570 Freedom Sport on trailer heavier than I predicted, anyone tell me where I went wrong?

Hi All

Just purchased a 2004 570 Quntrex Freedom sport on a dual axle galvanised trailer.  Got it weighed at the Balcatta recycling centre and its 1500kg.  I predicteded it should be under 1400kg (my towing limit).  I knew my car would struggle to tow at its limit for distances and for that reason had planned to eventually upgrade but I at least wanted to be within tow limit so I was all good from an insurance point of view and I could upgrade in my own time.  This is all a bit academic now as it only means I'll probably upgrade sooner rather than later but still puzzled where all the extra weight is coming from.  I had two methods for predicting the weight, listed below with assumptions.  Appreciate any comments where I may have gone wrong.

Method 1:

I had a 2001 560 Freedom sport on a single axle galv trailer weighed 1220kg (I didn't buy this boat)

Dunbier list the difference  between a single and double axle trailer that are both 5.7 m as 60kg. (the weight of another axle assembly).

I'd expect a small difference in boat weight (560 vs 570) and motor (100hp vs 130hp - both 4 strokes)

Fuel Qty was similiar between both boats when weighed and both had similiar gear (basics - anchor, bimimi, radios)

So I figured my 570 on a dual axle would be the 560 on a single + 100kg.  ie 1320 kg.

 

Method 2:

My trailer tare weight is 400kg (from the trailer plate)

Quintrex list 620kg as the "boat only" mass of the latest 570 Cruiseabout (I'm assuming similiar weight to my 2004 570 FS, I'm also assuming that "boat only" would include basic/standard equipment - seats, radio, etc)

Quintrex list 240kg for motor weight. (and Honda website lists my motor at 230kg, but I'll go with the higher)

I've probably got 20kg of fuel onboard and I've got no gear other than basic/standard equipment.  I've also got single battery.

So total of 1280kg.

 

At 1500kg (from the Balcatta recycling centre weigh bridge), method 1 is 180kg out and method 2 is 220 kg out.  Can anyone offer their thought on where this weight is?  Is Quintrex being cheeky with their boat weights?  Did the guy at the trailer place stamp the TARE after a few beers on a friday arvo, did I go to a dodgy weigh bridge, is there 200lt of sea water floating around under the floor boards?  All of the above??!!

Ironically I'm still 300kg under my Gross Comb Mass, so if I could magically transfer 100kg to the back of the car I'd be 100% legit if I ever had to make an insurance claim and they starting getting picky.  Also, as another side note, my hitch load is 75kg - within my limits without needing a distribution hitch.  Its at the bottom end of the 5-10% hitch load range I've heard of but the car handles nicely at all speeds.

 

Appreciate anyone taking a genuine interest in offering some explanation.  Thanks in advance for staying on topic, please dont bother to reply if you simply want to point out my shortcomings in assuming 1400kg would be enough or that I should have weighed it before buying.

Regards

Mondy


Posts: 212

Date Joined: 30/12/08

Tyres

Thu, 2017-02-09 18:35

 Did you allow for two extra tyres and rims 

extra chain on your anchor will add up quickly too 

was the weight accurate on the 560!

 

 

 

Posts: 315

Date Joined: 07/05/11

1500kg vs1400kg

Thu, 2017-02-09 19:19

 what car are you pulling it with?

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 Baron Sportsman

Just the depth that Varies

straith's picture

Posts: 422

Date Joined: 25/11/13

Motor brands can vary quite a bit too.

Thu, 2017-02-09 19:26

 Check the plates on them both and compare. I know yammys are a bit heavier than most.

Also whats the capacity and build quality like on the 2 fuel tanks? Underfloor arent they? 

Fuels the only real other factor id be checking again. As in amount actually in tank.

You're right though its all academic. Its not like youre giving the boat vack now.

Ofcourse you could just do what a very large portion of boat owners do now and ignore it? 

Im not advocating it but width and weight dont seem to be high on many peoples concerns when towing a boat from what ive seen.

The other thing id be doing is going over a tip weighbridge. Theyre pretty accurate.

Cheers 

Tim's picture

Posts: 2497

Date Joined: 26/09/06

Anchor

Thu, 2017-02-09 22:09

Anchor chain and rope can add a fair bit and are not included in the dry boat weight.
Other bolt on items like bimini etc are most likely added to that weight also so depends what level of fitout you have.
 
The manufacturers boat only (dry) weights are generally as they leave the factory with nothing in them. Normally dealers will do fitouts and add other items

Posts: 4

Date Joined: 05/02/17

missing weight

Thu, 2017-02-09 22:10

Thanks for the input so far.

Scaly Man:
yes, the 60kg difference between single and double axle would include two extra tyres and rims. Anchor chain -good point, but I've only got rope-no chain! 560 weight accuracy- good point, all this assumes weigh bridge weights are accurate. It may be the 560 (Mandurah weighbridge) was under and mine was over...

Travisd:
Subi Forrester, 2.5lt.

strait:
yeah-tempted to get another weighbridge reading. my local is the recycling centre/tip. no idea on accuracy...
re your comments on fuel tanks, my loosest assumption is probably the latest 570 cruise-about being similar to my 2004 FS...could be a number of differences throwing this out. and yeah, might double check fuel.

Thanks, will post more as new information comes to hand.
Mondy

Posts: 578

Date Joined: 23/04/14

OEM weights

Thu, 2017-02-09 22:20

Be careful with what the OEM says their boats weigh.  You have no idea if it's straight out of the mould/jig (as I suspect it is) or fully finished ready to go.  Seats, bimini, electronics, wiring, batteries, anchor etc all add up.

You only have to look at the listed weights of a handful of boats of similar size to see that there is no standard on how they obtain their published weights.

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Posts: 315

Date Joined: 07/05/11

It's fine

Fri, 2017-02-10 05:40

you could argue that you have only just gone over to have the added safety of tandem axles. Rather blow a wheel with a tandem than a single axle any day

1400 vs 1500 isn't here not there and the forester won't have any dramas with it. Stick to the speed limit and drive accordingly  

____________________________________________________________________________

 Baron Sportsman

Just the depth that Varies

Posts: 578

Date Joined: 23/04/14

Insurance

Fri, 2017-02-10 09:24

Probably won't see it that way if there was an incident. 

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Posts: 114

Date Joined: 16/10/10

Are the sheet thicknesses the

Fri, 2017-02-10 09:27

Are the sheet thicknesses the same for bothl boats.

0.2 of a mm over the boat would make quite a difference.

 

Cheers

 

Deckie's picture

Posts: 1296

Date Joined: 03/04/09

Tinnie

Fri, 2017-02-10 10:51

You will be surprised how things start to add up, even small things weigh a lot when you add lots of em.
I weighed my 4.2m tinnie the other day preparing for a trip to Steep Point.
It came up on the scales at 580kg with 30 lt of fuel.
I think the Forrester will be ok towing it but like was said, maybe get a "second opinion" on different scales.
If you are concerned about the insurance side, then maybe it is a good valid reason to upgrade. Well that's what you can tell the boss anyway. Haha
Good luck with that.

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Cheers & Stay safe

Posts: 4

Date Joined: 05/02/17

Hi all Awesome getting the

Fri, 2017-02-10 11:16

Hi all

Awesome getting the inputs. With the ideas being thrown up and thinking about it further I reckon my biggest flaws are: Method 1 - assuming the 570 is a just a 'little' heavier than a 560 (Craig - spot on, might have different thicknesses throughout boat) and Method 2 - assuming "boat only" weight from Quintrex allows for basic equipment.

...and Tinnie, you don't know the half of it!- Boss gave me permission for the boat BEFORE finishing kitchen reno's. So I'm a lucky man but need to tread carefully going fwd!

See you out on the water soon: transfers done, brakes on trailers repaired/adjusted, motor serviced (compressions good), weather........

avatinni's picture

Posts: 141

Date Joined: 06/06/10

 Just wondering if the weight

Fri, 2017-02-10 17:35

 Just wondering if the weight stated by quintrex is the hull only or including  floors and seats exc .

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

Plenty of ways it will happen.

Fri, 2017-02-10 18:54

 And it happens all the time. Tandem will add more than 60kg, regardless of what dunbier says. 40 mm axle will weigh 30 kg easy, set of springs more than that, then you have the rocker gear for the tandem and two steel rims and tyres. More like 100kg, I did the exercise once myself. Boat only might mean a completely bare hull, and EVERYTHING weighs something. 560 and 570 might have more than just 100mm inlength difference, beam also larger perhaps, could weigh 100kg more, you just don't know. Believe the weighbridge, mate, all the hypotheticals in the world can't win an argument with a weighbridge. I've weighed a few myself, and they are always heavier than you think they should be.

I went through the exercise of weighing absolutely everything I was taking away on a trip once and putting in the boat.. Had a set of scales and a basket for the smaller items--the final amount was a real eye opener.

Posts: 4

Date Joined: 12/01/17

Balcatta

Mon, 2017-02-13 10:03

I would try another weighbridge for sure just to be safe. That bridge is dodgy as at times