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Handlebar clamp rings: split rings for 22.2 to 35.0 mm bars, M4 / M5
How do I design a clamp that fits a bike handlebar? · Hardware · 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
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 6 in table
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.
Sizes
| bar Ø | ring OD | ears across (mm) | screw | screw and nut |
|---|---|---|---|---|
| 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 |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| bore | Ø = the bar (22.2 to 35.0) | handlebar section of the same Ø; the gap closes on it | clamp | clamp-ring-* |
| take-up gap | 2.0 | closes when the screw is tightened | designed | clamp-ring-* |
| screw holes | Ø4.5 (M4, bars to Ø26.0) / Ø5.5 (M5, Ø31.8 and Ø35.0) | ISO 273 medium clearance, screw and nut | designed | clamp-ring-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Sheldon Brown (Harris Cyclery) | Handlebar and stem dimension crib sheet: clamp and grip diameters | web | reference verify |
| BikeGremlin | Bicycle handlebar dimension standards: clamp 22.2 to 35 mm, grip 22.2 / 23.8 mm | web | reference verify |
Free files
★ Free files 6 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| clamp-ring-22.2 | 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 | STEP · STL |
| clamp-ring-23.8 | 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 | STEP · STL |
| clamp-ring-25.4 | 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 | STEP · STL |
| clamp-ring-26.0 | 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 | STEP · STL |
| clamp-ring-31.8 | 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 | STEP · STL |
| clamp-ring-35.0 | 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 | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=handlebar-clamp-rings
How it fits
Goes in or on
Bicycle handlebar diametersbore = the bar Ø (clamp)Connects to
17 mm ball joint for phone mountsa 17 mm ball stud unioned onto the ring
Camera tripod thread bossesa 1/4-20 boss unioned onto the ringAlso needed
Socket head cap screws, M2–M8M4 × 16 or M5 × 20 through the ears
Hex nuts, M2–M8M4 or M5 nut on the far earYou might also need
Questions
What bore should a handlebar clamp have?
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.
What screw does a bar clamp use?
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.
Can I put my own mount on these rings?
Yes: they are building blocks; union your part onto the outside and keep the bore, gap and ears as drawn.