SKU: 63299332735

Ronstan Series 55 Ball Bearing Orbit Block™ - Single - Becket - Swivel Head

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Description

Ronstan Series 55 Ball Bearing Orbit Block™ - Single - Becket - Swivel HeadSeries 55 Ball Bearing Orbit Block Single Becket Swivel Head Lightweight Kilogram for kilogram of working load, BB and RT Orbit Blocks are the world's lightest. The unique orbital design allows the bearing to only be in the active areas of the floating sheave. This minimises the mass of the inactive return race and hub. Weight and bulk are further reduced in the different block configurations. The ball bearing single and becket block has a through

Series 55 Ball Bearing Orbit Block™ - Single - Becket - Swivel Head

Lightweight
Kilogram for kilogram of working load, BB and RT Orbit Blocks™ are the world's lightest. The unique orbital design allows the bearing to only be in the active areas of the floating sheave. This minimises the mass of the inactive return race and hub.

Weight and bulk are further reduced in the different block configurations. The ball bearing single and becket block has a through-sheave becket arrangement. The result? The lowest weight possible.

Multi-sheave blocks have only single intermediate cheeks and an ultra-light and efficient head arrangement. This gives a 30% weight saving advantage over the nearest competitor. Other brands just link together their single blocks. This results in unnecessary double cheeks between each sheave, held together by a heavy steel channel across the top of the block.

Highest Working Load In Its Class
The orbital ball-bearing arrangement gives the largest possible bearing race diameter. This maximises load performance. The proven Ronstan 2-stage bearing system features high compression grade acetal ball bearings and a secondary full-contact bearing. This gives minimum friction across the full working load range.

The floating sheave and bearing system is supported by a fiber-reinforced load frame. The design was computer modelled to be stress optimised. The Dyneema® Link is produced from FSE Robline SK75 fiber, which is 10 times stronger and lighter than steel, and provides the final connection from the block to the load point.

Features:
  • Ultra Lightweight
  • Low friction 2-stage Orbital ball bearing system
  • Highest working load in its class
  • Low profile and compact
  • High performance cleating
  • Swivel shackle head for unlimited block rotation
  • Stainless steel shackle head for ultimate durability and compatibility with harsh fixing points
  • Ultra low profile integrated becket


Applications:
  • Mainsheet systems on dinghies, sportsboats and small keelboats to 9M(30')
  • Spinnaker sheets on dinghies, sportsboats and small keel boats to 9M(30')
  • Halyard, Vang and Backstay application on boats to 8M(26')
  • Control line applications on larger yachts
  • Ideal use for mainsheet systems and spinnaker sheets on dinghies, sportsboats and small keel boats to 9M(30')
  • Also ideal with halyard, vang and backstay applications on boats to 8M(26')
  • Spinnaker sheets on sportsboats and small keel boats (lateral lead blocks)
  • Control line applications on larger yachts


Materials:
  • Ball bearings - High compression strength carbon black Acetal
  • Stage 2 bearing - Carbon fiber reinforced, PTFE impregnated Nylon
  • Frame/Cheeks - Toughened, glass fiber reinforced Nylon
  • Rope Link: UV stabilized, multi-strand impregmented SK75 Dyneema®
  • Sheave: Carbon fiber reinforced, PTFE impregnated Nylon
  • Head fitting: Grade 316 stainless steel.


Specifications:
Sheave Ø: 55mm(2-5/32")
Max. Rope Ø: 10mm(3/8")
M.W.L.: 500kg(1,100lbs)
B. L.: 1,000kg(2,200lbs)
Weight: 88g(3.1oz)
Manufacturer : Ronstan
Manufacturer Part No : RF55110
UPC : 9316800440405
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 63299332735

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4.1 ★★★★★
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B
Verified Purchase
Barry Vercueil
New York, US
★★★★★ 5
Amazing Solar for the price
Color: Black/Orange, Color: Black/Orange
Great watch. Very good visibility. Ligh and feels quality. Easy to swap straps. Same size as my Casio Duro. Highly recommend.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 30, 2026
J
Verified Purchase
Jason G
Lowell, US
★★★★★ 1
Do not buy
Color: Green/Black
Do not buy. When I received the watch it did not work and the battery was dead. I bought a new battery and it killed that one as well after about a month.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 18, 2026
M
Verified Purchase
Miles Connell
Birmingham, US
★★★★★ 5
Inexpensive doesn’t mean cheap.
Color: Black/Orange
After 10 months, zero complaints. Well, I got rid of the horrible NATO strap 🙄. That’s a personal preference. Easy to swap out to whatever you like. Keeps accurate time meaning it’s the same time. I’m not micro analyzing it and the seconds gained/lost. It has a confident look and feel and makes you feel good when wearing it. Sure it’s not high priced but it’s not cheap. Very comfortable, light and not unincumbered. If this is what you’re looking at, you’d be satisfied. Great looking, durable and simple watch. Full confidence.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 25, 2025
B
Verified Purchase
Buyer
Chelsea, US
★★★★★ 3
Budget Seiko Prospex this is not
Color: Black/Orange
Bought this as a cheap work watch, but I guess all the budget went into the solar technology. No date adjust feature, gotta crank the crown over and over to adjust the date. (Also no screw-down crown, but that's expected at this price) Fake diver bezel. Lol why? Cringe as heck. Should of just put a compass bezel on there instead tbh. Cheap plastic crystal, scratches and mars just by looking at it. Okay NATO strap. Falls apart quickly, but it's easily replaceable with a better quality one. Decent lume on the hands, but none on the hour markers even though it looks like there is. Looks cool.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 13, 2025
M
Verified Purchase
Michael Miracle
Boise, US
★★★★★ 5
Simplicity
Color: Black/Orange
This watch was received exactly as advertised. First off the watch is economical compared to other watches that advertise the same details. I will say that I have gone through numerous Luminox watches only to be disappointed. This watch fits the bill. It does have solar cells which mean it needs to be exposed to light to keep running, not a problem. Three minutes under my surefire light I am golden. The bezel doesn't rotate actually no big deal for me. I have always required that the bezel moves not anymore after having a bezel that rotates I use it next to never. Here's why, the more I rotate the bezel the more the numbers wear off. The strap on the watch with the catches for the strap are perfect. They actually hold the watch strap in place in lieu of like other big name brands that just flop and slide. As far as everyday use goes this watch is my go to. To be honest I have purchased three. This is the only watch I will wear moving forward, yeah the glass my scratch but even the big names like the Luminox I spoke of earlier scratches too.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 4, 2026

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