Product comparison

Reduce Diameter Grip VS Standard Diameter Grip Booms

Tim Reinieren at


Boom tubes come in a variety of thicknesses, generally ranging from 26 – 30 mm., with the average diameter being in the 29-30-mm. region. Around 28 mm. would be considered the ‘median’ tube width. 

Above this mark would usually be classified as Standard Diameter Grip (SDG) as, until ten or so years ago, that was the most common size produced and, below this, is what you’d call Reduced Diameter Grip (RDG).

So, which is best for your style of sailing then?

First of all it’s important to define where the diameter is measured.

Many manufacturers have tapered boom arm tubes that make it harder to pinpoint what the usable diameter is.

The thickness of the original grip tape supplied also makes a difference.

Unifiber also tapers the tubes, but quotes their external tube thickness – not including the grip tape – in the harness line / hand-grip area shown by their printed line-setting markings. (Tape thickness not included, just the carbon or aluminium diameter, as this can vary as a result of wear over time.)


SDG is not necessarily weaker, as this of course mainly depends on the wall thickness specified by the manufacturer.


26-mm. RDG boom tube diameter


  • Can suit smaller hands, such as kids and ladies
  • More ‘direct’, fingertip handling and feedback sensation
  • Popular with cold-weather riders that claim to experience less cramp when using with mitts and gloves


  • Can wear palms of the hands and fingers more for those that grip the boom harder and/or slide their hands up and down the tubes a lot during wave rides or transitions.
31-mm. SDG boom tube diameter


  • Firmer grip sometimes preferred by larger hands and bigger sailors 
  • Often deliver positive weight-to-strength ratio



  • Arguably less energy efficient to ‘lighter-handed’ and/or smaller riders, especially in colder conditions.


Amongst the many issues to think about the types of sailing that each type suit are, broadly speaking, that wavesailors/freeriders and freestylers like to pick and choose between the two choices, whereas, most race booms on the market are SDG, which is mostly an issue of strength relating to the forces of longer arm extensions and pressure from more powerful sails.

That’s not a hard-and-fast rule of course, as the ‘feedback’ from thinner grips would be preferable to some performance slalom or speed riders, but, the heavy, settled power delivery that those types of sail deliver do demand less contact with the source and so the firmer grip and added strength of SDGs tend to influence choices.

Read more important factors to consider when buying a windsurfing boom

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