SKU: 16322879631

Ronstan RF56101 Series 55 Orbit Ratchet & Auto-Ratchet Block

Sale price$84.30 Regular price$93.67
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Description

Ronstan RF56101 Series 55 Orbit Ratchet & Auto-Ratchet BlockRonstan RF56101 Orbit Ratchet Block. Designed for applications where weight is of paramount importance. The securing loop is easily changed and we suggest that you use either a forged eye or shackle to secure the block as pressed steel fittings can be sharp and will prematurely wear the rope mounting. Features: Automatic and Manual ratchet in one block Up to 20: 1 holding power Easily fitted and securely retained Dyneema Link head Smooth easing of

Ronstan RF56101 Orbit Ratchet Block. Designed for applications where weight is of paramount importance. The securing loop is easily changed and we suggest that you use either a forged eye or shackle to secure the block as pressed steel fittings can be sharp and will prematurely wear the rope mounting.

Features:

  • Automatic and Manual ratchet in one block
  • Up to 20:1 holding power
  • Easily fitted and securely retained Dyneema Link head
  • Smooth easing of sheets
  • High performance cleating

Technical:

  • Sheave Diameter 55mm
  • Maximum Rope Diameter 10mm
  • Maximum Working Load 250kg
  • Breaking Load 500kg
  • Weight 78g

Materials:

  • Ball bearings - High compression strength carbon black Acetal
  • Stage 2 bearing - Carbon fibre reinforced, PTFE impregnated Nylon
  • Frame/Cheeks - Toughened, glass fibre reinforced Nylon
  • Rope Link: UV stabilised, multi-strand impregmented SK75 Dyneema

Applications:

  • Mainsheet systems on dinghies
  • Spinnaker sheets on dinghies
  • Control line applications on larger yachts

Some RT Orbit Blocks™ can be set to Automatic mode or Manual mode to suit the application or user’s preference.

OPERATION

MANUAL MODE
RT blocks leave the factory in Manual mode, with the black MODE switches on both sides of the block positioned away from the red ON/OFF knob.

Use the red ON/OFF knob to turn the ratchet ON or OFF.

AUTO MODE
With the block in Manual mode, turn the ratchet off by rotating the red ON/OFF knob to the OFF position.

Slide the black MODE switch firmly toward the red ON/OFF knob until it locks into the recess in the knob. Repeat with the MODE switch on the other side of the block.

The block is now in Auto mode.

To return to Manual mode, slide the black MODE switches on both sides of the block firmly away from the red ON/OFF knob. Now use the red ON/OFF knob to turn the ratchet ON and OFF.

We recommend using the RF613S shackle to securely attach the block to the existing deck eye on your boat. This helps the block maintain maximum freedom of movement and reduces the risk of wear on the Dyneema loop due to sharp edges on the deck eye, then use the 8072 Rubber Boot to keep the block upright and provide a neat finish. See related items.

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: 16322879631

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4.3 ★★★★★
Based on 18 reviews
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Product Reviews
A
Verified Purchase
Amazon Customer
Fort Morgan, US
★★★★★ 5
10/10
Size: 20oz
Awesome stuff, used it on some very dry rotted law mower tires just to see what it would do. Worked great holding air again
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 1, 2026
D
Verified Purchase
don
Fort Morgan, US
★★★★★ 5
Works well!
Style: 16 oz
This stuff works well. I've only ever used it after my tires had been punctured and ran flat... I haven't had a flat this wouldn't seal... 3 uses so far all 3 have fixed flats and been many miles put on since the repairs. I start with as little as possible and if it doesn't seal I just add more, I think I've managed to use far less than recommended and successfully sealed punctures. I've only used it on fat tire e-bike tires. I'm pretty comfortable with the seal and I have no plans to replace the tubes, which saves me a fair amount of trouble. I will update if it springs any leaks without new punctures. It's very easy to use and actually pretty clean especially compared to automotive type tire repair foams. The first repair I used it for was a brand new bike that just wouldn't hold air in the rear, totally unsure what caused it to keep losing air but 2 or 3 small doses of slime fixed it. The most recent slime repair, I had a wobbly bike ride which felt weird and I couldn't figure out why but a few hours after I had returned home both tires were totally flat. They both had a handful or more of some really heavy duty thorns stuck in the tire that likely barely punctured the tubes but the rear tire also had a roofing nail in it. I did not think the slime was going to fill that one, it was a pretty heavy leak once I removed the nail, but Slime did seal it and I've since ridden the bike twice and in the same rough conditions I normally would still holding strong at higher pressure than I normally ride, have yet to drop back down since refilling but I am hoping and expecting it won't be a problem. Two thumbs up. I always keep a small tube in my bike bag and I am confident if I ever need it while I'm out and about it will be useful.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 17, 2026
A
Verified Purchase
Artie
Pawtucket, US
★★★★★ 5
Who can live without slime great stuff and a good price. 👍
Style: 32 oz
If anyone has an outdoor anything that takes air. You should never be caught without this stuff. It seals your tires on almost anything and it lasts longer than you would expect. It’s easy to use and easy to clean up after using it. It will work well for anything that is supposed to hold air. Great product.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 11, 2026
M
Verified Purchase
Mudd
Massapequa, US
★★★★★ 5
Title: Reliable, Easy-to-Use, and Worth Every Penny
Style: 32 oz
I’ve been using Slime tire sealant for my fat tire e-bike, and I can say with confidence that this product delivers exactly what it promises. The application is simple, the results are consistent, and the peace of mind it provides is invaluable. For anyone who rides regularly — whether for commuting, recreation, or deliveries — this is a product that pays for itself many times over. The first thing I appreciate about Slime is how easy it is to install. The bottle is well-designed, the instructions are clear, and the process takes just a few minutes. You simply deflate the tire, remove the valve core, squeeze in the recommended amount, reinstall the valve core, inflate, and spin the wheel to distribute the sealant evenly. No special tools, no mess, and no guesswork — just a straightforward, user-friendly process. Performance-wise, Slime does exactly what it’s supposed to do: seal punctures quickly and effectively. I’ve had nails, thorns, and sharp debris puncture my tires while riding, and in every case where the leak was within the tread area, Slime sealed it instantly. There’s something incredibly reassuring about hearing that faint hiss of air for a second, then watching it stop as the sealant does its job. It’s a real-time reminder that this product is actively protecting you from being stranded. What sets Slime apart from other sealants I’ve tried is its durability. Once applied, it stays active inside the tube for months, ready to respond to new punctures as they happen. It doesn’t dry out quickly, it doesn’t clump up, and it doesn’t cause balance issues with the tires. For someone who rides almost daily, that reliability is a huge plus. Another thing I respect about this product is that it’s non-toxic and environmentally friendly. If a bit of sealant escapes during a repair, I don’t have to worry about it harming the environment. It’s also water-soluble, making cleanup easy if I ever need to replace a tube or tire. That attention to safety and sustainability shows that the company isn’t just making a great product — they’re doing it responsibly. The value for the price is excellent. One bottle goes a long way, and when you factor in the cost of replacing tubes, paying for roadside repairs, or even the inconvenience of being late because of a flat, Slime is an investment in both savings and peace of mind. For delivery riders like me, it’s especially valuable — every flat avoided means another day of work uninterrupted. In short, Slime is one of those rare products that I can recommend without hesitation. It’s easy to use, effective, long-lasting, and backed by a company that clearly understands the needs of cyclists and e-bike riders. It has already saved me from countless headaches, and I plan to keep a bottle on hand at all times. If you ride regularly and haven’t tried it yet, you’re taking an unnecessary risk — this is one of the best preventative tools you can add to your maintenance kit. Verdict: Five stars for performance, ease of use, and overall value. Slime is a must-have for any serious rider who values reliability and wants to keep rolling no matter what’s on the road.
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Reviewed in the United States on August 11, 2025
D
Verified Purchase
Dina Stewart
Alexandria, US
★★★★★ 4
Slime is good, pump is a disaster
Style: 1 gal, Style: 1 gal
The only reason I am giving this a 4 star(not zero) rating is the slime itself. The actual pump on the 1 gallon canister is awful. It makes so much mess, so I do not know whether I pumped the slime into the tubes or it all just spilled out of the base of the pump. The bottles worked great, but this time I needed to use more slime for a bunch of tires. What a slimy mess that was. Very poor pump design. Only after I spilled who knows how much of the slime, I finally washed it and was able to see the problem. The cap at the base of the pump got unscrewed and let all the slime lose. I screwed it back up and this should fix the mess next time I use it. Just a heads if someone encounters the same issue.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 22, 2026

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