NSU Fox

NSU Werke AG

Fox
Manufacturer	NSU works
Production period	1949 to 1954
class	Light motorcycle
Motor data
1-cylinder four-stroke / two-stroke
98 cm³ with 5.8 PS , 6.1 Nm , 85 km / h 123 cm³ with 5.4 PS , 6.1 Nm , 75 km / h

transmission	4-speed
drive	Chain drive
Brakes	Inner jaws
Wheelbase (mm)	1220

The NSU FOX 101 OSB is a motorcycle from NSU Werke AG in Neckarsulm , which was built from 1949 to 1954. The successor model from 1955 was the NSU Superfox .

Models and Features

The Fox was NSU's first redesign after the Second World War . It had a 98 cc four-stroke engine that developed about 6 hp (4.4 kW). It was presented at the Hanover industrial fair in 1948. In 1951 a version with a 123 cm³ two-stroke engine was added (type 125 ZB). From then on, the two models were referred to in sales brochures as FOX four-stroke and FOX two -stroke to differentiate .

The Fox was a design by Albert Roder , the then chief designer at NSU.

It had a number of new design features, including a pressed sheet metal frame and a cantilever rocker . The Fox was initially equipped with a three-speed, later with a four-speed transmission. The two-stroke Fox had a four-speed gearbox from the start.

The 98 four-stroke Fox is still one of the most economical ways to drive a real motorcycle: The standard consumption (according to the standard at the time) was 1.9 l / 100 km, the actual consumption values are around 2 to 2.5 l / 100 km .

In terms of registration, the NSU Fox is now a light motorcycle. It is therefore tax-free.

The Fox advertising slogan, “ Fixed drivers drive FOX! “, Came from Arthur Westrup , who was NSU's head of advertising at the time.

Engine and power transmission

The four-cycle engine had a gray cast iron cylinder and a light alloy cylinder head with overhead valves ( OHV ), which from a position below the cam shaft on the right side of engine via rocker arms , bumpers and rocker arms are actuated. The crankshaft drive, clutch and gearbox were housed in a common aluminum motor housing. All these parts were lubricated by the oil thrown around by the crankshaft without an oil pump ( centrifugal lubrication ). The crankshaft drive with only one cam disk was overhung, that is, both crankshaft bearings were on the same side of the crank. The crankshaft drove the input shaft of the transmission via helical spur gears. Both engine versions had a Bing single slide carburetor, the four-stroke 1/14/9 and the two-stroke 1/16/22.

The transmission initially had three and from 1950 four gears. It was switched to the left with a foot lever. A roller chain on the left side of the vehicle transferred the power to the rear wheel.

Frame and chassis

The NSU FOX had a torsion-resistant, pressed steel central frame open at the front with a rear swing arm, which was supported on the frame with an inclined central spring below the saddle. The saddle with a small tool container attached underneath was mounted on a long arm under the tank and was sprung in a so-called post guide that prevented lateral movements. The front wheel was guided on a rigid pressed steel fork with a pushed short swing arm with compression springs. The rocker arms on the right and left were connected by a bracket running behind the wheel for stiffening purposes. Front and rear suspension each had adjustable mechanical friction dampers. However, these were designed to be relatively weak, as is typical of the time.

Technical specifications

NSU four-stroke FOX (1954)

Type	101 OSB	125 ZB
Sales description	Four-stroke Fox	Two-stroke Fox
Construction year	1949-1954	1951-1954
engine	Single cylinder four stroke	Single-cylinder two-stroke
control	OHV	Flat bottom flask
Displacement	98 cc	123 cc
Bore × stroke	50 mm × 50 mm	52 mm × 58 mm
compression	1: 7.2	1: 6
power	5.8 hp at 6500 rpm	5.4 hp at 5000 rpm
transmission	3-speed / from 1950 4-speed	4-speed
overall length	1910 mm	1910 mm
wheelbase	1220 mm	1220 mm
tank	6.5 / from 1950 8 liters	8 liters
Empty weight	85 kg	84 kg
Top speed	85 km / h	75 km / h

Note: Specifications vary by source. Even in
official NSU publications there are slightly different information.

NSU FOX in racing

NSU Sportfox (100 cm³) for young drivers, 1950

Engine from 1952 with two overhead camshafts and a right-hand vertical shaft

NSU Rennfox with a so-called banana tank in the two-wheeled museum

NSU Rennfox "Blue Whale" from 1954 in the two-wheeled museum

Sportfox

In 1950, NSU brought out the Sportfox based on the series model. Thirty motorcycles were planned to be loaned to young racing drivers. However, the demand was so great that around 750 machines were built and sold. The engine developed 7.5 HP (5.5 kW) at 7000 rpm and the top speed was 100 km / h. Measures for this increase in performance were polished channels, reinforced valve springs and a larger inlet valve, a larger carburetor passage and a compression increased to 1: 8. Due to the extensive use of light metal, the Sportfox weighed only 65 kg. Outwardly, it differed from the production model in the lack of lighting, racing cushions instead of luggage racks or pillion saddles, drive chain without cover, shortened mudguards and an exhaust without a silencer. The Sportfox needed a gasoline-benzene mixture in the ratio 100: 40 as fuel.

Rennfox

For factory use in the class up to 125 cm³ from 1952 to 1954, NSU developed the Rennfox, but the engine had nothing in common with the engine of the series Fox. In the first version, the motor was designed as a square with a 54 mm bore and stroke. Initially with two overhead camshafts that drove a right-hand vertical shaft, it developed around 14 hp (10 kW) at 11,000 rpm. From 1953 it had a bore of 58 mm and a stroke of 47.3 mm as well as only one camshaft with a vertical shaft on the left side. In addition, the crankcase was narrower than in the first version. The engine developed 18 hp (13 kW) at 11,000 rpm in the summer of 1954. The top speed of the approx. 80 kg heavy machine with so-called “blue whale” disguise was 175 km / h.

In contrast to the series, the Rennfox initially had a five-speed, later a six-speed gearbox, and the chassis was also changed, including more easily adjustable struts on the rear swing arm instead of the central spring. At 18 ", the wheels were smaller than those of the standard Fox for the road.

Stages of development

NSU Rennfox:	1952	1953	Spring 1954	Summer 1954
Weight of the machine	90.0 kg	83.5 kg	80.5 kg	80.0 kg
Engine power	13.5 HP (10 kW)	15.5 HP (11.4 kW)	16.8 hp (12.4 kW)	18 HP (13 kW)
Top speed	155 km / h	160 km / h	168 km / h	175 km / h
Disguise	no	no	"Dolphin"	"Blue whale"

The "dolphin" fairing with a small windshield covered the handlebars and was pulled down to the side so that it covered the driver's legs. A characteristic was a "beak" over the open front wheel, which resembled the snout of a dolphin and gave the component its name. The “blue whale” fairing with a higher windshield also encompassed the front wheel and led the wind past the driver's arms and legs.

Championships

The Rennfox drove its first outings at the end of 1951, initially with 11 hp. NSU achieved its first major success with it when drivers Roberto Colombo , Otto Daiker and Wilhelm Hofmann finished one to three in the 1952 Eifel race at the Nürburgring . Colombo drove the five laps or 114.05 km on the Nordschleife in 1: 03: 54.5 hours. Otto Daiker became German champion later in the season .

1953 won Werner Haas , both the German and the world championship in the class up to 125 cc NSU. 1954 was Rupert Hollaus World Champion; In the same year he had a fatal accident with his Rennfox during training for the Grand Prix of Nations in Monza . Hollaus had won the Isle of Man TT on June 16 : 10 laps = 173.611 km on the Clypse Course in 1: 33: 03.4 hours. He also drove the fastest lap in 9: 06.4 minutes = 114.583 km / h with the Rennfox. German champion in 1954 was Werner Haas ahead of Hermann Paul Müller , both NSU Rennfox.

After Hollaus' fatal fall, concerns arose that full fairings on racing machines would increase the risk of falling, and doubts as to whether these aerodynamic means for achieving ever higher speeds were useful and beneficial for sport. The NSU Rennfox with "blue whale" cladding was the fastest eight-liter machine internationally in 1954.

literature

Klaus Arth: Fixed drivers drive Fox . Johann Kleine Vennekate Verlag, Lemgo 1997, ISBN 3-9804987-2-7 .
Peter Schneider: The NSU story . Motorbuch Verlag , Stuttgart 1997, ISBN 3-613-01853-5 .
Peter Schneider: NSU: Motorcycles 1900-1966 . Motorbuch Verlag , Stuttgart 2007, ISBN 978-3-613-02628-5 .

Web links

Commons : NSU Fox - Collection of Images

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Peter Schneider: NSU 1873–1984 • From high-bike to automobile . 2nd Edition. Motorbuch Verlag, Stuttgart 1988, ISBN 3-613-01086-0 .
↑ Ernst Leverkus: The great motorcycles of the 50s . 3. Edition. Motorbuch Verlag, Stuttgart 1993, ISBN 3-87943-849-8 , p. 79.
↑ Catalog 100 Motorcycles . Verlag für Handel und Wirtschaft, Munich 1952, p. 18 u. 30th
^ ^A ^b ^c ^d Edler / Roediger: The German racing vehicles. Reprint of the 1st edition from 1956. Fachbuchverlag, Leipzig 1990, ISBN 3-343-00435-9 , pp. 225-227.
^ Yearbook of International Motorsport. ADAC and AvD, 1955, p. 267 u. 268.
↑ Behrndt / Födisch / Behrndt: ADAC Eifel race. Heel Verlag, Königswinter 2009, ISBN 978-3-86852-070-5 , p. 250.
^ Yearbook of International Motorsport. ADAC and AvD, 1955, p. 131.
^ Yearbook of International Motorsport. ADAC and AvD, 1955, p. 264.

[Schneider-1] ↑ ^a ^b ^c ^d ^e ^f ^g Peter Schneider: NSU 1873–1984 • From high-bike to automobile . 2nd Edition. Motorbuch Verlag, Stuttgart 1988, ISBN 3-613-01086-0 .

[2] Ernst Leverkus: The great motorcycles of the 50s . 3. Edition. Motorbuch Verlag, Stuttgart 1993, ISBN 3-87943-849-8 , p. 79.

[3] Catalog 100 Motorcycles . Verlag für Handel und Wirtschaft, Munich 1952, p. 18 u. 30th

[Roediger-4] A ^b ^c ^d Edler / Roediger: The German racing vehicles. Reprint of the 1st edition from 1956. Fachbuchverlag, Leipzig 1990, ISBN 3-343-00435-9 , pp. 225-227.

[5] Yearbook of International Motorsport. ADAC and AvD, 1955, p. 267 u. 268.

[6] Behrndt / Födisch / Behrndt: ADAC Eifel race. Heel Verlag, Königswinter 2009, ISBN 978-3-86852-070-5 , p. 250.

[7] Yearbook of International Motorsport. ADAC and AvD, 1955, p. 131.

[8] Yearbook of International Motorsport. ADAC and AvD, 1955, p. 264.