Steeda billet vertical links installed

[Mike A.]

Comparison between the OE vertical links and the Steeda vertical links

Woah! That stock link is a wet noodle! :eyebulge:

Sponsored

 

[Norm Peterson]

Fortunately, the big loads on the IL are not in any of its 'flexy' directions.

But there is some benefit to be had from having the small-load directions stiffened,.


Norm

 

[rainier446]

Fortunately, the big loads on the IL are not in any of its 'flexy' directions.

But there is some benefit to be had from having the small-load directions stiffened,.


Norm

Based on what I read from your earlier statement, you would prefer spherical bushings on the vertical links versus the delrin? Since the spherical bushings allow the links to flex where needed but be stiff where needed? The delrin provides zero movement in any direction but I'm starting to believe this isn't necessarily a good thing.

 

[Norm Peterson]

Yes.

Delrin is fine as long as the rotation is about an axis located at the center of the cylindrical surface where the sliding occurs (yes, that's a bit fussy). But this can be harder to achieve than it sounds when the ends of the things you're connecting move in arcs instead of in straight lines and the things it connects can also flex. When the rotation is about some skew axis, Delrin starts developing induced forces that interfere with suspension movement (aka "bind"). Basically, you can't distort a cylinder of Delrin as easily as you can a cylinder of OE rubber or even polyurethane to accommodate the off-axis component of rotation that way.

A spherical is equally good in all rotational directions, up to the angular limitations of the joint. The downsides here are noise (if the sphericals are all-metal rod end type) and possibly load capacity (for a composite spherical fitted to a too-small space). And if you repeatedly bottom out a rod end, something will eventually break.

Then again, any sort of suspension link bushing or pivot should probably be considered a "wear part" anyway.


Norm

 

[high_glove_side]

Comparison between the OE vertical links and the Steeda vertical links - notice how easily the OE links bend/flex:

OE links (click to see video)



Steeda links (click to see video)

Man.. those stock ones. "Mush" isn't just a command for sled dogs apparently. :eyebulge:

 

[jc1804]

Comparison between the OE vertical links and the Steeda vertical links - notice how easily the OE links bend/flex:

OE links (click to see video)



Steeda links (click to see video)

not trying to play the devil, but the test you show does nothing for the tensile strength of either, isnt that what is really what is needed here? Not saying the steeda arn't FAR the superior, but under any conditions there should be no shear issue for either.

Just a thought when I watched the 2 vids

 

[David@Steeda]

Norm makes some good points. Sphericals are good for handling movement in multiple directions without inducing bind. As he also mentioned, they do wear out and they do induce noise - those are the tradeoffs.

However, there seems to be some confusion about what the intended purpose of this link is in this suspension and how it is loaded. The vertical link is only in this system to handle the brake torque during deceleration and movement around the hub during acceleration. The top point of the vertical link where it attaches to the upright is in-plane with the bottom point of the vertical link where it attaches to the lower control arm. What this means, is that through typical suspension travel there is no deflection or stress on the mounting points of the vertical link, as well as no deflections induced in some odd directions as suggested. The link simply rotates around the mounting hardware during suspension movement. In fact, if the lower control arm or upright were allowed to move in the way people think it is, then we would actually be getting changes in the rear caster, camber and toe of the vehicle which is obviously not desirable. This completely eliminates the need for a spherical bearing in the assembly since the range of motion in the spherical isn’t utilized in any way. This means that we don’t need to sacrifice NVH and part life in order to reach our desired results.

The goal for Steeda in the aftermarket link would be to reduce wheel hop and decrease braking distance by total deflection reduction of the part in tension and compression - that is why stiff, yet quiet Delrin bushings are utilized over the stock rubber bushings.

Lastly, there seems to be some confusion on the stiffness and elasticity of aluminum parts versus steel parts and the parts' ability to handle load. Steel in general is more brittle than aluminum, yet has a higher yield strength. However, part strength comes down to how the shape and interaction of the part is designed. It is very possible to get stronger and more fatigue-resistant parts out of aluminum than steel if designed correctly.

 

[jc1804]

Norm makes some good points. Sphericals are good for handling movement in multiple directions without inducing bind. As he also mentioned, they do wear out and they do induce noise - those are the tradeoffs.

However, there seems to be some confusion about what the intended purpose of this link is in this suspension and how it is loaded. The vertical link is only in this system to handle the brake torque during deceleration and movement around the hub during acceleration. The top point of the vertical link where it attaches to the upright is in-plane with the bottom point of the vertical link where it attaches to the lower control arm. What this means, is that through typical suspension travel there is no deflection or stress on the mounting points of the vertical link, as well as no deflections induced in some odd directions as suggested. The link simply rotates around the mounting hardware during suspension movement. In fact, if the lower control arm or upright were allowed to move in the way people think it is, then we would actually be getting changes in the rear caster, camber and toe of the vehicle which is obviously not desirable. This completely eliminates the need for a spherical bearing in the assembly since the range of motion in the spherical isn’t utilized in any way. This means that we don’t need to sacrifice NVH and part life in order to reach our desired results.

The goal for Steeda in the aftermarket link would be to reduce wheel hop and decrease braking distance by total deflection reduction of the part in tension and compression - that is why stiff, yet quiet Delrin bushings are utilized over the stock rubber bushings.

Lastly, there seems to be some confusion on the stiffness and elasticity of aluminum parts versus steel parts and the parts' ability to handle load. Steel in general is more brittle than aluminum, yet has a higher yield strength. However, part strength comes down to how the shape and interaction of the part is designed. It is very possible to get stronger and more fatigue-resistant parts out of aluminum than steel if designed correctly.

thanks for the info David. helped me with some info, as I stated before about metal strength but now knowing what its "total" purpose is the change to your links makes practical sense.

 

[Norm Peterson]

Dave - I was treading very lightly for a reason . . .


Norm

Sponsored