I never thought about why there was a pin in the mast base plate, never too old to learn something new

fb.watch/9POiInJH6A/

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choco said..
I never thought about why there was a pin in the mast base plate, never too old to learn something new

fb.watch/9POiInJH6A/

I believe it's there so the washer doesn't rotate when tightening the base.
It just happens to work as a safety device but you then lose some adjustment.
I used to have a plastic block that dropped in the larger part of the slot which did the same but gave max adjustment & the base could not come out.

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choco said..
I never thought about why there was a pin in the mast base plate, never too old to learn something new

fb.watch/9POiInJH6A/

Hi, yes that's a safety feature for when things have already gone wrong. The lug on the deckplate disc stops the mast foot from sliding out of the track. Not a bad idea.

But it's important to realise that when your deckplate comes undone it's often NOT because you haven't tightened it up enough. It's because your mastbase bearings aren't working properly.

Both bearings, above and below the U/J need to rotate freely, or else the action of tacking and gybing can undo the deckplate.
Some people get a double bolt deckplate to prevent this issue - but that's still a really bad solution because when the bearings don't work, the rotation causes the U/J itself to fail instead, because the tendon or Boje joint is continually twisted.

I'm always shocked how few people understand this basic issue. Even that video, linked to above, does not seem to understand the true problem.

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Basher said..

choco said..
I never thought about why there was a pin in the mast base plate, never too old to learn something new

fb.watch/9POiInJH6A/

Hi, yes that's a safety feature for when things have already gone wrong. The lug on the deckplate disc stops the mast foot from sliding out of the track. Not a bad idea.

But it's important to realise that when your deckplate comes undone it's often NOT because you haven't tightened it up enough. It's because your mastbase bearings aren't working properly.

Both bearings, above and below the U/J need to rotate freely, or else the action of tacking and gybing can undo the deckplate.
Some people get a double bolt deckplate to prevent this issue - but that's still a really bad solution because when the bearings don't work, the rotation causes the U/J itself to fail instead, because the tendon or Boje joint is continually twisted.

I'm always shocked how few people understand this basic issue. Even that video, linked to above, does not seem to understand the true problem.

But where the deck plate and tendon are separate pieces (eg. Chinook), the bottom metal bit of the tendon is free to rotate inside the 2-bolt base.

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Faff said..

But where the deck plate and tendon are separate pieces (eg. Chinook), the bottom metal bit of the tendon is free to rotate inside the 2-bolt base.

I never said it wasn't.
People buy a two bolt system because they think it's solving a problem. In fact it's usually just covering up a problem.
All systems are OK as long as the bearings work both sides of the U/J - and a lot of people don't realise how important that is.

I personally don't like the two bolt system because you lose mast track range and you can't shift the mast foot quickly. The lower disconnect point can also cause unnecessary problems and is usually an unneeded wear point.

I've had a mastbase slide because I didnt tighten it up enough, like Mr Cucci said in the video. Luckily it slid forward. If you adjust the mastbase in the water you cant always do it up as tight as on land an sometimes its a pain to go back in again. They should make all plates with a tab.

I've gone from 2 bolt to 1 bolt and back because of rig separation. I really miss having the adjustment range of the 1 bolt to the point of thinking I might fabricate a stopper for the track in order to use them safely again. I hadn't thought of attaching it to the plate though which is a pretty good idea.

Some boards tracks have a notch on the opening that prevents a loose mast base from coming out of the track. In order to remove the mast base you need to unscrew the base many turns. I find that safety feature pretty simple and clever. I have two boards with that type of track but never had my one bolt base to come loose.

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WillyWind said..
Some boards tracks have a notch on the opening that prevents a loose mast base from coming out of the track. In order to remove the mast base you need to unscrew the base many turns. I find that safety feature pretty simple and clever. I have two boards with that type of track but never had my one bolt base to come loose.

I've always used single bolt mast bases and in 40 years of windsurfing I've had one come loose once. My error in rushing rigging, which I've never made again.

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WillyWind said..

Chinook do this , its a good idea .

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WillyWind said..
Some boards tracks have a notch on the opening that prevents a loose mast base from coming out of the track. In order to remove the mast base you need to unscrew the base many turns. I find that safety feature pretty simple and clever. I have two boards with that type of track but never had my one bolt base to come loose.

Same, all my Carbon Arts are like that.

I had a single bolt come loose, slide forward and pop out the front of the track. This was 20 years ago on an F2 Xantos. I think the tracks they used had a flimsy plastic piece at the front. I was unbelievably lucky that a buddy was just behind me and grabbed the board before it went too far. I switched to 2-bolt bases the next day and have used them ever since, even though I don't think I've ever had a board with such a crappy mast track again.