Carbon Spoke Wheel Building Guidelines

Preliminary Information

Carbon spokes offer exceptional tensile strength but are significantly less tolerant of lateral bending and torsional stress compared to steel spokes. For this reason:

• Do not clamp or grip the carbon fiber section of the spoke at any time.

• Avoid spoke wind-up (twisting) during tensioning.

• Always use a dedicated spoke holder wrench to stabilize the spoke hardware when adjusting nipple tension.

Spoke Construction

Carbon spokes consist of three main components:

• Hub-end hardware (steel or titanium)
• Carbon fiber body
• Rim-end hardware (steel or titanium)

Nipple Compatibility

While hardware dimensions vary between manufacturers, thread standards are generally consistent. 

Carbon spokes require dedicated square aluminum nipples (5.5 mm hex) and are not compatible with standard brass or alloy nipples used in steel spoke builds. Our supplied nipples feature a self-locking design to reduce the risk of loosening under dynamic loads.

Rim Compatibility

Our ultra-light (1.8 g) titanium hardware carbon spokes are designed to be tensioned through rim bed access holes. Therefore, rims must include rim bed holes and are not compatible with UST (no-hole) designs.

Preparation

Spoke Length Calculation

At NTP, spoke length is calculated precisely based on:

• Rim geometry

• Hub dimensions

• Carbon spoke hardware specifications

Accurate spoke length is critical to ensure optimal wheel strength, durability, and tension balance. Due to the tight tolerances of carbon spokes, we strongly recommend practical test builds to validate theoretical calculations before production.

Rim Preparation

Rim nipple holes are drilled with specific angular orientations (four-direction drilling). Carbon spoke builds typically require greater drilling angles than standard configurations.

To ensure proper alignment and minimize stress on the spokes:

• A custom drilling program is created for each rim–hub combination

• Hole angles are optimized to prevent spoke misalignment or bending, which can lead to premature failure

• Rim bed holes are staggered to align with nipple angles, allowing easier tool access during assembly

Please provide hub specifications in advance. Our engineering team will develop a custom drilling layout to ensure your rims are properly prepared.

Hub Preparation

Carbon spokes are available with three hub-end designs:

• Round head

• T-head

• Threaded head

T-head and threaded designs help prevent uncontrolled spoke rotation under low tension, maintaining proper blade alignment for optimal aerodynamic performance.

Ensure that your selected hub is compatible with your chosen spoke type. If needed, consult your NTP project manager for confirmation.

Required Tools

To achieve consistent, high-quality results, the following tools are recommended for carbon spoke wheel building:

T-Handle Nipple Wrench (5.5 mm Hex)

Used to adjust nipples through the rim bed. We recommend tools designed for deep-section rims to accommodate varying rim depths.

3-Slot Spoke Holder Wrench (or tailor-made spoke holder)

Used to hold the metal spoke hardware at the nipple interface, preventing spoke twist during tensioning.

⚠️ Important:

 Never clamp the carbon fiber body directly.

Standard Wheel Building Tools

The following tools are identical to those used in steel spoke builds:

• Tension meter (e.g., Sapim, DT Swiss)

• Truing stand

• Dishing gauge

• Tension calibration device (for creating carbon spoke-specific tension charts)

Wheel Lacing

The lacing process is similar to steel spoke builds, with additional care requirements:

• Avoid twisting, bending, or lateral stress on the spokes

• Begin with the high-tension side:

• • Rear wheel: drive side

• • Front wheel (disc brake): disc side

• Ensure spokes adjacent to the valve hole are parallel, allowing easy pump access.

Initial Assembly

• Engage each nipple with approximately 5–8 turns.

• Once all spokes are installed, tighten nipples until no threads are visible.

Wheel Truing

The truing process follows standard procedures but requires greater care:

• Work gradually and evenly.

• Avoid inducing torsional stress or bending forces.

• Always stabilize spokes using a spoke holder tool during adjustments.

Recommended Spoke Tensions [Road Disc-Brake]

Carbon spoke wheels require stress relieving similar to steel builds, with a key difference in method:

• Apply pressure to the hub body, not the spokes

After stress relieving, perform final truing adjustments to achieve optimal alignment and tension balance.

For more technical support or custom engineering solutions, please contact your NTP representative.