STREAMLINED TENDON JOINT GREEN 86SH / SOFT (5 PCS)

1. Material and Composition

• High-Strength Urethane: It is made from a proprietary, high-density black polyurethane formula. Unlike transparent or colored tendons, this black urethane is specifically treated to resist UV degradation, which is the #1 killer of mast base joints.

• Shore Hardness: It is engineered to be stiff enough for direct power transfer but flexible enough to bend 90° during transitions or waterstarts.

2. Technical Dimensions

If you are buying a replacement "Streamlined Original" tendon, these are the standard specs:

• Length: Approximately 51mm (2 inches).

• Diameter: Approximately 20mm.

• Hole Alignment: The holes are pre-drilled and perpendicular (at 90 degrees to each other) to align with the stainless steel bolts of the base.

3. Performance Characteristics

• The "Nervous" Feel: Unlike rubber diabolos, the tendon has no "stretch." This means your sail's pumping action and movements are instantly translated to the board.

• Predictable Flex: It provides a consistent bend radius, which helps in maintaining the board's trim in high-wind conditions.

4. Safety & Maintenance (Crucial)

The tendon is a wear item. Because it is a solid piece of plastic, it doesn't "stretch" before it breaks—it snaps.

• The Warning Signs: Inspect the holes. If you see horizontal cracks or the holes becoming "oval-shaped," replace it immediately.

• Lifespan: Heavy users (wave or freestyle) should replace the tendon every 12 to 18 months, regardless of how it looks.

• The "Fail-Safe": In a Streamlined base, the tendon is always backed up by dual Spectra safety lines. If the tendon snaps, the lines catch the rig so you aren't separated from your gear.