We machine the SD111-style damper clamp for Ducati Streetfighter V2 and V4. Sold light alloy, 5-axis toolpaths, hard-anodized. The clamp has to hold the damper body on a 43 mm fork leg without crushing it.
Most of these show up on the first ride, not at the bench.
A clamp bored as one 43 mm circle and slit afterward relaxes into an oval. Torque the two M6 bolts and the fork leg takes the load, not the clamp. Clearance has to be split before the slit is cut, or the bore needs a light hone after slitting.
Damper clamps see vibration at the fork, not at the frame. A flat seating face on both bolt pads keeps preload. Burrs under the bolt head and a face that is not square to the hole will let the joint walk loose. We face both pads in the same setup as the holes.
Type II anodize grows 5–15 μm per surface. On an M6 thread that is enough to change the fit. Mask the threads or cut them undersize before coating. Reworking a hard-anodized thread is slow and often scraps the part.
A 0.2 mm gap at the mounting face tilts the damper body. The rod then runs at an angle through its stroke. You get a dead spot near full lock. Face flatness and the angle between the fork bore and the mount pad both matter here.
One setup for the bore, the slit and the bolt pads.
The fork bore, the damper mount pad and the two bolt holes all sit in one 5-axis setup on a Ø400 mm rotary table. Nothing gets re-fixtured between the bore and the mount face, so the angle between them stays where the drawing puts it. On a part this small the second setup is where the error usually creeps in.
We rough the bore 0.3 mm undersize, stress-relieve if the blank is 7075, then finish. The slit is cut last on a 0.8 mm or 1.0 mm slitting saw. For a 43 mm fork leg we leave a 0.05–0.08 mm radial clearance before the slit so the clamp pinches the leg instead of bottoming out on itself.
7075-T6 gives the highest yield strength of the alloys we stock and holds a thin clamp wall well. It also costs more and machines slower than 6082-T6, which is plenty for a bracket that only carries damper load. If the part will live on a street bike, 6082-T6 with a hard anodize is usually the better trade.
Anodize is a conversion coating, so it grows into the part. On a clamp with a 43 mm bore, 10 μm of coating per surface changes the fit by 20 μm across the diameter. We mask the bore and the threads, or cut them undersize by the coating thickness when the customer wants the coating everywhere. Type III hardcoat runs 25–50 μm and needs the same planning.
Match the fork diameter and the damper body before you order.
| Configuration | Fork leg | Damper body | Typical use |
|---|---|---|---|
| SD111 standard | Ø43 mm | Ø30–32 mm | Streetfighter V2, V4 |
| SD111 narrow | Ø43 mm | Ø28–30 mm | Aftermarket damper bodies |
| Oversize bore | Ø45 mm | Ø30–32 mm | Öhlins fork conversions |
| Blank body | As drawn | As drawn | One-off builds and prototypes |
A clamp like this rarely ships on its own.
16 simultaneous 5-axis centers. The clamp body, the bore and the angled mount pad come off one setup. Useful when the customer changes the fork angle and the mount face has to follow.
For simpler two-piece clamps and for the second operation on bolt pads. 12 four-axis mills and 27 three-axis machines handle the volume runs.
16 mill-turn centers cover spacer sleeves, damper pins and any round feature that needs to stay concentric with the bore.
One or two pieces in 6082 or POM so you can check fit on the bike before committing to a batch. Same toolpaths, same datums.
Anodizing in clear, color or hardcoat. Bead blasting, brushing and laser marking for a part number or torque spec on the clamp face.
First-article report, material certs and dimensional reports on request. Every clamp goes over a gauge pin and both bolt pads are checked for flatness.
Numbers apply to the SD111-style clamp family.
| Item | Range | Note |
|---|---|---|
| Tolerance | ±0.005 mm | On bore and mount pad |
| Surface finish | Ra 0.8–1.6 μm | As machined; finer on request |
| Bore sizes | Ø28–45 mm | Other diameters as drawn |
| Batch size | 1 to 10,000+ | No minimum order quantity |
| Lead time | 3–5 days | After drawing approval |
| Inspection | 100% before shipment | Reports on request |
Numbers come from our own shop floor and quality records.
Founded in 2011. Three wholly-owned plants in Dongguan and Singapore, 7,600 m² total, 150 technicians on the floor.
16 simultaneous 5-axis centers, 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers in the same shop.
Not just on a sample. Bore diameter, mount pad flatness and hole position are checked against the drawing on every run.
Raw material check, in-process monitoring and final inspection. Parts that fail the gauge pin check do not ship.
Send a STEP file or a sketch. We flag thin walls, coating build-up on threads and slit clearance before cutting metal.
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022. Uploads stay confidential; NDA on request.
The bracket carries damper load through a bolt joint on a vibrating fork. Bore-to-pad angle has to hold or the rod runs off-axis.
Teams change fork diameter and damper body between events. One or two pieces per revision, same datums as the production version.
Coating thickness changes the fit on every bore and thread. We plan the coating build-up into the machined size before the parts leave the mill.
IATF 16949:2016 process control applies to the same shop that cuts these clamps. Material certs and inspection reports travel with the batch.
Yes. We cut bores from Ø28 mm up to Ø45 mm as standard and anything else to your drawing. Send the fork leg diameter, the damper body diameter and the bolt spacing.
The bore is finished to a gauge pin at the drawing limit, so the clamp pinches the leg instead of bottoming out on its own slit.
7075-T6 has the higher yield strength and holds a thin clamp wall better. It machines slower and costs more, and it needs care when anodizing because of its copper content.
6082-T6 is enough for a clamp that only carries damper load, anodizes more evenly and costs less. On street bikes we usually recommend 6082-T6 with hard anodize.
Type II anodize grows 5–15 μm per surface, so a 43 mm bore shrinks by roughly 10–30 μm across the diameter. Type III hardcoat runs 25–50 μm per surface and changes it more.
Two ways to handle it: mask the bore and the threads, or cut them undersize by the coating thickness. We ask which one you want before the finishing step.
For a 43 mm fork leg we leave 0.05–0.08 mm radial clearance before the slit is cut. That lets the clamp close on the leg with bolt torque instead of hitting its own faces.
Too much clearance and the clamp distorts when tightened. Too little and the bolts run out of travel before the joint is tight.
The bore, the mount pad and the bolt holes are cut in one 5-axis setup. Nothing is re-fixtured between them, so the angle between the fork axis and the mount face stays as drawn.
The mount pad is checked for flatness after machining. A 0.2 mm gap there tilts the damper body and shows up as a dead spot near full lock.
Yes. Laser marking and engraving are standard, with a minimum character height of 1.5 mm. Below that the mark gets hard to read after anodizing.
We can put the mark on a flat face or on the mount pad, whichever stays visible with the clamp installed.
A STEP or IGES file is ideal. A dimensioned sketch works too if that is all you have. Add the alloy, the finish, the quantity and any inspection report you need.
You get a quotation and a free DFM analysis within 12 hours. Production can start within 24 hours after you approve the drawing.
Uploads are secure and confidential. We can sign an NDA before you send files if your process requires it.
Customer drawings and part-specific tooling are not shared outside the project.
Upload a STEP file or a sketch. You get a quotation and a free DFM analysis within 12 hours, and we flag coating build-up and slit clearance before any metal is cut.
12-hour quote100% inspectionNo minimum order quantityNDA on request
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
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