page_title: Lever arm shock absorber
section_title: Integral wishbones
hierarchical_section_title: Lever arm shock absorber / Integral wishbones
caption_attribution_description: Lever arm shock absorber as the upper wishbone of independent front suspension. Bentley-engined special. Cophill Farm vintage rally, near Chepstow, 2012.
context_page_description: Lever arm shock absorbers were the first form of hydraulic shock absorber or damper used for car suspension. They appeared in the 1930s and were most commonly used in the 1950s and 1960s, but were replaced by telescopic shock absorbers in the 1970s. One of the earliest patents for a hydraulic lever arm shock absorber was awarded in 1925 to Georges de Ram, who was already an established maker of friction disk shock absorbers.
  Hydraulic shock absorbers, invented by Ralph Peo in 1930, appeared as a development to replace the previous friction disks. These had, at best, provided a constant damping force, no matter what the size or speed of the suspension movement. With a viscous device using hydraulic oil, the resistance force increased with speed, so providing better damping for larger suspension bumps.
context_section_description: Many cars of this period began to use independent front suspension, often a double wishbone. The upper wishbone could conveniently also be used as the lever of the shock absorber, reducing the mass and bulk of the suspension, and also avoiding at least one ball joint. The spindle of the shock absorber now became the upper suspension pivot, usually double-ended.
  One of the last mass-production sports cars to still use lever arm shock absorbers was the MG B. This had a lever arm shock absorber as the upper wishbone. A popular handling upgrade in later years was to fit telescopic shock absorbers instead. The lever arm wishbone was still retained, but now as a simple wishbone with no damping.
caption: Front suspension, with a lever arm shock absorber forming an upper wishbone
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