Crane Moto’s 295-lb two-stroke giant-killer…
In 1970, Yamaha introduced the R5 350, featuring a steel duplex cradle frame derived from the company’s Grand Prix chassis and a 36-hp two-stroke parallel-twin engine — features that made the 350cc roadster a two-stroke David to the four-stroke Goliaths of the day:
“With the throttle cracked wide open it would run as fast as bikes twice its size. Get the revs up over four grand, and the R5 350 became a different machine — and it produced performance numbers to prove it, consistently running the quarter mile in the low 14 second range. That was on a par with Triumph’s 650cc 4-stroke T120, then a benchmark for performance.” –Motorcycle Classics
What’s more, the R5 like the twisties as much as the drag strip, proving itself on the circuit while remaining surprisingly adept as a daily rider:
“Power delivery, braking ability, ride quality, and handling all worked together on the Yamaha R5 to create a motorcycle that shone not just on highways and backroads but particularly on racetracks where amateur club riders would modify their R5’s for production-class road racing.” –Timeless 2 Wheels
After only three years, the soon-to-be iconic RD350 succeeded the R5, featuring a sixth speed in the transmission, reed-valve cylinders, and a front disc brake.
Enter our new friend Jesse Crane (@crane_moto), a Wisconsin-based motorcycle fanatic and chassis engineer for a major motorcycle manufacturer. Though he’s owned more than 50 motorcycles in his 40 years, Jesse had a very specific objective for this ’71 R5, which he bought as a seized-up basket case in the summer of 2021:
“The goal with the build was to get below 300 pounds with a full fuel tank. I am happy to say this R5 came in at 295 pounds fully fueled up.”
As a chassis engineer, Jesse knows the benefits of the old Colin Chapman: add lightness. For less unsprung weight, Jesse put his truing stand to use for the first time, lacing up a set of lightweight aluminum rims to the lightly polished OEM hubs…trued to within 0.005” runout! Meanwhile, the donor’s missing tank and seat were completed with an RD350 tank and lightweight café tail, and the frame was detabbed.
On the engine side, the R5 is sporting some choice RD upgrades, including an RD350 top end with reed valves, RD350 seven-plate clutch conversion, and RD350 engine side covers. Those slick chambers come courtesy of DG, and Jesse cut, bent, and rewelded the OEM kickstarter to clear the rear-sets and match the shape of the engine case — pretty trick!
The bike looks killer, but it’s the way it rides that’s the best treat. Jesse says there’s nothing quite like hustling a lightweight two-stroke through the mountains:
“In the Fall of 2022 myself and a friend took our Yamaha 2-Strokes down to the Tail of the Dragon in the Smokey Mountains…there is just something about the handling of a sub-300 pound motorcycle.”
Below, we talk to Jesse for the full story on this 295-lb giant-killer!
Yamaha R5 Café Racer: Builder Interview
• Please 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 an automotive/motorcycle fanatic since I can remember and have a history of owning close to 50 motorcycles over the years. At the moment I own 7 motorcycles in varying states of completeness, three of which are mini moto race bikes. My son and I race in the Road America SuperMoto series, and last year we took home a trophy in every class we entered.
In addition to the ’71 R5 I also have a ’75 RD350 that is still currently being built and a ’76 XS360 basketcase future project. The ’75 RD350 was actually the donor bike for a lot of the parts currently on the R5. The RD350 is a ground-up build, so a lot of the 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 a DC TIG welder. I do have a truing stand though, and laced/trued these aluminum wheels myself. I also installed the tires myself with a cheap set of spoons.
• What’s the make, model, and year of the bike?
1971 Yamaha R5.
• Tell us about the build.
I bought this bike in the summer of 2021. The engine was seized, and it was missing the fuel tank and seat. It was a basket case but had a clean and clear Wisconsin title.
I had a donor RD350 tank and custom café tail laying around, so I got to work. An RD350 top end was used along with RD350 pistons. This converted the R5’s piston port engine to a reed valve engine of the RD350’s. DG expansion chambers were added along with Keihin PWK 30mm flat slide carburetors.
The goal with the build was to get below 300 pounds with a full fuel tank. I am happy to say this R5 came in at 295 pounds fully fueled up. In the Fall of 2022 myself and a friend took our Yamaha 2-Strokes down to the Tail of the Dragon in the Smokey Mountains.
• Can you tell us what the bike is like to ride?
With a 52″ wheelbase the R5 is quick to turn in and light on its feet. The aluminum rims help keep the unsprung weight down, letting the suspension function more efficiently. The added hydraulic steering damper keeps high speed stability in check, and the bike is very stable at 85+ mph. The 350cc 2-stroke (now reed valve) engine has the stereotypical 2-stroke power delivery and comes on like a light switch at higher rpms. The light weight helps low rpm power delivery and it doesn’t feel sluggish coming off the line at all. The chassis is definitely what I like the most about the bike though. There is just something about the handling of a sub-300 pound motorcycle. The only remaining weak link of the chassis are the stock brakes, even though I have installed EBC shoes in the front and rear.
• Was there anything done during this build that you are particularly proud of?
My biggest accomplishment with the R5 build was achieving a sub-300 pound wet weight. Being a chassis engineer for a motorcycle company, I understand how important lightweighting is and how much of an impact weight can make on how a bike rides and feels.
This R5 project was also my first try at lacing and truing wheels. I felt over my head when I started the project, but plenty of YouTube videos helped me whenever I felt stuck. I am happy to report that I achieved under 0.006″ lateral and radial runout when truing.
The custom/modified kick starter is also pretty trick. It is an OEM kickstarter that I cut, bent, and welded into its final shape. The new shape of the kickstarter clears the rearsets and matches the shape of the chassis 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 allowing countless garage hours building all the race bikes and cafe racers of the past. I would also like to thank my buddy Cody Zainey, who visited from Indianapolis on a few occasions to help wrench/build this R5 over the past two years.
- Frame de-tabbed
- Custom rearsets and clubman handlebars
- 320mm rear rear shocks
- 6.5 LED headlight with custom fork-mounted headlight brackets
- OEM wheels hubs lightly polished
- Lightweight aluminum rims with new spokes (laced and trued by myself to within 0.005” runout)
- Shinko 712 tires
- Removed original friction type steering damper and fitted a hydraulic damper
- Still using original odometer…only 7437 miles showing
- RD350 top end with reed valves
- 30mm flat slide Keihin carburetors
- RD350 7-plate clutch converstion
- RD350 engine side covers
- Custom kickstart lever to integrate with engine
- DG expansion chambers