{
 "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": "bicycle-handlebar-diameters",
 "name": "Bicycle handlebar diameters: 22.2, 23.8, 25.4, 26.0, 31.8 and 35.0 mm",
 "kind": "standard",
 "category": "Everyday mounts",
 "group": "Bicycle",
 "year": null,
 "question": "What diameter is a bike handlebar?",
 "tags": [
  "bicycle",
  "handlebar",
  "bike",
  "clamp",
  "mount",
  "bar diameter"
 ],
 "aliases": [
  "handlebar diameter",
  "bike handlebar size",
  "handlebar clamp diameter",
  "31.8 handlebar",
  "35mm handlebar",
  "22.2 handlebar",
  "25.4 handlebar",
  "bike bar diameter mm",
  "handlebar grip diameter",
  "handlebar step",
  "handlebar stl",
  "handlebar dxf"
 ],
 "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/bicycle-handlebar-diameters/",
 "sheet_txt": "https://xemstudio.com/objects/bicycle-handlebar-diameters/sheet.txt",
 "sheet": {
  "basis": "Clamp and grip diameters from Sheldon Brown's handlebar crib sheet and BikeGremlin's handlebar standards; current popularity of 31.8 and 35 from Bikepacking.com's stem-clamp survey",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "A bar has two diameters that matter: the clamp section in the middle (where the stem holds it) and the grip section out to the ends (where grips, brake levers, shifters, lights and phone mounts go).",
   "Flat and riser bars are Ø22.2 (7/8 in) at the grips whatever their clamp size; drop bars are Ø23.8 (15/16 in) at the hoods and drops.",
   "Clamp sizes in use: 22.2, 23.8, 25.4 (the ISO size), 26.0 (Italian drop bars), 31.8 (oversized, the most common today) and 35.0 (modern trail bars). Older bars also came in 25.0 (French), 25.8, 26.4 and 27.0, not drawn here.",
   "Files: each diameter as a Ø × 100 mm section, axis on X, plus a DXF of the circle. They are the outside of the bar only: wall thickness differs between bars and is not part of the interface, so the inside is not drawn.",
   "Most bars swell or taper between the clamp and the grip section; measure where your part will sit. A clamp drawn to the bar Ø closes onto the bar: see handlebar-clamp-rings."
  ],
  "table": {
   "columns": [
    "clamp or section Ø (mm)",
    "inch",
    "where it is used",
    "from"
   ],
   "rows": [
    [
     "Ø22.2",
     "7/8 in",
     "BMX bars, older mountain bikes and small children's bikes; also the flat-bar grip, brake-lever and shifter section",
     "Sheldon Brown, BikeGremlin"
    ],
    [
     "Ø23.8",
     "15/16 in",
     "the drop-bar grip, brake-lever and bar-end section; also an older British clamp size on 3-speeds",
     "Sheldon Brown, BikeGremlin"
    ],
    [
     "Ø25.4",
     "1 in",
     "the ISO clamp size: most upright bars, older drop bars",
     "Sheldon Brown, BikeGremlin, Bikepacking.com"
    ],
    [
     "Ø26.0",
     "—",
     "the Italian drop-bar clamp size",
     "Sheldon Brown, BikeGremlin"
    ],
    [
     "Ø31.8",
     "1 1/4 in",
     "the oversized clamp: the most common clamp size today on road, gravel and mountain bars",
     "Sheldon Brown, BikeGremlin, Bikepacking.com"
    ],
    [
     "Ø35.0",
     "1 3/8 in",
     "the 35 mm clamp on modern mountain (trail) bars",
     "Sheldon Brown, BikeGremlin, Bikepacking.com"
    ],
    [
     "grip section, flat bars",
     "Ø22.2 (7/8 in)",
     "with clamp 22.2, 25.4, 31.8 or 35.0",
     "Sheldon Brown, BikeGremlin"
    ],
    [
     "grip section, drop bars",
     "Ø23.8 (15/16 in)",
     "with clamp 23.8, 25.4, 26.0 or 31.8",
     "Sheldon Brown, BikeGremlin"
    ]
   ]
  }
 },
 "sheet_text": "Bicycle handlebar diameters: 22.2, 23.8, 25.4, 26.0, 31.8 and 35.0 mm — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/bicycle-handlebar-diameters/  (CC BY 4.0)\nBasis: Clamp and grip diameters from Sheldon Brown's handlebar crib sheet and BikeGremlin's handlebar standards; current popularity of 31.8 and 35 from Bikepacking.com's stem-clamp survey\nCatalog version: 2026-10-20\n\nSizes: see table below\n- A bar has two diameters that matter: the clamp section in the middle (where the stem holds it) and the grip section out to the ends (where grips, brake levers, shifters, lights and phone mounts go).\n- Flat and riser bars are Ø22.2 (7/8 in) at the grips whatever their clamp size; drop bars are Ø23.8 (15/16 in) at the hoods and drops.\n- Clamp sizes in use: 22.2, 23.8, 25.4 (the ISO size), 26.0 (Italian drop bars), 31.8 (oversized, the most common today) and 35.0 (modern trail bars). Older bars also came in 25.0 (French), 25.8, 26.4 and 27.0, not drawn here.\n- Files: each diameter as a Ø × 100 mm section, axis on X, plus a DXF of the circle. They are the outside of the bar only: wall thickness differs between bars and is not part of the interface, so the inside is not drawn.\n- Most bars swell or taper between the clamp and the grip section; measure where your part will sit. A clamp drawn to the bar Ø closes onto the bar: see handlebar-clamp-rings.\n\nclamp or section Ø (mm)  inch  where it is used  from\nØ22.2  7/8 in  BMX bars, older mountain bikes and small children's bikes; also the flat-bar grip, brake-lever and shifter section  Sheldon Brown, BikeGremlin\nØ23.8  15/16 in  the drop-bar grip, brake-lever and bar-end section; also an older British clamp size on 3-speeds  Sheldon Brown, BikeGremlin\nØ25.4  1 in  the ISO clamp size: most upright bars, older drop bars  Sheldon Brown, BikeGremlin, Bikepacking.com\nØ26.0  —  the Italian drop-bar clamp size  Sheldon Brown, BikeGremlin\nØ31.8  1 1/4 in  the oversized clamp: the most common clamp size today on road, gravel and mountain bars  Sheldon Brown, BikeGremlin, Bikepacking.com\nØ35.0  1 3/8 in  the 35 mm clamp on modern mountain (trail) bars  Sheldon Brown, BikeGremlin, Bikepacking.com\ngrip section, flat bars  Ø22.2 (7/8 in)  with clamp 22.2, 25.4, 31.8 or 35.0  Sheldon Brown, BikeGremlin\ngrip section, drop bars  Ø23.8 (15/16 in)  with clamp 23.8, 25.4, 26.0 or 31.8  Sheldon Brown, BikeGremlin\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- Bikepacking.com: Stem clamp diameters: a brief history and survey results (31.8 most common, 35 on trail bikes) — web — reference [verify license at link] — https://bikepacking.com/gear/stem-clamp-diameters/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/index.json\nAPI: https://xemstudio.com/api/geometry?object=bicycle-handlebar-diameters\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
  },
  {
   "publisher": "Bikepacking.com",
   "title": "Stem clamp diameters: a brief history and survey results (31.8 most common, 35 on trail bikes)",
   "url": "https://bikepacking.com/gear/stem-clamp-diameters/",
   "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": [
  "handlebar-clamp-rings",
  "bicycle-seatpost-diameters",
  "bicycle-steerer-1-1-8",
  "bicycle-bottle-cage-bosses",
  "phone-mount-ball-17mm",
  "gopro-mount"
 ],
 "fits": [
  {
   "role": "Connects to",
   "items": [
    {
     "slug": "handlebar-clamp-rings",
     "why": "split clamp ring with the bore = the bar Ø (clamp)"
    }
   ]
  },
  {
   "role": "Alternatives",
   "items": [
    {
     "slug": "bicycle-seatpost-diameters",
     "why": "the other round tube people clamp to"
    }
   ]
  },
  {
   "role": "Also needed",
   "items": [
    {
     "slug": "phone-mount-ball-17mm",
     "why": "a 17 mm ball on the clamp for a phone head"
    }
   ]
  }
 ],
 "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": "bar outside",
   "exact": "Ø22.2 / 23.8 / 25.4 / 26.0 / 31.8 / 35.0",
   "mates": "stem, lever, grip or mount clamp of the same Ø",
   "fit": "clamp",
   "files": "bar-"
  }
 ],
 "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 diameter is a bike handlebar?",
   "a": "At the grips: Ø22.2 mm on flat bars, Ø23.8 mm on drop bars. At the stem clamp: 31.8 mm on most current bikes, 35.0 mm on many modern mountain bikes, 25.4 or 26.0 mm on older bikes."
  },
  {
   "q": "What size is a 31.8 handlebar at the grips?",
   "a": "Ø22.2 mm on a flat bar and Ø23.8 mm on a drop bar: 31.8 is only the clamp section in the middle."
  },
  {
   "q": "What diameter should a phone or light mount clamp be?",
   "a": "The diameter where it sits: Ø22.2 out on a flat bar, Ø23.8 on a drop bar, or the clamp size (usually 31.8 or 35.0) next to the stem."
  },
  {
   "q": "Is 25.4 the same as 1 inch?",
   "a": "Yes: 25.4 mm is exactly 1 in, the ISO clamp size."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "bar-22.2-L100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-22.2-L100.step",
   "stl": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-22.2-L100.stl",
   "note": "Handlebar section Ø22.2 (7/8 in) × 100 long, axis on X: the outside of the bar (the wall is not drawn); DXF = the exact Ø22.2 circle"
  },
  {
   "file": "bar-23.8-L100",
   "formats": [
    "step",
    "stl"
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   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-23.8-L100.step",
   "stl": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-23.8-L100.stl",
   "note": "Handlebar section Ø23.8 (15/16 in) × 100 long, axis on X: the outside of the bar (the wall is not drawn); DXF = the exact Ø23.8 circle"
  },
  {
   "file": "bar-25.4-L100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
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   "stl": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-25.4-L100.stl",
   "note": "Handlebar section Ø25.4 (1 in) × 100 long, axis on X: the outside of the bar (the wall is not drawn); DXF = the exact Ø25.4 circle"
  },
  {
   "file": "bar-26.0-L100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
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   "stl": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-26.0-L100.stl",
   "note": "Handlebar section Ø26.0 (—) × 100 long, axis on X: the outside of the bar (the wall is not drawn); DXF = the exact Ø26.0 circle"
  },
  {
   "file": "bar-31.8-L100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-31.8-L100.step",
   "stl": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-31.8-L100.stl",
   "note": "Handlebar section Ø31.8 (1 1/4 in) × 100 long, axis on X: the outside of the bar (the wall is not drawn); DXF = the exact Ø31.8 circle"
  },
  {
   "file": "bar-35.0-L100",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-35.0-L100.step",
   "stl": "https://xemstudio.com/files/hardware/bicycle-handlebar-diameters/bar-35.0-L100.stl",
   "note": "Handlebar section Ø35.0 (1 3/8 in) × 100 long, axis on X: the outside of the bar (the wall is not drawn); DXF = the exact Ø35.0 circle"
  }
 ],
 "markdown": "https://xemstudio.com/objects/bicycle-handlebar-diameters/index.md"
}