SKU: 24372248717

Ronstan Series 75 Core Block - Single [RF74100]

Sale price$138.47 Regular price$153.85
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Ships within 48 hours · Estimated delivery Aug 24 - Aug 29

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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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4.5 ★★★★★
Based on 8 reviews
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BeRock
Omaha, US
★★★★★ 3
Great mount / Terrible charge rate
Love the mount. Easy to install and with a small piece of double sided tape under the top edge, it’s very secure… The magnetic mount is strong enough to hold an iPhone max (at least mine). The charging ability is where it falls short *BAD! It will charge but, barely.. If you’re using maps, making calls, etc.. the phone continues to drain at an alarming rate…
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Reviewed in the United States on November 14, 2025
L
Verified Purchase
Lennie
Louisville, US
★★★★★ 4
Not suitable if you have a silicone case.
I'm waiting for delivery of new phone case, as the silicone one I have on my phone will not hold onto the magnet provided for this holder. Installation was a snap and I love how it looks in my car. Cost seems fair for the product. Fingers crossed that it will work fine once I get a new case.
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Reviewed in the United States on July 6, 2025
K
Verified Purchase
Kelly
Los Angeles, US
★★★★★ 2
Charger portion stopped working twice now
Works well until it doesn't. Was excited to get the phone mount off the car vent but I have gone through one replacement already and now I'm past the point to completely return it. Twice now the charging portion has failed. The first one stopped lighting up completely with in about a week and now this one just constantly flashes and no longer charges after another few weeks. I have tried different cords and outlets in my car with no success. The magnet portion however is strong and does hold the phone well.
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Reviewed in the United States on November 15, 2025
A
Verified Purchase
Amazon Customer
Boise, US
★★★★★ 1
Do not buy this junk... it will damage your car!
This junk broke my dash!!! See pictures
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Reviewed in the United States on July 11, 2025
M
MNPJACC
Massapequa, US
★★★★★ 5
Perfect for every day use
The Wincar Magnetic Wireless Phone Mount and Charger is a thoughtfully designed accessory tailored for Toyota 4Runner models from 2010 to the present, and it also fits well with other vehicles using a 17mm ball mount base. The package includes a sturdy mount, a 15W magnetic wireless charger, a charging cable, and two steel rings. These steel rings are particularly useful for those who do not own a MagSafe-compatible phone or case, ensuring broader compatibility.  I specifically purchased this charger and holder to use with my existing 17mm ball mount base, which I found challenging to match with most other products—especially for my Lexus GX460. While there are many phone holders on the market, very few offer the dual functionality of both MagSafe mounting and wireless charging in one unit. This all-in-one solution eliminates the need for multiple accessories, but it’s important to note that the charger /mount  require a power connection to operate.  In terms of performance, the Wincar mount and charger deliver impressively. When connected to a reliable USB-C charging source or a USB-C cigarette lighter adapter, the magnetic grip is strong, keeping the phone securely in place even during bumpy rides. The wireless charging is efficient, providing a reasonably fast charge without overheating or lag. The magnetic force is particularly robust, ensuring that the phone remains stable and aligned for optimal charging.  Overall, this mount and charger combination offers a seamless, convenient experience for anyone seeking a reliable phone holder and charger for their vehicle. For my needs, it has proven to be both practical and effective.
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Reviewed in the United States on June 30, 2025

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