I'm thinking of taking the roof off my 55 chrysler and making it a convertable, the problem is I don't want all the heavy mechanisims, I was thinking 3/8 steel rod frame with cavas steched over it. Any ideas?
Sounds like you want to build a Carson Top. www.rodandcustommagazine.com/howto/86421/index.html - 68k
I would use a larger diameter tubing. 1" .080 wall is stiffer and lighter. 1.25" .120 wall aluminum is way lighter and still better for structural rigidity. Have you ever picked up a 20' stick of 3/8" rod? It weighs more than a whole bicycle (which generally has about 20' of tubing, give or take), and you can bend it into a 'u' with your bare hands, unlike the bicycle frame. Also, where the top stretches over the rods, the larger the diameter of the rods, the less it will stretch the canvas out of shape there and look funny. Of course, steel rod is cheaper than aluminum tubing. Just my observations, I have never built a top frame. However, there is a reason bicycles are made from large diameter tubing instead of small diameter solid rod - the rigidity-to-weight ratio outweighs the extra cost of the raw materials. Even the cheapest bikes use tubing instead of rod. If you want a top that big to be both rigid AND a 2 person lift, instead of building a crane in your garage to lift it on and off, you will use tubing instead of solid rod.
You'll need to reinforce your frame before the roof comes off, or your door gaps are going to pinch closed. If it's a 2 door hardtop, you'll be able to retain functional side gl***, but it really seems a shame to cut the top off of a 2 door hardtop. If it's a four door, you're really going to have trouble with doors staying functional, and you won't have working side gl*** anymore. Sounds like a waste of a good car to me.
From a structural standpoint the car has a full rollcage which would also be used to support the top, the body is welded to the frame and rollcage.
Dude, good luck, more power to you. Let me know how it comes out. I was thinking about this too. Lots of trouble. I agree, tubing would be the way to go, definitely not rod. Godspeed.
I had an MGB on which the top frame came apart and folded up so the top and frame fit in the trunk. Of course, the size of an MG's top is a far cry from a 55 Chrysler's. Good luck.
No way it will fit in the trunk in one piece. The body is wider at the belt line (and probably even at the top of the windshield header) than the trunk opening. By a bunch. ***uming you don't have a height issue (i.e. a heavy chop), you will still have to make the top come apart into at least 2 peices (or fold) such that it will go in through the trunk opening sideways. That is ***uming that the width of the top is less than the length of the trunk, which I wouldn't count on with that car. The trunk may look cavernous by modern standards, but I think you will find that some simple tape measure work will eliminate any reasonable possibility of the roof fitting in the trunk and also being stiff enough to stay together at 70 MPH. I could see if you were going to stretch a canvas over a tube frame, and dis***emble the tube frame and put the tubes and folded canvas in the trunk, but making something like that survive at freeway speeds would be one hellacious feat of engineering. Most factory convertible tops from the 80s and older are only good to 90 MPH or so before the lift warps the bows, and they are pretty bulky and heavy ***emblies not intended to come apart easily. Designed by a team of professional engineers and a wind tunnel that can simulate things like 50 MPH crosswinds while driving at highway speed. I'd go lift off, and leave it in the garage.
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