BMW Motorcycles

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BMW R90/6 1975

Engine
Configuration Horizontally opposed air-cooled twin, pushrod operated valves, 2 per cylinder Lubrication Gear driven pump
Bore & Stroke 90 x 70.6 mm Ignition Kettering
Capacity 898 cc Charging system 12v  280w alternator
Compression Ratio 9.0 : 1 Starter Electric starter 0.5 hp
Maximum Power 60 DIN hp at 6500 rpm Transmission Gear driven primary drive, 3.09:1 bevel final drive (optional 3.20:1)
Maximum Torque 52.7 ft/lb (7.3 mkg) at 5500 rpm Gearbox 1st 4.40: 1 
2nd 2.86:1 
3rd 2.07:1 
4th 1.67:1 
5th 1.50:1
Fuel Bing CV type V64, 32mm 
Micronic air filter
Clutch Cable operated single plate dry clutch
Chassis
Frame Steel main and bolt-on subframe Wheels 1.85 x 19 front 
2.15 x 18 rear 
Spoked alloy rims
Dimensions  Weight: 210 kg wet 
Wheelbase: 1465 mm 
Length: 2180 mm 
Seat Height: 810 mm
Tyres 3.25 H 19 front 
4.00 H 18 rear 
Front Suspension Hydraulic telescopic  Brakes Front: 260 mm stainless undrilled disc with floating single piston caliper 
Rear: 200 x 30 mm drum
Rear suspension Boge dual dampers, springs adjustable for pre-load  Fuel Capacity 18 Litres (4 Imperial gallons) 
including 2.5l reserve 
Optional 22l tank available

Performance
Top Speed
Upright: 178 kph (110 mph) 
Prone: 188 kph (116 mph)
Fuel Economy
55.7 mpg (Imp.) at 68 mph

Acceleration
Standing 400m: 13.7 sec 
Standing 1000m: 26.1 sec

BMW-1974-R90-6-1.jpg
BMW R90/6
The 1975 BMW R90/6
Castrol 6 Hour winner