Towing and Launching a 5.3m RIB? - Page 2

Poly · 12 April 2007, 08:22

this link might be useful:

http://www.cuddles.abelgratis.net/audi.htm

Bigmuz7 · 12 April 2007, 09:46

On this general subject guys... Looking at 4x4 's some can tow the max 3.5 tonnes, others cant. And Looks can be very deceiving. Example Isuzu trooper LWB only 3.2 tonnes max. Diahatsu Fourtrak 3.5 tonnes . What is it that determines how much they can tow, is it the body style, chassis, or what ? Since a fourtrak is way lighter than the Isuzu ?

Searider · 12 April 2007, 12:03

It might be something to do with the ability to make a hill start. This will be determined by the first or low ratio gear when looking at big loads.

Channel Ribs · 12 April 2007, 16:21

Quote:

Originally Posted by Will Lankston

What is the smallest car that would get away with towing and launching a 5ish metre rib?

It might be worth looking at a fully inflatable rather than a rigid hull... A 5.3m Heavy Duty comes in at less than 300kg with the engine and console, many more options than the 700kg+ of a solid keeler.

Not to mention cheaper to buy, smaller engine to run and oh yes - they fly well too

philr · 12 April 2007, 16:34

If you passed your test in recent years you may need to get a further test to tow a trailer. I got mine 23 years ago when it was automatic. I mention this because I am guessing they make you take a test on the law, including towing weight. It was pointed out to me that if you don't have this and you have an accident your insurance company will refuse payout. OUCH!!!

Nos4r2 · 12 April 2007, 18:30

Quote:

Originally Posted by Searider

It might be something to do with the ability to make a hill start. This will be determined by the first or low ratio gear when looking at big loads.

More likely to do with chassis strength and suspension.
Fourtraks have electrically adjustable damping on the back shocks. Very useful when towing a heavy load.

Bigmuz7 · 13 April 2007, 08:47

Quote:

Originally Posted by Nos4r2

More likely to do with chassis strength and suspension.
Fourtraks have electrically adjustable damping on the back shocks. Very useful when towing a heavy load.

As I remember it, the Fourtrak uses a sub chassis with the body bolted on to it, but the Isuzu has more of a monocoque construction, but the fourtrak had a smaller engine, as its physical size is smaller, yet it could tow more ? I have a suspicion it has something to do with the body/chassis too, but what exactly is a mystery .. time for some 'google'ing

Neil Harvey · 13 April 2007, 10:36

Quote:

Originally Posted by Bigmuz7

As I remember it, the Fourtrak uses a sub chassis with the body bolted on to it, but the Isuzu has more of a monocoque construction, but the fourtrak had a smaller engine, as its physical size is smaller, yet it could tow more ? I have a suspicion it has something to do with the body/chassis too, but what exactly is a mystery .. time for some 'google'ing

That does not exactly stack up either. the 3.0l TD 2nd gen Toyota Hilux Surf has a chassis with body bolted on, and that only has about a 1800kg limit I think.

Sixy_the_red · 16 April 2007, 07:35

'Speciality' or more commercial oriented vehicles including the 4trak and the trooper (which is also a chassis construction BTW, or at least the older ones were) have a plated weight on the VIN plate which gives the maximum towing capacity. 'Normal' cars don't and the towing capacity is based on the curbside weight - as previously stated this is 50% for an unbraked trailer and 85% for a braked. (I didn't know that either until Mr Harvey mentioned it!

)

I have no idea how the plated towing capacity is worked out, but I suspect its a combination of stability, chassis / towbar construction, vehicle weight and COG, and will be a factor calculated at the design and test stage. Most pickups for example have a pitifully low towing weight - I believe the new Navara can only pull about 2.2T for instance - and I would suspect that this is to do with the lack of weight over the rear axle and generally more flimsy construction as a result of not having a proper bodyshell at the back.

I would also echo the comments about settling for a car thats 'just good enough'. If nothing else if you're straining the car all the time you'll just end up killing it. I also wouldn't really want to put a nice car anywhere near the sea! Buy a Rover 418SLD and a braked trailer and be done with it!

(85% weight is about 960kg if memory serves and it used to tow our Microplus without too much trouble.)

codprawn · 16 April 2007, 10:49

Yesterday I helped a mate tow his big old fishing boat - after a few miles with his 1 year old Jeep Cherokee 2.8 diesel we decided it wasn't safe to continue and hitched up my trusty old Discovery 2.5 - what a difference!!! The nasty noises coming from what I assume were the driveshafts on the Jeep sounded very expensive. Aside from the noises the Jeep just didn't feel right or safe.

Sixy_the_red · 16 April 2007, 10:53

Serves him right for buying a Jeep!

codprawn · 16 April 2007, 10:59

Quote:

Originally Posted by Sixy_the_red

Serves him right for buying a Jeep!

I think the Grand Cherokee would have been ok but looking at the website they both have the same towing limit of 3300kgs. I would have said the boat was about that but I have towed about 5 tons with my Discovery no probs(private roads).

Sixy_the_red · 16 April 2007, 11:14

Maybe it was the auto hubs letting go, or maybe just the tranmission bedding in? I dunno!

I'd still go for the Disco personally!