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Ronstan RF55110 Series 55 Orbit Ball Bearing Single Block with Becket and Swivel Mount

Manufacturer

Ronstan

<h3>Ronstan: Precision Sailing Hardware Built for Every Sailor</h3><p><strong>Ronstan</strong> is one of the most respected names in sailboat hardware — and with good reason. <a href="/11561-ronstan">Ronstan</a> traces its roots back to 1953, when two Australian sailors, Ron Allatt and Stan Lenepveu, founded Ronstan Marine Equipment Pty Ltd in Melbourne, Australia. What started as a passion project supplying handcrafted yacht fittings to their local sailing club gradually grew into a global enterprise recognized for engineering excellence and real-world performance.</p><p>Today, Ronstan is headquartered in Braeside, Victoria, Australia, with international offices in the United States and Denmark, and production facilities across three continents. The brand distributes to more than 40 countries and handles upwards of 4.9 million units out of its Melbourne facility every year. In November 2023, Ronstan joined Groupe Wichard, further cementing its place among the world&apos;s most influential marine hardware groups.</p><h3>Engineering That Performs On the Water</h3><p>What sets Ronstan apart from generic marine suppliers is its deep commitment to innovation and in-house manufacturing capability. Ronstan&apos;s engineering teams — spread across Australia, the United Kingdom, and Denmark — draw on diverse sailing traditions to develop products that meet the demands of wildly different markets: from club dinghy racers to offshore bluewater cruisers. The brand&apos;s catalog spans blocks, winches, travelers, furling systems, batten systems, stainless steel rigging hardware, and a full suite of deck gear. Ronstan is also the official hardware supplier to the Australian Sailing Team.</p><p>The brand&apos;s in-house manufacturing includes precision CNC machining of aluminum, brass, and stainless steel, as well as advanced plastic injection molding using high-performance engineering polymers — including composites reinforced with up to 60% long-strand glass and carbon fiber. This vertical integration means Ronstan controls quality from design to delivery.</p><h3>Core Product Categories</h3><p>Three categories stand out as workhorses of the Ronstan lineup. <a href="/11561-ronstan-fairleads-200387">Ronstan Fairleads</a> are purpose-designed to guide, contain, and correct the lead angle of control lines across a range of deck configurations — a deceptively simple piece of hardware that plays a critical role in clean, friction-free sail handling. For securing lines under load, <a href="/11561-ronstan-cleats-200268">Ronstan Cleats</a> offer a comprehensive range spanning jam cleats, vee cleats, and the brand&apos;s well-known C-Cleat&trade; and T-Cleat&trade; cam cleat families, each engineered for reliable cleating and easy release in all conditions. Completing the rigging equation, <a href="/11561-ronstan-shackles-200937">Ronstan Shackles</a> — including the innovative Triggersnaps&trade; snap shackle range — are individually proof-load tested and designed for intuitive one-handed operation, making them a trusted choice for racers and cruisers alike.</p><h3>From Dinghies to Maxis</h3><p>One of Ronstan&apos;s most distinctive qualities is its breadth. The same brand that equips Olympic-class dinghies also supplies hardware to some of the largest and fastest offshore racing yachts in the world. Whether you&apos;re outfitting a small club boat or a serious offshore campaigner, Ronstan&apos;s catalog has a solution engineered to the right weight, load rating, and finish for the task at hand.</p>

Part Number

RF55110
09/12/2036 10:35 AM
Sale Price

$36.73

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Usually delivered within 2 days

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Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Ronstan RF55110 Series 55 Orbit Block features an innovative orbital ball bearing design that delivers exceptional performance for sailing applications on boats up to 30 feet. This single block with integrated becket and swivel head mount combines ultra-lightweight construction with a maximum working load of 1,100 lbs, making it the lightest block in its class while maintaining superior strength.

Key Features:

  • Ultra-lightweight design at just 3.1 oz with 1,100 lb working load capacity
  • Two-stage orbital ball bearing system minimizes friction across full load range
  • Through-sheave becket arrangement for lowest possible weight
  • Swivel shackle head in 316 stainless steel allows unlimited block rotation
  • 55mm diameter sheave accommodates rope up to 10mm (3/8 inch)
  • Fiber-reinforced, stress-optimized load frame
  • Dyneema SK75 fiber link provides exceptional strength-to-weight ratio
  • Low profile and compact design for easy installation

Construction:

  • Sheave and bearings: Carbon fiber reinforced, PTFE-impregnated nylon with high-compression acetal ball bearings
  • Frame and cheeks: Toughened, glass fiber reinforced nylon
  • Head fitting: Marine-grade 316 stainless steel
  • Rope link: UV-stabilized multi-strand SK75 Dyneema

Ideal Applications:

  • Mainsheet and spinnaker sheet systems on dinghies, sportsboats, and small keelboats to 30 feet
  • Halyard, vang, and backstay applications on boats to 26 feet
  • Control line systems on larger yachts

Specifications:

  • Maximum Working Load: 1,100 lbs (500 kg)
  • Breaking Load: 2,200 lbs (1,000 kg)
  • Sheave Diameter: 55mm (2-5/32 inches)
  • Maximum Rope Diameter: 10mm (3/8 inch)
  • Weight: 3.1 oz (88g)

The RF55110's orbital bearing design positions the bearing only in active areas of the floating sheave, eliminating unnecessary mass from the inactive return race and hub. This engineering innovation delivers 30% weight savings compared to competitors while maintaining the highest working load in its class.

Products specifications

Type

Single

Diameter

3/8 Inch or 10 mm

Mount Type

Swivel Shackle

Weight

0.19

Becket

No Becket

Direction

Any

Integral Cleat

No Integral Cleat

Ratchet

Non Ratcheting

Safe Working Load

1100 Pounds

Sheave Diameter

2 5/32 Inches or 55 mm

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