Are these strakes NAMBA legal???

[Darin Jordan]

Gentlemen,

Dick suggested that I post this question to you guys to see what you'd say. I was working on this hull for N1, but may ultimately end up using it for O-Mono. I am a stickler for being legal, but don't mind exploring the rules a bit on occassion... Heck, what can I say, I'm a race-car driver... that's what we do! B)

So, what do you think... Legal or not??? I've read the rules carefully, and they DO say that the strakes must be parallel to the keel if they extend into the back half of the hull, but they also say that they can be up to 3/4" wide... There is no mention of which side of the strake must be parallel, nor do they say that the strakes must remain at a constant width...

I'm sure I'm stepping into a gray area, which is always dangerous, but at this point, there doesn't appear to be a defined rule that makes what I've done to this hull NOT legal, just doesn't is a little unclear as to whether it is...

The side of the strake closest to the keel IS parallel to the keel. The outside is up to a point, afterwhich the strakes get wider, but do not exceed the 3/4" maximum, measured as shown in the NAMBA rulebook, nor do they exceed the 3/16" maximum height limit.

Worst case is that I'll have to trim the outside of them down to make them parallel down both sides (with respect to the keel)...

I'm thinking it may be a little tough to control, but we'll see... Dick thinks it may drive the nose down too much by creating too much lift at the rear, but again, I'm a little new at this and am only working from theory (and by something that a successful local racer did to his N1 Mono boat...).

Any opinions would be appreciated...

Thanks,

 

[Ray Fuller]

Gentlemen,
Dick suggested that I post this question to you guys to see what you'd say.  I was working on this hull for N1, but may ultimately end up using it for O-Mono.  I am a stickler for being legal, but don't mind exploring the rules a bit on occassion...  Heck, what can I say, I'm a race-car driver... that's what we do!  B)

So, what do you think... Legal or not???  I've read the rules carefully, and they DO say that the strakes must be parallel to the keel if they extend into the back half of the hull, but they also say that they can be up to 3/4" wide...  There is no mention of which side of the strake must be parallel, nor do they say that the strakes must remain at a constant width...

I'm sure I'm stepping into a gray area, which is always dangerous, but at this point, there doesn't appear to be a defined rule that makes what I've done to this hull NOT legal, just doesn't is a little unclear as to whether it is...

The side of the strake closest to the keel IS parallel to the keel.  The outside is up to a point, afterwhich the strakes get wider, but do not exceed the 3/4" maximum, measured as shown in the NAMBA rulebook, nor do they exceed the 3/16" maximum height limit.

Worst case is that I'll have to trim the outside of them down to make them parallel down both sides (with respect to the keel)...

I'm thinking it may be a little tough to control, but we'll see...  Dick thinks it may drive the nose down too much by creating too much lift at the rear, but again, I'm a little new at this and am only working from theory (and by something that a successful local racer did to his N1 Mono boat...).

Any opinions would be appreciated...

Thanks,

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Dicks got it ,the nose of the boat will be forsed down the boat will run wet. Also it will never run in o mono with any kind of power the boat will roll over in the turn, it will not hold with any kind of speed. The reson for the extened strake was for the lack of power, it holds the boat up better in the straights and with the low power it was no problem in the turns. Also a strake is put on to help the boat go staight , this way you have is going to let the bot hunt for a place to run. I am sure there will be a lot of diff. pros and cons.to this Ray

 

[Darin Jordan]

Ray,

Thank you for the assessment... Since you designed the boat, I trust the you would know!

I'm unclear about a couple of things, so perhaps you could elaborate further...

First, when you say the boat will flip in the turns... what particular aspect of the design (my strake design...) contributes to this? Is it the fact that there is now a smaller area in the back of the boat for it to "settle into" as the hull rolls over with rudder input? Or, is it because there will be too much lift generated due to the strake extensions?

Second, when you say the hull will "hunt for a place to run", are you saying that it will dance around under speed and be tough to control, or were you referring to something else?

Third, I thought that strakes were suppose to help hold the hull in the corners as well?? I've sharpened these strakes from front to back, giving them a nice sharp edge... Should I NOT have done this???

The boat was done this way for N1 Mono... and that's where I'll run it (barring unforseen actions by the NAMBA membership! :blink: ) So long as I'm running this one in N1, and since we don't have N2 Mono, I'll likely keep it set up for that class, and use my other El Lobo 2 (fiberglass instead of Carbon) for O-Mono, so if many of these issues are power/speed related, I may not concern myself with them as much...

Thanks again for you valued input... It's nice having access to those who really know!

 

[crowebar]

I've spoke to a few higher ups and they feel that the word Strakes means just that. Not the inside of the strakes or the outside of the strakes, but the strakes themselves, inside and out. If that be the case then a CD (Contest Director) has the option of declareing your boat illeagle based on the current strakes.

As for hunting, as the boat rolls from one side to another it may grab the strake at the rear and act as a rudder. Many mono's will teeter a little back and forth from side to side when they run down the straight and I could sure see where it might push the boat left and right as it does.

Mostly it just looks like it will lift the tail and force the nose down making it slower. The more power you give it the worse it will get.

Sharpening the strakes is fantastic! Give the water a nice clean place to brake free. It's especially important to keep the transom edge sharp!

Good luck,

Dick

 

[Darin Jordan]

Thanks Dick,

I spent last night and part of this morning making some modifications to get these clearly legal... Basically, I trimmed off the outside edges near the back to make them parallel... I also shortened the inner strakes a bit to make them not quite full length...

I have a bit of sanding and filling to do now, but it's all part of the experiment... Should be finished and ready for paint in a week or so...

I'll post some follow-up pics to show the result...

Thanks Again!

 

[T.S.Davis]

woh

I was right? How'd that happen?

Dick, have you ever messed around with the rudder possition to help with hunting? By that I mean moving the rudder further from the transome maybe. maybe a deeper rudder. I know it's a little off the subject but since Darin might be looking at that type of thing.

 

[Darin Jordan]

...but since Darin might be looking at that type of thing.

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I'll take ANY information that makes this all make sense! :blink: