Been trying to work out why some times my sails need a couple of cm's more or less downhaul. Using the same extension etc. I've got 2 Severne apex 490 mast, I was thinking that maybe they where different lengths so I put them side by side and nope they are the same then today I discovered that one mast has a longer bottom section and shorter top so if you mix the tops and bottoms up the overal length is either 3cm shorter or 3cm longer.

Glad it wasn't me going crazy but why would they do that?

would they be from different years ?

Different bend curves so one requires more downhaul to rig properly.

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mr love said..
Different bend curves so one requires more downhaul to rig properly.

No different lengths as I said above

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seanhogan said..
would they be from different years ?

Possible

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mr love said..
Different bend curves so one requires more downhaul to rig properly.

You missed his point .. the OP already has solved his problem .. he has x2 490 masts and it was due to the different point of the split in the 2 piece mast and he was mixing the tops & bottoms resulting in different lengths.

He said..."so if you miix the tops and bottoms"...he did not say he was mixing the tops and bottoms....so Ben..have you been mixing them??

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JakeNN said..

mr love said..
Different bend curves so one requires more downhaul to rig properly.

You missed his point .. the OP already has solved his problem .. he has x2 490 masts and it was due to the different point of the split in the 2 piece mast and he was mixing the tops & bottoms resulting in different lengths.

Some brands make a longer top section to a mast if they want a more flex top and a smaller top section to a mast if they want a stiffer top. Usually this is just race masts and as a result the bottom sections have to vary in length to be the same length.
Also some brands have masts built by different factories, Goya for instance have an 85% mast and a 90% mast, one was built in the US and the other in Europe, this helped with ease of distribution on both sides of the Atlantic.

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Ben1973 said..
2 Severne apex 490 mast .. if you mix the tops and bottoms up the overal length is either 3cm shorter or 3cm longer.
... why would they do that?

here is a summary of the original post with only relevant information .. unnecessary words are deleted.

I'll go with Mr Love's answer, the longer bottom with the shorter top will probably be a stiff top bend curve and the longer top with shorter bottom will probably be a soft top curve.

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Ben1973 said..
I've got 2 Severne apex 490 mast
onemast has a longer bottom section and shorter top
why would they do that?

You missed the question too.
Let's try again.

Yep, 2 x 490 masts. But the ferrule is in differnt places on each assembled 490. So if you mix em up youre 3cm out.

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Ben1973 said..
why would Severne do that?

Here's the question above?

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olskool said..
Yep, 2 x 490 masts. But the ferrule is in differnt places on each assembled 490. So if you mix em up youre 3cm out.

He knows that.

OK so the question is, "why would they do that?"
And I think to make two different bend curve masts, as I said above, a soft tip and a stiff tip.

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decrepit said..
OK so the question is, "why would they do that?"
And I think to make two different bend curve masts, as I said above, a soft tip and a stiff tip.

interesting ... i remember that the North black series was sold in different flex curves within the same year .. but they were clearly labelled.

i wonder if Severne ever sold the Severne Apex 490 with two different flex curves ... or as suggested above, they changed the curve between years.

Jeezzz lads the lock down has everyone testy! Ease upon the keyboard warrior tactics.

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decrepit said..
OK so the question is, "why would they do that?"
And I think to make two different bend curve masts, as I said above, a soft tip and a stiff tip.

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decrepit said..
OK so the question is, "why would they do that?"
And I think to make two different bend curve masts, as I said above, a soft tip and a stiff tip.

I don't think that's it as both mast are the same diameter it's just the join is in a different place, also the say they are the same bend/flex

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Ben1973 said..
I don't think that's it as both mast are the same diameter it's just the join is in a different place, also the say they are the same bend/flex

Oh well just a change in manufacturing technique I guess

Just another overnight thought.
masts really need to be taped at the join to stop grit getting in and jamming then up. Camber induces, would be a big problem if they sat on top of the tape. So maybe one year the sail designer/s decided they really had to move the battens on their slalom sails. Then discovered the camber inducers were getting fouled by the tape. 2 solutions shift mast join or redesign the sails.

I found this video interesting, now I know how the spiral marks on the mast are made.

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decrepit said..
Just another overnight thought.
masts really need to be taped at the join to stop grit getting in and jamming then up. Camber induces, would be a big problem if they sat on top of the tape. So maybe one year the sail designer/s decided they really had to move the battens on their slalom sails. Then discovered the camber inducers were getting fouled by the tape. 2 solutions shift mast join or redesign the sails.

Yep, I'd go with that. Apex came out with R8, We're three generations on from that now.


the intgrated ferrule could definitely cause rotation issues if a camber inducer seats on it.