dilemma over trim tabs

[behavin]

hi all ..hoping someone may have some advice or experience on trim tabs

i have a 6.8m ribcraft with a central midships console and 4 individual jockey seats with double a frame and a suzuki df 250 as a lump on the back.

as you can imagine she is stern heavy and in rough seas will drop back into troughs lifting the bow and on occasions causing quite an uncomfortable ride.

i am wondering if fitting tabs would stop the sterns tendancy to fall down keeping the boat flatter and also to reduce the amount of wash she generates at slower semi plane/displacement speeds...?

tab sites suggest having due to the tightness of the transom narrow tabs that are quite deep ...almost square....

also is it worth having adjustable trim tabs or plumping for the fixed "dampened" ones..??

thanks for any thoughts

pete

[jwalker]

Pete, get adjustable tabs they will enhance your boat. Do a search, it's well documented on Ribnet. One comment, my own opinion, they need to protrude from the rear of the boat a fair distance... So long and narrow backwards not the more common narrow along the length of the hull V.

[richardjawilson]

Hi, get adjustable ones, but they are more. I have a set of 'damped tabs' called smart tabs. They do work but they are pretty average.

Pays your money etc etc................

[nik]

will trim tabs improve performance? As in giving the hull the attributes of a longer one.

Nick.

[jwalker]

Yes, they will.

[nik]

And are they prone to damage if you do a lot of stern first landings?

[Chris]

I just went through the whole tab fitting experience and you can find more here....

http://rib.net/forum/showthread.php?...ight=trim+tabs

An excellent addition to my boat IMHO, however I did not fit the tabs to correct any particular issues with the boat it already ran extremely well and had none of the issues that you are experiencing due to weight distribution.

I am sure the tabs will help you improve the comfort when heading into the rough stuff however I would also be looking at what can be done to improve the handling of the boat without the tabs. Perhaps more weight in the bow? are all your seats and console bonded in or could they be moved forward without a complete rebuild?

a 250 on the back of a 6.8 sounds like a lot of power and it sounds like you will not be able to use it anyway in anything but flat calm, would it be worth looking to trade the engine in for a more lightweight unit?

Do you have any pics of the boat?

[Mollers]

Originally Posted by Chris

a 250 on the back of a 6.8 sounds like a lot....

Thinking about it, this rig sounds like an exercise in arse burying.

In my limited experience of Ribcraft boats (Roycruse' 585), some of the hulls can be a tad bow light. To add to that, you've got all the gear a midships or aft of and you've got a heavy 4st 250 on only 6.8m of hull length.

A pic would be interesting.

[behavin]

i will try and get a picture on here if i can work it out...
bear with me..
yes it is a lump on the back but at rest the tubes dont actually touch the water unlike some ribs.
she was originally a inshore safety boat for ocean rowers.

[Bigmuz7]

Originally Posted by behavin

i will try and get a picture on here if i can work it out...
bear with me..
yes it is a lump on the back but at rest the tubes dont actually touch the water unlike some ribs.
she was originally a inshore safety boat for ocean rowers.

I hope they didnt need a tow home