Library › Car design › Suspension geometry ·

Semi-trailing arm suspension

Name: Semi-trailing arm suspension dimension sheet
Creator: Xem Studio
License: https://creativecommons.org/licenses/by/4.0/

What is a semi-trailing arm? · Standard part · basis: Design rules and figures from the cited sources; example geometry by Xem Studio

Also called: semi trailing arm, bmw semi trailing, weissach axle, semi trailing camber, rear suspension types, semi trailing toe change, semi-trailing arm geometry

Exact dimensions. True size, with no printing tolerance added.

sizes: 1 in table

Notes

A semi-trailing arm pivots on an axis inclined about 50-70 deg, mixing trailing-arm and swing-axle behaviour: the trailing part adds understeer, the transverse part adds roll oversteer, and the two largely cancel (AutoZine).
Camber changes with wheel travel; it was common on older BMW, Mercedes and Porsche models before multi-link took over (AutoZine).
Used on: BMW 3-Series (1982), Mercedes 560SEC, Porsche 911, Porsche 928 (Weissach axle).

Semi-trailing arm suspension size chart

parameter	value or range	source
Pivot axis inclination	about 50-70 deg	AutoZine

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

AutoZine Technical School

Suspension: trailing arm, semi-trailing arm, torsion beam, multi-link

web

Publisher's page; dimensions are facts

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.

Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=semi-trailing-arm

Schematic, not to scale.