doghousedevil
Well-known member
when constructing radius rods,how short is too short? right now i'm wanting to go 22".
rear radius rods
- Thread starter doghousedevil
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bob w
Still crazy after all these years!
On the '25 Dodge I built last winter I used 28.5" bars from the front pivot point to the center of the rear axle. At this length there is quite a bit of pinion angle change as the suspension moves up and down. So far this has not proven to be a problem driving. The rear suspension has about 4" of movement. Art Morrison's ladder bars come in 30" & 32" lengths. They are commonly used on many pro street type cars. If you must use short bars it would be much better to do a parallel four link. You might get by with a short bar if you limit rear suspension travel.
donsrods
Well-known member
Yep, this is one of two areas where bigger really is better.
If you take this to the extreme and look at a 1 foot wishbone vs a 3 foot one, you can see how the arc of the short one would not move very freely without binding. So if you can get a longer one in there your ride is going to be less choppy and erratic. Much easier on welded mounts and all too.
Don
If you take this to the extreme and look at a 1 foot wishbone vs a 3 foot one, you can see how the arc of the short one would not move very freely without binding. So if you can get a longer one in there your ride is going to be less choppy and erratic. Much easier on welded mounts and all too.Don
DirtWorshiper
Well-known member
The shorter the radius arm is when used on a rear suspension, the twitchier it's going to be at highway speeds. Also a shorter radius arm puts a tremendous amount of force on the forward mounting point.
I know this from my off-road experience. I've done both style rear suspensions- the longer the arm, the better. Early Broncos do much better across the board when the front radius arms are lengthened. This applies to four links as well, however like bob w said, if you had to go short you would probably be better with a parallel four link.
I know lots of wheel travel is not the goal of most rodders, but a good ride is.
Also go heavy with whatever you use to connect your radius arm to the frame and axle-hiem, ball joint, bushing, etc.
I know this from my off-road experience. I've done both style rear suspensions- the longer the arm, the better. Early Broncos do much better across the board when the front radius arms are lengthened. This applies to four links as well, however like bob w said, if you had to go short you would probably be better with a parallel four link.
I know lots of wheel travel is not the goal of most rodders, but a good ride is.
Also go heavy with whatever you use to connect your radius arm to the frame and axle-hiem, ball joint, bushing, etc.
RPM
The Rat Master!
We build the radius rods for Spirit cars and they are 27" They are the same length that Speedway sells. Speedways are 7/8" and Spirit was having trouble with them bending. We make ours from 1" DOM and we have not had a problem with them.
SmallBlock Jimmy
Well-known member
This is some good info, thanks for sharing fellas!
