You WILL buy a Gladiator and 37’s after you watch this - Off Roading explained

[FitfulGoat]

I’ll just leave this here. Another great look at the physics of overcoming obstacles, with Lego’s!

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[ACAD_Cowboy]

The point I was getting at was by lowering the very heavy engine, transmission and transfercase relative to the axles, you lower the roll centers of the truck making it far more stable in off camber, slope and side slope ( and combinations there of) situations.

 

[danielspivey]

All in all though it's a good demonstration. Larger tires do give more ground clearance but secretly give you more mechanical advantage ie longer lever to move the truck. The basic geometry and simple machines at play are great for keeping kids thinking while you stack rocks and swear.

The double sided tape is an analog to airing the tires down... until he gets silly. I've been on a 110% grade and it's uncomfortable knowing that how you packed your gear may decided if you sleep in a bed tonight.

Wow, 110% ? Is that the same as 70%? Have a picture?

 

[ACAD_Cowboy]

100% is 45 degrees, 110% is ~47.75° which is more up than over.

 

[ACAD_Cowboy]

A representative video of the act. I'll have to dig around in the video and picture archive for mirror rock, a flat slick god forsaken piece of Massachusetts.

 

[dcmdon]

All in all though it's a good demonstration. Larger tires do give more ground clearance but secretly give you more mechanical advantage ie longer lever to move the truck. The basic geometry and simple machines at play are great for keeping kids thinking while you stack rocks and swear.

The double sided tape is an analog to airing the tires down... until he gets silly. I've been on a 110% grade and it's uncomfortable knowing that how you packed your gear may decided if you sleep in a bed tonight.

You've actually got it backwards. Larger tires give the tire's contact patch a longer lever arm to resist the torque of the motor. That is why you need lower gears with larger tires. Another way to look at it is a larger tire has a larger circumference. For a single revolution, the vehicle goes farther.

A larger tire effectively raises the gearing of the vehicle.

 

[PyrPatriot]

You've actually got it backwards. Larger tires give the tire's contact patch a longer lever arm to resist the torque of the motor. That is why you need lower gears with larger tires. Another way to look at it is a larger tire has a larger circumference. For a single revolution, the vehicle goes farther.

A larger tire effectively raises the gearing of the vehicle.

So you need a larger gear number, to get a lower gearing (i.e from 4.10 to 4.88)?

 

[ACAD_Cowboy]

Yes, a numerically higher number means a lower gearing ratio. .8:1 means .8 turns of input for 1 turn of output. 1:1 is equal and 2:1 means 2 turns of input for 1 turn of output.

As the ratio lowers (number gets bigger) the speed of the gearing system goes down but the torque multiplication goes up.

 

[ACAD_Cowboy]

Wow, 110% ? Is that the same as 70%? Have a picture?

So fresh from the jaws of massmog: photos of mirror rock. I'm not the photog and despite multiple requests for side shots, this is what we got. you can infer the angle from the trees and from how much of my roof you can see, if you squint you can make out the lens covers on my lamps. I prefer going up to going down, everything is falling forwards and complaining as opposed to going up where everything is snug in seats and not fighting to breath as you ride the brake in gear.

 

[ACAD_Cowboy]

Again, watch the trees as a slope guide.

Bonus video, always be aware of the water you are driving through in terms of depth, contents and where your sensitive parts are.

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