Questions on a new Product

[color=red:604631598f]I have been working on several projects and one is about to come to ahalt I have developed Rockrail that extend out 5 inches and have a groove along the bottom to assist in hi-lifting you Jeep and to keep the jack from sliding on you. I would like some input on what people think and what demand this product would have on the market. I would like to know if the option to slide out you rockrails was there how many of you guys would use it. Do you think that this ability to keep your rig from getting dents in the doors from the jack is worth it? And the abilty to jack your truck under off camber passes in order to change a flat make a repair or just jack past a obstacle is that inportant?
Please Email any opinions. all will be helpful either good or bad.



Rember if you are in Need of custom fabrications I have always said If you can dream it I can build it!

Call Me at TRC off road[/color:604631598f]

Joe:

This seems overly complex for the purpose of shielding the door from jack gouges, and while the groove for holding the jack on uneven surfaces is a smart idea, I wonder how that would affect the "sliding" ease of the rail. But, that's just my two cents.

BTW, an idea of this broad appeal should get a wider audience - you might want to try posting this on Non-Tech or Mod boards.

Mike in NJ

A few thoughts:

How would this product compare in cost with some of the other rock rail products already available? Most of us are on a budget, so if the added complexity is going to make it more expensive than competing products, my guess is that many folks (myself included) would opt to save the cash and go with a solid, basic product like Custom 4x4.

How much weight does the added complexity of the slide-out feature add? Armor adds weight, and weight hurts performance (in probably every aspect of what might be termed "performance"). Prospective buyers will each need to assess whether the added benefits of this product (real, or perceieved) are worth the weight penalty.

A longer lever arm equates to more ability to do damage. I would be very concerned about the "cantilever" effect of jacking the weight of one entire side of the vehicle from a rail that's extended 5 inches out from the body. This has to increase the stress on both the rocker panel and the inner subframe exponentially as compared with a "standard" rock rail design. How is this being addressed -- or has it? Vis-a-vis my comment above regarding weight, I would guess that the necessary reinforcements to make this possible will result in a considerable weight penalty.

I have been in the market for rockrails for quite some time but will not do it until I get a transfer case issue resolved. When I do, I will be weighing functrion, form and cost. I don't think that the extra functionality that you describe at the expense of form and cost will fit into my equation as Eagle has suggested.

as long as the hi-lift contact point doesn't interfere with strength, durability and price(which i couldn't see it doing that) then i say good and go for it.

answers to ?'s

Weight and price

Weight first The weight difference is 1.6 pounds per rail so between the two that’s 3.2 pounds not a weight that would make any significant difference. Most of your weight is in the actual rail because I use 3/16 carbon steel most mass produced and custom made use 1/8 steel.

Price is equal to all the rock rails I have seen on the net.

Leverage.

Most rock rails rely on the rockers of the truck for structure and weight bearing capacity. These rails spread the weight of the vehicle along the floor and the rocker of the vehicle dividing your weight at any point by 4 so if conventional rails would exert 400 pounds of force per inch these would only exert 100 pounds. This is because of the large surface area of contact.

How does it spread the weight?

The same way a tracdozer or a tank does with the weight to surface area ratio. So a 10-ton tank may only put 200-500 lbs of pressure over a square inch and your jeep is much higher like 1000-1300lbs ranges. So that will also explain why your jeep is much faster to get stuck on soft ground.

Cantilever force is not much great I calculated around a 25% increase in Weight that would be exerted on the rocker so it was designed to take 4 times the amount of weight. And your cantilever effect is from your point of attachment where the weight load is being placed (rocker area) so your fulcrum is only 5 inches not as much as you are concerned about.

Most things overlooked by people who make these things are attachment point. Some guy’s use though bolts the worst idea unless you cut your floor up and drop in a spacer so you do not collapse the tube. Next are self-tapers they can bee easily pulled out with as little as 150lbs of pull force.
I use a fastener developed in Germany that is an improvement on a 1936 invention I will not give the name of it but the pull out force from 14 gauge steel like in the unibody of an xj is 1500-1800lbs that 200 lbs less than the burst pressure of that gauge steel much stronger.

Joe --

Although I was not born there, my mother's favorite expression was, "I'm from Missouri -- show me." I am a licensed architect with education and background in engineering. Without either a physical model or good drawings to go along with your explanation, I'm afraid I am not persuaded.

I realize that you are looking for feedback in order to decide whether or not to proceed into fabrication. All I can tell you -- speaking only for myself as a tight-fisted Yankee -- is that your explanation is not adequate to persuade me to try your product over something like Custom 4x4's, whose product I have seen on multiple Cherokees and know how it goes together.