Valiant weight-distribution?

[UpNorth]

Hi everybody!

This is my first post, and I am relatively new to ribbing.
My Valiant v450 is a bit stern heavy. It is my first RIB, and I am happy with it, but I am playing with the idea of distributing some of the weight of the boat towards the bow.

My boat look exactly like the one in the pic (that't NOT me at the helm).

The bench seat holds a 25 ltr fuel tank and the battery. I want a larger tank, and in retrospect i should've gone for a boat with a built in tank i guess. But I got the boat+engine at a pretty sweet price brand new, so I went ahead and traded in my boring old Hansvik 18. What are my options as far as fuel tanks go? I have a bow locker, and I would love a tank in there if possible. Are there any "soft" tanks around that I could fit in there, or would I have to get one custom made for the proportions inside the bow locker? This would move 25-50 kgs to the front..

I have a 60 hp Mercury 4-stroke at the back. Marine Power says the 60 weighs in at 107 kgs, while the 50 is 112 kgs, so I don't think going for a smaller engine would've helped much. Of course a 2-stroke would, but I like my 60 (the little boat goes like stink).

I have temporarily removed the A-frame, thus removing some kilos.

Another possibility is to move the console and bench seat forwards. Is this recommendable? It would eat up some space in front of the console and leave some "unusable" space at the stern. But again, weight moved forward should mean getting it faster on the plane?

The current setup with two people in the bench seat = almost impossible to plane unless one of us shift our bodyweight forwards. Once planing there is no problem until slowing down again.

I shouldn't need trimflaps or tabs on such a small RIB i suppose, but if that's the easiest fix I'm willing to give it a try.

Any tips or recommendations would be greatly appreciated!

Thanks guys!

[Brian]

I would be tempted to move the seat/console forward.
Not too much though.
The fuel tank moving is not a good idea as its weight will vary.

[Jackwabbit]

We went through the same situation earlier this year, take a look at this thread.
http://www.rib.net/forum/showthread.php?t=9901

It has made a big difference!

[Tim M]

I have a 4.1m RIB. When I first installed the console (double jockey) I put it really near the back so I had deck space in front of it. When going at semi-planning speeds you could bearly see over the bow it was so high. So i moved the console forward. I'm so glad I did; boat sits really nice and level now, plus if I'm in it on my own and I go over a big wave the boat doesn't feel like it's going to flip over any more.

Edit: I doubt your A-frame weighs that much so probably won't make any difference. Thigns like battery and fuel tank will. I needed an extra fuel tank to extend my range. I didn't want to use any deck space if possible, so I manged to get a triange shaped tank which fits nicly at the very front of the bow above my anchor locker. It's ideal cos it hold just over 30 litres, doen't take up any useable space and helps to keep the bow down if there's weight in the back. I'll post a photo of the tank if i can find one.

[ADS]

The Valiant Vanguards have notoriously bad weight distribution -very stern heavy. DanielTD5, who posts on here had a V450 and I believe he put some lead in the bow locker to keep the nose down, although he had a 40HP 2-stroke, and your 60HP 4-stroke will be a lot heavier.
I would recommend moving your console forward, is it a jockey or the standard valiant seating? There are flexible tanks on the market, but I would just stick with 2x 25 litre tanks on a boat under 5m.

Regards

Alex

[UpNorth]

Thanks for replying guys!

Moving the console and seat seems the way to go then. Tim, you're right, my A-frame doesn't make much of a weight difference, I actually removed it because the engine "collides" with the top of the frame when tilting it all the way up. It's a small frame compared to the rather large/tall engine, whith the A-frame in place and the engine tilted as far as it goes w/o touching the frame the propeller still touched the water.

Tim, what is your triangular fueltank made of? I doubt I want to place a tank on top of the bow "seat"/locker as it would make sitting at the bow impossible, but I would like to see a picture of the tank if you can find it.

But I definetly want a larger tank (or a second one) as my range is limited. How about a secondary tank in front of the console? I have a cooler there now, not been used for cooling yet (beer usually consumed before it goes warm)! Does anyone know of any fueltanks made out there that you can sit on (as my cooler now is used as a seat anyway)?

I'll strongly consider moving the console and seat, but it will no doubt require longer steering cables and looks it's gonna take some work. But no doubt worth it I guess.

[Tim M]

The fuel tank is plastic (poly something or other). Youl could easily sit on it; it has a flat top and is very sturdy.

[codprawn]

You could always try using some sand bags in the bow until you get around to moving the console - sand tends to be dirt cheap and very heavy when it gets wet!!! Not the end of the world if you chuck it over the side either!!!

[jwalker]

Originally Posted by codprawn

- sand tends to be dirt cheap ..

[Daniel TD5]

Been there done that

i had a vanguard v450 as ADS said 40 hp mariner and if you want a longer range you have to fit a 25l tank next to the old one i did that as well

and i made a plane the rib was to say sky happy the only way out
is to fit a jockey consul and keep the rear bench in place which will balance the craft but the gp hull is still not the best its built for the med not the british weather if you add a new tank with the existing seating the boat will slip down any waves and the prop will not grip bringing you to a stop which can be quite bad

i ended up with about four stone of lead in the anchor locker in the vanguard move the battery in to the the locker by your feed it should never be in with the fuel tank

if you move the seat and steering forward watch out as the gp hulls are solas type and are sealed with no drain any holes in the deck not sealed will
allow water in to the hull with no rear drain it will fill up and wreck the boat

in the end i sold it and went for the Dr450 with a bench and jockey
and a 50 hp which was fine and would reach 34 knots

as you can see from the pictures in below taken flat out check the bow height

Daniel

[UpNorth]

Thanks all.

Fitting a jockey console in front of the bench seat is an option I'll consider. Or maybe a single jockey seat between the excisting console and the bench.
In any case the battery is coming out of the bench and will be moved towards the bow.

If the weather permits (been raining for 60 days straight), I will try out codprawns sandsolution in the bowlocker before fiddling with the seating setup.

Daniel, is that an S-5 Jockey console you have on the DR?

I see that the SR4 "clan" are very happy with Nauticus smart tabs. Newbie-question: will these help? My father is going to the U.S. anyway, and he'll pick them up for me (along with Keelguard, alot of beaching during summer).

Thanks again for helping me out!

[boatster_sr4]

HI Upnorth,

I am certain the Nauticus tabs will resolve your problem. My Searider had a problem with getting onto plane when I first got it. It is fitted with a 19 gallon fuel tank and stainless steel bench seat all in the rear. When I would accelerate the bow shot skyward and took quite awhile to climb onto plane. While on plane the boat would porpoise in small swells.

After I put the trim tabs on the boat literally popped onto plane without any hesitation. And the boat never porpoises at all, almost like shocks really. I would highly recommend giving them a try before rearranging your boat layout.

Boatster