I have a 2011 Jeep Patriot that I want to use to carry a 300 lb motorcycle with a hitch carrier. I loaded the bike on there once and it almost bottomed out to where I don't think I would have made it out of my parking garage. The toungue weight limit is 250, but f it.
I'm thinking I can fix this with either cargo control rear springs or a lift kit. There is a lift kit available but I'm cheap and I don't want to pay for it considering these would be regular springs I could purchase anywhere if I only knew the specs.
I know the vehicle has a 3,300 lb curb weight and coil over spring set up.
Someone on a patriot forum posted all this for the purpose of figuring out what spring to get for a lift, but they didn't post the answer:
What I measured: Coil spring wire diameter Compressed height (vehicle sitting on level ground with no extra weight, full tank of gas) Free length (was measured for me by another forum member) Number of active coils at rest (see compressed height note)
How I measured: Coil spring diameter: The coils are not perfectly round, so I took several measurements from different places and averaged them. Compressed height: The springs sit in/on rubber isolators, so it's not possible to measure from the top to the bottom from the outside. So I measured from the bottom of the top coil to the top of the bottom coil (measured the inside), then added in the coil thickness times 2. Free length: Measured for me by a forum member. Number of active coils: This is just a simple count of coils not touching another coil or one of the isolators. Free to move. So from the bottom I looked where the spring was free then started counting up until only a fraction of a free coil was left. I then estimated to only about a 1/4 turn so it could be + or - an 1/8 of turn, which doesn't change the rates all that much (+/- 10 lb/ins and +/- 50lbs loaded pressure).
I plugged all of these numbers into this spring rate calculator: http://www.pontiacracing.net/js_coil_spring_rate.htm
So here are my findings. Front SpringFree Height: 13.75"Loaded (install) height: 7.305"Wire Diameter: 19/32" (0.590")OD of spring: 6.75" (ID: 5.57) w/Pigtail ends (4.75" OD / 3.57" ID) Active coils: 3.25
Spring Rate: 224.31 lbs/inPressure @ loaded height: 1445.68 lbs
Rear SpringFree Height: 13.25"Loaded (install) height: 8.5"Wire Diameter: 1/2" (0.500")OD of spring: 4" (ID: 3") w/Pigtail ends (3.375" OD bottom / 3.75" OD Top) Active coils: 5.5
Spring Rate: 372.71 lbs/inPressure @ loaded height: 1770.37 lbs
QUESTION: What should I get carry my motorcycle without issue?