Ronstan Series 75 Core Block - Single [RF74100]
SKU: 24372248717

Ronstan Series 75 Core Block - Single [RF74100]

Sale price$138.47 Regular price$153.85
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Description

Ronstan Series 75 Core Block - Single [RF74100]Series 75 Core Block Single Core Blocks are a true all round solution. A tuned 2 stage bearing system provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle high dynamic or static loads. Acetal sheave, alloy cheeks and stainless fixings complete the durable package. For reliability and a long service life, these blocks are the right choice for sheets, halyards and

Series 75 Core Block™ - Single

Core Blocks™ are a true all round solution. A tuned 2-stage bearing system provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle high dynamic or static loads. Acetal sheave, alloy cheeks and stainless fixings complete the durable package. For reliability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing.

Universal Bearing
Dynamic and high static load performance

The Ronstan Universal Bearing incorporates our proven 2-stage bearing system

Stage 1 - Under moderate loads, Acetal ball bearings ensure minimum friction.

Stage 2 - Under heavy loads, where deformation of ball bearings alone would result in increased friction, a sliding Acetal bearing on a polished stainless steel race takes over, maintaining low friction performance.

Additionally the ball bearings are configured to act as a thrust bearing between the sheave and cheeks, preventing the sheave from rubbing on the cheeks and causing friction when the line lead in and out of the block isn't perfect. Particularly important for cheek blocks.

Alloy Cheek Plates
Block cheeks are manufactured from the highest quality alloy for maximum strength. Material optimisation and the cut-away design minimises weight and allows easy fresh water rinsing of salt and debris from the bearings. Cheek design has been further styled with flaring at the block throat and reduced gap between the cheek and sheave, minimising rope wear.

Universal head
The head assembly incorporates a brass bearing washer to provide smooth 360™ rotation of the post and shackle. A set screw arrangement allows the head to be locked at 0™ or 90™.

Shackles are high quality forged grade 316 stainless steel.

Features:

  • Class leading performance and sleek, contemporary styling
  • Excellent dynamic and high static load performance
  • Less than half the friction of the nearest competitor
  • Universal head with full 3-axis articulation
  • Head posts can be locked at 0 or 90 degrees, by using a 2.5mm Hex/Allen Key
  • Central hub hole can be used as a becket take-off or tie-up point


Applications:
  • Ideal for mainsheet, halyard and spinnaker sheet applications on boats to 14M (46')
  • Various control line applications on larger yachts


Materials:
  • Sheave: U.V. stabilized Acetal
  • Cheek body: Aluminium Alloy
  • Ball Bearings: High compression strength carbon black Acetal
  • Shackle, head post & hub: Grade 316 stainless steel


Specifications:
Sheave Ø: 75mm(3")
Max. Rope Ø: 14mm(9/16")
Pin Ø: 8mm(5/16")
M.W.L.: 1,500kg(3,300lbs)
B. L.: 3,000kg(6,600lbs)
Weight: 354g(12.5oz)

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: 24372248717

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4.3 ★★★★★
Based on 2360 reviews
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AreTrue
West Palm Beach, US
★★★★★ 4
Smell
Size: Queen (2 Count), Color: Original White (Cooling)
The fact that there are not more comments on the smell of these pillows has me worried about some of yall. Listen, I LOVE the weight, and the firmness, it’s perfect for that. However, these pillows are RANK. They have a very strong mildew-ish smell that lingers. I took the outer cover off and washed it and let the pillow air out for a few days, the smell is still very strong when you press your face against it, which one does because it is in fact designed for that purpose. It smells so bad. It’s nauseating. I can smell it through two pillowcases and blanket that I threw on top of them hoping an extra layer would trap the smell. I’ll bake them in the Texas sun tomorrow and hope that helps, because otherwise these are the perfect pillows for someone who wants to feel like they are hugging a torso but can’t stand the sound/feel of someone else breathing. I don’t know…4 stars, if the smell goes away I’ll come back. Update: many many days later. Either they don’t really smell anymore or I got use to it. They’ve held their firmness and shape well. I like them.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 9, 2026
S
Verified Purchase
Samantha
Dallas, US
★★★★★ 5
Actually Cooling Pillow
Size: Queen (1 Count), Color: Original White (Cooling)
This is a really nice pillow, I was worried it would be too soft or too firm but it's just right and it's actually cooling, it feels cool every time I touch it. I've noticed an improvement in sleep since using it. Would recommend!
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Reviewed in the United States on May 27, 2026
T
Verified Purchase
Tyler and Kaela
Birmingham, US
★★★★★ 5
Repurchased in King Size – Still Love These Cooling Pillows
Size: King (2 Count), Color: Original White (Cooling), Size: King (2 Count), Color: Original White (Cooling)
After using the queen-size version of these pillows for over a year, we purchased the king-size set when we upgraded to a king mattress. Both my husband and I really like them. The cooling feature works well, and we like that each side feels different—when I run cold, I use the softer bamboo side, while my husband prefers the cooler side since he tends to sleep hot. They fit well in our king-size pillowcases and feel supportive in all sleeping positions, whether I’m on my stomach, side, or back. I also appreciate that you can remove some of the filling to adjust the firmness. The covers are washable, which makes them easy to maintain. Overall, we’re very happy with this repurchase and the long-lasting comfort.
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Reviewed in the United States on April 15, 2026
M
Verified Purchase
Mystery Fan
Draper, US
★★★★★ 3
Not great at cooling
Size: Queen (2 Count), Color: Original White (Cooling)
Each pillow cover has 2 sides, one marked for cooling, and the other a different fabric. The cooling side is about the same effectiveness as having a silk or satin pillow cover. It's only cool when you first touch it. The cooling side doesn't seem to absorb or wick moisture, so if you are sweaty - it keeps the moisture in place. You'll definitely want a regular pillow case over the pillow cover. In fact, if you suffer from night sweats, the non-cooling side is actually more comfortable. The pillow fill is ample, and simple to squish around for more support for your neck, etc. Think bean bag. But it will retain your impression after use. I find I need to do as I did when I had down pillows - give it a few good shakes in the morning when I make the bed to get it evened out for the coming night. In all, it is a well-made and comfortable pillow to sleep on, but it does not excel in cooling.
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Reviewed in the United States on May 29, 2026
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Verified Purchase
Carol C
Fort Morgan, US
★★★★★ 5
excellent pillows i bought two sets!!
Size: Firm Queen (2 Count), Color: Original White (Cooling)
I ordered these for my son who has neck issues and has gone through so many pillows trying to find one that he liked. They’re heavy, so i was worried that they might be “too” heavy to be able to sleep on comfortably, so I ordered a second set, one firmer than the other (just in case) and gave him a set for Xmas and he loved the first set so much without even trying the less firm ones.He also needs the cooling factor and these offered that, too. They are filled with pieces of memory foam (tons of it) and each pillow can be modified by removing some of the foam. The covers are beautiful, high quality fabric with a zipper so ts easy to remove or replace the foam pieces. The size is perfect and they keep their shape. I kept the second set i ordered rather than returning them and i love the pillows. I actually modified two by removing some of the foam pieces. I kept the foam pieces in a zippered pillow protector and i can always adjust mine when or if i need to. 1000% love these.
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Reviewed in the United States on March 22, 2026

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