Seeking suggestions for trailer modifications please - Page 2

jyasaki · 24 June 2016, 16:54

[QUOTE=jeffstevens763@g;720762]its higher yes good for
clearance over rough ground, but needs deeper water to float the boat off.[quote]

Most SIBS (and many RIBS) all sit high on the trailer, as the shape of the boat means the hull can't nestle down between the wheels as a hard boat usually does. They all take a lot of water to launch (except roller trailers, I guess.) Not that springs don't makes a difference - they do. But you'll never sit the boat as low as a hard boat will.

Quote:

if you have the tow ball too high buy a drop plate for your vehicle tow sure or similar will have than dont forget you need longer bolts.measurment should be about 16 inch to the ball top from memory

Ball height on the tow vehicle should be determined by the road to frame measurement at the wheels. You (ideally) want the trailer frame to be level when hitched up.

jky

T4Syncro · 24 June 2016, 17:00

[QUOTE=jyasaki;720784][QUOTE=jeffstevens763@g;720762]its higher yes good for
clearance over rough ground, but needs deeper water to float the boat off.

Quote:

Most SIBS (and many RIBS) all sit high on the trailer, as the shape of the boat means the hull can't nestle down between the wheels as a hard boat usually does. They all take a lot of water to launch (except roller trailers, I guess.) Not that springs don't makes a difference - they do. But you'll never sit the boat as low as a hard boat will.

Ball height on the tow vehicle should be determined by the road to frame measurement at the wheels. You (ideally) want the trailer frame to be level when hitched up.

jky

Cheers again guys. I'll take a look at that when I get a few minutes this weekend. Mine definitely is a bit tail down, but not sure by how much.

jeffstevens763@g · 24 June 2016, 17:44

Quote:

Originally Posted by Brian

Mr. Gurnard, sir,

(Sorry to hijack the thread, but)
what type of trailer do you use for your F-RIB and do you dismount the engine when trailing, or.....
do you stow the F-Rib in your car?

Brian look up the guppy goes to sea on gurnard's threads he has a great report from the boat arriving to using it on several adventures that's were he might be now cheers

smokeyjoe47 · 25 June 2016, 22:21

Quote:

Originally Posted by T4Syncro

Hi All,

Got an issue with my new SIB and trailer. I know, it's a "Classic" issue, but I'm specifically looking for suggestions on how to tackle it for my setup. The dreaded bouncy castle trailer ride has got to stop! I've been looking at my trailer and boat then scratching my head as best approach. I have used the search facility and found some posts and ideas, now I want to work out what to apply to my situation. The trailer has two bunks that the outer tubes sit on fine, but the keel has two small ones and only the forward one touches once the boat is on the trailer. Cue pictures to save the thousand words..

I also wanted to pop my proper post cherry..

So this is the boat.

and this 20hp 4stroke heavy lump hangs on the back. Never owned a 4stroke, I'm still amazed at the weight!

But the transom on the trailer looks like this...

I'm happy to approach a local fabricator who has many years of marine experience, or DIY it. However I want a decent solution either way. Also I'd quite like to incorporate the facility to attach the trailer board to whatever I do.

Do I:

Change the central bunk for one long-un that reaches past the transom and also enables me to support the engine?
Get some extendable arms made that slot into those holes in the box section that supports V shaped across the transom and again, support the engine?
Use a "Tansom Saver" type option or just block of wood and luggage strap?
Anything else you good people suggest?

Thanks in advance,

Dan

Hi Dan,
I just joined the forum after looking at your trailer, which is way too short for the inflatable. I don't know if you can extent the "tongue", but you must have solid support under the transom. A cross member of the frame that is positioned under the transom with two "mini"- posts that have some carpeted short pieces of wood on a swivel attached to them would be ideal.
Before that I would get some fenders for the wheels! You don't want rocks hitting your pontoons. As for the position of the bunks: why not under the pontoons?
I have been towing a Zodiac Mark III GR for over 30 years, with bunks under and besides the tubes and 4 rollers under the inflated keel.
Mind you, in 1978 there were not suitable trailers abailable so I had to design one myself - of course it fits like a glove and launching is a snap.
smokeyjoe47

T4Syncro · 26 June 2016, 10:45

Hi Smokey Joe, thanks for taking the time to signup and offer advise. You're certainly in a good spot at Mission for some interesting place along the Fraser River! You're about an hour East of a good friend of mine.

As for the fenders, already in hand just awaiting delivery. Rubber and high speed stones are never going to have a happy ending....

Again I agree about the lenght, however the transom hangs 34cm past the last support and I recon I can adjust the trailer to get the boat at least 40cm further forward. I've got a window of time today so fingers crossed.

Cheers,

Dan

T4Syncro · 27 June 2016, 17:35

I had a solid 20 minutes spare time yesterday so messed around with the trailer and got the transom vertically level with the rear small bunk and rear most section of the trailer. I think it sits ok like this but before I start changing this rear bunk I'm again checking with you more experienced good people.

I can bring it further forward still if I need to.

jeffstevens763@g · 27 June 2016, 20:20

Hard to tell but if your position is transom over the bolt line that will be bang on.

Cheers

T4Syncro · 28 June 2016, 09:09

Quote:

Originally Posted by jeffstevens763@g

Hard to tell but if your position is transom over the bolt line that will be bang on.

Cheers

Cheers again Jeff, that's where it is

T4Syncro · 01 July 2016, 13:51

Winch and Mudguards arrived. Hopefully tomorrow I'll get it all sorted out!

Northern Pike · 01 July 2016, 16:01

I think your trailer bounces because your axle is too far forward, in relation to your load weight. You likely have very little tongue weight. There are formulae for that. I think your tongue weight should be about 15% of your total trailer weight.

Northern Pike · 01 July 2016, 16:14

Here's mine:

T4Syncro · 01 July 2016, 16:49

Quote:

Originally Posted by Northern Pike

I think your trailer bounces because your axle is too far forward, in relation to your load weight. You likely have very little tongue weight. There are formulae for that. I think your tongue weight should be about 15% of your total trailer weight.

Hi thanks for the reply. The trailer itself doesn't bounce its the unsupported transom making the engine nod and sets up a bounce in the boat on the trailer. The boat is now 40cm(ish) further forward. I'll hopefully make the remaining changes over the weekend and give it a road test and go from there

Northern Pike · 01 July 2016, 17:40

As you can see my transom sits on a pad in the centre. I also use a transom saver bracket to support the lower unit.

T4Syncro · 11 July 2016, 10:19

First trial after shifting it all around last week. Works 10x better now, a few minor alterations as the rear support was temporarily packed to support the transom. Only bounce now is from the fact the boat is rubber and full of air

Thanks everyone for help with this.

Dan