Maximum driveway down grade to garage

[Buzzworthy]

We are planning to build a garage for our Cyclone 3612 fifth wheel. The lot we want to put it on next to our house has a down grade from the street toward the back of the lot. I have asked the factory, but they were unable to answer the question. Question is - what is the maximum down grade for a driveway to a level garage floor that will allow me to back in the RV without dragging the rear end of the fifth wheel on the garage floor. For this question, presume the fifth wheel is parallel to the driveway, and the driveway is 80 feet long. If anyone has a similar driveway, grade calculation is rise / run x 100. Thanks.

 

[truknutt]

So if I have this straight...You need to know two things 1) the distance from the rear tire back to the "lowest hanging item" - probably the rear stabilizing legs when they are in their highest position and 2) the height from the ground up to the base of said rear stabilizing jack pad. This will give your your Rise & Run. Am I correct?

 

[scottyb]

If you want % grade, Like truknutt said, divide the minimum clearance height by the length from the rear axle to the lowest point, then multiply by 100. (H/L x 100) If you want the angle in degrees, on a scientific calculator divide the height by the length, and press the ARCTAN button.

 

[Buzzworthy]

So if I have this straight...You need to know two things 1) the distance from the rear tire back to the "lowest hanging item" - probably the rear stabilizing legs when they are in their highest position and 2) the height from the ground up to the base of said rear stabilizing jack pad. This will give your your Rise & Run. Am I correct?

Actually, I was thinking of calculating the percent grade of a driveway, but your suggested calculation should give me the up-grade tolerance of my fifth wheel. I'll do some measurements tomorrow. Thanks for the info. You turned the light on for me to calculate the grade of my fifth wheel.

 

[Buzzworthy]

If you want % grade, Like truknutt said, divide the minimum clearance height by the length from the rear axle to the lowest point, then multiply by 100. (H/L x 100) If you want the angle in degrees, on a scientific calculator divide the height by the length, and press the ARCTAN button.

Yes, you and trucknutt are right. I will do some measurements and calculations tomorrow. Thanks for the info.

 

[porthole]

You could find the picture I posted of my driveway my jacks hit.