Corley
New Member
OK, so let's say you have hairpins, radious rods, or whatever you wish to call them. Now let's say you remove the front axle (or rear if you have them there), leave the hairpins attached to the axle. Lay it all out there so you can pick up the end of one hairpin (the end that was attached to the frame), with the axle still flat on the ground. What's going to happen is the other hairpin is going to go up exactly the same amount. Now have a buddy go over there and stomp on that hairpin and see what happens to the one you are holding onto. Whap, and it's also on the floor, pulled out of your hands.
Now raise your end just 1", and put your hand under the end you are holding. Have your buddy stomp on the other one again, and see what words come out of your mouth. The only option to it not hurting like hell is that something bends.
Drive over little bitty bumps day after day, time after time, and it's bend after bend to those suspension parts. This is not a good thing! Yes, you will be able to get away with it (and the accompanying poor ride it contributes to) for quite a long while, 'cause steel is pretty forgiving. Eventually something will break. (EXCEPTION: If the other end of the car has real independent suspension, then the frame will just rotate for each bump, instead of parts bending. This will only cause a jerky ride, with less stress on the parts, and is not nearly so unsafe.)
Ask yourself why no auto manufacturer has EVER built a car like that. Ask yourself how many times you can bend and stress those parts before they fail. If you are comfortable with the answers, then go for it. It's simply put, not a safe design. Every single little tiny bump you go over stresses them, the big ones stress them the most, of course, but make no mistake, even a 1/4" difference in height stresses those parts! There is really no mystery here at all, it's simply the laws of physics. Gosh, throw in a tubular axle, and things get even worse, because now since the axle resists twisting motion much more effectively when it's a tube than when it's an I beam, the hair pins must take all the stress. If nothing else, you should at least use rubber bushes instead of heim joints or clevis' for that application and let it have a tiny bit of give. And please, never ever bend those threaded suspension parts for alignment, do it some other way.
If you don't believe me on this, go get some 2x4s, and make a big U, the shape of your front axle with hairpins installed. Now do the stomp test on the end that would attach to the frame and see what happens... Sorry to go on for so long, but it seems like some people may not understand the physics of this. If you really do understand it and still want to run hairpins, then good luck and go for it. We are working with all different levels of mechanical experience and knowledge here, so we need to encourage sound design.
PS I drove at an angle into 5 different driveways at random just to test the height difference using the family SUV, and measured the wheel arch openings. They ranged from 3" to 9". It really doesn't matter how fast or slow you go, you still will see the same amount of flex / stress.
Now raise your end just 1", and put your hand under the end you are holding. Have your buddy stomp on the other one again, and see what words come out of your mouth. The only option to it not hurting like hell is that something bends.
Drive over little bitty bumps day after day, time after time, and it's bend after bend to those suspension parts. This is not a good thing! Yes, you will be able to get away with it (and the accompanying poor ride it contributes to) for quite a long while, 'cause steel is pretty forgiving. Eventually something will break. (EXCEPTION: If the other end of the car has real independent suspension, then the frame will just rotate for each bump, instead of parts bending. This will only cause a jerky ride, with less stress on the parts, and is not nearly so unsafe.)
Ask yourself why no auto manufacturer has EVER built a car like that. Ask yourself how many times you can bend and stress those parts before they fail. If you are comfortable with the answers, then go for it. It's simply put, not a safe design. Every single little tiny bump you go over stresses them, the big ones stress them the most, of course, but make no mistake, even a 1/4" difference in height stresses those parts! There is really no mystery here at all, it's simply the laws of physics. Gosh, throw in a tubular axle, and things get even worse, because now since the axle resists twisting motion much more effectively when it's a tube than when it's an I beam, the hair pins must take all the stress. If nothing else, you should at least use rubber bushes instead of heim joints or clevis' for that application and let it have a tiny bit of give. And please, never ever bend those threaded suspension parts for alignment, do it some other way.
If you don't believe me on this, go get some 2x4s, and make a big U, the shape of your front axle with hairpins installed. Now do the stomp test on the end that would attach to the frame and see what happens... Sorry to go on for so long, but it seems like some people may not understand the physics of this. If you really do understand it and still want to run hairpins, then good luck and go for it. We are working with all different levels of mechanical experience and knowledge here, so we need to encourage sound design.
PS I drove at an angle into 5 different driveways at random just to test the height difference using the family SUV, and measured the wheel arch openings. They ranged from 3" to 9". It really doesn't matter how fast or slow you go, you still will see the same amount of flex / stress.
