GCS Stem Installation & Care Guide
GCS Stem
―Installation & Care Guide
English
Components
Read before installation
Riding mountain bikes can be dangerous. Incorrect installation of cockpit components can lead to loss of control, serious injury, or death. Read these instructions fully before installing your PEMBREE GCS Stem. If you are unsure about any step, consult a qualified bike mechanic.
Box Contents
- 1 × PEMBREE GCS Stem
- 6 × Stainless steel bolts (pre-installed)
Tools Required
- 5 mm hex key
- Torque wrench (recommended)
- Motorex Anti-Seize (recommended) or equivalent
Product Specifications
- Handlebar clamp diameter: 31.8 mm / 35 mm (model dependent)
- Length: Refer to product marking
- Rise: 0°
- Steerer compatibility: 1 1/8” (28.6 mm) only
Preliminary Checks
1. Steerer Tube Length
Ensure the fork steerer is cut cleanly and leaves approximately 2–3 mm of clearance below the top of the stem or top spacer once installed. This ensures correct headset preload.
2. Clean Contact Surfaces
Ensure the steerer tube and handlebar clamping areas are clean and dry. Do not apply grease to steerer or bar interfaces.
3. Bolt Preparation
Remove bolts and apply a small amount of grease to threads and under bolt heads.
Installation
GCS Stem
Tools
Support
Need additional product support? View this guide on our Help Centre.
1. Fit Stem to Steerer
Remove all bolts and front clamps. Slide the stem onto the steerer tube ensuring the stem body centre line is facing up. Install top cap and preload bolt and torque to the manufacturer’s specifications. (Note: tighten gradually until headset play is removed but steering remains smooth. Do not over tighten).
2. Tighten Steerer Clamp
Reinstall and lightly tighten the two steerer clamp bolts. Align the stem with the front wheel. Then torque both bolts evenly to 9 Nm, alternating between bolts.
3. Position the handlebar
Position the handlebar centrally in the stem (use the centreline of the PEMBREE GCS handlebar if used). Mount the clamps onto the stem body using the top bolts only. (Note: use the X to identify the correct side for each clamp). Torque both bolts evenly to 9 Nm, alternating between bolts.
4. No Gap
Important: Ensure there is no gap at the top of the stem and an assembly gap at the bottom of the clamps.
5. Secure Lower Clamp
Screw in the lower two clamp bolts and torque them evenly to 9 Nm, alternating between bolts. Ensure the bars are aligned and secure, checking that the steering rotates freely without any play.
ⓘ Bolt & Safety Notes
- Use only supplied or PEMBREE approved bolts.
- Do not substitute lower-strength fasteners.
- Ensure full thread engagement in all bolts.
- Inspect components after any crash or heavy impact.
🔧 Maintenance
- Check bolt torque periodically.
- Re-grease bolts during routine servicing.
- Inspect the stem regularly for cracks, deformation, or corrosion.
- Replace immediately if damage is found.