The Zirkle Commission

 

Technical Specification

Year 1976

Model R75/6

Displacement 1000cc (61 cu in)

Power 60hp (45kW)

Torque 52 ft⋅lbf (70 N⋅m) @ 5,000 rpm

Transmission 5 Speed

Forks USD Showa

Alternator Silent Hektik 12 V • 400 Watts

Spark Plugs Bosch WR6DC

Fuel Tank 4.76 US gal (22 l; 4 imp gal)

Tires Bridgestone Spitfire 110/90 18 front • 110/90 18 rear

Rims BMW 2.50x18 front • 2.50x18 rear

 

Starting with a BMW R75/6 manufactured in 1976, we repaired and braced the frame along with removing the factory tabs before refinishing in a gloss black powder coat. We fitted our custom subframe with a flush mount brake light and turn signals. The front end consists of a pair of Showa USD forks mounted via a custom triple tree, whilst rear suspension is equipped with a pair of Öhlins shocks with external reservoirs. The exhaust is a full stainless system finished with a pair of quiet-core mufflers from Cone Engineering. The result is a classic cafe racer with modern handling characteristics, excellent brakes and ample power.

The original engine has been rebuilt with displacement increased to 1000cc and a compression ratio of 9.0:1. The heads have been refurbished. A hi-output ignition system powers a dual coil mounted under the gas tank. The Mikuni carburetors have been jetted and tuned to suit. The factory airbox was drilled in the style of a 1977 R100RS. The starter was upgraded to a lightweight hi-torque unit to take less draw the from lithium battery, housed safely under the gas tank in our custom battery tray. The factory charge system was replaced with a modern upgraded unit

A /5 headlight bucket is mounted to a pair of Showa USD forks. Brakes consist of a pair of Brembo radial calipers with a gold finish, operated by an under-tank master cylinder. The headlight has been modified to LED for brighter light and less draw on the battery.


The Speedometer has been rebuilt and customized, including orange pointers. The gauge incorporates a speedo, a tach and indicator lights. Hand controls are new OEM units, modified to suit the custom wiring harness. All original hardware was zinc plated.

 

A custom front hub is laced to an 18” BMW rim anodized black with stainless steel spokes. The rear utilizes the factory rear hub, laced to an 18” factory rim. The gas tank, front fender and headlight bucket finished in Forest Service Green Glasurit paint and wears original brass roundels. Pinstripes are hand painted in the style of the German flag.

 
 
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The Karthik Commission

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The Pine Commission