If there's one thing hot rodders have, it's a lot of options. Which options you choose depends a lot on your priorities. Are looks more important than comfort? Is performance more important than budget?
One big priority for a lot of hot rodders these days is traditional styling. Traditional is synonymous with "early." Unfortunately, "early" can be synonymous with outdated technology. And outdated technology can be synonymous with failure, especially if being able to drive your hot rod is also a priority.
This is especially true when you're talking about suspensions where, in addition to style, your choices will affect performance and, most importantly, safety. If it's only about traditional appearance, then wishbones are at the top of the list. Split 'bones were the prominent suspension choice during the first years of hot rodding, and still look great on early cars. When it comes to performance, however, look for those 'bones at the opposite end of the list.
The problem with split wishbones is that they have to take a lot of twist, especially when driving on uneven roads or making turns into driveways and similar conditions. If the limited articulation can't handle the stress, you end up with twisted, bent, and broken parts.
A four-bar system beats those 'bones every time. With a pair of lower bars to locate the axle front to rear, and a pair of upper bars to control axle rotation and hold the pinion angle stable, plus a Panhard bar controlling side-to-side (lateral) movement, this type of suspension has all the advantages except one. Which brings us back to style. For many traditional rodders, four-bars, like IFS, is a style about 20 years too late for a Fifties-influenced rod.
Some creative rodders have figured out how to have the best of both worlds by building a triangulated four-bar system using wishbones as the lower arms of the setup. On a triangulated four-bar, the upper bars are angled from the frame rearward and inward, closer to the center of the axle. The angle helps center the rearend, eliminating the need for a Panhard bar-which opens up room for the exhaust and other components.
Believe it or not, we were at Hollywood Hot Rods the very day Ryan Rivers and Troy Ladd were building a triangulated four-bar system for a '32 roadster, using wishbones for the upper and lower arms. The upper bars are mounted out of sight, inboard and high on the 'rails. The lower arms are mounted in plain view, where they have all the appearance of split wishbones. Looks old-timey. Works new-timey. It's win-win for hot rodders who like tradition and performance.
These Ford wishbones are on...
These Ford wishbones are on the way to being transformed into upper and lower four-bars for the roadster, using the accompanying tie rod ends, sleeves, bungs, and bushings, plus some fabricated sheetmetal brackets. The '36 rear 'bones will become the lower bars and the shorter '35-41 front 'bones (on the right) will become the upper bars.
Here, the smaller-diameter...
Here, the smaller-diameter 'bones, which will be the upper arms, have already been cut to fit. The tapered end (left) will be bracketed to the frame and pivot on a urethane tie rod end from SO-CAL Speed Shop (shown on the left). The other end will be bracketed to the rear axle and pivot on a urethane bushing in a steel sleeve (on the right).
Troy Ladd drilled the axle...
Troy Ladd drilled the axle end of the upper arms for the steel sleeve that will hold the bushing.
Instead of leaving a portion...
Instead of leaving a portion of the upper arm extending beyond the sleeve, he instead chose to cut the arm right at the sleeve for a cleaner look.
Brackets were fabricated from...
Brackets were fabricated from 1/8-inch cold rolled plate to hold the forward end of the upper arms to the boxed framerails. The bracket is tack welded here, but will later be welded, of course. The tie rod ends with urethane bushings are more contemporary looking than the overall theme of the roadster, but they will be invisible after the body is dropped onto the frame.
A smaller pair of tabs was...
A smaller pair of tabs was built, also from 1/8-inch plate, to mount the upper arms to the rear axle, just to the outside of the third member housing. These arms are fastened with a bolt, and will be plenty strong to handle the longitudinal force.
Note the section of 2-inch square tubing stuck between the axle and the C-notch in the frame (arrow). These were used on each side to establish the proper ride height and pinion angle while Ryan accurately located the upper and lower arms. The mounting tabs at the front and rear of these upper arms were sized to keep the front and rear pivot points horizontal (and the arms parallel to the ground) at ride height.