{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "handlebar-clamp-rings",
 "name": "Handlebar clamp rings: split rings for 22.2 to 35.0 mm bars, M4 / M5",
 "kind": "hardware",
 "category": "Everyday mounts",
 "group": "Adapter blocks",
 "year": null,
 "question": "How do I design a clamp that fits a bike handlebar?",
 "tags": [
  "clamp",
  "handlebar",
  "bar clamp",
  "pipe clamp",
  "split ring",
  "mount",
  "adapter"
 ],
 "aliases": [
  "handlebar clamp",
  "handlebar clamp step",
  "bar clamp 31.8",
  "35mm bar clamp",
  "22.2 handlebar clamp",
  "split clamp ring",
  "tube clamp cad",
  "handlebar mount base"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 6,
 "url": "https://xemstudio.com/objects/handlebar-clamp-rings/",
 "sheet_txt": "https://xemstudio.com/objects/handlebar-clamp-rings/sheet.txt",
 "sheet": {
  "basis": "Bore = the bar Ø from bicycle-handlebar-diameters; screw clearance holes ISO 273 medium; ring wall, width, ears and the 2.0 take-up gap are my design",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A building block for anything that clamps on a round bar: union your phone mount, light bracket or bag hook onto the ring's outside and keep the bore and gap as drawn.",
   "The bore is exactly the bar diameter, so the ring touches the bar all round with no overlap; the 2 mm gap at the bottom is designed take-up: tightening the screw closes it and grips the bar (fit class clamp).",
   "Ring wall 4, width 16. Bars up to Ø26.0 take one M4 screw (Ø4.5 clearance, 5 mm ears); Ø31.8 and Ø35.0 take one M5 (Ø5.5 clearance, 6 mm ears). The screw and nut are the catalog's ISO 4762 screws and ISO 4032 nuts.",
   "Fit check: each ring placed on its bar section from bicycle-handlebar-diameters: zero common volume and zero distance (touching), see files/assemblies/handlebar-clamp-fit-report.json.",
   "The same rings fit any round tube of the same Ø: seatposts of equal size, e-scooter or stroller tubes once their Ø is published or scanned."
  ],
  "table": {
   "columns": [
    "bar Ø",
    "ring OD",
    "ears across (mm)",
    "screw",
    "screw and nut"
   ],
   "rows": [
    [
     "Ø22.2",
     "30.2",
     "12",
     "M4, Ø4.5 clearance",
     "M4 × 16 + M4 nut"
    ],
    [
     "Ø23.8",
     "31.8",
     "12",
     "M4, Ø4.5 clearance",
     "M4 × 16 + M4 nut"
    ],
    [
     "Ø25.4",
     "33.4",
     "12",
     "M4, Ø4.5 clearance",
     "M4 × 16 + M4 nut"
    ],
    [
     "Ø26.0",
     "34",
     "12",
     "M4, Ø4.5 clearance",
     "M4 × 16 + M4 nut"
    ],
    [
     "Ø31.8",
     "39.8",
     "14",
     "M5, Ø5.5 clearance",
     "M5 × 20 + M5 nut"
    ],
    [
     "Ø35.0",
     "43",
     "14",
     "M5, Ø5.5 clearance",
     "M5 × 20 + M5 nut"
    ]
   ]
  }
 },
 "sheet_text": "Handlebar clamp rings: split rings for 22.2 to 35.0 mm bars, M4 / M5 — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/handlebar-clamp-rings/  (CC BY 4.0)\nBasis: Bore = the bar Ø from bicycle-handlebar-diameters; screw clearance holes ISO 273 medium; ring wall, width, ears and the 2.0 take-up gap are my design\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A building block for anything that clamps on a round bar: union your phone mount, light bracket or bag hook onto the ring's outside and keep the bore and gap as drawn.\n- The bore is exactly the bar diameter, so the ring touches the bar all round with no overlap; the 2 mm gap at the bottom is designed take-up: tightening the screw closes it and grips the bar (fit class clamp).\n- Ring wall 4, width 16. Bars up to Ø26.0 take one M4 screw (Ø4.5 clearance, 5 mm ears); Ø31.8 and Ø35.0 take one M5 (Ø5.5 clearance, 6 mm ears). The screw and nut are the catalog's ISO 4762 screws and ISO 4032 nuts.\n- Fit check: each ring placed on its bar section from bicycle-handlebar-diameters: zero common volume and zero distance (touching), see files/assemblies/handlebar-clamp-fit-report.json.\n- The same rings fit any round tube of the same Ø: seatposts of equal size, e-scooter or stroller tubes once their Ø is published or scanned.\n\nbar Ø  ring OD  ears across (mm)  screw  screw and nut\nØ22.2  30.2  12  M4, Ø4.5 clearance  M4 × 16 + M4 nut\nØ23.8  31.8  12  M4, Ø4.5 clearance  M4 × 16 + M4 nut\nØ25.4  33.4  12  M4, Ø4.5 clearance  M4 × 16 + M4 nut\nØ26.0  34  12  M4, Ø4.5 clearance  M4 × 16 + M4 nut\nØ31.8  39.8  14  M5, Ø5.5 clearance  M5 × 20 + M5 nut\nØ35.0  43  14  M5, Ø5.5 clearance  M5 × 20 + M5 nut\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Sheldon Brown (Harris Cyclery): Handlebar and stem dimension crib sheet: clamp and grip diameters — web — reference [verify license at link] — https://www.sheldonbrown.com/cribsheet-handlebars.html\n- BikeGremlin: Bicycle handlebar dimension standards: clamp 22.2 to 35 mm, grip 22.2 / 23.8 mm — web — reference [verify license at link] — https://bike.bikegremlin.com/3784/bicycle-handlebar-dimension-standards/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/handlebar-clamp-rings/index.json\nAPI: https://xemstudio.com/api/geometry?object=handlebar-clamp-rings\n",
 "sources": [
  {
   "publisher": "Sheldon Brown (Harris Cyclery)",
   "title": "Handlebar and stem dimension crib sheet: clamp and grip diameters",
   "url": "https://www.sheldonbrown.com/cribsheet-handlebars.html",
   "formats": [
    "web"
   ],
   "license": "reference",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "BikeGremlin",
   "title": "Bicycle handlebar dimension standards: clamp 22.2 to 35 mm, grip 22.2 / 23.8 mm",
   "url": "https://bike.bikegremlin.com/3784/bicycle-handlebar-dimension-standards/",
   "formats": [
    "web"
   ],
   "license": "reference",
   "license_verified": false,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "bicycle-handlebar-diameters",
  "socket-head-cap-screws-metric",
  "hex-nuts-metric",
  "phone-mount-ball-17mm",
  "camera-thread-bosses-1-4-20",
  "gopro-mount"
 ],
 "fits": [
  {
   "role": "Goes in or on",
   "items": [
    {
     "slug": "bicycle-handlebar-diameters",
     "why": "bore = the bar Ø (clamp)"
    }
   ]
  },
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "phone-mount-ball-17mm",
     "why": "a 17 mm ball stud unioned onto the ring"
    },
    {
     "slug": "camera-thread-bosses-1-4-20",
     "why": "a 1/4-20 boss unioned onto the ring"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "socket-head-cap-screws-metric",
     "why": "M4 × 16 or M5 × 20 through the ears"
    },
    {
     "slug": "hex-nuts-metric",
     "why": "M4 or M5 nut on the far ear"
    }
   ]
  }
 ],
 "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": [
  {
   "feature": "bore",
   "exact": "Ø = the bar (22.2 to 35.0)",
   "mates": "handlebar section of the same Ø; the gap closes on it",
   "fit": "clamp",
   "files": "clamp-ring-"
  },
  {
   "feature": "take-up gap",
   "exact": "2.0",
   "mates": "closes when the screw is tightened",
   "fit": "designed",
   "files": "clamp-ring-"
  },
  {
   "feature": "screw holes",
   "exact": "Ø4.5 (M4, bars to Ø26.0) / Ø5.5 (M5, Ø31.8 and Ø35.0)",
   "mates": "ISO 273 medium clearance, screw and nut",
   "fit": "designed",
   "files": "clamp-ring-"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "What bore should a handlebar clamp have?",
   "a": "The bar diameter itself (22.2, 23.8, 25.4, 26.0, 31.8 or 35.0 mm), with a split that closes on the bar. Open the bore by your process allowance only, never by guesswork."
  },
  {
   "q": "What screw does a bar clamp use?",
   "a": "M4 for bars up to 26.0 mm and M5 for 31.8 and 35.0 mm in these rings: one screw through the ears with a nut."
  },
  {
   "q": "Can I put my own mount on these rings?",
   "a": "Yes: they are building blocks; union your part onto the outside and keep the bore, gap and ears as drawn."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "clamp-ring-22.2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-22.2.step",
   "stl": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-22.2.stl",
   "note": "Split clamp ring for a Ø22.2 bar: bore Ø22.2 (= the bar), wall 4, 16 wide, 2 take-up gap between two 5 ears, Ø4.5 M4 clearance hole on the ear centre 19.85 below the bar axis"
  },
  {
   "file": "clamp-ring-23.8",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-23.8.step",
   "stl": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-23.8.stl",
   "note": "Split clamp ring for a Ø23.8 bar: bore Ø23.8 (= the bar), wall 4, 16 wide, 2 take-up gap between two 5 ears, Ø4.5 M4 clearance hole on the ear centre 20.65 below the bar axis"
  },
  {
   "file": "clamp-ring-25.4",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-25.4.step",
   "stl": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-25.4.stl",
   "note": "Split clamp ring for a Ø25.4 bar: bore Ø25.4 (= the bar), wall 4, 16 wide, 2 take-up gap between two 5 ears, Ø4.5 M4 clearance hole on the ear centre 21.45 below the bar axis"
  },
  {
   "file": "clamp-ring-26.0",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-26.0.step",
   "stl": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-26.0.stl",
   "note": "Split clamp ring for a Ø26.0 bar: bore Ø26.0 (= the bar), wall 4, 16 wide, 2 take-up gap between two 5 ears, Ø4.5 M4 clearance hole on the ear centre 21.75 below the bar axis"
  },
  {
   "file": "clamp-ring-31.8",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-31.8.step",
   "stl": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-31.8.stl",
   "note": "Split clamp ring for a Ø31.8 bar: bore Ø31.8 (= the bar), wall 4, 16 wide, 2 take-up gap between two 6 ears, Ø5.5 M5 clearance hole on the ear centre 25.15 below the bar axis"
  },
  {
   "file": "clamp-ring-35.0",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-35.0.step",
   "stl": "https://xemstudio.com/files/hardware/handlebar-clamp-rings/clamp-ring-35.0.stl",
   "note": "Split clamp ring for a Ø35.0 bar: bore Ø35.0 (= the bar), wall 4, 16 wide, 2 take-up gap between two 6 ears, Ø5.5 M5 clearance hole on the ear centre 26.75 below the bar axis"
  }
 ],
 "markdown": "https://xemstudio.com/objects/handlebar-clamp-rings/index.md"
}