Motorcycle frame

from Wikipedia, the free encyclopedia

The motorcycle frame is the supporting chassis of the motorcycle . The essential drive elements such as the engine , transmission and wheel suspension , but also the steering , energy storage ( fuel tank ), seats , trim parts and, if necessary, trailer couplings are attached to it. In some designs, the motor-gear unit can also partially take on the supporting function of the frame. Modern motorcycle frames weigh between 8 and 17.6 kg including the swing arm.

Modern motorcycle frame (bridge tube frame from Kawasaki)

General

Wooden frame
Daimler riding car (1885)

While the Daimler riding car from 1885, as the forerunner of motorcycles, still had a wooden frame, with series production and experience with bicycle frames, metal quickly established itself as a material. The different performance and weight classes as well as the adaptation to a wide range of applications require a large number of frame variants, which are also structured differently depending on the perspective.

Structure according to the supporting material

Wooden frame

Technically prepared in unit production and were derived from the coach-motorcycle frame of wood only when Daimler-riding car ( Hickory ) and short time at Bekamo ( ash ) found.

Steel frame

Steel is still the most common material for motorcycle frames today. High strength, easy processing and low costs speak for this material. High-strength steel tubing with a round or rectangular cross-section (for box profiles) or deep-drawn sheet metal (for central press frames ) is used.

Aluminum frame

The first motorcycle frame made of drop-forged aluminum had the Neander motorcycle from 1924. Frames made of aluminum can bring advantages through weight savings. However, processing is more difficult and the starting material more expensive. The manufactured parts can be joined together by TIG or MIG welding . Complicated molded parts produced by casting , die-casting or forging can also be combined with continuously cast profiles or deep-drawn parts. The first motorcycles that were delivered in large numbers with aluminum frames were the Suzuki GSX-R 750 and the Honda NS 400 R from 1985.

titanium

The first attempt with a motorcycle frame made of titanium was the off-road motorcycle from BSA from 1966. Husqvarna launched a competition motorcycle with a titanium frame in 1971, followed by another one-off with a single-loop titanium frame in 1998.

Carbon fiber reinforced plastic

Frames made of carbon fiber reinforced plastic (also called “carbon fiber” or “carbon”) were previously only found in motorcycle racing. The first racing motorcycle with a CFRP frame was the Tomos from 1978. In 1983 the Armstrong (250 cm³ displacement) appeared with a CFRP frame weighing 8 kg, followed in 1985 by the Heron-Suzuki.

magnesium

In 1988, again only in racing, parts of the frame were used for the experimental motorcycle "Elf-5" made of cast magnesium .

Composite frame

Various raw materials are combined in the composite frame. For example, steel tubes are used from the steering head to just before the engine suspension / swing arm bearing (front frame), the swing arm bearing and the rear frame are made of cast aluminum. A prominent example is the Benelli TNT .

Outline according to execution

Tubular frame

For tubular frames, mostly round, but also oval or angular (square tube) frame profiles are used. In the early days, based on bicycles, standard round profiles were used. These were pre-bent and hard soldered or welded , reinforced with gusset plates or sleeves at stressed points . Initially, it was made manually, and it was expensive and time-consuming. Today, hand-made tubular frames are only produced for individual pieces or small series. Machine multi-spot welding systems or welding robots are used for series production . This leads to a significant reduction in production time and human labor input with more uniform quality and lower costs in large-scale production. In the 1950s square steel tubes and in the 1980s square aluminum tubes were introduced into series production.

Box frame

The box frame with a large cross-section made of angular sheet metal profiles can be viewed as a special form . The first and most prominent example is the White Mars from 1920. The bar-shaped frame box had a U-profile and, in addition to its load-bearing function, also accommodated other components such as the tank. The motor was also bolted to the frame in a non-load-bearing manner and suspended.

Pressed steel frame

Pressed steel frame with welded, screwed and riveted connections
Opel Motoclub (1929)

In order to reduce manufacturing time and costs, machine pre-formed and punched frame parts made of sheet steel were used in presses . The frames could be manufactured cost-effectively from main parts that were symmetrical in the horizontal longitudinal plane; additional gusset plates or sleeves were not required. This design was used as one of the first motorcycles in the Neander P3 from 1927 and in the Opel Motoclub , which was manufactured under a Neander license, from 1928. The prefabricated frame parts were riveted and screwed, which enabled a significantly faster production.

In 1949 NSU Fox offered a mass-produced press steel frame with frame halves connected by welding as a central press frame . The frame of the Vespa motor scooter (1946) was similar in production with a shell frame made of sheet steel that was reinforced with tubes for rigidity. The manufacturer Kreidler has been producing a folded central press frame in its foil models since 1957 . The central press frame was also offered in large numbers in the weaker models of the small MZ ES . Today, sheet steel frames can be produced inexpensively and in large numbers. For reasons of stability, this design is suitable for motorcycles and scooters with low engine power. More recently, the central press frame can be found on the XV models from Yamaha .

Sprue

One of the few examples of the frame design using cast technology (aluminum) is the Heinkel Perle from 1954. In combination with other frame materials (composite frames), load-bearing cast aluminum parts are used in frame construction. From 2004 Yamaha delivered a screwed cast aluminum frame on its Fazer FZ6 model .

Structure according to the frame shape

Motorcycle frame, distribution of types (2013)

Monotube frame

Single tube frame
Laurin & Klement Type 1 (1899)

The monotube frame was created from the diamond frame of the bicycles. It is characterized by a narrow pipe guide in the plane of symmetry . The motor is attached to the bottom of the frame profile. The fuel tank is saddled onto the upper frame tube ( saddle tank ). Low costs, especially when using uniform cross-sections, but often weaknesses in rigidity. In order to improve this, the upper frame tube to the steering head, which bears the main load, is usually larger, and the girder is mostly forked. Monotube frames are used today almost exclusively on light motorcycles (125 cm³ displacement) or low-performance motorcycles.

Central tubular frame

Central tube frame
( nimbus "stovepipe")

In the case of the central tube frame, the individual upper frame tube is dimensioned larger in order to increase strength and, in addition to the load-bearing function, often also has a receiving function. In the early days, the central tube frame was called a tank tube frame . In 1924, a motorcycle with a tank pipe frame was presented in the TX motorcycle from the Berlin manufacturer Westendarp & Pieper . A thick tube served as the main frame and fuel tank to which the engine and footrests were attached. The “Deutschlandfahrt-Modell” by Ernst Neumann-Neander and the Nimbus “Ofenrohr” from 1924 had a central tubular frame .

In 1947 Moto Guzzi provided the tubular frame of the Due cilindri racing machine with a large hollow beam on the steering head, which originally served as an oil reservoir. After the last Vincent motorcycles were manufactured in 1956, the Swiss Fritz W. Egli acquired the rights and began selling the engines in his chassis from 1969. Egli improved the idea of ​​the central tubular frame and began selling the Egli central tubular frame in one-off production a. a. with Japanese engines (e.g .: Egli Kawasaki, Suzuki, Yamaha).

A central tube frame known as a curved backbone tube frame was presented by NSU at Rennmax in 1953 . From Honda this principle was in the Honda CX 500 used by 1978 in an amplified version. Today the tubular backbone frame is only used by a few manufacturers.

Double tube frame

Double tube frame
with straight suspension ( BMW )
Double tube frame
made of square tube ( Suzuki GS500 )

Double beams spreading out from the plane of symmetry from the steering head to a lower frame point result not only in a clear transverse stiffening of the frame, but also in a favorable arrangement of the engine and gearbox between the frame tubes. Both improve handling and safety. This frame shape was created in the 1920s. The Moto Guzzi model from 1921, the BMW R 32 from 1923 and the D-Rad were groundbreaking . The double tube frame is still the basis of many motorcycle chassis today. Currently (as of 2013) Harley-Davidson uses double tubular frames in its entire model range; Japanese manufacturers use this design especially for chopper models.

The stiffening effect of the closed, spread loop shape was also used in many pressed steel frames. Due to their open press cross-sections, they are not tubular frames. In the sheet steel design at BMW from 1928 on the models BMW R 16 and BMW R 11 , as well as at Zündapp in the K models from 1933, they were also known as box frames . The torsional stiffness of such frames always remained problematic.

Double loop pipe frame

Double loop tubular frame
( Norton Manx )

In 1950, the double-loop tubular frame , known as the " feather bed frame ", was introduced on Norton racing motorcycles. The typical features of the feather bed frame are the tubes that cross at the steering head and the soft tube bends. The then excellent properties of this pipe construction, which was guided in a double loop, also convinced other manufacturers. From 1969 to 1996 the double loop tube frame with a frame reinforcement on the steering head (gusset plate) and a strong oval tube was installed at BMW. The weight of this frame, including the swing arm, was 17.6 kg for the BMW R 100 S. In the meantime, in terms of market share, the double loop tubular frame has been replaced by the tubular bridge frame, in which the motor-gear unit is included as a load-bearing assembly.

Bridge tube frame

Bridge frame made of aluminum ( Honda Fireblade SC59 )

The bridge tube frame or bridge frame was developed from the double loop tube frame by removing the double beams and including the motor-gear unit as a load-bearing assembly. The bridge tube frame also bridge frame (this is very often made of aluminum) is now used by almost all manufacturers of powerful motorcycles. With the BMW K 100, BMW used a tubular space frame as a bridge frame for the first time , in which the engine-transmission unit was used as a load-bearing element; the frame weight was 11.3 kg.

Tubular space frame

Space frame
( Ducati S2R Monster)

A further stiffening of the tubular steel frame results from the creation of additional frame triangles. The resulting pattern led to the naming. The stability, but also the manufacturing effort is high due to the many connection points. The tubular space frame, developed by Moto Guzzi in 1952 , is used in modern motorcycles with high performance. In manual production it is manufactured for special individual pieces or with automatic multi-spot welding systems in large series. Users are BMW , Ducati , KTM , MV Agusta and Italjet , where the uncovered frame parts are used in a visually style-defining way. The weight of the tubular space frame of the MKM 1000 was 11.6 kg.

Monocoque

Monocoque
( Kawasaki ZZR 1400 )
Backbone frame
( Yamaha )

Through the use of box profiles, the motorcycle frame has been increasingly built around the engine over the years. The first newer monocoque frames were the so-called "Delta-Box" frames from Yamaha and the frame of the Kawasaki ZX-12R (2002) called monocoque . The Ducati 1199 Panigale and the Kawasaki ZZR 1400 currently use a monocoque frame made of aluminum.

Structure according to engine and gear installation

Closed single-tube frame as a rigid frame ( DKW RT 125 )
Open monotube frame with straight suspension at the rear ( Horex Regina )

Closed frame

Based on the bicycle , only the closed monotube frame was used at the beginning of motorcycle development. The motor sits in the lower frame triangle and is well protected against mechanical damage. The disadvantage of a closed single-tube frame is, on the one hand, the high center of gravity, since the frame tube is passed under the engine and transmission, and, on the other hand, the lower lateral stability. These disadvantages of the single-tube frame were reduced with the closed, double-tube frame connected by cross tubes, which is still used today. Simple versions have only one top tube.

Open frame

As a variant, the open frame was created, in which the engine and transmission were also used as load-bearing components . In 1903, Rösler & Jauernig first developed a motorcycle with a frame that was open at the bottom. The frame is open in the lower part, in which the engine and transmission are placed. This reduces the total weight and the center of gravity. With a tight screw connection, however, vibrations are also transmitted to the frame. With elastic suspension, the motor-gear unit can only contribute to a limited extent to stabilization. As a result, these frames, if designed as single-tube frames, are not very rigid. This open frame, also known as the central tube bridge frame , was used from the MZ TS 250 , for example .

Today the open monotube frame is only used for light mopeds and motorcycles with low power. In contrast, the open frame has established itself as a double tube frame, tubular bridge frame and tubular space frame. Different pipe cross-sections are also combined to increase rigidity.

Structure according to the rear suspension

Rigid frame ( Rikuo VL )
Straight suspension ( EMW R 35 )
Full swing chassis ( BMW R27 )

Rigid frame

With the rigid frame, the rear axle is firmly bolted to the frame. This construction comes from the early days of motorcycle development. Due to the lack of rear suspension, unevenness in the road surface can only be absorbed by the tire or the entire motorcycle, which leads to uneven driving behavior with little comfort. The development of the swing saddle has improved driving comfort. However, the unsprung masses remained high. This construction, which was widespread until the 1930s, is only used today for choppers for optical reasons.

Straight suspension

The straight-line suspension tried to improve the handling and comfort of the rigid frame. Thanks to the spring elements attached to the rear end of the frame, the axle can move vertically independently of the frame and thus compensate for unevenness. The increased comfort is offset by a significant additional weight with less spring travel. The sliding guides wear out and then worsen driving safety. In addition, the distance between the rear wheel and the motor / gear unit, which is fixedly mounted in the frame, changes constantly during compression, which means additional effort for power transmission (thrust piece for cardan drive or tensioner for chains or belt drives). This construction is outdated today.

Swing frame

In the swing arm frame, the rear wheel is guided in a swing arm that is mounted close to the transmission output. The rear wheel describes a circular path around the bearing point during compression, the changes in distance during suspension are small. Significantly greater spring travel can also be achieved. Therefore, this frame shape (with two lateral or one central spring element) is state of the art today. If a swing arm is used for the suspension at both the front and rear, it is referred to as a full swing chassis .

See also

literature

  • Helmut Werner Bönsch: Advanced motorcycle technology. 1st edition. Motorbuch Verlag, Stuttgart 1985, ISBN 3-613-01054-2 .
  • Gaetano Cocco: Pure motorcycle technology. 1st edition. Motorbuch Verlag, Stuttgart 2001, ISBN 3-613-02127-7 .
  • Mario Colombo: Moto Guzzi. 3. Edition. Motorbuch Verlag, Stuttgart 2000, ISBN 3-613-01274-X .
  • Tony Foale, Vic Willoughby: Motorcycle Chassis Today . 1st edition. Motorbuch Verlag, Stuttgart 1988, ISBN 3-613-01226-X .
  • Kurt Mair: The motorcycle. 2nd Edition. Richard Carl Schmidt Verlag, Berlin 1937. (Reprint: ISBN 978-3-86852-307-2 )
  • Peter Witt: Motorcycles . 1st edition. Verlag Technik, Berlin 1989, ISBN 3-341-00657-5 .
  • Stefan Knittel: Motorcycle Lexicon. BLV Verlag, Zurich u. a. 1981, ISBN 3-405-12226-0 .

Web links

Remarks

  1. ↑ Cocco, p. 163, calculated with the same weight of a bridge frame, the thickness of an aluminum sheet to 2.5 mm, the thickness of the steel sheet to 0.86 mm.
  2. ↑ u. a. in the Hoffmann governor from 1951.

Individual evidence

  1. ↑ BEKAMO  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (accessed on May 28, 2013)@1@ 2Template: Toter Link / www.zweiradtechnik-eich.goracer.de  
  2. ^ Cocco, p. 162.
  3. ↑ Thomas Trapp: Neander. Heel Verlag, Königswinter 1996, ISBN 3-89365-546-8 , p. 40.
  4. ↑ Mair, p. 195.
  5. ^ Cocco, p. 163.
  6. ↑ motorcycle-usa.com Memorable Motorcycles BSA Titanium (accessed July 19, 2013)
  7. ↑ BSA titanium frame
  8. ↑ google.books.de American Motorcyclist (accessed July 19, 2013)
  9. ↑ motorradonline.de ( Memento of the original from December 3, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Technology and driving report Poggipolini-Husqvarna (accessed on July 19, 2013) @1@ 2Template: Webachiv / IABot / www.motorradonline.de
  10. ↑ a b c d Helmut Werner Bönsch: Progressive motorcycle technology. Motorbuch Verlag Stuttgart, 1st edition. 1985, ISBN 3-613-01054-2 , pp. 220-222.
  11. ↑ armstrongfactoryracing ( memento of the original from September 27, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (accessed on July 21, 2013) @1@ 2Template: Webachiv / IABot / armstrongfactoryracing.com
  12. ↑ motorradonline.de (accessed on May 28, 2013)
  13. ^ Alan Cathcart: ELF Motorcycle Chassis Designs. ( online at: motorcyclistonline.com , accessed July 15, 2013)
  14. ↑ Jürgen Stoffregen: Motorcycle technology. 7th edition. Vieweg and Teubner, Wiesbaden 2010, ISBN 978-3-8348-0698-7 , p. 286.
  15. ↑ bma motorcycle magazine, 6/12; Mars A 20 - White Mars , accessed July 19, 2013.
  16. ↑ Thomas Trapp: Ernst Neumann Neander and his motorcycles. 2nd Edition. Bonn 2001, ISBN 3-89365-546-8 , p. 86.
  17. ^ Helmut Werner Bönsch: Introduction to motorcycle technology. 3. Edition. Motorbuch Verlag, Stuttgart 1981, ISBN 3-87943-571-5 , p. 235.
  18. ^ Foale, p. 7.
  19. ↑ a b c d e f MOTORRAD Catalog 2013. Motorbuch Verlag, 2012, ISBN 978-3-613-30720-9 .
  20. ^ Mair, p. 194.
  21. ^ Karl Reese: Motorbikes from Berlin. 1st edition. Johann Kleine Vennekate Verlag, Lemgo 2002, ISBN 3-935517-05-X , p. 144.
  22. ↑ TX motorcycle
  23. ↑ Colombo, p. 368.
  24. ↑ egli-racing.ch ( Memento of the original from June 15, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (accessed on July 13, 2013) @1@ 2Template: Webachiv / IABot / www.egli-racing.ch
  25. ↑ Central tubular frame of the Vincent-Egli → [1]
  26. ↑ Colombo, p. 182.
  27. ↑ Moto Guzzi Normale (1921)  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / www.motorcycleclassics.com  
  28. ^ Mair, p. 187.
  29. ^ Paul Simsa : Development of the motorcycle chassis. In: MOTORCYCLE. 2/78
  30. ↑ Knittel, p. 55.
  31. ^ Helmut Werner Bönsch: Introduction to motorcycle technology . 3. Edition. Motorbuch Verlag, Stuttgart 1981, ISBN 3-87943-571-5 , p. 230.
  32. ↑ Quattro cilidri 500 cc , see → Colombo, p. 374.
  33. ↑ MKM 1000 ( Memento of the original from October 5, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.motorradonline.de
  34. ↑ Knittel, p. 48.
  35. ^ Paul Simsa: Development of the motorcycle chassis . In: MOTORCYCLE. 1/78