Math Question: ATV “Booster” Ramps for Truck Bed.

[BoosTT]

My Polaris Sportsman 500 4x4 BARELY fits inside my 6.4’ truck bed. Barely meaning: I need to force the tailgate closed (compressing the tires) and the atv bumper is way too close to the trucks rear window for comfort. I also want to leave the tonneau cover attached and having the tailgate down is not an option due to towing. To sum it up: truck bed is about 7” shorter then I want.

I’m planning on building some ramps for inside the truck bed (lifting the front atv wheels). This would essentially “increase” my truck bed length as the atv would be on an angle.

How high do these ramps need to be? Tip: You have the overall ATV length and wheelbase/tire diameter (only the front wheels get lifted, so the pivot point length is about 54”).

Truck bed length: 76”- 4” (tonneau cover)=72”
ATV length (distance from tire to tire/the parts that touch the tailgate and front of truck bed): 79”
ATV tire diameter: 25”
Ramp height: ?

I don’t know the answer. I’m thinking around 10”.

[Wagonbacker9]

Get a couple cinder blocks (or similar sturdy objects) and get the ATV up on them. I'm assuming you're going to want the ramps to clear just under the tonneau, so the ramp is under, and if the tire rolls over it, it hits the cab glass before it bends the tonneau. If that doesn't accomplish your goal, stack some more height, then figure out what % grade you want for ease of loading. Unless you plan on packing items under the ATV in transport, I would just make it so that they go to immediately in from of the rear wheels when the front wheels are at the position you desire, this will make it the easiest to load.

You could model this all day, but nothing will be as effective as just mocking it up.

[Prince Valiant]

You could model this all day, but nothing will be as effective as just mocking it up.Well, not quite all day. But mocking it up will work best....since there is no one way to look at this, and a couple other factors could come into play. I'll give it a shot though:

from a math standpoint, you're kinda looking at a right triangle problem...

c=√(a^2+b^2) in which we believe we know c and a, so we can solve for ramp height b...

There are a couple ways to look at it, but I'm going to try from the way that makes the most sense to me...which isn't saying a lot.

Want to give yourself ~7" extra room? Then you know ~54" is the wheelbase, and 54" +12.5" will be length from which we pivot, so (c) = 66.5 in the equation, (a) will be 66.5-7" since it's ~7" you wish to gain, so 59.5", and b will be the ramp height.

c=√(a^2+b^2), solving for b gives us b=√(c^2-a^2) so b=√(4422.25-3540.25)=√882=29.7" ramp height to gain another 7" of clearance, or to state it another way, shorten your ATV another 7" in terms of floor space in the bed.

But of course, are your front tires being compressed against the bed? Or the bumper? If it's the tires, raising it will also change what part of the tire contacts it will change too...and I know of no math to calculate for that.

Putting the tonneau on and mocking it up seems to make the most sense, since we don't really know exactly what you're looking for, and mocking it up will be able to help you visualize the results you desire better. Though ultimately, I'm not sure if you'll end up getting what you want with the tonneau on...

[-stew-]

Take your tailgate off.

/thread.

[Wagonbacker9]

Well, not quite all day. But mocking it up will work best....since there is no one way to look at this, and a couple other factors could come into play. I'll give it a shot though:

from a math standpoint, you're kinda looking at a right triangle problem...

c=√(a^2+b^2) in which we believe we know c and a, so we can solve for ramp height b...

There are a couple ways to look at it, but I'm going to try from the way that makes the most sense to me...which isn't saying a lot.

Want to give yourself ~7" extra room? Then you know ~54" is the wheelbase, and 54" +12.5" will be length from which we pivot, so (c) = 66.5 in the equation, (a) will be 66.5-7" since it's ~7" you wish to gain, so 59.5", and b will be the ramp height.

c=√(a^2+b^2), solving for b gives us b=√(c^2-a^2) so b=√(4422.25-3540.25)=√882=29.7" ramp height to gain another 7" of clearance, or to state it another way, shorten your ATV another 7" in terms of floor space in the bed.

But of course, are your front tires being compressed against the bed? Or the bumper? If it's the tires, raising it will also change what part of the tire contacts it will change too...and I know of no math to calculate for that.

Putting the tonneau on and mocking it up seems to make the most sense, since we don't really know exactly what you're looking for, and mocking it up will be able to help you visualize the results you desire better. Though ultimately, I'm not sure if you'll end up getting what you want with the tonneau on...
You need to set up another triangle for the front bumper and make sure its set up correctly in relationship, etc... to model it correctly you're either going to have to CAD it, or just throw it in the truck and test it out.

[Lash]

Take your tailgate off.

/thread.

No shit. It only takes 2 seconds.

[BoosTT]

Take your tailgate off.

/thread.

This is option b. lol. To clarify: I tow a travel trailer and want the tonneau cover and tailgate to keep firewood dry.

[BoosTT]

You need to set up another triangle for the front bumper and make sure its set up correctly in relationship, etc... to model it correctly you're either going to have to CAD it, or just throw it in the truck and test it out.
This is as far as I got. No way it's 30" plus, because people use automotive ramps to fit Atvs in 5.5 foot beds.

[Prince Valiant]

This is as far as I got. No way it's 30" plus, because people use automotive ramps to fit Atvs in 5.5 foot beds.Why not use this then? Already built and plenty sturdy...

[BoosTT]

Why not use this then? Already built and plenty sturdy...

I want to build a custom fit setup, so I can add "bumpers" to prevent rear window damage, yet not increase enough space for the atv to move. Basically, I want to build a wooden ramp that I can bolt to the front tie downs in the truck bed and close the tailgate and not need to strap the atv down. A strapless system with the tailgate up.

[spooln30]

Your obviously not taking the easy road. Your talking about a soft tonneau cover?

[The Shaolin]

Sec...

After doing the math: Remove the tailgate. :)

I drew the truck bed in CAD, made two "tires" tangent to the truck bed, and then spaced them the required distance apart (79-1 radius=66.5"). As you can see, you're going to need to gain 47" of height in the bed. Haha.

http://farm9.staticflickr.com/8089/8530412227_e2711b08ee_o.jpg

[BoosTT]

I'm now more confused then ever! I think I'm going to try the automotive ramps this weekend and see how it fits.

Heres two places that sell what I want to build:

http://www.schtrailers.com/ATVriser.html
http://www.torchrivermfg.com/ATV_Risers.html/

[Wagonbacker9]

Gives you a basic idea of what your dimensions are if nothing else...

[Prince Valiant]

On the CAD drawing, it seems to show the wheelbase as 66.5" when it's actually 54"...or am I seeing something incorrectly?

[-stew-]

So the truck costs fifty grand, and then you gotta fork over a wad of cash to make the useless short bed useful? Fuck that. Full size cclb trucks are not that unmanuverable that I would want to deal with bullshit like this to do something as simple as haul an atv.

[Prince Valiant]

I'm sure most of the shorter bed comes not from manuverability concerns, but fitting it into garages while still having 4 doors/etc.

[Lash]

On the CAD drawing, it seems to show the wheelbase as 66.5" when it's actually 54"...or am I seeing something incorrectly?

That's what I though too. Overall length is 79". Axle to axle is 54".

[Prince Valiant]

Looking at the cad drawing I realize that the only way to gain the 7 inches is from using the wheelbase as the hypotenuse...so 54 inches.

b=√(54^2-[54-7]^2)=√(2916-2209)=√(707)=26.6"

So that will leave the height required as 26.6"

[The Shaolin]

On the CAD drawing, it seems to show the wheelbase as 66.5" when it's actually 54"...or am I seeing something incorrectly?

I don't know what the heck I was thinking. I only subtracted one wheel radius instead of two. Coffee hadn't set in yet...haha!


Looking at the cad drawing I realize that the only way to gain the 7 inches is from using the wheelbase as the hypotenuse...so 54 inches.

b=√(54^2-[54-7]^2)=√(2916-2209)=√(707)=26.6"

So that will leave the height required as 26.6"

Winnar. If I change the 66.5" dimension to 54", the lift block height you need is 26.6.

[BoosTT]

I don't know what the heck I was thinking. I only subtracted one wheel radius instead of two. Coffee hadn't set in yet...haha!



Winnar. If I change the 66.5" dimension to 54", the lift block height you need is 26.6.

Thanks!!!

Based on this information, I think I'll go a different route. The tires would stick up about 6 inches above my bed rails (perfect if I had a toolbox). I don't know if I'm comfortable putting the atv up that high while towing. I guess I just end up removing the tailgate. lol.

Thanks again for the math and cad work.

[Wagonbacker9]

Thanks!!!

Based on this information, I think I'll go a different route. The tires would stick up about 6 inches above my bed rails (perfect if I had a toolbox). I don't know if I'm comfortable putting the atv up that high while towing. I guess I just end up removing the tailgate. lol.

Thanks again for the math and cad work.

Why don't you try it 6" lower and see how it works? The tires have some give, so there should be slop in your measurements.

[spooln30]

Yeah that's what I was saying. If you have a soft tonneau cover just remove the tailgate. You can still keep things dry in the bed. Or many get one of those metal gates that bend outward.

[BoosTT]

I tried the automotive ramps. Still couldn't close the tailgate, but the Atvs bumper was about 3" away from the trucks rear glass.