01-10-2009, 10:04 PM
You asked for the formula for figuring grades. Rather than edit my last post again, I'll do a new reply. If you divide the length of your run into the elevation change, you will get the %, but I use an easier method. A 1% grade drops 1 foot in 100 feet of linear running, 2% drops 2 ', 3% drops 3', etc. Multiply your linear feet of the run by 12 to get the number of inches. A 1% grade will drop 1 inch in 100 inches of run, 2% 2", 3% 3", etc. I don't worry about computing the number of inches in a particular radius curve. In the previous post I took 17 feet plus 6 feet for a total of 23 feet multiplied by 12 = 276 inches. To make things easier, I rounded up to 300 inches. Thus a 3% drop over 300 inches = 3 inches per 100 inches = 9 inches.