 26 year-old owner of Germany’s Black Bean Motorcycles. Together with his father — “the senior” — Axel services, repairs, and rebuilds engines on pre-1985 motorcycles — no fuel injection systems or ECUs.

“Most of the time I’m a one man show. Sometimes the senior looks around and helps me doing tricky stuff or gives me ‘old man tips & tricks.'”

Honda CB350K Custom

With a master’s degree in automotive engineering, Axel also builds custom motorcycles, some of which have already graced the pages of some of the world’s most prestigious publications. The bike you see here is a 1974 CB350K that entered the shop for a frame-off restoration and engine overhaul. However, as time went on, the client decided he wanted something custom, in a style that hadn’t really been seen before — not your conventional cafe racer, tracker, scrambler, etc. The old man had the answer:

“One day the senior came into the shop and had the idea to steer the project towards the 1940s. Something completely different with fenders pulled far down and curved shapes.”

Honda CB350K Custom

The handlebars were inspired by the boardtracker era, and Axel managed to blend a wealth of other styles very harmoniously into the build. We especially like the hand-bent copper oil lines, and the fact that Axel and his father rebuilt the engine with a focus on better oil supply to the bearings — ensuring this CB350K is ready to be ridden for years to come.

The tail section was formed with a hammer and English wheel out of 3mm aluminum, and the exhaust is a fully custom stainless steel system built in-house and complies with strict German TÜV rules. It’s actually fairly quiet, says Axel, which befits the style and riding experience of the completed build:

“It’s amazingly comfortable, with the right setting on the rear springs and the right oil in the front damper, the motorcycle glides smoothly. The completely covered front wheel gives you the feeling that you are cutting through the wind.”

Honda CB350K Custom

All in all, this is one gorgeous CB350 like we haven’t seen before, and a testament to how far Axel’s skills have progress since he started Black Bean Motorcycles just four years ago.

“I have finally reached a point where I can do almost everything in my own shop. Saddlers and varnishers still have their jobs. But the rest is all done in-house. That makes me proud.”

Below, we talk to Axel for the full details on the build, and showcase some more lovely shots from photographers WE! shoot it.

Honda CB350 Custom: Builder Interview

Honda CB350K Custom

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

Hi my name is Axel, I’m 26 years old and I’m the owner of Black Bean Motorcycles. I’ve been building and customizing for about four years under the Black Bean Motorcycles label — for two years I’ve been going full time. Most of the time I’m a one man show. Sometimes the senior looks around and helps me doing tricky stuff or gives me “old man tips & tricks.”

Most of the time we overhaul engines up until 1985, all with carburetors. You won’t find any injection systems or control units with us. We try to carry out almost all machining operations on engines etc. in-house. Motorcycles played an important role for me very early on. Among other things, because my father was a passionate collector of Italian vintage motorcycles. The customizing then came all by itself. Initially based on the try and error principle.

After completing an apprenticeship at Mercedes Classic and successfully completing a master’s degree in automotive engineering, it was only natural to open my own shop.

CB350K Custom

• What’s the make, model, and year of the bike?

It’s a Honda CB350K Twin from 1974.

• Why was this bike built?

We built the bike for a customer.

CB350K Custom

• What was the design concept and what influenced the build?

At first, the concept was not really fixed. The order was initially a frame-off restoration including a complete engine overhaul. Because that is actually our area of expertise, engine construction and carburetor repairs.

Only with the passage of time and the increasing progress of restoration did it become clear that we wanted to build something optically that hadn’t existed before. Not a normal Cafe Racer, Scrambler, Flattracker or similar.

CB350K Custom

One day the senior came into the shop and had the idea to steer the project towards the 1940s. Something completely different with fenders pulled far down and curved shapes. The idea of the handlebar was based on the style of the “BoardTracker” at the time. All other shapes and lines are a mix of different styles.

Honda CB350K Custom

Everything else should be as clean as possible. The engine should stand out in its raw form. With many details, such as the hand-bent copper oil lines and some CNC milled components.

Much has been rebuilt inside the engine. Our primary focus was on a better oil supply to the bearings, as that was often the problem with the Cb350K model. The camshaft needle bearings and all other bearings including the crankshaft were replaced. The compression was increased, the cylinder head was completely machined and optimized. And so much more!

CB350K Custom

The tail was formed by us from 3mm aluminum with the help of a hammer and English wheel. The rear frame was cut off and completely modified. The front end is adorned with a completely overhauled suspension fork. The braking system has been completely overhauled and optimized. Furthermore, the swing arm was extended and a Tarrozi footrest system was installed.

Here we had to give some thought to the braking mechanism. Since we don’t like the usual construction with the help of a long rod directly on the rear brake. It does not work well. So we came up with a redirection ourselves and designed and manufactured it.

Honda CB350K Custom

The entire exhaust system was manufactured by us. It is made of stainless steel and complies with the German TÜV rules. Thus the motorcycle is 100% street legal.

• Does the bike have a nickname?

No, we haven’t given the bike a name yet. The owner and rider need to decide this for themselves.

 CB350K

• Can you tell us what it’s like to ride this bike?

It’s amazingly comfortable, with the right setting on the rear springs and the right oil in the front damper, the motorcycle glides smoothly. The completely covered front wheel gives you the feeling that you are cutting through the wind.

Despite the relatively compact exhaust system, the motorcycle is also quite quiet. Which, however, fits the general picture perfectly.

CB350K Custom

• Was there anything done during this build that you are particularly proud of?

Hmmm that’s a tough question. Actually there is not one component or something. It’s more the whole construct. I have finally reached a point where I can do almost everything in my own shop. Saddlers and varnishers still have their jobs. But the rest is all done in-house. That makes me proud. Four years ago I had relatively few tools and options, and I’m now ready to be able to do everything myself. Everyone knows that if you want to do something right, do it yourself. So I know that it is 100% precise work.

Honda CB350K Custom

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2 Comments

  1. Nice bike! Seems to me the front fender is mounted backwards. I’ve looked at a lot of bikes from the 40’s, the rear part of the front fender should be longer about equal with the front of the fender not shorter.

  2. Amazing motorcycle! but crap photos, next time get someone to shoot it that knows bikes.

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