X Frame Riviera on a two post lift

[Zimm63]

It can be done. No modifications were needed to the lift. Borrowing an idea from a guy who made a rack to be able to use his two post as a storage lift for his Porsche, I came up with bridging accross the arms.

My lift is a Ben Pearson with removable lifting pads. I put the Riv on stands in the proper place and measured the distances. Using 2" X 3" tubing with a 1/4 wall, I made two pieces, one for the front, one for the back. The lift pads are mounted inboard, on the added tubing. They pick the car up at the widest point in the frame at the front, and at the rear control arm mounting point. The metal used to bridge between the lift arms is held to the arm with a pin consisting of a lift pad extension at each end. I used bimetal hole saws in my drill press to make the mounting holes.

The front to back distance is just about 6 feet. The pictures show what it looks like from under the car, and with the car absent. It is a bit of a pain to rig, as you have to slide the tubes under the car then lift them onto the arms and line them up for the pins. There is some going back and forth to get it right.

The car seemed solid and steady when lifted. I would be interested in what some of the engineering folks who hang around here have to say.

[Bhigdog]

Looks scary to me.............Bob

[Zimm63]

Why do you say scary? All lifting is on the frame, it can't have a leg come loose. I was worried about the overhang, but the thing sits there solid as you please.

Not being defensive, but want to know why there might be a problem.

Zimm

[Paul K.]

Nice idea Zimm. When I bought my Riv 30 years ago, the twin post lifts were more common. These were the ones that positioned under the a-arms and the rear axle. Sketchy is using a chassis rack. yours looks like a good retrofit.

[Bhigdog]

Why do you say scary? All lifting is on the frame, it can't have a leg come loose. I was worried about the overhang, but the thing sits there solid as you please.

Not being defensive, but want to know why there might be a problem.

Zimm

I'm not a structural engineer but it looks to me like what you are doing, in effect, is lengthing the arms, by about a foot in the rear. That would multiply the bending moment on the arm attachment points. Probably be OK, and your pix looks like there is a noticible bend in the rear 2X3. Again, that's just how it hits me. A failure of the system would probably be sudden and catastrophic though. Not being offensive, just some food for thought............Bob

Edited September 6, 2010 by Bhigdog (see edit history)

[Zimm63]

Darn if I see any bend in the rear tube. I will have to put it up again and check. As to lengthening the arms, I would disagree. The car is lifted on the 2X3 tube which is, in turn, lifted by the lift.

The idea that failure would be sudden is thought provoking enough for me to put this out there again.

[Bhigdog]

Reconsidering, I agree with you on the arms not being lengthened. It does look like the pix shows a bow. Could be just the optics. As I said, just food for thought. When things go South sometimes it happens real fast.........Bob