Seldén tie-on ball bearing blocks in 30 mm, 40 mm and 60 mm sheave sizes for dinghy booms, mast bases and other lashing points where a lightweight articulating block fit is preferred over a fixed shackle mounting.
How to choose
A tie-on block attaches directly to a fitting point with a lashing rather than a shackle. This gives a tighter, lighter, more articulating fit than a shackle-mounted block, and eliminates a metal swivel and shackle from the assembly. The block sits close to its attachment point and moves naturally with the load direction. The recommended lashing method for the BBB30 tie-on is three turns of 2 mm line.
Choose sheave size to match your line diameter. The BBB30 tie-on suits lines up to 8 mm for control lines and lighter mainsheet applications on smaller dinghies. The BBB40 tie-on suits lines up to 10 mm for mainsheets and spinnaker systems on two-handed boats. The BBB60 tie-on also suits lines up to 10 mm and steps up to Delrin ball bearings for higher loads on larger dinghies and keelboats.
For the BBB60 size, a heavy duty version is available with stainless steel ball bearing races and Acetal bearing cages. Choose the heavy duty version where loads are high and sustained, such as on a loaded mainsheet system or spinnaker sheet on a performance keelboat.
What's in this collection
The BBB30 single tie-on (403-101-08R) suits lines up to 8 mm with stainless steel ball bearings and glass fibre reinforced polyamide sheave and cheeks. The recommended attachment is three turns of 2 mm lashing line.
The BBB40 single tie-on (404-101-16R) suits lines up to 10 mm with stainless steel ball bearings and glass fibre reinforced cheeks. Attaches by lashing to the fitting point without a shackle.
The BBB60 single tie-on (406-601-14R) suits lines up to 10 mm with Delrin ball bearings and glass fibre reinforced cheeks for dynamic mainsheet and sheet applications on larger boats.
The BBB60 single tie-on heavy duty (406-601-64R) adds stainless steel ball bearing races and Acetal bearing cages for higher sustained loads. Construction and line size are otherwise the same as the standard BBB60 tie-on.
