Description
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:Â 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:Â 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”:Â 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.
