SKU: 21363720135

Ronstan Series 40 Ball Bearing Orbit Block - Cheek [RF45151]

Sale price$30.34 Regular price$33.71
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Ships within 48 hours · Estimated delivery Jul 17 - Jul 22

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Description

Ronstan Series 40 Ball Bearing Orbit Block - Cheek [RF45151]Series 40 Ball Bearing Orbit Block Cheek Features: Ultra Lightweight Low friction 2 stage Orbital ball bearing system Highest working load in its class Low profile and compact High performance cleating Base suits curved mounting surface Low mounting points for maximum strength Lightweight Kilogram for kilogram of working load, BB and RT Orbit Blocks are the worlds lightest. The unique orbital design allows the bearing to only be in the active areas of

Series 40 Ball Bearing Orbit Block - Cheek

Features:

  • Ultra Lightweight
  • Low friction 2-stage Orbital ball bearing system
  • Highest working load in its class
  • Low profile and compact
  • High performance cleating
  • Base suits curved mounting surface
  • Low mounting points for maximum strength

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 minimizes 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 It's Class

The orbital ball-bearing arrangement gives the largest possible bearing race diameter. This maximizes 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 modeled to be stress optimized.

Recommended fasteners - 3 x 4mm (5/32") countersunk head screws

Applications:

  • Mainsheet systems on spinnaker sheet on dinghies to 5m (16ft)
  • Spinnaker sheets on dinghies, sportsboats and small keel boats to 5m (16ft)
  • Halyard, vang and backstay applications on boats to 8m (26ft)
  • Control line applications on larger yachts

Materials:

  • Ball Bearings - High compression strength carbon black Acetal.
  • Stage 2 Bearing - Glass fibre reinforced, MoS2 impregnated Nylon
  • Frame/Cheeks - Toughened, glass fibre reinforced Nylon
  • Sheave - Carbon fiber reinforced, PTFE impregnated Nylon
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: 21363720135

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4.4 ★★★★★
Based on 19 reviews
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Stacey Cohick
Belleville, US
★★★★★ 5
Perfect
Size: X-Large, Color: (601) Bittersweet Pink / Stone / Stone
They were perfect
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 27, 2026
S
Verified Purchase
Susan Brown
San Leandro, US
★★★★★ 5
Very Comfortable!
Size: Medium, Color: (601) Bittersweet Pink / Stone / Stone
Very comfortable. Don’t slip off back of heal. Love the colors.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 25, 2026
C
Verified Purchase
C. V.
Louisville, US
★★★★★ 5
😊
Size: Medium, Color: (601) Bittersweet Pink / Stone / Stone
These are really nice except I don’t like all the colors of them so I’m getting different ones same company just different colors. I don’t like the thick ones these are perfect.. 🤩
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Reviewed in the United States on February 24, 2026
K
Verified Purchase
KDK in Texas
Belleville, US
★★★★★ 3
Pretty Colors to Encourage Me to Walk!
Size: X-Large, Color: (601) Bittersweet Pink / Stone / Stone
Hum. Extra large does not seem extra large. I have a slender but size 10-10.5 foot. Will keep but was hoping for a looser fit. Bought to match an Under Armour walking outfit.
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Reviewed in the United States on May 16, 2026
P
Patti J Fredley
Chelsea, US
★★★★★ 5
Socks
Size: X-Large, Color: (601) Bittersweet Pink / Stone / Stone
So cute
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 6, 2026

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