Gee sure is slow around here. Looking for opinions on the front axle for the Jappic build. In the original photo's of the car it has a rather spindly looking front axle. I'm trying to keep that look but open to suggestions. I am thinking along the lines of 1 1/2" .120 wall DOM tubing. If that doesn't sound sturdy enough I could use the old angle steel inserted and welded inside to stiffen it up. So is 1 1/2 ok? The way it's mounted has most of the flex stress'es coming from the wheel to the spring mount and it's kinda long on this car. So if anyone wants to chime in that isn't helping the wife plan a tactical attack on retailers this Friday I would appreciate it. And if you are, I'm so sorry.

Yep, it sure is slow 'round here, not much to keep me occupied when I come in from the
barn to warm up.
That would be way over kill Michael. Many 1100 lb. midgets run 1.75" x .110" wall straight front
axles, and they take a whole ell of a lot more punishment than even the most robust Cyclekart
is possible of.
1.5" x .095" 1020 DOM would be more like it given the straight axle and the inspiration design
of you've chosen. That would give you a safety factor about 9 times the materials yield strength.
And I'm sure you wouldn't have any problems on the worst track you will ever see with .083" 1020,
which would have a safety factor of 6.6.
If you chose to go with 4130 CMS you could even get away with a 1/16" which would give you a
safety factor of 6.2. Even 1020 DOM would stand up to 5.2 times it's yield point at this wall thickness.
I'm basing this data on a 32" king pin center line axle with a 250 lb. static load on it. The lighter tube
would be more of a problem if your design called for bending.
Of course the lighter the tube the more difficulty you will have trying to weld it with MIG.
But if you have a well equipped shop and are well versed in the art of welding, no problem.
I personally TIG weld just about everything below 1/4 inch simply because it gives me so
much more control over the end result.
Denny Graham
Sandwich, IL



Edited 3 time(s). Last edit at 2018-11-19 07:06 AM by Denny Graham.

Thanks Dennis. I think I'll choose the 1 1/2.x.o95 wall. I still feel better with DOM tubing, but as I've said before I tend to overbuild because of my background. It's hard to get your head around top speeds way under 100mph after all these years. As for the welding, I'm ok, but for this I will take it to a friend who welds for an aircraft manufacturer for a living. I could get it together, but no amount of flat black spray paint could hide it. And if you can't hide it with flat black you can't hide it. I did find these online and was looking at placing the axles through the opening, welding them from the bolt head side and using the assembly as the spindle set. I could also weld the tie rod arms on at the angle I require. Seems they would look good and save a ton of fabricating. I would have this much in them in parts and labor. https://www.speedwaymotors.com/Posies-Super-Slide-Springs-1064-Quarter-Elliptical-Spring-Axle-Mount,21301.html Just a thought. I'm hoping to get this darn thing started soon, but I've promised myself no hurry or deadline, just get it right.