Hairpin question?

I'm fixing to start making the hairpins for my truck. And the way everything turned out i have to make a drop plate off the frame to make the hairpins the normal way but i really don't like the look of the drop plate coming off the frame and was wondering could i make the hairpin like the top pic instead of the bottom normal way. Would they be weaker i guess is what I'm asking

Either ways fine but if you like the lower pic just exstend it back to the lower part of the zed section of the frame,and connect it there.i dont think it will hurt anything?just add a spreder brace in the middle of the hairpin.if your makin them anyway.

Like Tom said,
if strength is your concearn, just add in spreader braces or cross braces.

Yep, both styles of radius rods are commonly used. I actually prefer the one in the top drawing as it lets you mount the end that goes to the frame a little higher because of the straight bar on top.

I used the same one on my '27.

Don

Cool thanks guys! I was worried about making the top bar straight I didn't know if it would be weaker than the bottom i wanted to bolt it through the frame instead of having to drop a plate down..

Man this place rocks ask a question and get and answer within a few minutes now back outside and see if i can make them

Thanks again for the help guys

The one you drew is actually stronger that the one Don pictured, because the point of pressure is back at the pivot, instead of out on the upper bar. (no offense Don) But if Don's worked okay then yours should be even stronger. The addition of a plate at mid way would make it even stonger, but you probably don't need it.

Yeah, actually the one on my '27 is pretty spindly compared to what Dan and I are using today, but it was on the street for 7 years solid with no signs of cracking or whatever.

Dan and I have often commented that we really overbuild stuff, I guess all us hot rodders do. If you look at some of the components sold in the hot rod market their brackets and stuff is much thinner than any of us would feel comfortable doing. Even the brackets and mounts on production cars are sometimes very thin and only welded in places, not all the way around.

But you are right, when I look at my '27 today (I built it 20 years ago) I am surprised that I built it with skinnier stuff than I would use now.

Don

I have used the top design with no problems. It is easier to form and less welding. FWIW , I made mine out of 7/8 solid. It was cheaper and sure stronger. Very little extra weight. I had the holes drilled and the tap started on a lathe.

Thanks Guys i got them made today . I made them like the top drawing. Got the axle hung and she is taking shape. The wife has been cooking pies and stuff all day maybe get her to break loose and take some pics tomorrow.

Thanks again

One of the big name Midget builders used that style.Might have been Kurtis.

The Engineers in the crowd might tell you it will transfer weight a little differently under hard braking.

Definitely nothing to worry about on the street.

Accually, the Kurtis hairpins are more like the bottom drawing. After market 'pins use 7/8'' DOM , 3/16'' wall tubing. It's much stronger than solid stock. Another option would be to run the legs of the 'pins angled to each other instead of on a parallel or to offset the axle arc in the rear mounting plate. The 'pins you built will give you all the service you want.

Youngster

One more thing... don't forget to weld a sleeve thru the frame and use grade 8 bolts.

Youngster

Youngster said:

One more thing... don't forget to weld a sleeve thru the frame and use grade 8 bolts.

Youngster

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Excellent points.

Don

Yeah i'm going to sleeve the frame. thats one reason i didn't want a drop plate. Here is a couple pics of what i made if you see something wrong feel free to let me know

looks real good ,what kind of spring and axel is that?

chopper tom said:

looks real good ,what kind of spring and axel is that?

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Its the old 49-53 chevy truck axle and the sping is from speedway

tiny1 said:

Here is a couple pics of what i made if you see something wrong feel free to let me know

Click to expand...

No, looks pretty solid. What is your tie rod clearance going to be like when the frame settles down with engine and all installed? It is hard to tell from the pictures, but it looks like the space might become tight then.

Don

Looks Great........

That really looks good, Tiny
Very nice job. '22

tiny1 said:

Yeah i'm going to sleeve the frame. thats one reason i didn't want a drop plate. Here is a couple pics of what i made if you see something wrong feel free to let me know

Click to expand...

Hey Tiny thoughs batwings look awful familiar.... you bin eyeballin my build pics dude.

Everything looks great....... as usual.

Thanks guys

donsrods said:

No, looks pretty solid. What is your tie rod clearance going to be like when the frame settles down with engine and all installed? It is hard to tell from the pictures, but it looks like the space might become tight then.

Don

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Its 6 1/2" between them Don I'm hoping its going to enough space I'm going to use a cross steer setup of some sort i may have to change it.

roddguy said:

Hey Tiny thoughs batwings look awful familiar.... you bin eyeballin my build pics dude.

Everything looks great....... as usual.

Click to expand...

lol yep i been watching you. Those on your truck looked the best to me of all I've seen.