BMW R 32
The BMW & R 32 was the first motorcycle of the German manufacturer BMW.
- 2.1 Motor 2.1.1 Development History
- 2.1.2 Setup
- 2.1.3 carburetor
- 2.1.4 ignition
History
The R 32 was developed by Max Friz responsible, who took part in May 1923, a prototype of the trip " through the mountains of Bavaria " of the ACM ( Automobile Club Munich). The first Hindelang - Oberjoch race on September 16, 1923 BMW stepped in with the two R 32.
On September 28, 1923, BMW presented the R 32 on the German Automobile Exhibition in Berlin for the first time to the public.
Precursor " Helios motorcycle "
The Bayerische Flugzeugwerke developed, built and sold in 1919 the motorcycle Helios - first as a product of the " Bavarian Aircraft Works ", then under the name "BMW " to the end of production on 10 November 1923 Helios 1015 produced originated from supplier parts and the first BMW. Boxer motor M 2 B 15 " Bavaria motor", which was built here across.
Concept of development
No component of the R 32 was in itself new, but the compilation set standards and brought numerous benefits that made the concept a milestone for BMW and motorcycle history. The boxer engine was - unlike the manufacturers Douglas Motors and D wheel - mounted longitudinally, ie the crankshaft axis lying in the direction of travel. Therefore, a very good cooling of the cylinder and the critical area of the exhaust valves was achieved. The very flat and in this mounting position and short motor revealed a low center of gravity, which was the driving benefit. By directly flanged gearbox, the flywheel with the dry clutch could be combined. The transmission of power between the crankshaft and transmission was produced directly without gears or chains. The drive shaft to the rear wheel was in contrast to the former chain or belt drives almost completely maintenance-free and pollution -free.
BMW put this bike to the modular principle of future production batches. Chassis and transmission with the base engine were largely identical; the differentiation of the displacement classes with 500 cc, 600 cc and 750 cc, and after sports and touring models have been implemented by modified cylinder bores, crank and head-end or side-valve cylinder heads and cylinder.
Sporting successes
The R 32 was used by private and company drivers at races.
The participation in the following race is occupied:
- Hindelang - Oberjoch race 1923: two BMW at the start, two first prizes and the best time of the day. One of the drivers was the factory rider Rudi Empire.
- Race "around the Lausitz " 1924: Head nail in class 4 ( 1st place), fastest time of the day.
- Race "Around Landshut " 1924: Franz Biber in class 4 of the privateer ( 1st place); Rudi Empire in class 4 industry driver ( 1st place); Katzl in class 4 industry driver (2nd place).
With the introduction of the sports model R 37, R 32 was assigned the role of a reliable tour motorcycle.
Marketing
The price of the bike in 1925 was in accordance with the price list of BMW 2,200 Reichsmarks - lights, horn, speedometer and pillion were not included. Production was stopped in 1926 after 3090 units; Successor was introduced in late 1925 R 42, which was improved in many ways and despite increased capacity 700 Reichsmark cost less - lights, horn and speedometer were standard - and continued the success of the R 32.
Technology
Motor
The engine with the designation M 2 B 33 was designed as a longitudinally-mounted two-cylinder boxer, four-stroke engine with SV - valve control.
History of development
The precursor M 2 B 15, developed by foreman Martin Stolle modeled after the engines of the British motorcycle manufacturer Douglas Motors, was the first boxer engine from BMW and was as of December 1920 as " Bavaria - small motor " with 6.5 HP at Douglas Motors and Victoria sold and used in the private label Helios. There he were each mounted transversely ( ie, with the cylinder axis in the direction of travel ); in this mounting position, the course of the cooling fins was technically correct.
Construction
The motor housing was divided horizontally. An intermediate gear above the crankshaft drive of the camshaft or a higher -plane, which in turn drive the ignition system in the next level. Through this cascade of gear motor for a boxer engine built relatively high.
The camshaft opened over short roller plunger valves.
Carburetor
The carburetor, an in-house design of BMW, the air sucked through the flywheel housing.
The amount of mixture ( " gas valve" ) and mixture composition ( " air slide ") was set over 2 lever on the right handlebar.
Ignition
A high-voltage magneto from Bosch or a dynamo were secured with a tie on a platform above the crankshaft. The spark was provided via a lever on the left handlebar.
Drive
The R32 had a manual transmission with drive shaft on the right side of the unsprung rear wheel.
BMW described the power transmission from the gearbox to the rear wheel as " shaft drive ", the drive shaft as a " propeller " and the gearbox on the rear as " gimbal " - technically correct, it was just a shaft driving the rear wheel, as there was no universal joints.
Horizontally divisible gearbox housing was flanged to the motor housing. The input shaft of the 3- speed transmission was driven by the single-plate dry clutch in the flywheel to the crankshaft. The output shaft drove a Hardy disc in the drive shaft to direct extension.
The kickstarter is not actuated parallel to the vehicle longitudinal axis; to a Kegelradumlenkung was installed in the gear housing. This elaborate diversion was abandoned until five years later when R 52 and R 57.
Landing gear
The chassis is a tube frame with no rear suspension (rigid frame), the front fork is a solid short rocker with leaf spring suspension. The saddle height was 72 cm.
The first version had no front brake; later a drum brake was installed.
The rear wheel is slowed by a foot -operated wedge block brake that acted on its own brake rim.