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  Ramp Travel Index (RTI) enter both in blue and press CALC
Simulates a 20 degree ramp
Inches tire above ground:    Wheelbase inches:
RTI Score:     Inches up 20º ramp: ''


This calculator estimates the Ramp Travel Index (RTI) without having access to a "real" ramp.

Ramp Travel Index is based on climbing a 20 degree ramp with one tire while keeping the trailing tire in line. At the point where any tire begins to lift into the air is where it's calculated. Measure from the bottom of the ramp to the center of the bottom of the tire (use a plumb from the hub to find center). This distance traveled in inches is divided by the wheelbase in inches and multiplied by 1000. What this gives you is a percentage of travel up the ramp in relation to your wheelbase. Basically if your wheelbase is 100 inches, and you travel 75 inches your RTI will be 750 (75% or .75 X 1000).

Since this is based on math we can use a formula to estimate your RTI. The trick is to get one tire off the ground while the other three remain touching the ground. Then measure from the bottom of the lifted tire to ground. I've seen forklifts being used, climbing up a steep rock face, even climbing stairs. I suppose you could climb different things and use the calculator to find the RTIs. Then take the average of all. In any event, if you're curious I've provided a calculator that will get you an idea of your RTI. Anything above a 500 is great, there are a few rigs out there that can do perfect 1000's or better. How will you do?

Formula used

RTI = Tire Height/sin(20*PI/180)/Wheelbase*1000
Inches Traveled = Tire Height/sin(20*PI/180)

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