90 Years of BMW Motorrad - Max Friz

The aircraft engine manufacturer BMW unveiled its first motorcycle in late 1923, and it was a passionate aircraft engine designer - Max Friz - who was behind its creation. Forever credited as the father of the first BMW bike - the R 32 - Friz's story leading up to this groundbreaking motorcycle is as interesting as it is varied.

Born nearly 130 years ago on 1 October 1883 in Urach, Max Friz started his apprenticeship with the Kuhn steam engine company in Cannstatt at the age of 15 - an incredibly exciting time to be involved with engineering development of any kind. From 1902 to 1904 he attended the Royal Building Trade School in Stuttgart-Esslingen before moving in 1906 to work in the design office of the Daimler company.

There, he started to make a name for himself in motorsport, where he made a major contribution to the design of the racing engine for the 1914 Mercedes Grand Prix car that won the French Grand Prix of the same year. However, it is in aviation where Friz' passion truly could be found. After all, he would have been an impressionable 20-year-old when the first powered flight by the Wright brothers made headlines around the world in 1903 - and no doubt inspired countless young men to become engineers.

Although the aviation industry had by many scarcely been considered worthy of attention in its infancy, the outbreak of war in 1914 changed everything and offered great opportunities for companies such as Rapp Motorenwerke - a predecessor of BMW.

At the end of 1916, having become frustrated with his suggestions for engine development being ignored by the chief engineer at the Daimler engine company, Friz applied for a position with Rapp.

At this time, war was being waged in the air for the first time, and the aerial battles demanded continuous improvements in aircraft and aero engines. A significant challenge for the engineers was the constantly increasing average altitude at which the fighting was taking place. Basically, the higher you were able to fly, the better the strategic advantage, as long as your engine didn't lose too much power, or worse, stall in the decreased atmospheric pressure.

At Daimler, Friz had tried in vain to develop an oversized high compression engine that would not lose as much power at altitude as other engines, but it wasn't until he moved to Rapp Motorenwerke in Munich in 1917 that he was able to put his own idea for a high altitude engine into practice.

In spring 1917, a commission from the Reichswehr were inspecting the Rapp engine plant to decide which engines - Daimler or Benz - would be produced under licence at the Rapp engine plant. General Manager Franz Josef Popp seized the opportunity to present Friz new concept to the commission of experts - even though it only existed in his design drawings, with no prototype to show.

However, the commission were suitably impressed with the potential of this high altitude aero engine with its innovative carburettor and many other technical details. The Reichswehr placed an order for 600 units - even before a single working prototype had been produced - turning Rapp Motorenwerke into an essential contributor to the war effort virtually overnight. Orders flowed in from the military and by the end of the war, more than 3,100 IIIa aero engines had been commissioned - and Rapp had become BMW.

Friz' BMW IIIa aero engine was in fact far superior to any other German aero engine of that period and no doubt saved the Rapp company of the time, which would almost certainly have disappeared without the effort and talent of this excellent designer.

But after the conflict ended in November 1918, the impact on the entire German aircraft industry was huge - especially for BMW, which had been building nothing else but Friz's IIIa engine in 1918. The Treaty of Versailles then forbade BMW to build aero engines at all, but before the ban came into effect, Friz had already designed the successor to the IIIa - known simply as the BMW IV.

This Treaty would in fact ban the production of aircraft in Germany for many years, but just before the ban came into effect, a test pilot, Franz Zeno Diemer, took off in a DFW 37/III from Oberwiesenfeld airfield next to the BMW plant. His plane was powered by BMW IV six-cylinder engines and reaches the previously unattained altitude of 9,760 metres during an 87-minute flight. This world record is to be the first of many for BMW, although post-WWI Germany is not allowed to join the Fédération Aéronautique Internationale, so the record is not officially recognised.

Not only had the Allies banned Germany from building aircraft and aero engines, they had in addition demanded that all aviation assets manufactured up to that point be handed over or destroyed. As a consequence, BMW Managing Director Franz-Josef Popp began looking for alternatives to keep the employees working, so tasked Friz and his design department with making new products to sell to the peacetime market.

Engines were designed for boats, cars, trucks and motorcycles. One of these engines was the M2B15 'boxer' that was developed by Martin Stolle and supplied to quite a number of other motorcycle manufacturers to power their machines. However, the management felt that BMW could do better than just supplying the engines and should build its own complete motorcycle.

Friz was asked to come up with a suitable package. The result was the R 32 of 1923 (see separate story) and the rest, as they say, is history.

90 Years of BMW Motorrad - The R 32

Developed on the drawing board in 1922, the first BMW motorcycle - known as the R 32 - caused a sensation when it was unveiled at the Berlin Exhibition in 1923. Beautiful to look at and economical to run, the R 32 was the cornerstone upon which BMW built a history of motorcycling excellence…

In the years following World War I, having been forbidden to build aircraft engines by the Treaty of Versailles, the BMW company had been forced to look at other options for engineering production. Needing to survive and diversify, it had built four-cylinder series engines for lorries and boats, but it was the development of the two-cylinder M 2 B 15 engine that it supplied to several motorcycle manufacturers, that shaped the immediate future of the company.

BMW's General Manager Franz-Josef Popp and his engineering colleagues had decided to make a big move, realising that the best way to support BMW's good reputation as an engine manufacturer was for the company to build its own modern motorcycle. The engineer given the task of building BMW's first motorcycle was Max Friz (see separate story), who had made a great name for himself as an outstanding engineer even before World War I.

Taking up the challenge, Friz had a large drawing-board and a stove installed in the guest room of his house opposite the plant premises, completing his concept in its full, original size in December 1922. His idea was to fit the existing engine in a position crosswise to the direction of travel, meaning that the crankshaft would run lengthwise through the motorcycle. The gearbox, with its shafts also in lengthwise arrangement, is driven directly by a friction clutch, the two housing shells are bolted on to one another. A drive shaft, finally, provides the link between the gearbox and the rear wheel.

There are already several horizontally-opposed engines in the market, such as the ABC motorcycle built in Great Britain that featured an engine in transverse arrangement, and both the FN motorcycles built in Belgium and Pierce motorcycles from the USA came with a drive shaft. However, Max Friz was the first engineer to combine all these features in creating the perfect harmony of the BMW R 32.

BMW proudly presented its first motorcycle on 28 September 1923 at the German Motor Show in the Kaiserdamm Fair Halls in Berlin. This pitched the Munich Company against no less than 132 other motorcycle manufacturers in Germany alone - but at the same time BMW is warmly lauded for the unique technical concept as well as the highly attractive, trendsetting looks of the new machine.

The BMW R 32 entered series production before the end of the year and the first motorcycles were delivered to customers at a price of 2,200 reichsmarks, following the end of galloping inflation in Germany. Although this made the R 32 one of the most expensive motorcycles in the market, sales developed very well indeed.

BMW's new motorcycle stood out from the competition not only through its smoothly-clad engine/gearbox unit, but also through its frame structure, with two fully enclosed steel tube hoops running parallel to one another. Fitted low down within the machine, the flat Boxer engine improves the centre of gravity and, accordingly, the motorcycle's handling and riding characteristics most significantly. And although the front wheel fork allows only minor spring travel, the use of leaf springs provides a certain inherent damping effect.

Jet-black burnt-in paintwork and elaborate white decal lines set standards in the quality of the motorcycle's finish. But the technical components are of course even more important, BMW riders stating proudly from the beginning that they really benefit from BMW's experience as a manufacturer of aircraft engines. This involves both the choice of materials - with light alloy, for example, being used on the pistons for the first time - as well as the high standard of functional dependability and reliability hardly ever seen before in a motorcycle.

Build quality and reliability were key features of the success of this debut boxer twin. There was no chain-drive between the engine and the gearbox - an area easily prone to damage - and there was no chain or belt leading to the rear wheel. The valve shafts as well as the springs are sealed off and are dust and oil-tight at the top on the cylinders. In conjunction with the fully-contained lubricant circuit, this serves to keep the motorcycle clean and to significantly facilitate maintenance at all times.

At 122 kg (or 184 kg with original sidecar) the 494cc R 32 was not heavy, with the 8.5 hp engine powering it to an impressive top speed of 95 km/h. It wasn't the fastest machine out there, but was certainly quick enough to hold its own among the competition. After all, the roads were not made of smooth tarmac in those days, rear suspension was limited to the springs in the rear saddle, and reliability was much more important to owners than outright top speed. Fuel economy was also of great importance, especially in times of galloping inflation, so the fact that the R 32 only sipped around 3 litres of fuel per 100 kilometres was another big factor in its success story.

Success on the racetrack has always been one of the best (or most enjoyable?) ways to promote a new motorcycle in general and - in particular - a new brand entering the market. Rudolf Schleicher, a young engineer at BMW, was well aware of this important point and therefore started thinking about his racing ambitions after finishing the detailed design and engineering work on the R 32. On 2 February 1924 he ended the day in the Mittenwalder Steig Hill-Climb Race in record time on his BMW, becoming the first of many winners in the long motorsport history of Bayerische Motoren Werke.

Using a cast light-alloy cylinder head designed and built by Schleicher, together with overhead hanging valves encapsulated beneath a cover hood, three BMW works riders entered the Stuttgart Solitude Race on 18 May 1924, each of them winning their individual categories. Winning other significant races throughout Germany and with Franz Bieber bringing home the first championship, BMW gained a reputation as a leading manufacturer on the racetrack in its very first year of motorcycle production. Works and private motorcycle riders from Munich then dominated the German motorcycle racing scene in the years to come.

A large number of R 32 BMWs have survived in private collections or as exhibits in museums all over the world. As the very first BMW motorcycle, the R 32's transverse-mounted boxer engine and cardan shaft to transfer power to the rear wheel remain two of the most important characteristics of BMW motorcycles to this day. An impressive 3,090 of them were built from 1923 to 1926 by a small team in the Munich factory. Innovation, quality and reliability were the key foundations on which this - and all BMW bikes ever since - were built…

90 Years of BMW Motorrad - The R 37 - BMW goes racing…

The immediate success of the original R 32 established BMW as a serious player in the motorcycle industry some five years before the company even started the development of cars. Furthermore, this iconic motorcycle also paved the way for a sports model that took the brand into racing at the highest level. Enter the R 37…

With 494cc, 8.5 hp and a top speed of over 90 km/h, the original 120 kg R 32 had quickly earned a good reputation as a safe, well-handling motorcycle, with its easy maintenance and well-known reliability. Having achieved these important objectives, the talented engineers in the BMW factory were soon thinking about 'tweaking' the engine and chassis so they could go racing competitively on it.

Undoubtedly convincing his colleagues that 'racing improves the breed', a young engineer - and active motorcycle racer - Rudolf Schleicher, was put in charge of the project, despite the fact that he has only been with BMW since 1923. This gifted engine designer, still only in his Twenties, developed the first light-alloy cylinder head for the R 37 in 1924. The brand's long experience and unsurpassed expertise in the field of light alloys is the key to the success of this - and the single-cylinder R 39 engine that follows - the first standard-production engines with aluminium cylinder heads.

Of course, there is a big difference between road riding and the exciting world of motorsport, and this is what spurs BMW engineers on to further develop the high-quality Boxer concept, using knowledge gained from aircraft engine manufacture, but adapted for motorcycle production and professional racing - which always places the highest demands on materials and technology. The R 32's standard output of 8 bhp is considerably enhanced with the R 37 competition version - in fact, it achieves twice the power of its predecessor with 500cc and 16 bhp.

More than just a 'tuned' R 32, the R 37 featured a more efficient overhead valve system that was both oil- and dust-proof, which was a big improvement over the exposed systems that could be vulnerable to the weather. The cylinder heads were made from lightweight aluminium and the lights were removed to underline the sporting character of this machine.

The R 37 was a little heavier than its predecessor, but the increased horsepower propelled it to a more than respectable 115 km/h (70 mph). Fuel economy suffered slightly (4 litres/100 km) but the excellent performance made up for this. With a sales price of 2,900 Reichsmarks the R 37 was the most expensive motorcycle in the German market. As a result, it was not a sales success (only 152 were produced in its 1925-1926 lifespan) but this racing derivative of the R 32 took the brand into all sorts of motorsport competitions across the world, helping establish BMW's reputation as a premium manufacturer.

Success in motorsport was very important at the time to prove not just reliability and endurance qualities, but also performance in all conditions. For the R 37, success was immediate, and long lasting. BMW test rider Franz Bieber won the 1924 German 500cc championship, with Rudolf Reich winning it in 1925 on the R 37. Although new to the world of racing, BMW enjoyed a wave of success: 91 wins in 1925, 105 in 1926, and 171 in 1927. In Germany, BMW won every single title in all classes up to 500cc between 1924 and 1929.

But it was abroad where the biggest headline came, when none other than Rudolf Schleicher won BMW's first major international trophy - a gold medal in the International Six Days Trial in Great Britain in 1926 - the toughest cross-country event in the world at that time. As it was the first time that a German rider had won the event, this helped bring the BMW brand to the attention of the world and prove it meant business. In reality, it was just the start of a long relationship with performance, speed and competition that continues to this day.

Schleicher would later assume responsibility within BMW for the development of engines for standard-production cars and racing models, but thanks to his love of engineering, his passion for motorsport and his belief in personally using these products to prove their worth - both on and off-road - the seeds had been sown for many more exciting models on which to satisfy a rider's thirst for competition and adventure.

For further press / media information contact:

Scott Croaker
Product Communications Manager
783 Springvale Road
Mulgrave VIC 3170
Australia
Tel: +61 (3) 9264 4150
mailto: scott.croaker@bmw.com.au

Miles Davis
Marketing Manager Motorrad
783 Springvale Road
Mulgrave VIC 3170
Australia
Tel: +61 (3) 9264 4021
mailto: miles.davis@bmw.com.au