Towball Weight

[Berleyguts]

Hi Raiders,

I haven't been online for a while... just too busy with life. I busted my trailer on New Years Eve and it took me I while to sort something out. I thought I'd have a go at welding it but I ended up buying a new one a few weeks ago. Some mates helped me get the boat of the old one and on to the new one, then we set about adjusting it. I felt it was too heavy at the towball to move around easy (I have a steep drive and need to move it about a bit at home) and I also thought we had it sitting too high. We moved the axle as far forward as we could but I still wasn't happy.

So, yesterday, I lowered the skids and rollers to a height I am comfortable with and moved the boat back on the trailer about 6 inches (I had to take the jockey wheel off and move it forward of the winch post to do this). Weight on the towball is now just over 27kg and is manageable, although I'm the kind of guy that might get sand kicked in his face, so if it was lighter I'd be happier!).

Does 27kg at the towball sound OK? I don't know the overall weight of the rig. It is a 4m Stacer runabout, with a 25hp Yamaha. I don;t keep the fuel tank in the boat at home and the anchor is out at the moment too.

I guess my main concern is moving it around off the trailer, as I think my vehicle can manage towing it OK. Tow vehicle is a 1994 VW Transporter, rated to 750kg unbraked, 2000kg braked.

Appreciate your help.

Thanks,

Baz

[Brian]

Baz,

I find your enquirey very interesting at this point. We have just returned from an 800km round trip to the coast. We were on our way on Saturday when I saw a bloke in a paddock looking at us as we went past. I thought, he's not looking at us he's looking at something. I was watching in the rear view mirror and realised the boat was lifting in the air. I found a safe spot and stopped, to find the whole winch post has broken off at the base plate on the draw bar of the trailer. The only thing holding the boat on was the rear strap over the back. Anyway we got back to town and I ended up replacing the whole post and winch, as I had already had it welded one before.

Balancing a trailer is very important as it can affect the whole way the thing will tow. I understand that, if there is too much weight at the back the tralier can start to bounce and become unstable, movng from side to side. The more weight at the front the more it will ride stable, but you have the problem of lifting it or trying to move it. I work on the principal of, with both hands I can lift the trailer onto the towball, with some effort but I'm not going to blow a heart valve. I would say about 60kg. Think of a 20 litre bucket x 3 full of water. I think 27kg might be too light.

My boat is a 4.93 m Clarke. it is a bit heavier than your average tinny. When I do go anywhere it is 100km open road for at least 100ks, so towing is important as opposed to being about town in 60kph zones to the local boat ramp.

Hopefully others will add their knowledge.

Cheers,

BP

[helliconia]

I agree, the lower the tow ball weight the more upward force you will get on the winch post and tow ball which will result in instability while towing. I'm not sure of the car/trailer/boat profile you have while towing, but less downward force while towing gives the lift of the wind under the bow less resistance.

If you want to run it like that I would be making sure the hitch has a good solid grip under the ball, and that your winch post etc is strong enough to resist the lift. You don't want the front of your boat bouncing on the trailer in transit either. I use a ratchet strap over the bow to the trailer just because I'm a bit paranoid about that happening. I figure the winch strap is holding it forward on the trailer and the ratchet strap holds it down.

[pjbink]

The rule is a dowload of 7 - 10% of the rig weight. So 27kg might be just OK or a little on the light side. As others have said swaying is the issue with light towball weight. You haven't said what you are towing with or if you are doing highway speeds, factors that also can contribute.

[Berleyguts]

The rule is a dowload of 7 - 10% of the rig weight. So 27kg might be just OK or a little on the light side. As others have said swaying is the issue with light towball weight. You haven't said what you are towing with or if you are doing highway speeds, factors that also can contribute.

Thanks all for the feedback. I had mainly thought about moving the boat around off the vehicle - hadn't thought about sway while towing. I don't want that!

My tow vehicle is a 1994 VW Transporter 2.5 litre van. I think the trailer on it's own weighs 120kg. I will have to find a weighbridge to weigh the whole rig, I guess.

I mainly travel from Quakers Hill to Wisemans Ferry, so around 80kmh (well that's the speed limit anyway ) but also to Botany/Port Hacking and also some highway travel. Have boat will travel.

I am thinking I may have to move the boat forward a few inches again. I will put the fuel tank and anchor in and weigh it again. In the meantime I might move both up the front for towing to be sure. I would struggle to lift 60kg and move the boat around on my own on the slope through the soft ground and gravel, although it will be OK with the jockey wheel once I get it over the bumps and onto the flat concrete at the top of the drive.

Cheers,

Baz

[helliconia]

If it is only an issue when moving it around why not roll the boat back on the trailer a bit to balance the weight more when your pushing it around.

You could use the winch to move it back by looping it around a cross bar on the trailer and back to the bow point then winching it back slowly. Doing it this way you could balance it so there's barely any weight on the hitch, and still have it rigged for good towing performance by reverting the strap to its normal position and winching it back to the post.

Might be a bit of a pain to do everytime but it's better than hernia surgery!

[Fester]

Too little weight on the tow ball or even a boat or any trailer loaded with too much weight to the rear will result in the DEATH wobbles and trailer and sometimes towing vehicle depending on weight upside down on the highway taking out innocent people!if you are pushing your boat around on soft or uneven ground buy the jokey wheel with the big wide pump up tyre, better than towing your boat unsafely!

[Berleyguts]

If it is only an issue when moving it around why not roll the boat back on the trailer a bit to balance the weight more when your pushing it around.

You could use the winch to move it back by looping it around a cross bar on the trailer and back to the bow point then winching it back slowly. Doing it this way you could balance it so there's barely any weight on the hitch, and still have it rigged for good towing performance by reverting the strap to its normal position and winching it back to the post.

Might be a bit of a pain to do everytime but it's better than hernia surgery!

Good thinking, 99! I will weigh it again, too... I realised that I would have had it higher than the towball, so that may make a difference.

Also, a good tip from Fester. I will look at a big pump up tyre... at least until I can afford to lay more concrete.

Cheers,

Baz

[macnaz]

Good thinking, 99! I will weigh it again, too... I realised that I would have had it higher than the towball, so that may make a difference.

Also, a good tip from Fester. I will look at a big pump up tyre... at least until I can afford to lay more concrete.

Cheers,

Baz

Hey Burley i have to maneuver my boat around by hand and its a real pain as well as hard work particulary when i wanna have a fish on my own. What i am going to make over the next month or so is a motorised jockey wheel, maybe u can look into wether they are available comercialy or wait around till i have mine goin and ill post up here on how i have designed it. The main parts in what i am making will be about 200 bucks so that may be cheaper than concrete.

Edited March 30, 2011 by Macnaz

[Fester]

Motorised jokey wheels are available, have seen them on that big auction site.

[Berleyguts]

Or put a towball on a ride-on mower, or even quad bike!... "What do you mean, "MORE TOYS???", darling? These are important and necessary tools!"

Baz

[Guest Aussie007]

u could have just made it very easy and posted a picture of your boat if its just a simple 4m tinny with thin gunnels 27kg on the tow ball is a fair bit of weight i had a 3.75m tinny the weight on the tow ball would have been around 8kg max and towed beautiful up to 130kph on the other hand if u have thick gunnels forward steer false floor etc etc... things change post a pic mate or tell us what boat u have so we can google it

[Berleyguts]

u could have just made it very easy and posted a picture of your boat if its just a simple 4m tinny with thin gunnels 27kg on the tow ball is a fair bit of weight i had a 3.75m tinny the weight on the tow ball would have been around 8kg max and towed beautiful up to 130kph on the other hand if u have thick gunnels forward steer false floor etc etc... things change post a pic mate or tell us what boat u have so we can google it

Good point... and since the old Kombi has been traded for a younger model, I need to change my avatar anyway! I think I have it sorted but will take a pic anyway. Boat is a 4m Stacer runabout as originally stated - it has wide gunwhales, forward steer of course and false floor. I really need to find out how much the whole rig weighs, I guess. I moved it forward on the trailer again on Saturday but for some reason I can't get a reading on the scales now. Go figure! It feels better anyway...

It will get a test run to Wisemans Ferry the weekend after next and I can fine tune it there, in between .

Cheers,

Baz