Hi all,
I'm beginning restoration on a Rupp GP. I have obvious frame damage, but in order to rectify it, I need to know if the bottom of the frame (talking about the main portion, not the rear) had an upward sweep to it beginning at about the rubber bushing mount, moving towards the rear?
In other words, does it "sweep" up a bit in some sort of preload fashion towards the seat hoop, or is the bottom of the frame pretty much flat?
I have both of those conditions on the same frame. Thank you in advance for any information, or drawings.
David,
It may be easier to go down to the Kart I.d. Section and view pictures there. I posted photos of a 63 GP (single piece frame) and 64 GP (two piece frame). The tubing bends are similar for the Darts. https://www.vintagekartforum.com/forumdi...php?fid=52
Here are the bends and swoops and whoopty-do's. Scott, thanks, I have looked at everything I could find on the net regarding the GP. Maybe it's my eyes, but I cant tell if the frames are straight, or if they are bowed, especially with floor pans and seats. Thanks again.
David, you came to right place. Several Rupp experts visit this forum, including Scott E. Until one of them weighs in, and/or posts a photo or two of the bottom of a "known-to-be-straight" G.P., I'll make a prediction.
I think that they'll tell us that rails were originally straight as viewed from the side. I think they'll conclude that the "sweep up" toward the rear that you're noticing is simply sag from a too-heavy driver hitting a too-big bump, too many times. As viewed from below, the main rails are supposed to have a very slight bend toward the center. That can be confirmed by measuring the width between the rails at the seat hoop, and comparing to it to the width at the front axle.
One last prediction: you'll be able to straighten it!
(12-28-2017, 06:00 PM)doug tenney Wrote: David, you came to right place.
Thank you Doug, and I am pretty sure your predictions are accurate. Rear hoop/seat area is spread out to I cant measure and compare with front at axle. Spread so much that the holes for the front and rear sections do not line up. Another prediction: I will straighten one side, and will replace a length of tubing on the other, since the tubing is flattened from being hammered. I just wanted to be sure of the geometry before whacking the frame.
Just be SURE you insert a solid splice into both ends of tubes to be joined. Chamfer the end of both tubes and drill both tubes about Ø3/16", about 3/8" from the ends of the cut. Insert the splice rod halfway into one tube and plug weld through the hole. Push the second tube over the splice rod and leave a gap of about 1/8" for welding. Plug weld the second tube thru the hole, then groove weld the joint, ensuring full penetration into the splice rod. Grind the resulting weld smooth and paint. Safe, strong and neat. You'll never know it was repaired. Ted
might be just as easy to replace that whole one side ..?? ..
TJ.,, i was fixing up a kart and found the folks before me that repaired it stuffed a piece of a 1 " axle in frame rail about 8 " long ..wonder how good that chassis flexed ..even stranger they went threw a lot of trouble grinding it all down to fit inside ...Lol..
Robron could probably give you measurements to go by. Better yet just make you a new one. He's very reasonable, and would save you a bunch of work. Just a thought.
Thanks all for the comments and recommendations. I will assume the frame is spoda be flat and straight. 10-4 on the splices and rosebuds Ted. RobRon floor is in the works which will aide me in the alignment, as will the rear bolt-on end of the kart.
