Ronstan Series 55 Ratchet Orbit Block, Single Cleat Swivel Auto
- Brand:
- Ronstan
- Part no:
- RF56120
Image: aztekcomputers.com
Where to buy
Specifications
- Bearing
- Ball
- Swivel
- Swivel
- Ratchet
- Auto
This Ronstan Series 55 ratchet block has a single cleat and a swivel, and it is the auto version. The sheave is anodized aluminium and runs on acetal ball bearings, while the frame is glass fiber reinforced nylon. The sheave has 12 gripping faces to hold the line, giving up to 20:1 holding power. In auto mode the ratchet engages only under load, so the sheet eases out freely once the load comes off.
Our take
A sheave with 12 gripping faces and up to 20:1 holding power means the block itself does much of the holding, not your grip. This one is the auto version, so the ratchet engages under load and lets the sheet run free when the load is released.
From our buying guide
Ball-bearing blocks give the lowest friction on lines running under moderate loads. Plain bearings have more friction, but handle very high and static loads.
Check before you buy:
- A ratchet block is rated for the full sheet load.
- Any becket's load limit suits the job, since a becket can be rated below the block itself.
- A soft-attach block will be looked after, since Harken warns soft attachments are prone to wear and recommends them only for regularly maintained race boats.