Shock Angle

[javi]

Hello guys, I found some aluminum laying outside and was wondering what the benefits of moving your shocks over to make them more angled.
I was looking at the gearhead lift kit and you could also move it to the side.
Thats kind of the angle or thing that I am talking about.

 

[6sharky9]

Laying the upper section of the shocks down is called Alpha Angle...What this does is changes the relation between shock movements and wheel travel.

A shock straight up and down that has 3 inches of as travel an example will allow the tire to move the same 3 inches.

Mounted in alpha angle you can increase the wheel travel using less shock travel..so now you might have 3.5 inches of wheel travel using 3 inches of shock travel as an example. Of course we are on a much smaller scale with the rc trucks but you get the idea.

You need to use longer than stock shocks to do this as to not lower the truck too much and actually lose travel...100mm shocks will require them to be layed down even more to not raise your COG so much and hurt performance...I found 93mm eye to eye shocks mounted in this fashion to be perfect for the scx10 with 4.2"/4.3" tire diameters.

The suspension acts a little softer when its layed down as well so re tuning may be in order if you think its too soft for you.

The suspension will act much like a rock crawler which tends to be more smooth over terrain/obstacles

Ive been doing my shocks this way for a while now and love it...I made some custom extension as I couldn't find anything aftermarket I liked.
The ones ive seen add too much weight on the shock hoops and have adjustments you will most likely not ever use..Making a set custom to fit your truck is really simple to do.

 

[Highmark]

Hello guys, I found some aluminum laying outside and was wondering what the benefits of moving your shocks over to make them more angled.
I was looking at the gearhead lift kit and you could also move it to the side.
Thats kind of the angle or thing that I am talking about.

It depends on what you have and what you use it for.

I'm assuming you have an SCX-10, and if so then no just leave your shocks where the are. There are more positive gains to be had from altering your suspension geometry than the shock angle. Although Sharky thinks he's somehow getting some benefit from moving his shocks, it's due to the types of shocks he's using, not the changed ACF (angle correlation factor) of the shocks if anything.

The more you lean in shocks the more leverage is placed on them when your car articulates - making your suspension softer. Additionally your shocks will be placed at more of an angle the farther the suspension cycles resulting in a regressive spring rate - so it will become softer the more it travels as the shock lays down. These attributes are fine for cone dodgers -but not ideal for most scale trucks.

 

[6sharky9]

I did do it more for the lowering than added travel but the added travel has helped in some situations...Its not a huge drastic change in travel..The shocks are 3mm longer and I gained that in down travel...Not up travel where you have tire rubbing issues.

Rock crawlers are better performers over obstacles and terrain hence the Alpha Angle shock mounting you find on 99.9999 percent of rock crawlers.

They do it to keep COG as low as possible and for articulation..They wouldn't do very well if you stood those tall shocks up.


Why doesn't the wraith come with straight up and down shock or rock crawlers??

A small change in the direction of improved performance using that mounting system is far from a bad move in general.

Yes the shocks do get softer as the reason explained in more detail..but that's not something you cant overcome with more pre load or heavier oil to compensate.

I have zero clearance issues with the added travel and didn't raise my COG.

I personally like it on my honcho..it climbs things my rubicon cant..so to me its a proven method should one choose to try it ...If you try it and don't like it its not hard to go back to the straight up and down mounting.

If you have stock 90mm shocks the best you can do is mount them in the last hole leaning in the directions of the trans on all 4 corners.

If you try to lay the stock shocks down any more you will start to lose ride height creating less travel as your tires will rub on the rear cage and front fender on a honcho and more so a problem with a full rear fender body.

 

[K.O.M.]

I'm not trying to really lay into anyone in particular, but there is a lot of mis-information going on here.

For the sake of simplicity, let's assume that you will leave the lower shock mount where it is, and only move the upper shock mount.

1. For ANY given shock length, you actually LOSE wheel travel and LOWER the vehicle once the shock is angled from vertical. Basic right angle triangle geometry. Wheel travel is always vertical (ok, at a small arc dictated by your links) call it side A, the distance the upper shock mount is from the original vertical point is side B, and the shock is the hypotenuse, side C.

To make an extreme case, if you were to mount your shock completely horizontal, you would have zero vertical wheel, but gain horizontal travel (useless unless you want to run into or back into things all the time).

So, unless you physically make the shock longer, mounting it at any angle will result in less vertical wheel travel.

2. Moving the top of the shock absorber has a more subtle effect on the car's suspension. What is changing here is the angle of action of the shock absorber. Changing the angle makes the shock absorber more, or less, progressive. A progressive suspension setup describes the situation where the suspension becomes stiffer as the shock/spring/suspension is compressed. Leaning the shock absorber over further results in a more progressive suspension. This is useful in landing off big jumps (helps stop the car from bottoming out). Standing the shocks straighter helps in rough conditions, or tracks with lots of quick changes of direction.

So, you are actually making INITIAL DAMPING softer by leaning the shocks over, but the shocks "stiffen" as it goes through it's travel.

So just about everything posted up to this point has been the reverse of what actually happens.:twisted:

 

[Highmark]

I did do it more for the lowering than added travel but the added travel has helped in some situations...Its not a huge drastic change in travel..The shocks are 3mm longer and I gained that in down travel...Not up travel where you have tire rubbing issues.

If you only did it to compensate for longer shocks why not just use a 3mm internal limiters, or the correct size shock? Instead you've got a bracket that's torqueing your plastic shock towers that aren't all that strong to begin with.

Rock crawlers are better performers over obstacles and terrain hence the Alpha Angle shock mounting you find on 99.9999 percent of rock crawlers.

Oh are they? I thought Ford Pinto's ruled the world :roll:. I want you do me a favor really quick ... google "Alpha Angle Shock". You're literally the only person in the world using that term like that. The term is the shock's alpha angle, all shocks have one, even if it's standing straight up.

They do it to keep COG as low as possible and for articulation..They wouldn't do very well if you stood those tall shocks up.

Really?

Again, all suspension tuning will always come back to what you're using your rig for.

A small change in the direction of improved performance using that mounting system is far from a bad move in general.

I didn't say it was a bad move, I said in my opinion it didn't have as much of a benefit as you claim it does.

Yes the shocks do get softer as the reason explained in more detail..but that's not something you cant overcome with more pre load or heavier oil to compensate. .

Actually, that's exactly how you could / would compensate, if that's what you were going for.

I personally like it on my honcho..it climbs things my rubicon cant..so to me its a proven method should one choose to try it ...

Any of my rigs will crawl things a stock rubicon can't - so what?

If you don't like it its not hard to go back to the norm or buy those heavy brackets to mount to the shock hoops so you can use 100mm shocks to get travel you will never use..Not to mention raising the COG hurting performance in other areas.

How is that applicable to anything?

 

[6sharky9]

If you only did it to compensate for longer shocks why not just use a 3mm internal limiters, or the correct size shock? Instead you've got a bracket that's torqueing your plastic shock towers that aren't all that strong to begin with.



Oh are they? I thought Ford Pinto's ruled the world :roll:. I want you do me a favor really quick ... google "Alpha Angle Shock". You're literally the only person in the world using that term like that. The term is the shock's alpha angle, all shocks have one, even if it's standing straight up.

Really?

Again, all suspension tuning will always come back to what you're using your rig for.



I didn't say it was a bad move, I said in my opinion it didn't have as much of a benefit as you claim it does.



Actually, that's exactly how you could / would compensate, if that's what you were going for.




Any of my rigs will crawl things a stock rubicon can't - so what?




How is that applicable to anything?

I used 7mm spacers inside the shock to limit them to 93mm...they were 100mm..Even mounting them straight up and down it sat to high for my liking and did worse on side angles than it did stock..So to lower it without losing the added travel I layed them down..So now I have more downward articulation than I had stock but didn't raise my COG..And my upward travel stops 1mm before scrapping the rear cage on my honco and on the front its not so much it wants to rip my fender off..yet still have better downward travel like so without raising COG or having to use much taller shocks..I wanted more travel without the height and accomplished it with an improvement in performance...Its just a way of doing it that's worked for me and works for many real 1:1 vehicles...so im sticking to what I say about it...Its not WRONG to do it this way as you can do it other ways as well...Its preference and this one is mine.

 

[6sharky9]

By the way; I use mine as an all purpose trail rig..Im not trying to clinb verticle rock however like some dedicated crawlers can..But I have noticed an improvement in its crawling capabilities over having the shock mounted straight up and down..So no matter how little or how much it is ive noticed it as an improvement...Whats different with that than some kits that angle your shocks towards the center of the differential besides making it more soft?..Same situation?...Is it just hype or does it actually improve performance??

 

[Highmark]

I'm not trying to really lay into anyone in particular, but there is a lot of mis-information going on here.

For the sake of simplicity, let's assume that you will leave the lower shock mount where it is, and only move the upper shock mount.

1. For ANY given shock length, you actually LOSE wheel travel and LOWER the vehicle once the shock is angled from vertical. Basic right angle triangle geometry. Wheel travel is always vertical (ok, at a small arc dictated by your links) call it side A, the distance the upper shock mount is from the original vertical point is side B, and the shock is the hypotenuse, side C.

To make an extreme case, if you were to mount your shock completely horizontal, you would have zero vertical wheel, but gain horizontal travel (useless unless you want to run into or back into things all the time).

So, unless you physically make the shock longer, mounting it at any angle will result in less vertical wheel travel..

No this is incorrect.

2. Moving the top of the shock absorber has a more subtle effect on the car's suspension. What is changing here is the angle of action of the shock absorber. Changing the angle makes the shock absorber more, or less, progressive. A progressive suspension setup describes the situation where the suspension becomes stiffer as the shock/spring/suspension is compressed. Leaning the shock absorber over further results in a more progressive suspension. This is useful in landing off big jumps (helps stop the car from bottoming out). Standing the shocks straighter helps in rough conditions, or tracks with lots of quick changes of direction.

So, you are actually making INITIAL DAMPING softer by leaning the shocks over, but the shocks "stiffen" as it goes through it's travel.

Sounds like you're an independent suspension sort of guy.

Anyway this is also incorrect (in regards to a 4 link / 3 link). Shocks will begin to lay down thus inreasing the mechanial advantage the axles have over them as they approach bump.

Traditional wisdom is that shocks should be at 90*, or approaching it at full bump.

 

[Meatwad]

So after funny searches for alpha angle leading to either sharky's posts here on rcc or surgical bone implants, I found an example of it in a vehicle's suspension system.

So how is the alpha angle being controlled at a 0.7:1 ratio of the theta angle (as is suggested for proper operation)? Or better yet calculated?

Btw alpha angle is not laying the shocks down...

 

[pastimesteve]

I just want to know, will any of this make time travel possible, or Jack Benny come back, or my standard definition television work? :lol::wink:

Just kidding with you guys. This thread, however, has reminded me of why I did not choose a profession that required a lot of math.

Steve

 

[Highmark]

So after funny searches for alpha angle leading to either sharky's posts here on rcc or surgical bone implants, I found an example of it in a vehicle's suspension system.

So how is the alpha angle being controlled at a 0.7:1 ratio of the theta angle (as is suggested for proper operation)? Or better yet calculated?

Btw alpha angle is not laying the shocks down...

The alpha angle is the angle of the shocks in relation to 90* both from a side, or front/rear view.

ACF = cos(alpha)

 

[6sharky9]

The alpha angle is the angle of the shocks in relation to 90* both from a side, or front/rear view.

ACF = cos(alpha)

Ok..so if a shock is 90 degrees or straight up and down is this also Alpha ?..or is it when you angle it down from 90 degrees that makes it alpha?

 

[K.O.M.]

No this is incorrect.
Sounds like you're an independent suspension sort of guy.

Anyway this is also incorrect (in regards to a 4 link / 3 link). Shocks will begin to lay down thus inreasing the mechanial advantage the axles have over them as they approach bump.

Traditional wisdom is that shocks should be at 90*, or approaching it at full bump.

Tell me, specifically what is wrong, and give mathematical proof.

This is what I get for trying to give a simple answer to what seems like a simple but is really complex question.

Like I said, let's keep it simple and work in 2 dimensions (x, y) looking at the truck from the side view, for the time being.

We're using the SCX10 shock mounting as an example. The lower shock mounts are fixed, stock. The only way to "lean the shocks over" as I paraphrase what part of the original post was asking, is to move it along the longitudinal x-axis, and is shown in one of the photos. If you don't lengthen the shock as you move the upper mount further and further away from the vertical mounting position, the wheel get's pulled up along the vertical y-axis. You lower the ride height.

At the stock shock mounting location, the axles are pretty much running into chassis parts at full compression. The more that shock is "laid down" using the method shown in this thread so far, the less vertical (y-axis) wheel travel you will have available, part of that total travel has already been used up. See above.

I'll hold the point here until you can prove me wrong otherwise. Then we'll talk about I.S. and 3/4 link and even trailing/leading tele-lever arms 'till the cows come home.

P.S. Please don't take this as a pissing contest, as there is potential for a lot of knowledge to be learned by all in this thread. "thumbsup"

 

[6sharky9]

Tell me, specifically what is wrong, and give mathematical proof.

This is what I get for trying to give a simple answer to what seems like a simple but is really complex question.

Like I said, let's keep it simple and work in 2 dimensions (x, y) looking at the truck from the side view, for the time being.

We're using the SCX10 shock mounting as an example. The lower shock mounts are fixed, stock. The only way to "lean the shocks over" as I paraphrase what part of the original post was asking, is to move it along the longitudinal x-axis, and is shown in one of the photos. If you don't lengthen the shock as you move the upper mount further and further away from the vertical mounting position, the wheel get's pulled up along the vertical y-axis. You lower the ride height.

At the stock shock mounting location, the axles are pretty much running into chassis parts at full compression. The more that shock is "laid down" using the method shown in this thread so far, the less vertical (y-axis) wheel travel you will have available, part of that total travel has already been used up. See above.

I'll hold the point here until you can prove me wrong otherwise. Then we'll talk about I.S. and 3/4 link and even trailing/leading tele-lever arms 'till the cows come home.

P.S. Please don't take this as a pissing contest, as there is potential for a lot of knowledge to be learned by all in this thread. "thumbsup"

You definitely lose ride height as you move a shock forward..The main reason I had to go to 93mm to maintain my original ride height but gain some travel..I also had to use a heavier weight oil and more preload to compensate for how soft the shocks reacted..I now can use all the upward travel I can possibly have using the tire size I use without any rubbing..its slightly more than stock but not over traveled.

I think its more a discussion on rather or not mounting them at an angle is a bad thing or not as good as having them mounted straight up and down.

The drawbacks (Body roll) if any can be fixed with shock tuning as long as you don't go too far with the angle,,hence my only going 93mm and not 100mm and leaning them down even morel..I believe I have very very minimal body roll ( I think less than stock), increased my travel and kept my low COG...Other ways to do this but this is what ive chosen to get my results.

If its my saying or calling it Alpha angle and im wrong then so be it...My explanations of how it works is not wrong so I stand by my explanations
of how it works...I can go back and just call it shock angle.

 

[K.O.M.]

6sharky9 we get exactly what you're trying to convey. My response was to Highmark saying that the first part of my original post was incorrect.

You have just in fact proven what I said since you had to go to the longer shock length to gain back some of the lost travel.

I'll cut to the chase by saying that Highmark is only partially correct with his/her comment regarding how dampers react to a 3 or 4 link suspension design, I just want to know that there is enough attention span and/or tolerance in this forum to have a discussion regarding actual suspension design in 3 dimensions before we embark on this odyssey. :lmao:

BTW, be careful with that diagram with the alpha angle--it show a trailing arm which is yet another factor--it doesn't show if the control arm is attached to a solid axle or independent suspension (like the original Losi JRX2).

 

[6sharky9]

Well..im just happy with my set up and that's all that matters I suppose..I would just consider why most rock crawlers use the shocks at such an angle if it had no benefits...why not just much shorter shocks mounted 90 degrees if it better all around? ..My guess is to keep COG low and have the articulation the need...I don't think an SCX10 can out crawl a serious well set up rock crawler...But a rock crawler can do what most any SCx10 can do better IMHO...I just added a small effect as to what a crawlers advantage is..Im not the first and wont be the last..lol

Ill agree to disagree on whats the better set up and be happy with mine for now...I may try a different set up one day to see if its any better.

 

[6sharky9]

This is a custom crawler I had and used stock 90mm axial plastic shocks,,,The tires were Panther T485 that measured 5 inches in diameter..I had about the same in articulation.
More than I could've used before the tires hit the body for sure...It was an Exceed 1/10 scale crawler with a custom carbon fiber chassis.

 

[anuthabubba]

Some things 'work' on RC models (air, land & water) that don't work on 1:1 vehicles.

 

[Highmark]

K.O.M. sorry if I sounded blunt or rude - that wasn't my intention (busy day at work). I'm going to itemize my thoughts on this just to stay organized. "thumbsup"

1. For ANY given shock length, you actually LOSE wheel travel and LOWER the vehicle once the shock is angled from vertical. Basic right angle triangle geometry. Wheel travel is always vertical (ok, at a small arc dictated by your links) call it side A, the distance the upper shock mount is from the original vertical point is side B, and the shock is the hypotenuse, side C.

To make an extreme case, if you were to mount your shock completely horizontal, you would have zero vertical wheel, but gain horizontal travel (useless unless you want to run into or back into things all the time).

Regarding ride height - if moving the shock accross a horizontal line with the fulcrum being the bottom shock mount, then certainly this is the case. However if you're free to move the shock vertically (and why wouldn't you be? You're already moving it) then there is no loss in ride height.

Regarding travel - the equation is ACF = cos(alpha). ACF is the Angle Correction Factor or the relationship between shock travel and wheel travel.
Source: Pirate4x4.Com - The largest off roading and 4x4 website in the world.

Here's a real world example from one of my first rigs back in 2004 - notice how little the shock is compressed?: