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Crane Moto’s 295-lb two-stroke giant-killer…
In 1970, Yamaha launched the R5 350, that includes a metal duplex cradle body derived from the corporate’s Grand Prix chassis and a 36-hp two-stroke parallel-twin engine — options that made the 350cc roadster a two-stroke David to the four-stroke Goliaths of the day:
“With the throttle cracked huge open it could run as quick as bikes twice its dimension. Get the revs up over 4 grand, and the R5 350 grew to become a distinct machine — and it produced efficiency numbers to show it, constantly operating the quarter mile within the low 14 second vary. That was on a par with Triumph’s 650cc 4-stroke T120, then a benchmark for efficiency.” –Bike Classics
What’s extra, the R5 just like the twisties as a lot because the drag strip, proving itself on the circuit whereas remaining surprisingly adept as a every day rider:
“Energy supply, braking means, trip high quality, and dealing with all labored collectively on the Yamaha R5 to create a bike that shone not simply on highways and backroads however notably on racetracks the place beginner membership riders would modify their R5’s for production-class highway racing.” –Timeless 2 Wheels
After solely three years, the soon-to-be iconic RD350 succeeded the R5, that includes a sixth velocity within the transmission, reed-valve cylinders, and a entrance disc brake.
Enter our new buddy Jesse Crane (@crane_moto), a Wisconsin-based bike fanatic and chassis engineer for a serious bike producer. Although he’s owned greater than 50 bikes in his 40 years, Jesse had a really particular goal for this ’71 R5, which he purchased as a seized-up basket case in the summertime of 2021:
“The purpose with the construct was to get beneath 300 kilos with a full gasoline tank. I’m pleased to say this R5 got here in at 295 kilos absolutely fueled up.”
As a chassis engineer, Jesse is aware of the advantages of the outdated Colin Chapman: add lightness. For much less unsprung weight, Jesse put his truing stand to make use of for the primary time, lacing up a set of light-weight aluminum rims to the frivolously polished OEM hubs…trued to inside 0.005” runout! In the meantime, the donor’s lacking tank and seat had been accomplished with an RD350 tank and light-weight café tail, and the body was detabbed.
On the engine facet, the R5 is sporting some alternative RD upgrades, together with an RD350 prime finish with reed valves, RD350 seven-plate clutch conversion, and RD350 engine facet covers. These slick chambers come courtesy of DG, and Jesse minimize, bent, and rewelded the OEM kickstarter to clear the rear-sets and match the form of the engine case — fairly trick!
The bike appears killer, however it’s the best way it rides that’s the most effective deal with. Jesse says there’s nothing fairly like hustling a light-weight two-stroke via the mountains:
“Within the Fall of 2022 myself and a buddy took our Yamaha 2-Strokes all the way down to the Tail of the Dragon within the Smokey Mountains…there may be simply one thing in regards to the dealing with of a sub-300 pound bike.”
Beneath, we speak to Jesse for the total story on this 295-lb giant-killer!
Yamaha R5 Café Racer: Builder Interview
• Please inform us a bit about your self, your historical past with bikes, and your workshop.
I’m a 40 12 months outdated mechanical engineer dwelling close to Milwaukee, Wisconsin. I’ve been an automotive/bike fanatic since I can keep in mind and have a historical past of proudly owning near 50 bikes through the years. In the mean time I personal 7 bikes in various states of completeness, three of that are mini moto race bikes. My son and I race within the Street America SuperMoto sequence, and final 12 months we took dwelling a trophy in each class we entered.
Along with the ’71 R5 I even have a ’75 RD350 that’s nonetheless presently being constructed and a ’76 XS360 basketcase future undertaking. The ’75 RD350 was really the donor bike for lots of the elements presently on the R5. The RD350 is a ground-up construct, so lots of the elements had been used to construct this R5. My storage is nothing particular, and all customized elements had been made with an angle grinder, hand drill, and a DC TIG welder. I do have a truing stand although, and laced/trued these aluminum wheels myself. I additionally put in the tires myself with an inexpensive set of spoons.
• What’s the make, mannequin, and 12 months of the bike?
1971 Yamaha R5.
• Inform us in regards to the construct.
I purchased this bike in the summertime of 2021. The engine was seized, and it was lacking the gasoline tank and seat. It was a basket case however had a clear and clear Wisconsin title.
I had a donor RD350 tank and customized café tail laying round, so I started working. An RD350 prime finish was used together with RD350 pistons. This transformed the R5’s piston port engine to a reed valve engine of the RD350’s. DG enlargement chambers had been added together with Keihin PWK 30mm flat slide carburetors.
The purpose with the construct was to get beneath 300 kilos with a full gasoline tank. I’m pleased to say this R5 got here in at 295 kilos absolutely fueled up. Within the Fall of 2022 myself and a buddy took our Yamaha 2-Strokes all the way down to the Tail of the Dragon within the Smokey Mountains.
• Are you able to inform us what the bike is prefer to trip?
With a 52″ wheelbase the R5 is fast to show in and light-weight on its toes. The aluminum rims assist preserve the unsprung weight down, letting the suspension perform extra effectively. The added hydraulic steering damper retains excessive velocity stability in examine, and the bike may be very secure at 85+ mph. The 350cc 2-stroke (now reed valve) engine has the stereotypical 2-stroke energy supply and comes on like a lightweight change at greater rpms. The sunshine weight helps low rpm energy supply and it doesn’t really feel sluggish coming off the road in any respect. The chassis is certainly what I like probably the most in regards to the bike although. There may be simply one thing in regards to the dealing with of a sub-300 pound bike. The one remaining weak hyperlink of the chassis are the inventory brakes, despite the fact that I’ve put in EBC sneakers within the entrance and rear.
• Was there something accomplished throughout this construct that you’re notably pleased with?
My greatest accomplishment with the R5 construct was reaching a sub-300 pound moist weight. Being a chassis engineer for a bike firm, I perceive how vital lightweighting is and the way a lot of an affect weight could make on how a motorcycle rides and feels.
This R5 undertaking was additionally my first strive at lacing and truing wheels. I felt over my head after I began the undertaking, however loads of YouTube movies helped me every time I felt caught. I’m pleased to report that I achieved underneath 0.006″ lateral and radial runout when truing.
The customized/modified kick starter can also be fairly trick. It’s an OEM kickstarter that I minimize, bent, and welded into its closing form. The brand new form of the kickstarter clears the rearsets and matches the form of the chassis higher than what I see on typical R5/RD350 builds.
• Is there anybody you’d prefer to thank?
I wish to thank my implausible spouse, Kayla Crane, for placing up with my bike obsession and permitting numerous storage hours constructing all of the race bikes and cafe racers of the previous. I’d additionally prefer to thank my buddy Cody Zainey, who visited from Indianapolis on a number of events to assist wrench/construct this R5 over the previous two years.
Construct Sheet
Chassis:
- Body de-tabbed
- Customized rearsets and clubman handlebars
- 320mm rear rear shocks
- 6.5 LED headlight with customized fork-mounted headlight brackets
- OEM wheels hubs frivolously polished
- Light-weight aluminum rims with new spokes (laced and trued on my own to inside 0.005” runout)
- Shinko 712 tires
- Eliminated unique friction kind steering damper and fitted a hydraulic damper
- Nonetheless utilizing unique odometer…solely 7437 miles exhibiting
Powertrain:
- RD350 prime finish with reed valves
- 30mm flat slide Keihin carburetors
- RD350 7-plate clutch converstion
- RD350 engine facet covers
- Customized kickstart lever to combine with engine
- DG enlargement chambers
Comply with the Builder
Picture Album: Flikr
Instagram: @crane_moto
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