by QueticoBill » Tue Nov 29, 2016 3:44 pm
Still trying to grasp and comprehend this. 8' chassis, with 9" overhang at rear and 15" at front with a design based on the "New Cub" or pretty similar to that. Allow for a tongue box so that is what just what BobHenry - 138" front of tongue box to rear of TD box; thus 48" from rear of TD or 39" from rear of chassis - which is just 3" behind current position. Getting the profile curves of the front and back to align with bottom of fairly deep chassis doesn't allow me to slide TD body further forward. The hitch is now about 37" in front of frame, and it seems I need to extend that almost 36" to be able to jack knife - maybe a little less. All that to say that is from rear of TD to hitch is 14' 9" and based with axle moved 3" its 10' 9" or around 73% to back; whereas if I leave The axle where it is it would be 71% to rear. Just not quite grasping the basis of the 35 or 40/65 or 60 rule of thumb - chassis, teardrop box, teardrop box + tongue box, or hitch to rear. Here's my attempt at using the spread sheet, but weights are guesses, and I think on high side.
TRAILER BALANCE SPREADSHEET
Instructions
Enter your own data in the boxes with red numbers
Read off results in boxes with blue numbers
Basic measurements in
Body length from rear - A 120
Hitch center from rear - B 177
Wheel center from rear - C 51
Extra weight measurements in
Extra weight 1 from rear - D1 12
Extra weight 2 from rear - D2 129
Extra weight 3 from rear - D3 0 Lever Moment
about about
Basic Weights % of Basic lb rear, in rear, in-lb
Basic trailer weight 100% 1000
Weight of tongue 5.0% 50 148.5 7425
Weight of axle/suspension 12.0% 120 51 6120
Body weight (total - tongue - axle) 83.0% 830 60 49800
Extra Weights (not included in Basic) lb
Extra weight 1 150 12 1800
Extra weight 2 100 129 12900
Extra weight 3 0 0 0
Results
Total trailer weight, lb 1250 78045
LCG from rear - X, in 62.4 % of Total
Weight on axle, lb 1137 90.9%
Weight on each wheel, lb 568
Weight on hitch, lb 113 9.1%