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Old 27th July 2007, 11:06 AM   #2
Ian Fox
STARBOARD
 
Join Date: Aug 2006
Posts: 532
Default RE: sunken mast track

Hey Thomas,

That's a real worry, could be your board has shrunk around the track sitting in storage since 2004 (??), or maybe was crushed in transit, or even could be the guys in the factory forgot to do up the vent screw and some of the foam used to inflate the HS111 has leaked out.

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A simplistic explanation could be that lowering the mast track allows the foot of the sail to sit closer to the deck and thereby more effectivly "closing the gap" more than if the track/base/rig was sitting higher. In practice, that is not nearly as critical as some imagine, although it's also a positive side effect.

More seriously, a recessed mast track is deliberately used to lower the centre of drive (effort) and reduce roll around the board's longitudinal axis created by the rig (mast base).

[[The distance between the (theoretical) longitudinal roll axis of the board and top of the mast foot sitting on the deck effectively creates a theoretical leverage, which side loading forces from the rig can use to (try to..) "twist" (roll) the board around the longitudinal axis. By reducing that distance, the leverage is reduced, and leverage being exponential, even a small reduction in distance produces a noticeable gain when riding the board. Well, you did ask ! ]]

The benefit of recessing the track (mastbase) is more significant on boards that are (relatively) thick (especially relative to width) around the mast track area (such as .... HS111).

You'll notice an improvement in the ride characteristics/handling/control of a board with this feature, especially at high/er speeds sailed close to the limit.

Cheers ~ Ian
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