Longest I see with quick look on Amazon: Resorting to AutoCAD, still a little on the steep side: Going to give it a try, hopefully ok with pooch.
DOG RAMPS Dog ramps are a long running issue for me. I first had one when I had my rottweiler. That dog was 120 pounds and as she got older she could not leap into vehicles. Lifting her was a bit of a chore. I did it -- but it was a sort of Homer Simpson act. She did not like being lifted and would squirm and I would stumble about before shoving her into the car. A ramp saved both of us from injury. It seems you want to build your own and that is great, but maybe my experience will help you with your project? My big goldens are 97 and 93 pounds. They CAN get in my Subaru Outback, but they usually won't, without A LOT .of hassle. One of them was in a car accident with me when she was a pup and somehow survived and I think she is passing her anxiety off to the second golden. I can lift them in without much trouble, but my husband forbade it -- Mendel -- don't tell him I still do it now and again. My latest ramp is WeatherTech. They want $140 for it now, I got mine six or so years ago for $89. Indeed, the ramp came by UPS and the next day a second ramp showed up. I refused delivery and several days later another ramp showed up.... I am sure you have looked at WeatherTech, but they have two styles. The EasyRamp and the PetRamp. I have the Pet Ramp. Not a great fan, but it works. They claim it is 15 inches wide. It is, but that includes the molded edges -- subtract those and I don't know 13" or 12" inches wide. It has a steep pitch when I use it with my Outback. The pitch would be less in a rig closer to the ground, of course. The dogs hate it, but will use it. I think they would be better with it if it were wider. The surface has a ribbed rubber (?) covering so the dogs have excellent traction. Both "feet" have rubber cleats(?) to stop sliding -- very important -- and they work well. My smaller dogs don't mind the ramp -- width? Finally, folding it can really pinch your fingers. I still manage to get "bit" after six years. Don't have experience with their EasyRamp. Had a sliding wood ramp with the rott. Don't remember details, but it was much longer than the ramp I have now. Heavier too. It was wooden so sometimes sliding was a bit "sticky." Used indoor/outdoor carpet for the surface. It worked O.K. Was destroyed when a tree smashed my rig. kris
Thanks @cyberpriusII! DIY yielded to expedience: I ordered this (pictured above) 71" Max Length & 20" Width Dog Car Ramps,Large Dog Folding Ramp with Non-slip Carpet Surface,Pet Stairs Ramp for Large Cars,SUVs, Trucks & Outdoor Steps, Durable Dog Stairs for Large Dogs Up to 285LBS : Amazon.ca: Pet Supplies The lack of side curbs is concerning, but allow it to fold more compactily for sure. Weighs around 20 pounds. Hopefully our Shiba Inu will breeze up it, but I've a hunch that may take some coaching. He's 14+, so in his sunset years, a little lame.
Mendel, Taking the tangent of the angle yields the }Rise over Run of the ramp. That should give you the information needed. JeffD
I think you will be fine without sides. 20" -- so probably 16"-18" wide walking surface. Shiba pups are around 50 pounds, right and not real broad like a rott, so I bet it will work fine. And the pitch looks very good. With the Outback floor being some 27" above ground, it makes for a bit of a slope. Of course, you start talking engineering, I am at a bit of a loss, but if you need air-speed velocity of an unladen swallow kris