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Does anyone know if the McCulloch karts were made from chrome moly or mild steel? I need to have a new bumper bent up and I don't want to use dissimilar tubing.

Thanks!
Dean

My guess is that it's Chromium-Molybdenum, as it cracks so easily; I think that mild-steel would bend (more) before fracturing.

I recently bought a 7/8" bender, but failed to give a verbal "okay" to place a bulk tubing order. If I have any money left when I get back home (writing this from Lido Beach, Florida, on The Gulf of Mexico) I'll go ahead and place the order for 7/8" 4130 tube. I plan to re-make an R1 chassis to replace one of the ones I picked up over the summer.

I already did the layout in a tube bending program: http://www.rfdm.com/gallery/album112/R1 ... 001?full=1

By comparison, a front bumper would be a piece of cake

Dean, maybe it'd be better to use mild steel for the bumper. It's more yielding. More than one kart manufacturer in the olden days did just that, though it might have been more for cost savings.... Ted

ted johnson wrote:Dean, maybe it'd be better to use mild steel for the bumper. It's more yielding. More than one kart manufacturer in the olden days did just that, though it might have been more for cost savings.... Ted

Not a bad idea, since it has to be spliced to the main frame anyway. There's no problem welding chrome-moly to mild steel.

Given the cost of 4130 tube, and using a brand new style bender (different configuration than my hydraulic bender) I'm seriously considering bending the R1 chassis in mild-steel for the first go-'round.

I beleive DOM steel tubing was more the norm as opposed to an exotic like Chromo which was costly and needs a welding machine like "tig" to weld. Tom

R-1 frame specifications-7/8-inch 1020 steel
if you're interested the R-1 weight distribution is front 43% rear 57%
weight less engines 109 lbs

1020 DOM steel tubing, weld it with any process you chose so says; http://www.ProtoFab.com. They offer many sizes and lengths for sale too. TL

Cool-thanks guys!