RF55151%3A%20SERIES%2055%20ORBIT%20CHEEK%20BLOCKBall%20bearing%20single%20sheave%20Orbit%20Block%26trade%3B.%20Requires%203%20x%205mm%20(3%2F16%22)%20Fasteners.%0D%0AFEATURES%0D%0A%0D%0AUltra%20Lightweight%0D%0ALow%20friction%202-stage%20Orbital%20ball%20bearing%20system%0D%0AHighest%20working%20load%20in%20its%20class%0D%0ALow%20profile%20and%20compact%0D%0ARecessed%20underside%20to%20suit%20cruved%20mounting%20surface%0D%0A%0D%0ASPECIFICATIONS%0D%0A%0D%0ASheave%20diameter%20(mm)%2055%0D%0AB.L.%20(kg)%201000%0D%0AM.W.L.%20(kg)%20500%0D%0AMax.%20Rope%20diameter%20(mm)%2010%0D%0AWeight%20(g)%2070%0D%0AFastener%20%26Oslash%3B%20(mm)%205%0D%0AQty.%20Fasteners%203%0D%0A%0D%0APRODUCT%20INFORMATION%0D%0ALightweightKilogram%20for%20kilogram%20of%20working%20load%2C%20BB%20and%20RT%20Orbit%20Blocks%26trade%3B%20are%20the%20world%26rsquo%3Bs%20lightest.%20The%20unique%20orbital%20design%20allows%20the%20bearing%20to%20only%20be%20in%20the%20active%20areas%20of%20the%20floating%20sheave.%20This%20minimises%20the%20mass%20of%20the%20inactive%20return%20race%20and%20hub.%20Weight%20and%20bulk%20are%20further%20reduced%20in%20the%20different%20block%20configurations.%20The%20ball%20bearing%20single%20and%20becket%20block%20has%20a%20through-sheave%20becket%20arrangement.%20The%20result%3F%20The%20lowest%20weight%20possible.%0D%0AHighest%20working%20load%20in%20its%20classThe%20orbital%20ball-bearing%20arrangement%20gives%20the%20largest%20possible%20bearing%20race%20diameter.%20This%20maximises%20load%20performance.%20The%20proven%20Ronstan%202-stage%20bearing%20system%20features%20high%20compression%20grade%20acetal%20ball%20bearings%20and%20a%20secondary%20full-contact%20bearing.%20This%20gives%20minimum%20friction%20across%20the%20full%20working%20load%20range.%20The%20floating%20sheave%20and%20bearing%20system%20is%20supported%20by%20a%20fibre-reinforced%20load%20frame.%20The%20design%20was%20computer%20modelled%20to%20be%20stress%20optimised.%0D%0AAPPLICATIONS%0D%0A%0D%0AMainsheet%20systems%20on%20dinghies%2C%20sportsboats%20and%20small%20keelboats%20to%209m%20(3ft).%0D%0AHalyard%2C%20Vang%20and%20Backstay%20application%20on%20boats%20to%208m%20(26ft).%0D%0AControl%20line%20applications%20on%20larger%20yachts.%0D%0A%0D%0AMATERIALS%0D%0A%0D%0ABall%20bearings%3A%20High%20compression%20strength%20carbon%20black%20Acetal.%0D%0AStage%202%20bearing%3A%20Carbon%20fibre%20reinforced%2C%20PTFE%20impregnated%20Nylon.%0D%0AFrame%2FCheeks%3A%20Toughened%2C%20glass%20fibre%20reinforced%20Nylon.%0D%0ASheave%3A%20Carbon%20fibre%20reinforced%2C%20PTFE%20impregnated%20Nylon.