View Full Version : Mastdebate

29th September 2006, 03:49 AM
Soft or stiff long or short, what do people like?

Let's say a North ICE 5.3 recommended mast 400 / 430, the luff is 440
so a long extension and a short soft mast or shor extension and long mast stiffer? Could one say if you are light >75kg you would prefer a softer feel and the 400 mast and heavy 85kg+ prefer a 430 mast stiffer.

What would a 80Kg person like? a 400 mast make the sail feel softer and twisting even more than the ICE is already doing, maybe better in marginal condition, and when overpower 430 mast maybe?

What do people think, person preferences??

29th September 2006, 02:37 PM
Interesting indeed! Being lightweight, I prefer a softer, i.e. shorter, mast. So for your 5.3 I would probably go for the 400.

29th September 2006, 02:39 PM
Interesting indeed! Being lightweight, I prefer a softer, i.e. shorter, mast. So for your 5.3 I would probably go for the 400.

30th September 2006, 12:00 AM
Hi think,

I'm about 70kg and I often go with the shorter mast with some healthy extension (18-40cms). While it does loosen up the top a bit, I find that with today's sails the top section of the sail provides more vent than drive. So on the scheme of things I'm of the opinion that a certain amount of liveliness up top doesn't adversely hurt performance. However, I have other sails where I'm using very little if any extension, and the performance is still great with the proper flex. So, if you have the 400 and the 430, it might be interesting to experiment a bit to see how you like the resulting performance.

More recently I broke a 400 bottom section, but I have a some tops left from earlier masts. Given the fact the 430 bottom section was only about 12-13cms longer than the 400 bottom, I did some experiments to see how things worked out. I put a 370 top on the 430 bottom. The overall length was in the proper range, but the result was a bit bizarre. Way too much shape in the bottom of the sail and the top was uselessly loose. Not a viable combination.

Yet, for a couple years I had great luck using the 400 base and the 370 top together, but the 400 and 370 bottoms were the exact same length with the 400 being slightly stiffer. Although this mix and match thing is kind of outside your questions, some different combinations are possible, as long as the differences aren't too great. So one could find some success matching the 430 bottom with the 400 top, or maybe the reverse using the 400 bottom and the 430 top. Of course, the masts need to be compatible a the ferrule connection.

2nd October 2006, 03:11 PM
A tough question. I have a history of using lots of sails with around 440-445 luff on 4m masts. I'm 69 kilos. I think it depends a lot on the sail of extending this much is a good option or not. Generally, I don't think a too loose top os stuff like that is the problem. Rather the overall softer 400 mast make the sail "fold" easier in its mid par as a result of the mast bending too much sideways. How early this happens depend on the sail and wether its a probelm depends on the rider. A heavier rider i likely to load the sail up more and therefor reach this folding point more often. However, even for a light sailor like me you can reach this point if you sail with a kind of locked in powered up style.

As for the general feel of the sail, everything will be a tad softer and more reactive with a softer (shorter) mast, but the power and profila can generelly be tuned just as well with a softer mast.

Also the exact mast you use matter. With rdms, some masts are allready a big soft and don't generally respond that well to lots of extension. I use the Hot sails Maui Hot Rod series of RDMs and they hold up for extension very well. The GulfTech needle 100 iUsed before worked well too.

3rd October 2006, 08:01 AM
I have a severene S1 5.3 06 recommended mast rdm400. This has lots of luff curve and a fair bit of tension through the centre but an average amount of twist at the top. This combination feels so right on the water that I wouldnt`t mess with it. Not that I could, I dont own a 430 rdm and the sleeve is way to narrow for a standard diameter mast.

I have a North Ice 4.5 06 and this rigs with much less luff curve and less tension through the centre. This feels like it could be tuned to different masts quite easily.

It is hard to avoid the randomness of trial and error when making these rig variations.On the overpowered days I tend to prefer a softer mast, rig combination.The simplicity of having everything rig on the same mast is a bonus.

3rd October 2006, 11:04 PM
Hi Ola H.,

In your comments above, you raise an interesting point about a sail tending to "fold" in its mid part due to sideward bending. In my earlier post above, I was remiss in not noting that my comments were relative to use of SDM masts. While have 2 Gulftech RDMs (430 and 490cm), at this juncture I haven't yet logged much time on them. Also, the two newer sails that I match up with them do not require too much extension.

In any case, I wondered whether the folding phenomenon is as pronounced with SDMs as it is with RDMs. I know that RDMs perform a bit differently due to their geometry, so it is my thought that SDMs might be less subject to folding due to their larger diameter base and mid section. Any thoughts?

5th October 2006, 12:31 AM
Well, it was some time since I sailed an SDM, but the foling _can_ happen with these mast too. Some SDMs are actually quite soft (NEVER trust a printed IMCS number). That said, the "typical" rdm acts a bit softer than the "typical" sdm down the middle of the mast, I would say. IN the case of RDM, the Powerex is pretty much the standards mast and is a bit soft in its mid part in 400 length (and even softer in 430). The GT needle 100 400 holds up a bit better to long extensioning, I would say and the reason is that it stiffer i the mid part. The Hot Rod is stiffer still but both still fall within the "PX norm" is fit sails cut for Powerex well.

6th October 2006, 12:33 AM
Thanks Ola for your thoughts concerning my question. I guess I've been lucky extending my older SDMs (Fiberspars), but I think that has to do with the fact that they tend to be a little stiffer in the bottom to mid section.

It is good to know that the 100% Gulftech 400 RDM extends well. I anticipate buying a new Hansen Sails 400 RDM very soon, and its my understanding that Bill Hansen will be patterning his mast line very similarly to the Gulftechs (same overall flex characteristics). With my 5.0 sail I need about 20cm of extension. Not too much lift, but more than required for my other RDMs.