Brief description

Spoke lacing is the technique of arranging and connecting the spokes of a wheel between the hub and the rim. This arrangement is crucial for the structural integrity of the wheel, determining how load, traction, and braking forces are distributed. In modern tension wheels (like bicycle wheels), the lacing pattern defines the strength and durability of the wheel.

Use / Function

• Load Distribution: Transfers the vehicle’s weight from the axle to the ground through the spokes (in compression for wood, in tension for wire).
• Torque Transmission: Transfers rotational force from the hub to the rim (essential in drive wheels).
• Lateral Stability: Provides lateral stiffness to prevent the wheel from buckling (tacoing).
• Shock Absorption: Allows for some flexibility to absorb bumps from the terrain.

Operating principle

Lacing works through triangulation and tension (or compression).

• Compression Wheels (Wood): Spokes act as solid columns. Weight is transferred directly through the spoke beneath the hub to the ground.
• Tension Wheels (Wire): The hub “hangs” from the upper spokes. All spokes are under tension. When load is applied, tension in the lower spokes decreases but should never reach zero.
• Crossed Patterns: By crossing spokes, an angle is created that allows torque (acceleration/braking) to be transmitted without the hub twisting independently of the rim.

How to create it

3-Cross Lacing (Standard for Tension)

1. Preparation: You need a hub, a rim, spokes of the correct length, and nipples.
2. First Group (Key Spoke): Insert the first spoke into the hub and connect it to the rim. This is the key spoke.
3. Drive Side: Insert the next spokes leaving gaps in the hub and rim according to the pattern (usually every 4 holes in the rim).
4. Non-Drive Side: Repeat the process for the other side of the hub, ensuring proper staggering.
5. Crossing: When inserting the final spokes, cross them over and under existing spokes (e.g., over two, under one) to interlace them.
6. Tensioning and Truing: Tighten nipples evenly. Adjust tension to align the wheel laterally (lateral true) and radially (roundness), and to ensure the hub is centered (dishing).

Materials needed

• Spokes: Usually stainless steel wire or hard wood.
• Nipples: Small nuts that hold the spoke to the rim.
• Rim: The outer hoop.
• Hub: The central core.
• Tools: Spoke wrench, truing stand.

Variants and improvements

• Radial: Spokes go directly from hub to rim without crossing. Lighter and more aerodynamic, but does not transmit torque well (bad for disc brakes or drive wheels).
• Crossed (1, 2, 3, or 4 cross): Spokes cross each other. Higher number of crosses = greater absorption and torque transmission capacity.
• Crow’s Foot: Combination of radial and crossed spokes.
• Bladed Spokes: Flat for aerodynamics.
• Butted Spokes: Thinner in the middle to save weight and increase elasticity.

Limits and risks

• Fatigue Failure: Continuous cycles of loading and unloading can break spokes, usually at the elbow (near the hub).
• Out of True: If a spoke loosens, the wheel wobbles, which can cause accidents or irregular braking.
• Excessive Tension: Can damage the rim (cracking around holes) or the hub flange.