SMART BARS ARE THEY SMART??

for those without a ARB store nearby, what was the results?

Andrew

They essientialy drop a dummy kangaroo weighing 60kg from the roof of the workshop onto all 3 types of bars and film it using a high speed camera and record the deformation. The plastic bar showed very little signs of damage afterwards, but flexed so much the vehicle it would have been fitted to would have sustained many thousands of dollars worth of damage. The alloy bar was completly destroyed as would have been the car behind it. The steel bar flexed a little, but sustained no permant damage and the vehicle would have sustained little or no damage. Very graphically shows the advantage of steel over the others.
Certainly helped with my decision on which material is the best to use. As the ARB guy said to me, Most vehicles have a steel chassis which is what the bar is mounted to, so why would you fit a weaker material as a bar and expect it to protect your car?

Did they just have the visable plastic section, or all the smartbar pieces mounted properly?

All 3 bars where mounted to a substantial frame and I assume used the correct mounting brackets, but you would have to ask ARB to be sure.

Now lets talk about the other part of ARB's equation

Smartbar and alloy bar dissipated the energy of the impact into the bending of and breaking of metal and plastic, the steel bar dissipated the enrgy into bending and breaking of the passengers. The energy HAS to be dissipated somehow...

Have you hit a roo with a metal bullbar?
It's a pain when the bar sit firmly against the tyre in the middle of no-where.

If you hit a reasonable size roo with alloy, plastic or metal - there is going to be major damage to the vehicle.

This is why I am trying plastic this time.

Garyin oz....what a load of crap. the plastic and alloy bars tried to absordb the energy, but failed and as such collapsed....probably back into the cars radiator or perhaps the end of the bar puctured the tyre. Either way not good protection, which is why we fit bars to our vehicles isnt it? Or is it just to look tuff and shiny.
The steel bar dissapatted the energy by flinging the dumbass kangaroo off to the side of the road, which is exactly what I would want to happen.
Marquis I have hit many mnat roos in my travels ( 2 last week) and there is no way I would travel on country roads with any thing less than a well designed steel bar fitted to my vehicle. You only need look at the posted pictures to see what would happen in the event of a striking a decent sized roo with one of the plastic bars.

Sorry Wheeler, there was energy expended in deforming the alloy and plastic. The steel bar did not absorb any energy, it transmitted the energy into the chassis of the vehicle.

"...The steel bar dissapatted the energy by flinging the dumbass kangaroo off to the side of the road, which is exactly what I would want to happen...."

For every action, there is an equal and opposite reaction. The Kangaroo is only half the picture. Go back to school, year 11 physics. (Newtons third law of motion). BTW the Kangaroo absorbed it's share of the impact before it untimely demise. The force of the kangaroo hitting the bar is the same as the bar hitting the kangaroo, no more, no less.

My point was that if the energy is not dissipated in the collapse of metal/plastic (including your steel) bars and/or chassis, than it is transferred ultimately to the occupants of the vehicle. No interest in plastic bars myself, and yes, I intend on getting a steel one. My interest was only in the incorrect physics involved in the statements.

Sorry GaryInOz, I'm with Wheeler on this one. If what you say is true, if I was to jump off a 20 storey building onto a concrete footpath, then an amount of energy, equal to that which has just broken every bone in my body, will also attack the concrete and make a big-@rse hole right there for the ambo's to have to dig/scrape me out of!!!! I don't think so!!!

No, the vast majority of the energy is absorbed by young skippy.

Try to imagine a sparrow hitting a Kenworth @ 100k/h. That's a more exaggerated example of the same skippy hitting a big 4x4. Sure, the smaller the vehicle and the larger the animal, then the more there will be a shift in the dynmaics. A Charade hitting a Water Buffalo would not be a pretty site for the SES blokes.

So, whilst I agree you "could" have a point (depending on how big skippy is versus how big the 4x4 is and what sort of bar it has), given the example put forward, I would rather be in my Patrol with it's steel bar, than a plastic-fantastic bit of krap.

Cheers

Roachie

"...if I was to jump off a 20 storey building onto a concrete footpath, then an amount of energy, equal to that which has just broken every bone in my body, will also attack the concrete and make a big-@rse hole right there for the ambo's to have to dig/scrape me out of!!!!..."

Umm yes it does leave a hole, actually,just as it would if you threw 20kg concrete slab of the top of the Empire State Building..........

Ever hit a slab of concrete with a steel shafted sledge hammer???? obviously not...............(hurts the hands like a ****, AND breaks the concrete)

Don't confuse energy of an impact with the inertia of the items impacting. This is the part where bigger is better related to the masses of the objects.

A bullet can blow a hole straight through you, yet you weigh in at ~80000 times as much as the bullet (1g vs 80 kg). Water can cut steel.....................

For a material to "absorb" any energy it must deform or heat up. This is why you need to use a hammer to bend nails over. For a material to "transfer" energy it should not undergo any change in physical appearance. This is why the conrods in you engine work, they TRANSFER the energy from the piston to the crankshaft without deforming (Nissan 3.0l TD excepted). This transfer of energy is exactly the same as the transfer of energy from the steel bar into the chassis when hit by a skippy.

What Gary is referring to is the effect of Newton's first Law of Motion - not really a point worth arguing I reckon - "For every force there is an equal and opposite reaction" is how it's commonly stated.

As for steel bars providing superior protection - well, I switched to a plastic bar precisely because, after a low speed collision with an ARB steel bar fitted to my then vehicle, I did major damage to the front 5 panels + radiator, and wrote off the bar too.

Maybe the collision would have written off a plastic bar too, but it's a lot lighter to carry around for a start. Similarly, the tests on them show that (at least for low velocity impacts, much of the energy from the impact is absorbed by the bar, which temporarily deforms acting in a similar manner to an airbag, ). For those who challenge such tests - why are those carried out by ARB more reliable than those carried out by a rival manufacturer ?

The Smart Bars meet all relevant standards, as far as I am aware, and I'll trust those over any manufacturer's testing, which in my opinion will be (understandably) designed to demonstrate that their product is superior to a competitor's.

regards
Terry

'Tis actually Newtons Third Law of Motion ;-)

Duuuh........

(I wondered about that after I put a number to it, but knew if I were wrong, I'd be corrected soon enough) ;-)

Some of the Smart bar models can be fitted with winches, I'm pretty sure.

regards
Terry

Geeeeezzzz they fit bars close to the car nowa days! I know it's all about areo dynamics and crap, but there's not much room there for flex. I mean the whole principle about the smartbar is that they flex isn't it? It's going to flex right into ur bonnet!

It's the same with these alloy bars you see on Rodeos, hiluxs and prados. What's the point?

I have no doubt in my mind that these plastic bars are tough, some of the polycarb we were using in security cameras was much, much, much stronger that the other brands of cast aliminium and steel. Some of these plastic alloy's are bloody amazing. You could smash "plastic" cameras with a 10 pound sledge over and over and you'd end up buckling the roof that it was mounted to and the camera would still be working! I think I would deffinataly have the mind set of feeling better protected behind steel, just not sure if it would make that much difference. I think the worry for me is these designs! I won't some space between my bar and my car! (hey I like that).

What a waste of money!

Bisalloy :-)

Now that would be one tuff mutha!!!

dropped a 3 ton rock onto the bisalloy floor of my trailer today. not even a little dent.....and the floor is only 4mm thick,,,,or thin,,,,depends on how ya lookat it....lol.
tho i would have to see what a bisalloy bar would weigh against a steel one,,,that stuff is pretty heavy.

meow.

rick.