Lightweight giant slayer: Yamaha R5 350 Cafe Racer (2023)

Crane Moto 2-Stroke Giant Killer £295…

In 1970, Yamaha introduced the R5 350 with a steel stand frame two-stroke derived from the company's Grand Prix chassis and a 36 hp parallel twin engine - features that made the 350cc roadster the two-stroke David to the four-stroke Goliath of the day :

“With the throttle wide open, he would go as fast as bikes twice his size. Rev it above 4,000 and the R5 350 became a different machine - and it proved it with performance, consistently completing the quarter mile in the low 14 seconds range. This was on par with Triumph's 650cc 4-stroke T120, which was the benchmark of performance at the time." –Motorcycle classic

What's more, the R5 loves the corners as much as the drag strip, proving itself on the track while remaining surprisingly proficient as a day-to-day driver:

“Power delivery, braking ability, ride quality and handling all worked together on the Yamaha R5 to create a bike that shone not only on highways and back roads, but most notably on the racetracks where amateur club riders modified their R5s for production grade road racing . -Timeless 2 wheels

After only three years, it will soon become an iconRD350it replaced the R5 with a six-speed transmission, reed cylinders and a front disc brake.

Introduce our new friend Jesse Crane (@crane_moto), a motorcycle fanatic from Wisconsin and a chassis engineer for a major motorcycle manufacturer. Although he has had over 50 bikes in his 40 years, Jesse had a very specific goal for this '71 R5 he bought as a scrap bin in the summer of 2021:

“The goal of this build was to go below 300 pounds with a full tank of fuel. I'm happy to say this R5 weighed 295 pounds with full fuel."

As a chassis engineer, Jesse knows the virtues of old Colin Chapman:add lightness. For less unsprung mass, Jesse first fitted his leveling stand by bolting a set of lightweight aluminum rims to lightly polished OEM hubs…measured to within 0.005” of deviation! In the meantime, the missing tank and donor seat have been supplemented with an RD350 tank and cafe light tail, and the frame has been removed.

As for the engine, the R5 has a selection of RD upgrades, including an RD350 overhead reed valve, an RD350 seven-plate clutch conversion and RD350 side engine covers. These smooth chambers come courtesy of DG, and Jesse cut, bent and re-welded the OEM kickstarter to clean the rears and match the shape of the crankcase - nice trick!

The bike looks killer, but the best treat is the way it rides. Jesse says there is nothing better than racing a lightweight two-stroke through the mountains:

“In the fall of 2022, a friend and I rode our Yamaha two-strokes up the tail of the dragon in the Smokey Mountains…there is something about riding a bike under 300 pounds.”

We chat with Jess below for the full story of this 295-pound giant killer!

Yamaha R5 Café Racer: Interview with the builder

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

I am a 40-year-old mechanical engineer living near Milwaukee, Wisconsin. I have been a car/motorcycle fanatic for as long as I can remember and have owned close to 50 motorcycles over the years. Currently, I have 7 motorcycles at various stages of advancement, three of which are mini racing motos. My son and I ride in the Road America SuperMoto series and last year we took home a trophy in every class we competed in.

In addition to the '71 R5, I still have the 1975 RD350 in production and the future 1976 XS360 cage design. The 350 RD 350 was actually the donor bike for many of the parts currently available on the R5. The RD350 was built from the ground up, so a lot of parts were used to build this R5. My garage is nothing special and all custom parts were made with an angle grinder, hand drill and DC TIG welder. However, I do have a leveling pad and installed/repaired these aluminum rims myself. I also mounted the tires myself with a cheap set of spoons.

• What is the make, model and year of the bike?

Yamaha R5 from 1971.

• Tell us about creating.

I bought the bike in the summer of 2021. The engine is seized, the tank and the saddle are missing. It was a tough deal, but he had a clean and clear title in Wisconsin.

I had a donor RD350 tank and a custom cafe tail, so I got to work. An RD350 shank is used along with RD350 pistons. This was converted by the R5 piston engine into a reed valve engine for the RD350. DG expansion chambers were added along with Keihin PWK 30mm flat carburettors.

The goal of the build was to go below 300 pounds with a full tank of fuel. I'm happy to say that this R5 weighed 295 pounds with full fuel. In the fall of 2022, a friend and I took our 2-Stroke Yamaha to Tail of the Dragon in the Smokey Mountains.

• Can you tell us what it's like to ride a bike?

With a 52-inch wheelbase, the R5 turns quickly and is lightweight. Aluminum rims help reduce unsprung weight, making the suspension work more efficiently. The added hydraulic steering damper controls high speed stability and the bike is very stable at over 85mph. The 350cc two-stroke engine (now with a reed valve) has the stereotypical two-stroke power delivery and fires up like a light switch at higher rpm. The light weight helps deliver low-rpm power and doesn't feel sluggish at all when it comes off the belt. However, the chassis is by far what I like most about the bike. There is something about handling a bike under 300 pounds. The only remaining weak link in the chassis is the stock brakes, although I fitted EBC boots front and rear.

• Is there anything about this construction that you are particularly proud of?

My greatest achievement with the R5 was getting it under 300 pounds wet. Being a chassis engineer for a motorcycle company, I understand how important light weight is and how heavy weight can affect the ride and feel of a motorcycle.

This R5 project was also my first attempt at wheel binding and alignment. I was busy when I started the project, but many YouTube videos helped me when I got stuck. I am pleased to report that I achieved less than 0.006 inch of lateral and radial runout during straightening.

A custom/modified starter is also a nice trick. This is an OEM kickstarter that I cut, bent and welded to its final shape. The new kickstarter shape removes the resets and matches the chassis shape better than what I see on typical R5/RD350 builds.

• Is there anyone you'd like to thank?

I would like to thank my fantastic wife, Kayla Crane, for putting up with my motorcycle obsession and spending countless hours in the garage building all the race bikes and cafe racers of yesteryear. I would also like to thank my friend Cody Zainey who has visited me several times from Indianapolis to help build this R5 over the last two years.

construction sheet


  • Frame removed
  • Clubman Custom Resets and Steering Wheels
  • 320mm rear shock absorbers
  • 6.5 LED headlight with custom fork mounted headlight brackets
  • OEM hubs lightly polished
  • Alloy rims with new spokes (connected and corrected 0.005" deviation myself)
  • Gume Shinko 712
  • The original steering friction damper was removed and a hydraulic damper was installed
  • Still using the original odometer… it only shows 7437 miles

Drive system:

  • RD350 top end with reed valves
  • Keihin 30mm straight carburettors
  • Modification of the RD350 clutch with 7 discs
  • RD350 engine side covers
  • Custom starter handle for engine integration
  • DG expansion chambers

Follow the builder

photo from the album:Flickr

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