Café Mod: Yamaha RD350B by Marthijn Kip

Yamaha RD350B Cafe Racer

A 70s Café Smoker from the Netherlands… 

For many of us, at some point in our lives, motorcycles have been more than just a hobby,  adventure, or even a profession — they’ve been a lifeline. The wind and throttle seem to have their own healing powers, while tackling a full-on build can be immensely grounding, giving us purpose and direction during hard times.

Yamaha RD350 Cafe Racer

So it was for our new friend Marthijn Kip of the Netherlands, a mechanical engineer who pulled off his first project at the age of just 14: a moped-engined pocket bike with 4.5″ wheels!

“The frame and seat-tank combo we (Dad and myself) built from scratch. I have built several bikes since then, varying from race-ready MX50 (moped cross) bikes to a supermoto.”

Yamaha RD350 Cafe Racer

Marthijn comes from robust motorcycle stock. His father is a 50cc grand prix racer who builds his bikes from scratch during the harsh Dutch winters, then races in the summer. So when a family tragedy made it hard to remain positive, Marthijn found his way back to motorcycles, giving himself a project to occupy his mind:

“I wanted to build at ‘true’ 1970’s café racer. Built with ample budget and means. As if I got it from my dad and kept it those 50-odd years.”

Yamaha RD350 Cafe Racer

For the donor, he chose one of our favorite two-stroke street bikes, a Yamaha RD350 — specifically, a 1975 Yamaha RD350B:

“I fell in love with the RD and I just wanted to sharpen the lines already there. Almost all the parts used in the build came from either swap meets or the breakers yard. And are pre-1985.”

Yamaha RD350 Cafe Racer

We love that Marthijn kept the modifications as period-correct as possible, and then there’s his wealth of fabrication work — fuel filler cap, gauge cluster, rear sets, mufflers, side panels, and more — all done with the most basic shop tools:

“I’m really proud of the parts I made from scratch. I have a workshop with limited tools, so most is done by drill press, hacksaw, and perseverance — this is almost meditation, and builds karakter.”

Yamaha RD350 Cafe Racer

The result is a leaner, sharper, more powerful RD capable of surprising some of the modern machinery on the Dutch roads:

“It’s a blast to ride, it’s nice and flick-able in the corners. It brakes on a dime to a full stop. With the mild tuning already done it can keep up with most bikes — it’s fun to tease the newer class 600s with.”

Yamaha RD350 Cafe Racer

Below, we talk to Marthijn for the full story on this gorgeous green RD350 café racer.

Yamaha RD350B Café Racer: Builder Interview

Yamaha RD350 Cafe Racer

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

I’m Marthijn, 41 years of age, married. I live in the Netherlands. I started riding motorcycles at age 8 on a Honda XR75. At the age of 14, I built my first (project) bike, a pocket-bike on 4.5” wheels with a moped engine. The frame and seat-tank combo we (Dad and myself) built from scratch. I have built several bikes since then, varying from race-ready MX50 (moped cross) bikes to a supermoto.

Currently I work as an mechanical engineer in the field of mechatronics, and I solely build bikes as a hobby in my spare time.

Yamaha RD350 Cafe Racer

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

This build is based on a Yamaha RD350B from 1975.

Yamaha RD350 Cafe Racer

• Why was this bike built?

I build this bike to occupy my mind during a time when I struggled to keep positive thoughts. It’s my personal bike. And I wanted to keep my “heritage” going, as I learned a lot from my dad growing up with bikes — I tried to show my skills.

Yamaha RD350 Cafe Racer

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

I wanted to build at “true” 1970’s café racer. Built with ample budget and means. As if I got it from my dad and kept it those 50-odd years. Dad is still with us, and is a self-made 50cc grand prix racer who practically builds his bikes completely from scratch during the winter, to compete in the summer.

I also fell in love with the RD and I just wanted to sharpen the lines already there. Almost all the parts used in the build came from either swap meets or the breakers yard. And are pre-1985.

Yamaha RD350 Cafe Racer

• What custom work was done to the bike?

– Repainted metallic green
– Re-upholstered Giuliari seat
– Swapped rear suspension for fully adjustable Koni’s (proud to be Dutch)
– Fitted a custom ECU-controlled ignition
– Fitted clip-ons
– Fitted lamp brackets to lower the original headlight
– Made my own gauge cluster
– Made glassfiber side panels with air scoop
– Fitted expansion cambers
– Made folding rearsets with a TZ-style cable operated rear brake
– Fitted a Kreidler moped rear light converted to LED
– Fitted a Rickman-style front fender with an oversized mounting bracket to look like a stiffener
– Fitted a 320mm front brake disc with a Brembo P8 caliper and a 11mm Brembo master cylinder.
– Fitted a large K&N cone air filter (from a Rover V8) to the Y-boot
– Fitted a YZ250 fuel tap to keep the fuel guzzling
– Fitted Domino grips with a ridge on the throttle
– Polished all aluminium parts
– Fitted oval blinkers

• Does the bike have a nickname?

This bike remains un-named. I know its intention, which doesn’t need to be named. The bike and build process did their job and provided a (healthy) distraction.

Yamaha RD350 Cafe Racer

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

It’s a blast to ride, it’s nice and flick-able in the corners. It brakes on a dime to a full stop. With the mild tuning already done it can keep up with most bikes — it’s fun to tease the newer class 600s with.

At traffic lights or at any stop it’s a great conversation starter. The green makes it standout; the exhaust and intake make its presence heard; it’s hard to miss but still it appeals to most people. I guess the blue license plate helps (which indicates that it’s older than 50 years).

Yamaha RD350 Cafe Racer

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

I’m really proud of the parts I made from scratch. I have a workshop with limited tools, so most is done by drill press, hacksaw, and perseverance — this is almost meditation, and builds karakter.

• Fuel filler cap, made from billet to look TZ-like, without the use of an MILL!
• Gauge casings and cluster. I pressed the gauge casings from aluminum plate and pipe, which was my first time forcing metal in to a shape with a hydraulic press.
• The aluminium mufflers with end caps.
• Rear sets and cable operated rear brake.
• Glasfiber side panels with functional “ram-air” scoop for the air filter.
• Making the pickup for the electronic ignition.
• Shortening the shock absorbers.
• Used beer-bottle caps to plug the holes in the top yoke.

Detailed description of the build: cafemodrd350.blogspot.com

Leave a Comment

Your email address will not be published. Required fields are marked *

*