Questions about sway bars

[jebster]

I was thinking of adding sway bars to my mud/monster truck but don't have a lot of experience with them and had a few questions.

1. If I ran a sway bar for the rear axle would that provide some roll reduction benefit or do I need front and rear sway bars? I ask because a rear install is pretty easy but the front may be a challenge.
2. Do they work best if attached to the axle or can I mount them to the trailing arms? Again, this is a question of convenience for my install because getting to the axle would take more work.
3. Does the alignment need to have the vertical link (going from the axle or trailing arms up to sway bar arm) need to be 90deg to the sway bar arm or can it be swept away?

In the pics below you can see the options I'm considering. First will require me to make a mounting block inside the frame and the second uses existing frame holes. Benefit of the first is I don't interfere with upper link mounting holes but it does cause the vertical link to extend out. The second option seems to give better vertical link alignment, uses existing holes but limits my upper link mounting options and I have to drill the hole to fit the torsion bar.

Advice is welcome.

[tallyforeman]

I've seen many trucks run a sway bar only in the rear. Depending on the power you are running, you may not need two.

Ideally, you'll want your end link at a 90 at ride height to get the most resistance either way. I have mine on the axle.

Sent from my Nexus 6 using Tapatalk

[jebster]

i was thinking about this a little more. maybe I'm backwards but wouldn't having the attachment points on the trailing arms provide a stronger torsional resistance than at the axle? given the longer distance from the link chassis mount point to the axle it would have a longer lever which equates to more force. having the attachment point at the mid-point of the trailing arm cuts that lever arm length down. in other words for the same amount of sway bar "twist" you could use a smaller diameter sway bar if the attached at the mid-point vs the axle.

[Lanky]

It'd be the opposite... the closer the link is to the axle the greater Torsional resistance the sway bar has... this can be used as a tuning aspect when running trailing arms. Rather then keep changing diameter of swaybar, you can move the link point on the TA. Same idea with moving the link on the sway bar arm. Closer to the bar, more resistance, further less...

[altd896]

In much the same way as an arm mounted spring is effectively softer because of the extra leverage from the length of the arm as opposed to axle mount, the effect on the sway bar would be similar.

Noticing your using the AX10 chassis, the stock battery tray can be mounted where the lugs on the underside will mount a sway bar in a similar fashion to on the Wraith.

[jebster]

Originally Posted by Lanky

It'd be the opposite... the closer the link is to the axle the greater Torsional resistance the sway bar has... this can be used as a tuning aspect when running trailing arms. Rather then keep changing diameter of swaybar, you can move the link point on the TA. Same idea with moving the link on the sway bar arm. Closer to the bar, more resistance, further less...

Originally Posted by altd896

In much the same way as an arm mounted spring is effectively softer because of the extra leverage from the length of the arm as opposed to axle mount, the effect on the sway bar would be similar.

Noticing your using the AX10 chassis, the stock battery tray can be mounted where the lugs on the underside will mount a sway bar in a similar fashion to on the Wraith.

I ended up having different mounting points. As you can see in my build thread (jebster's mud truck) the front sway bar is mounted to the axle and the rear sway bar connects to the trailing arms.

Based on what you posted if I want similar resistance I would use a more rigid sway bar on the front to balance them based on the different mounting points? I actual did the opposite. My simple test, lift up a wheel and note how far it goes before the other side of the axle starts to lift up, showed that the front and rear axles behave very similar they way I have it. Maybe it is just not sensitive enough to noticed the difference.