Sas

[75K30]

Ahhhh the mighty debate of front shackle VS rear swing designs.
WHile I have heard about the front swing shackle allowing the axle to move forward, and aggree that on paper this might seem reasonable, but in all practical applications this becomes less than true.
See when a vehicle reaches an obstacle, and the tire is up against something that it must climb, the front swing shackle, has to move against the natural movement of the truck. As the truck moves forward, or at least tries, the axle naturally tries to move back, but since the rigid portion of the spring wont allow this, it has to fight under severe tension to reach its goal. This design just works against the natural properties of the suspension cycle. Not only does the spring have to work against the natural compression of the suspension cycle, it is forced to work against a more natural method of movement.
Now with a rear swing shackle, the axle can now move up and over the terrain with a more natural movement, and does not have to fight the weight of the truck to do so.

Alright lets talk now about this movement when used in normal driving applications.
The rear swing shackle can and will drive better on the street. See, again the natural movement and ability to absorb any bumps in the road is easier to achieve when the axle movement is not rigid.
As the tire hits a bump, it naturally wants to react in the opposite direction that the vehicle is moviing. The rear swing shackle permits this without resistance, but the front swing shackle actually fights this with the exact opposite reaction, and thie equates to a terribly rigid ride. Neg arch springs were designed to make thie rate of motion less likely to create such a mess, but add some arch to them and the above problems become more complicated with the front swing shackle.

Add into this the wheel base changes that occur during the normal range and the front swing shackle is more likely to promote "wheel wobble". This can make for an interesting ride, and the rear swing shackle is far less likely to have these issues.

Longer shackles and springs that are capable of greater travel will be more likely to have these issues when used with a front swing shackle.

This front swing shackle idea is not a very good one, and while on paper may seem like a decent concept, is not a very practical solution on the trail..........

[batty1214]

Okay, I can see what you are saying, and that kinda goes with the way my thinking was, but I am kinda new to the rock crawling thing, so, it's nice to get someone elses thoughts