Frame Service & Maintenance | Dirtlab CP

Frame Service & Maintenance

Concentric Pivot (C Pivot) platform — exploded diagrams, parts reference and bolt torque specifications

Paratu CP eMTB (EC2) Iuhu CP Pedal (C3) Orange items = eMTB only

Exploded Diagram — Concentric Pivot Service Hardware

Colour key: Orange = Paratu CP EC2 eMTB only • Blue = chain guide assembly (both) • Black/grey = common to both frames

Parts List — Concentric Pivot 145-185 Service Hardware

Concentric pivot 145-185 service hardware parts list

Ordering spares: Use the P/N (part number) when contacting sales@bikelab-inc.com. Items with orange numbers are Paratu CP eMTB-specific (not used on Iuhu CP pedal frame).

Bolt Torque & Spec Table

Critical: Always use a calibrated torque wrench. Over-tightening carbon is not covered under warranty. Apply Loctite 243 to all pivot bolts as specified. Grease tool contact faces before installing any bolt or axle. For Maxon motor electrical service see Maxon Motor & Electrical Service →

Headset — FSA, low-profile upper bearing with alloy ring

Same headset on the Paratu CP and the Iuhu CP. The headset follows the design of Bikelab and the headset maker FSA. The upper bearing is a low-profile bearing. Under it sits a thin alloy (silver) spacer ring: it adapts the upper bearing to the upper cup chamfer — the cup is 45°, the upper bearing is 36°. This ring is part of the system; it is fairly new and also used by other brands, so not every mechanic has seen it yet.

The silver ring always sits UNDER the upper bearing. Without it, or with it on top of the bearing, the bearing does not seat on the 45° cup chamfer and the headset gets play and creaks.

Assembly order

Grease everything: the inside of the cups, both bearings, the crown race, the silver ring and the steerer. Grease prevents creaking later on.
Bottom: press the lower crown race onto the fork crown, place the lower bearing on the crown race, fit the lower cup into the frame.
Slide the fork through the head tube into the lower bearing.
Top: fit the upper cup, place the silver ring in the cup first, then the upper bearing on top of the ring.
Push the split compression ring (conical wedge) over the steerer into the bearing, then the top cover.
Spacers (max. 25 mm), stem, top cap. Preload the headset with the top-cap bolt before tightening the stem bolts.
Check: the fork turns freely and there is no play (hold the front brake, rock the bike).

Headset parts are shipped taped together in two sets: top (stem side) and bottom (fork side). The cups carry the reach-adjust offset marks (0 mm or ±5 mm) — see Reach Adjust. Spare headset and cups: Paratu CP / Iuhu CP spare parts.

Headset All headset parts — **All headset parts**
Left to right: lower bearing · crown race · lower cup · upper cup · silver alloy ring · low-profile upper bearing · split conical wedge · top cover.

Headset Bottom set — all parts — **Bottom set — all parts**
Crown race, lower cup, lower bearing.

Headset Bottom — bearing on the fork crown race — **Bottom — bearing on the fork crown race**
Press the crown race onto the fork crown, then seat the lower bearing on it.

Headset Bottom — detail on the crown race — **Bottom — detail on the crown race**
The bearing sits flat and fully down on the crown race all the way round.

Headset Bottom — assembled, crown race in the bearing — **Bottom — assembled, crown race in the bearing**

Headset Bottom — lower bearing in the cup — **Bottom — lower bearing in the cup**
The lower bearing goes into the lower cup in the frame.

Headset Top set — silver ring in the cup — **Top set — silver ring in the cup**
The silver alloy ring goes into the upper cup FIRST.

Headset Top — bearing ON TOP of the silver ring — **Top — bearing ON TOP of the silver ring**
The low-profile upper bearing sits on the silver ring.

Headset Top — conical wedge (compression ring) fitted — **Top — conical wedge (compression ring) fitted**
Split wedge around the steerer, into the bearing.

Headset Top — assembled — **Top — assembled**
Top cover on, then spacers, stem and top cap.

Service question about your CP frame? Marvin helps you on a video call or by email.