Front Straight Axle Suspension Design?

I am drawn to under slung suspensions. Very old time looking. How would you put together a front suspension with parallel to the frame leaf springs?

This would be for a T roadster like car.

 

I'd put it together using nuts and bolts. Duct tape tends to fall off when it's hot and welding is too tough to take apart for service.

A quick search of "underslung" brought up tons of results...

 

Most "modern" underslung suspensions bring the frame and other components down into scrubline territory. This due to the fact that horseless carriage era "underslung" cars had 28-32" or larger wheels/tires and the frame was well above the road. Hard to do with a 15-21" wheel/tire combo.

 

This is how I did mine


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The last "underslung" car I know of, was the Triumph TR3 from the fifties. It had an underslung rear axle, 15" tires, very little rear suspension and low ground clearance.

For your roadster would suggest 16" wire wheels (30s Ford) or larger. You must use fairly large wheels and/or limited suspension travel if you want decent ground clearance.

See if you can find a 30s frame and turn it upside down. Hang the axles above the frame. You will have to use your own judgement here, to fit things together in a sensible way. The important point is to keep the steering box in the same relation to the spring and axle if you want it to steer well with no bump steer.

By the way some "sporty" models from the 20s and 30s, like the Auburn Cabin Speedster, got an underslung rear end and a lowered front end in an unusual way.

They cut the frame in half behind the front suspension, flipped it over, and welded it back together with the rear half dropped a few inches. This gave a lower frame, underslung rear end, and stock front suspension and steering.

Do a search for Auburn Cabin Speedster for an example.

Later. Here are some shots of the Cabin Speedster. Note the stock leaf spring front suspension, and note how the frame dips right behind the spring, then goes back under the rear axle, with a cover over the spring which is above the frame.

The web site the pic came from, with more pictures and description.

http://www.conceptcarz.com/z19227/Auburn-Cabin-Speedster.aspx

 

Notice how deep the frame rail is, how it dips under the rear axle, and how little room there is between the frame and axle, and frame and ground. Also how big the wheel is, that is a 17 or 18" wheel with about a 6.00 tire. This means it must have stiff suspension and limited suspension travel to keep from bottoming. In other words a sports car.