Hydraulic or Electric trim tabs on ribs? Anybody using them?

boatster · 07 May 2005, 20:43

I am considering the installation of adjustable trim tabs to my Avon SR4. I currently have self adjusting oil filled trim tabs and they definitely have improved the ride and hole shot but I want to be able to control them so I was thinking of installing new ones. Currently heading into seas the tabs help but not as much as I would like. The compromise is in returning seas the tabs are still down which can lead to stuffing etc. Since I cannot adjust the tabs I have to set it to work for both heading and following seas, a compromise for sure. The adjustable trim tabs would allow me to put more downward angle into heading seas and lift them out in following seas. If I'm crossing diagonally in either sea condition I can likewise lift one tab and feather the other down a little to keep me leaning somewhat into the waves.

My question is does anyone here have adjustable trim tabs in your boats? If not, why? If so, can you share your experiences? Do you prefer the electric or hydraulic version?

Boatster

boatster · 07 May 2005, 21:58

Here is a pic of the gas filled strut trim tabs that I currently have installed:

sunrider · 07 May 2005, 23:53

I've used hyraulic adjustable tabs on my RIB with very good results. Mine is bigger (24') and can be very heavy when full loaded, and I've found the tabs to be absolutely necessary. Can't find my camera but when I do I'll add a picture because the ones I use are very large - over two feet wide per side. I tried smaller ones, then Bennet Marine sent these to try and they worked very well although I've never seen such big ones on a similar size boat. I would definately suggest adjustable over fixed, for many reasons.

boatster · 08 May 2005, 03:07

Hi Sunrider,

What do you think about the Lenco electric trim tabs versus the Bennet? Also, how far down do you put your tabs in a heading sea? ( in degrees roughly) How about following seas, do you usually lift them all the way out? Also do they help in short period windswell chop 6-8 second period stuff? Right now my boat pounds hard sometimes in 2-3 foot chop heading into the swell. The stern of my boat is a little heavy but I was wondering if the trim tabs would level the boat off when coming off the top of a wave heading into the next....

I'm almost certainly going to upgrade my trim tabs though. Thanks.

boatster

boatster · 08 May 2005, 19:02

I somehow get the feeling that our main UK contingent of ribbers do not use trim tabs?

Pete7 · 08 May 2005, 19:37

Boatster hi,

correct very few ribs over here have them. Do you have power trim and tilt on the Tohatsu ? and is that not effective enough ?

Whilst we are on about 4m Avons, Oli is having problems with his leaning over to Port. Is your engine exactly in the middle of the transom ? could you measure it and find out for us.

http://www.rib.net/forum/showthread....4285#post94285

Thanks

Pete

tunawish · 08 May 2005, 19:47

ribster i think the real issue with your hull may be the deadrise and the shape of the hull.. most of the hulls overseas are made for the rough water they operate in.... tabs are certainly great to help bring the hull deaper into the water in head seas but it is still a compromise for a hull that can't handle the conditions your in....
as far as the lenco tabs i've had experience with both them and the bennets. Not on my rib but on my rampage and my friends center console. the bennets are great but are much more complicated system although they have been around for 25+ years. The lencos are a snap to install and maintain plus they are very fast acting that may be an advantage for your rib. If i needed to install a new pair in whatever boat i were to buy next i would use the lenco for the reasons listed above. otherwise they both do the same thing very well

boatster · 08 May 2005, 20:58

Hi Tunawish,

actually I usually run in pretty rough conditions. Crossing from the mainland out 27 miles to the channel islands can get pretty rough ( 3-4' seas @ 4-6 second period + wind chop) The boat actually cuts really well in the rough stuff but its the departure angle from the crest of one wave into the face/crest of the next that causes the pounding. I need to keep my nose down (too much weight in the rear I suppose). In any case I am pretty sure getting the adjustable trim tabs will be the call.

I like the Lenco for their electrical efficiency and simplicity. I will post my result when I get them on and tested.

boatster

codprawn · 08 May 2005, 21:04

You could always try moving heavy items like passengers etc forward - or carry some bags of sand!!!

boatster · 08 May 2005, 21:08

HI Pete7,

I do have power trim on my outboard but the trim tabs still help smooth out the ride and increase onto plane time by a huge amount. I am seriously surprised that there is no feedback from UK ribbers on trim tabs. I am certain that if you Chaps gave them a try you'd notice the difference like day and night.

And I do not work for any of these Yankey trim tab companies either.

boatster

Brian · 09 May 2005, 13:53

Stung into action by Boatster.

I have Bennett Sport tabs and swear by them.
In fact I cant imagine running my boat without them.
Not only do they give you roll and pitch control, but it is also great fun steering the boat by using only them (yaw).
Here is Bennetts download simulator:
http://www.bennetttrimtabs.com/

boatster · 10 May 2005, 23:39

My last "ToP" on this subject:

I gather there aren't many UK ribbers that use trim tabs. I wonder why?

It seems over here in the US there are more boaters that have trim tabs than those that don't.

Boatster

boatster · 11 May 2005, 00:06

I just noticed Jwalker uses trim tabs also:

codprawn · 11 May 2005, 02:57

Quote:

Originally Posted by boatster

My last "ToP" on this subject:

I gather there aren't many UK ribbers that use trim tabs. I wonder why?

It seems over here in the US there are more boaters that have trim tabs than those that don't.

Boatster

Could be RIBS don't need them as much - especially ones built for rough water with deeper v hulls???

The Jackeens · 11 May 2005, 07:16

We have a very basic form of auto trim tabs on Zebedee. Certainly makes it easier getting on the plane. Also help in a head sea !

Us

boatster · 11 May 2005, 07:40

Quote:

Originally Posted by codprawn

Could be RIBS don't need them as much - especially ones built for rough water with deeper v hulls???

Not to press the issue but actually Jwalker has trim tabs and his boat is:
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX

Also Brian posted above:
Make: Scorpion Sports Crui
Length: 9m +
Engine: Ib/d Yanmar 300hp-di

I'm running an Avon Searider SR4 which is about as deep a hull as any other just length challenged.

I'm not trying to drive a point or an agenda but am curious why they aren't as popular for UK ribbers as I've noticed a significant jump in seaworthyness even with my automatic trim tabs.

I would really love to see what Jwalker has to say about trim tabs.

boatster

Pete7 · 11 May 2005, 07:47

Quote:

Originally Posted by boatster

I'm not trying to drive a point or an agenda but am curious why they aren't as popular for UK ribbers as I've noticed a significant jump in seaworthyness even with my automatic trim tabs. boatster

Never really felt that a well balanced rib between 5 and 6.5m needed them. On ribs in this range, trimming the outboard will have the desired effect of helping to hold the bows down when going into a head sea or getting a heavily laden dive boat up onto the plane.

Its another cost and something else to go wrong. Given the choice I would rather have a second VHF or GPS for the money.

Peter

Brian · 11 May 2005, 11:07

Cant help feeling that Pete7 has touched upon a couple of good points here.
In the US, the entry-level cost to ribbing is considerably higher than in the UK. Hence some, having scraped together enough money to get themselves waterborne, one cant necessarily go the extra mile initially by investing in trim tabs.
When you do get some cash together, the tabs come quite low down the priority list, with VHF, hand helds, plotters etc. assuming greater perceived importance.
Added to that is the fact that if you haven't got a VHF, you cant make a call. If you dont have tabs, "well, we will get round it somehow and does it make much diference anyway, does it?" tends to be the attitude.
As you say, once you have them and use them, then they become very important. They just dont seem that way when you are starting out.

jwalker · 11 May 2005, 11:21

Quote:

Originally Posted by boatster

Not to press the issue ......
....I would really love to see what Jwalker has to say about trim tabs.

Fekk, you're persistent.

Right, boats list into the wind. I reckoned a cabin would make this consideably worse so I fitted tabs. The reason listing is a pain is that the boat will land on that side of the hull and it will be virtually flat to the water and, consequently, a very hard landing. It also allows fore and aft trimming whilst still keeping the angle of the drive correct for the hull. I have heard stories of being able to drive the bow right down to an almost dangerous extent... on my boat you can't.

Happy now?

boatster · 11 May 2005, 17:22

Persistent indeed!!!

I agree that considering all the other necessities trim tabs could be percieved as doelfins or some "enhancing" part of a setup (unnecessary). I can say from my experience that they are actually quite necessary, at least for me.

I will now unceremoniously let this thread die!!