{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "semi-trailing-arm",
 "name": "Semi-trailing arm suspension",
 "kind": "standard",
 "category": "Car design",
 "group": "Suspension geometry",
 "year": null,
 "question": "What is a semi-trailing arm?",
 "tags": [
  "vehicle design",
  "suspension geometry",
  "rc design",
  "aerodynamics",
  "guide"
 ],
 "aliases": [
  "semi trailing arm",
  "semi-trailing arm suspension",
  "bmw semi trailing",
  "weissach axle",
  "semi trailing camber",
  "rear suspension types",
  "semi trailing toe change",
  "semi-trailing arm geometry"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": false,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/semi-trailing-arm/",
 "sheet_txt": "https://xemstudio.com/objects/semi-trailing-arm/sheet.txt",
 "sheet": {
  "basis": "Design rules and figures from the cited sources; example geometry by Xem Studio",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "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)."
  ],
  "table": {
   "columns": [
    "parameter",
    "value or range",
    "source"
   ],
   "rows": [
    [
     "Pivot axis inclination",
     "about 50-70 deg",
     "AutoZine"
    ]
   ]
  }
 },
 "sheet_text": "Semi-trailing arm suspension — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/semi-trailing-arm/  (sheet CC BY 4.0)\nBasis: Design rules and figures from the cited sources; example geometry by Xem Studio\nCatalog version: 2026-10-20\n\nSizes: see table below\n- 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).\n- Camber changes with wheel travel; it was common on older BMW, Mercedes and Porsche models before multi-link took over (AutoZine).\n- Used on: BMW 3-Series (1982), Mercedes 560SEC, Porsche 911, Porsche 928 (Weissach axle).\n\nparameter  value or range  source\nPivot axis inclination  about 50-70 deg  AutoZine\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- AutoZine Technical School: Suspension: trailing arm, semi-trailing arm, torsion beam, multi-link — web — Publisher's page; dimensions are facts — https://w.autozine.org/technical_school/suspension/tech_suspension21.htm\n\nNo true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.\nAPI: https://xemstudio.com/api/geometry?object=semi-trailing-arm\n",
 "sources": [
  {
   "publisher": "AutoZine Technical School",
   "title": "Suspension: trailing arm, semi-trailing arm, torsion beam, multi-link",
   "url": "https://w.autozine.org/technical_school/suspension/tech_suspension21.htm",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "camber",
  "caster",
  "kick-up",
  "toe-front",
  "toe-rear",
  "ackermann"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "What is the Weissach axle?",
   "a": "A semi-trailing variant that limits braking toe-out (AutoZine)."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/semi-trailing-arm/index.md"
}