myiW Current Conditions and Forecasts Community Forums Buy and Sell Services
 
Hi guest · myAccount · Log in
 SearchSearch   ProfileProfile   Log in to check your private messagesLog in to check your private messages   RegisterRegister 
Mast extension questions

 
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion
View previous topic :: View next topic  
Author Message
kaletor



Joined: 27 Jun 2007
Posts: 12
Location: SF Bay Area

PostPosted: Sun Apr 21, 2013 12:06 pm    Post subject: Mast extension questions Reply with quote

Hi,

I have two questions about mast extensions. Here is the gear I have:

Masts: 400 and 430 Skinny 91% Carbon (NP)
Luff dimensions of 3 sails I use: 414(4.9), 430(5.4), 466(6.3)
Mast extension: Chinook 38cm Aluminum

It is convenient to use a single extension for all of my sails.. Having said that:

1) Are there any issues(mast flexibility maybe?) with using a 38cm extension when I use my 430 mast with my mid sized sail(luff=430)? Should I use a shorter extension so the mast can flex more?

2) Is it a good idea to use an aluminum extension with carbon masts?

I am an intermediate windsurfer so I would not want to spend ~$100 for marginal gains but I am wondering if the above have any significant effect..

Thanks!
Back to top
View user's profile Send private message
coachg



Joined: 10 Sep 2000
Posts: 3549

PostPosted: Sun Apr 21, 2013 12:28 pm    Post subject: Reply with quote

Aluminum’s fine and it just depends on how your 5.4 rigs on the 430 with 30+ cm extension suck up into the mast. I had to buy a short skinny extension because the long extension shoved up into the base of the mast made the lower part of the mast so stiff that the extension pulleys wouldn’t line up properly with the sail pulleys and they kept slipping off and binding while trying to down haul. If you have no problem rigging it, then don’t bother with another extension. Only get another extension if you have problems rigging the 5.4 or you need to have two separate sails rigged.

Coachg
Back to top
View user's profile Send private message
adywind



Joined: 08 Jan 2012
Posts: 665

PostPosted: Sun Apr 21, 2013 12:29 pm    Post subject: Reply with quote

Find out what size mast is recommended for the 5.4. If they recommend a 430 mast and if the sail has an adjustable luff top /as I'm sure the case is/, release it some so the mast protrudes from the top and you have enough room at the foot for the extension and 3 fingers of slack for min/ max downhaul adjustment. If the luff top is fixed then use the 400 mast with long extension /the worse case scenario /.
It's Perfectly fine to use aluminum extension with a carbon mast.
In general smaller size sails allow for more fluctuation from manufacturers recommendations, so don't be afraid to experiment. As long as the rig looks and feels fine you are good to go.
Back to top
View user's profile Send private message
swchandler



Joined: 08 Nov 1993
Posts: 10588

PostPosted: Sun Apr 21, 2013 2:26 pm    Post subject: Reply with quote

Coachg brought up an important point, the ability to rig a second sail. Also, it would be good to have a backup extension should you have a failure or problem with your primary extension. Extensions are pretty dependable, but they still can break or suffer a component failure. Lastly, it's not a good idea to insert an extension with better than 50cm into a mast because it puts a lot of stress on the bottom of the mast, and it just might be extending a bit beyond the re-enforcement built into the mast. I would recommend buying a medium extension that will give you up to 28cm of boost.
Back to top
View user's profile Send private message
isobars



Joined: 12 Dec 1999
Posts: 20935

PostPosted: Sun Apr 21, 2013 7:58 pm    Post subject: Reply with quote

If an extension sticks up into the mast far enough to affect mast stiffness (i.e., it binds when the mast is flexed), the mast is being point loaded and is much more likely to break at the base of the mast or the top of the extension.

Mike \m/
Back to top
View user's profile Send private message
PeconicPuffin



Joined: 07 Jun 2004
Posts: 1830

PostPosted: Mon Apr 22, 2013 7:09 am    Post subject: Reply with quote

Aluminum extensions with carbon masts are no problem at all.

In addition to the slight (but real) performance concern about having a long extension inside the mast, I invite you to consider that it's actually way more convenient to have more than one mast base extension. Setting aside the short term costs of buying them, anything you can do to reduce rigging time is a gift.

I have one extension set at "0" for all my sails that require no additional length, and separate extensions for all my other sails. It's very nice to simply grab the right extension and go. I built up to this over time...first I had one extension, then two (so I could keep two sails rigged), then two and a shorty (shorties are the least expensive, and rig all of your "extensionless" sails), etc.

.02 (okay more like $60 a pop, but your time may be worth it!)

_________________
Michael
http://www.peconicpuffin.com
Back to top
View user's profile Send private message Visit poster's website
kaletor



Joined: 27 Jun 2007
Posts: 12
Location: SF Bay Area

PostPosted: Tue Apr 23, 2013 10:11 pm    Post subject: Reply with quote

Thanks guys! I'll start with a shorty for convenience and as a backup. Appreciate all the responses.
Back to top
View user's profile Send private message
beaglebuddy



Joined: 10 Feb 2012
Posts: 1120

PostPosted: Wed Apr 24, 2013 2:38 am    Post subject: Reply with quote

I've seen more bent aluminum extensions or snapped carbon extensions than broken masts.
Back to top
View user's profile Send private message
PeconicPuffin



Joined: 07 Jun 2004
Posts: 1830

PostPosted: Wed Apr 24, 2013 11:26 am    Post subject: Reply with quote

kaletor wrote:
I'll start with a shorty for convenience and as a backup.


Good decision! You won't regret it.

_________________
Michael
http://www.peconicpuffin.com
Back to top
View user's profile Send private message Visit poster's website
swchandler



Joined: 08 Nov 1993
Posts: 10588

PostPosted: Wed Apr 24, 2013 3:12 pm    Post subject: Reply with quote

"I've seen more bent aluminum extensions or snapped carbon extensions than broken masts."


In my 28 years of windsurfing, I've never broken or bent a mast extension. I wish I could say the same about masts.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum

myiW | Weather | Community | Membership | Support | Log in
like us on facebook
© Copyright 1999-2007 WeatherFlow, Inc Contact Us Ad Marketplace

Powered by phpBB © 2001, 2005 phpBB Group