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.
Technical Information
Applications
Ideal for mainsheet, halyard and spinnaker sheet applications on boats to 1m (33ft). Various control line applications on larger yachts. Alloy sheave models are available for use with wire.
Materials
Sheave: U.V. stabilised Acetal. Cheek body: Aluminium Alloy. Ball Bearings: High compression strength carbon black Acetal. Shackle, head post & hub: Grade 316 stainless steelFork pin: Grade 2205 stainless steel
We would love to keep in touch with you! Sign up to our quarterly newsletter and receive news, tips, and updates right in your inbox.
Newsletter
Our use of cookies
We use necessary cookies to make our site work. We'd also like to set optional cookies to help us improve it.
We won't set optional cookies unless you enable them.
Using this tool will set a cookie on your device to remember your preferences.
Necessary
Necessary cookies enable core functionality such as security, network management, and accessibility. You may disable these by changing your browser settings, but this may affect how the website functions.
Name
Description
PHPSESSID
Preserves the visitor's session state across page requests.
form_key
Protects visitor's data from Cross-Site Request Forgery Attacks.
guest-view
Stores the Order ID that guest shoppers use to retrieve their order status. Used in “Orders and Returns” widgets.
login_redirect
Preserves the destination page the customer was loading before being directed to log in.
mage-banners-cache-storage
Stores banner content locally to improve performance.
mage-cache-sessid
The value of this cookie triggers the cleanup of local cache storage.
mage-cache-storage
Local storage of visitor-specific content that enables ecommerce functions.
mage-cache-storage-section-invalidation
Forces local storage of specific content sections that should be invalidated.
mage-messages
Tracks error messages and other notifications that are shown to the user, such as the cookie consent message, and various error messages. The message is deleted from the cookie after it is shown to the shopper.
private_content_version
Appends a random, unique number and time to pages with customer content to prevent them from being cached on the server.
section_data_ids
Stores customer-specific information related to shopper-initiated actions such as display wish list, checkout information, etc.
user_allowed_save_cookie, cookie_consent
Stores the user's cookie consent state for the current domain.
X-Magento-Vary
Configuration setting that improves performance when using Varnish static content caching.
Preferences
Preference cookies are used to store settings and information that changes the website look and functionality.
Name
Description
store
Remembers the user's selected language version of a website.
Marketing
Marketing cookies help us provide our visitors with relevant content, browsing history, and product recommendations.
Name
Description
product_data_storage
Stores configuration for product data related to Recently Viewed / Compared Products.
recently_compared_product
Stores product IDs of recently compared products.
recently_compared_product_previous
Stores product IDs of previously compared products for easy navigation.
recently_viewed_product
Stores product IDs of recently viewed products for easy navigation.
recently_viewed_product_previous
Stores product IDs of recently previously viewed products for easy navigation.
_fbp
This cookie is installed by Facebook to store and track visits across websites.
Analytics
Analytics cookies help us understand how our visitors interact with the website. It helps us understand the number of visitors, where the visitors are coming from, and the pages they navigate. The cookies collect this data and are reported anonymously.
Name
Description
add_to_cart, remove_from_cart
Used by Google Tag Manager. Captures the product SKU, name, price and quantity added or removed from the cart, and makes the information available for future integration by third-party scripts.
dc_gtm_*
Throttles request rate when Google Analytics is deployed with Google Tag Manager.
_ga, _gat, _gid, _ga_*, _gat_*
This cookie is installed by Google Analytics. They are used to collect information about how visitors use our website. We use the information to compile reports and to help us improve the website. The cookies collect information in a way that does not directly identify anyone.
Ball Bearing 
