The BMW R 65, a quintessential middleweight motorcycle, boasts a 650cc engine that distills the essence of traditional BMW engineering. While its 82mm-bore barrels are shorter than those of its larger brethren, the heads are comparable, resulting in a more compact powerplant. This narrower engine design eliminates the traditional concern of dragging cylinder head covers on the pavement.
The R 65’s engine features a single camshaft, situated below the crankshaft and driven by a single-row roller chain, which transfers motion to the cylinder head-mounted, needle-bearing-suspended rockers via four steel-capped aluminum pushrods. BMW’s innovative design of new valve lifters, where the pushrods sit inside the hollow lifters, practically beside the cam lobes, is a testament to the company’s commitment to precision engineering.
The R 65’s power delivery is smooth and refined, courtesy of a lightweight, single-plate dry clutch and a spring-loaded cush drive assembly. The modular gearbox, identical to that found in 1979 BMWs, provides seamless shifting, while a second cush drive mechanism in the final drive shaft ensures a silky-smooth transmission experience. With its 3.44:1 ratio, the R 65 is perfectly suited for a mix of urban commuting and spirited country roads, making it an ideal choice for riders seeking a balance of comfort and performance.
Key Specifications
Engine Type
Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder
Engine Capacity
39.6 cubic inches / 649.6 cc
Max Power
45 hp / 32.8 kw @ 7250 rpm
Max Torque
45 Nm / 4.6 kgf-m / 33.2 lb-ft @ 6000 rpm
Fuel Tank Capacity
5.8 US gallons / 22.0 L
Weight (Wet/Kerb)
463 lbs / 210 kg
*n/a – information not provided by manufacturer
All Specifications
Make & Model
Model
BMW R 65
Year
1978-79
Engine
Engine Type
Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder
Displacement
39.6 cubic inches / 649.6 cc
Bore x Stroke
82 x 61.5 mm
Compression Ratio
9.2:1
Max Horsepower
45 hp / 32.8 kw @ 7250 rpm
Max Torque
45 Nm / 4.6 kgf-m / 33.2 lb-ft @ 6000 rpm
Engine Management System
2 x Bing constant depression carburetors
Cooling System
Air cooled
Performance
Top Speed
n/a
*n/a – information not provided by manufacturer
Transmission
Gearbox
5 Speed
Final Drive
Shaft
Electrical & Electronics System
Starter
Electric
Chassis & Suspension
Front Suspension
Telescopic hydraulic forks
Front Suspension Travel
6.9 inches / 175 mm
Rear Suspension
Long swinging arm with adjustable strut
Rear Suspension Travel
4.3 inches / 110 mm
Wheels & Brakes
Front Tire Size
3.25 -18
Rear Tire Size
4.00 -18
Front Brakes
Single disc
Rear Brakes
Drum
Dimension & Weights
Fuel Tank Capacity
5.8 US gallons / 22.0 L
Wet (kerb/curb) Weight
463 lbs / 210 kg
Features
82mm-bore engine barrels
650cc engine capacity
32mm CV carburetors
Single camshaft
Roller chain driven camshaft
Aluminum pushrods with steel caps
Needle-bearing-suspended rockers
New valve lifters design
Hollow lifters with pushrods inside
Hydraulic tensioner for cam chain
Lightweight single-plate dry clutch
Spring-amp cush drive assembly
Modular R65 gearbox
3.44:1 rear axle ratio
18-inch front and rear wheels
Metzeler high-mileage tires
Drum brake at rear
Single-leading-shoe front brake
Fade-resistant drum brake
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*We strive to provide the most comprehensive and accurate specifications possible. However, certain details may not be available if the manufacturer did not disclose them or if the information is no longer publicly accessible. If you find any discrepancy with any data on this site, please feel free to let us know at contact@throttlecraze.com
