Record-setting 1955 BMW R50 Sidecar Rig at Bonneville: The Great White Dyno

Reader Contribution by Kevin Brooks
1 / 4
2 / 4
3 / 4
4 / 4

The Brooks Motor Works crew with their record-setting 1955 BMW R50 sidecar rig at Bonneville Salt Flats, 2011, where they set a new record of 94.333mph in the Vintage Sidecar Gas 500cc class.

At Brooks Motor Works our motto is, “The Past is not what it used to be.” But what do we mean by that?

The perspective of history can give us a different perception of events passed. Our beloved BMW motorcycles are an appropriate example. Once shiny new cherished possessions, they became with the passage of years and miles just another old motorcycle. More years pass and they become ‘interesting old bikes’ but slow and outdated, morphing in more recent times into ‘Vintage and collectible classics’ and once again becoming cherished possessions.

I refurbish BMW’s, repair BMW’s, and restore them to their former glory. But why stop there? They can be made much better than new in so many ways and still retain the exact same appearance externally. A vintage BMW that accelerates harder, stops better, has better road holding, 12-volt electronic digitally controlled ignition and 150-watt alternator to power real lights AND an electric vest to keep you warm on those brisk fall and spring rides! And the only external indicator that all these attributes are hidden inside waiting for you is the 12-volt battery. What’s NOT to like?! So what has this got to do with racing at the Bonneville Salt Flats? A Lot!

We use our Bonneville excursions to test a host of improvements to all aspects of our machines that they can be shown to be reliable and rideable. The Bonneville Salt Flat is known as the Great White Dyno; and serves well as our engine proving grounds and for the bikes in general, as well. And in August 2011, they did quite well indeed!

We dove right in with our record holding sidecar rig running in the Vintage Sidecar Gas (SC-VG 500cc) Class. This year we added a fabulous dustbin fairing fabricated by Dean Paulus and painted by Bob Clark of Puget Sound Autobody. We are back this year with different carburetion and a new exhaust system to boost upper end breathing.

A quick run to check the jetting and we are back in line for a speed run. The lines are blissfully short this year and the motor is still warm when we hit the salt with a Speed Run of 94.528mph! We had the sidecar rig into Impound within six hours of our arrival!

Kevin Brooks gets a push start before starting his run.

The next morning we are out bright and early, too amped up to sleep and excited about the potential the sidecar had demonstrated the previous afternoon. Record return runs are all conducted first thing on the morning following the qualifying run. And we are well up in the line and waiting impatiently for our shot at the record. When we are two contestants back we start the motor to warm her up. She starts a little reluctantly in the cool morning air, but once spun up, sounds positively awesome! When our turn comes we launch with a little push from Bruce and Barb, and slipping the clutch out to 6,000rpm she finally hooks up and we are flying toward 9,000rpm. After making the shift to second I get a little sideways, but soon have her straightened back up and headed for the timing lights. The shift to third is crisp as always and we tuck in behind the windscreen to minimize drag. I have the throttle to the stop now and watch the tach climb quickly to 8,000 then 8,100rpm. The two-mile marker flashes past; I am into the timing zone; then the quarter mile markers have all gone by and the three-mile marker and the end of the lights; almost before I am settled into the ride, all is done.

Kevin making his run at Bonneville.

I sit up and slow quickly, making the turn toward the recovery road. It feels really good, and I know the record is in the bag. We get the timing slip from the timing shack and do a quick computation. We have blasted thru the old record by over 7mph to set a new SC-VG 500cc record at 94.333mph! With a VINTAGE 1955 R50 BMW!

The past is definitely NOT what it used to be! (The factory claimed 87mph top speed for a solo R50 back in the day.) But we are not done with the Flying Egg yet. I believe that a little additional development will nudge us up over the 100mph mark!

Learn more about Kevin Brooks and Brooks Motor Works at

Motorcycle Classics Magazine
Motorcycle Classics Magazine
Motorcycle Classics Magazine Featuring the most brilliant, unusual and popular motorcycles ever made!