29 mm Zircon Block — Becket

Harken 29 mm Zircon Block — Becket

The Harken 29 mm Zircon Block with Becket expands the Zircon line from eight models to eighteen, adding six new models with 29 mm sheave diameters. These smaller sizes make Zircon appropriate for control lines where multi-part purchases are required, such as Cunninghams rigged under the deck or jib leads that need to move forward quickly for more power through chop. Zircon reacts immediately to even the slightest fluctuations in line load, providing the helmsperson with instantaneous response when easing sheets or control lines in light air.

At the heart of Zircon performance are industrial ceramic ball bearings mounted inside caged races. The cages keep the bearings evenly spaced so they cannot bunch up, touch, or stop each other — the result is a remarkably free-running block with very little energy lost to friction. Give an unrigged Zircon block a strong spin and it will keep spinning for an exceptionally long time. Zircon bearings are more than 700% stronger in compression than stainless steel bearings of the same size, meaning they stay smooth and will not deform within recommended load limits. Critically, they also absorb far less energy before they begin to roll, which becomes especially apparent when easing a sheet or multi-part control line in light air. When used with expertise, that translates directly into better sail shape and more boat speed.

Zircon is not intended as an all-purpose alternative — no single block family is — but these compact 29 mm models bring Zircon-level performance to the fine-tuning systems where it matters most. The becket attachment point allows the block to anchor a purchase system, making it well suited for cascades, vangs, outhauls, and other multi-purchase arrangements.

Key Features

• Industrial ceramic ball bearings in caged races for ultra-low friction
• Bearings over 700% stronger in compression than equivalent stainless steel bearings
• 29 mm sheave diameter accommodates lines up to 6 mm (1/4 in)
• Becket attachment for use as a fixed end in purchase systems
• Extremely lightweight at just 12.6 g (0.44 oz)
• Compact 54 mm (2 1/8 in) overall length
• Maximum working load: 80 kg (175 lb)
• Breaking load: 240 kg (525 lb)
• Ideal for Cunninghams, jib leads, vangs, and other multi-part control lines on small boats and dinghies