Harken 57mm Double Zircon Block

Product Description

The core of the new Zircon blocks are industrial ceramic ball bearings
mounted inside caged races. The cages keep these bearings apart
so they don’t bunch up, touch, and stop each other. The result is
a VERY free-running block with less energy lost to friction than in
even our current Carbo blocks. Give an unrigged Zircon block a
strong spin, and it spins an incredibly long time.
Why ceramic bearing balls? Ceramic is a more familiar name for
the metallic oxide Zirconia. Zircon bearings are more than 700%
stronger in compression than stainless bearings of the same size.
So, they won’t deform if used within the recommended load limits.
More importantly, they don’t absorb as much energy before starting
to roll. This becomes evident when you need to ease a sail in
very light air. These blocks respond! You feel even the slightest
fluctuations in sheet load. When used expertly, that means better
sail shape and more speed.
For the same bearing sizes, ceramic withstands incredible
compression loads, but beyond the limit, they tend to crush not
flatten. So, apply them thoughtfully in your rig. We’ll be the first
to admit Zircon blocks are not for everyone. They’re more efficient
than other Harken small boat blocks, but more expensive too. Here’s
how we see it: 1. This is competitive. If we don’t offer this level of
performance, someone else might. 2. Sailors know best. If they try
one and find value, they will buy more. The opposite is also true.
We’re good with that.

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