90mm vs 100mm shocks

[DowntownScience]

I highly recommend reading this before making a decision.

http://www.axialracing.com/blog_posts/3996

Personally I like the height that 100's give my bumper and Trans plate but don't like all the flex. Too much will get you all twisted up over obstacles.

The 90's have the perfect amount of flex but lead to scraping on obstacles due to the lower chassis height.

Still experimenting....right now my theory is 100mm shocks with the stock axial 10mm bump stops. The height I want with the same amount of travel as the 90's. Will be putting them on today.

There must be a reason that the stock scx10 suspension setup works so good out of the box with very little articulation.

[DickyT]

90mm Proline's on my 1.9 rig, 90mm Icon's on my 2.2. Both perform very well and are butter smooth.


The 1.9 - Old Skool - 4" articulation









The 2.2 - WranglAR - 4.75" articulation

[Stormchaser]

Originally Posted by (redbeard)

I use the 100mm Kings and dont have any issue with drive line angles. It all about the preload setting....keep it at a lower static height to get more droop.

Measurements for the Kings are 100mm uncompressed and 70mm compressed.(if I remember right)

Thanks redbeard.

[Yubacitycrawler]

I run 100's all around. 90's seem to limit it a little

[guido5526]

What about old man emus? Any one running those and if so how are they for form fit and functionality? I'm torn between those or the Kings on my build.

[TacoCrawler]

On many of the rigs I'm seeing at my local runs...
...the suspension is not preloaded properly.
And the oil viscosity is way too thick.

The coil springs that come with many aft. mrkt. shocks are often too stiff...
^ or the pre-load is set to 0% up travel remaining.
And this pushes the static ride height upwards making the chassis
sit too tall and bounce along like a toy.

The shock(s) travel perimeter's should be preloaded
so that the static ride height is 60/40 %
^ that means 60% up travel (compression) and 40% down travel (droop) when static.

I pre-load mine closer to 50/50

This usually entails using softer coil springs...
then what comes with the majority of shocks sold.
But the coil spring's extension must still remain seated
at both the upper shock collar and lower cup at full extension.
Sooo... both spring rate/length as well the oil viscosity play a critical role here.

Obviously chassis weight will also be a deciding factor
as to what spring rate/oil viscosity is required.
My junk weighs in at around 8 - 9 lbs.

IMO... down travel (droop) is more advantageous then compression
when it comes to a crawler's articulation/ride realism.

If yer a balls to the walls basher... different story.
Compression will likely be more critical.
But ya still want some up travel remaining even then. (60/40)

I have a friend whom removed his C. springs altogether...
his rig crawls purdy well. Relying on droop rather then compression.
But it's all slow speed maneuvering.

I run 100mm Traxxas Ultra BB's
inexpensive and work well.
But even then I needed replace with softer coil springs.

Another thing I see done wrong is shock oil weight.
It does not generally need be so thick in viscosity.
When utilizing softer C springs the rebound is slowed down to the point
that the chassis does not return immediately to self level or static ride height.

I run a three hole piston in my Traxxas Ultra's
along with synth. 25 wt up front and 20 wt out back.
The ride is compliant and offers a more realistic visual.

A 100mm shock is the longest shock one should do on an scx-10
unless the upper shock mount is extended upwards in compensation.
Longer then 100mm and drive shaft(universal) bind will occur during full droop.

Maybe not perfect for some scaler's...
but I like them, they stroke smoothly and don't leak
are easy and inexpensive to rebuild.

pictures 'cuz I was bored...
^ (plus pictures bring more entertainment)





I now use these black Losi mfgr'd C springs instead...
but realize these would not fit standard diameter shock bodies.





flex appeal...

[DowntownScience]

Originally Posted by TacoCrawler

On many of the rigs I'm seeing at my local runs...
...the suspension is not preloaded properly.
And the oil viscosity is way too thick.

The coil springs that come with many aft. mrkt. shocks are often too stiff...
^ or the pre-load is set to 0% up travel remaining.
And this pushes the static ride height upwards making the chassis
sit too tall and bounce along like a toy.

The shock(s) travel perimeter's should be preloaded
so that the static ride height is 60/40 %
^ that means 60% up travel (compression) and 40% down travel (droop) when static.

I pre-load mine closer to 50/50

This usually entails using softer coil springs...
then what comes with the majority of shocks sold.
But the coil spring's extension must still remain seated
at both the upper shock collar and lower cup at full extension.
Sooo... both spring rate/length as well the oil viscosity play a critical role here.

Obviously chassis weight will also be a deciding factor
as to what spring rate/oil viscosity is required.
My junk weighs in at around 8 - 9 lbs.

IMO... down travel (droop) is more advantageous then compression
when it comes to a crawler's articulation/ride realism.

If yer a balls to the walls basher... different story.
Compression will likely be more critical.
But ya still want some up travel remaining even then. (60/40)

I have a friend whom removed his C. springs altogether...
his rig crawls purdy well. Relying on droop rather then compression.
But it's all slow speed maneuvering.

I run 100mm Traxxas Ultra BB's
inexpensive and work well.
But even then I needed replace with softer coil springs.

Another thing I see done wrong is shock oil weight.
It does not generally need be so thick in viscosity.
When utilizing softer C springs the rebound is slowed down to the point
that the chassis does not return immediately to self level or static ride height.

I run a three hole piston in my Traxxas Ultra's
along with synth. 25 wt up front and 20 wt out back.
The ride is compliant and offers a more realistic visual.

A 100mm shock is the longest shock one should do on an scx-10
unless the upper shock mount is extended upwards in compensation.
Longer then 100mm and drive shaft(universal) bind will occur during full droop.

Maybe not perfect for some scaler's...
but I like them, they stroke smoothly and don't leak
are easy and inexpensive to rebuild.

pictures 'cuz I was bored...
^ (plus pictures bring more entertainment)





I now use these black Losi mfgr'd C springs instead...
but realize these would not fit standard diameter shock bodies.





flex appeal...

How does your rig sidehill with such soft suspension?

How about steep climbs? Do you get any front tire lift?

Not a fan of droop.

To my knowledge droop is achieved by running a shorter spring on a longer shock body or by running a properly tuned shock attached using a droop kit.

Short springs in longer bodies leave much to be desired when there isnt constant force against the spring retainers. Slop isn't good.

Droop kits are better but just put your tires to far up inside the wheel wells at full compression. Can't use the extra stroke in that regard anyhow!

Just use the right sized shock for your height preference and tune the spring and oil weights to fit your driving style.

[DowntownScience]

Bump....

http://www.axialracing.com/blog_posts/3996

[Captainkickass]

You could always use limiting straps combined with longer shocks and regular length springs at a 50/50 droop or more/ less based on preference, to give a lower static ride height and keep tires from going too deep into the fender well because shock body bumps full compression. I use traxxas big bores with this setup and i get 58* incline angle, great sidehilling (proper spring selection crucial as well as COG) and have about a coke can of of articulation and roughly 3 inch of ground clearance. My only hinderance being non bent links in back for "scale reasons". Never have i used springs that dont fit shock throughout suspension cycle but if i did limit straps can help there too. Just my 2 cents


Sent from the clouds

[DowntownScience]

Originally Posted by Captainkickass

You could always use limiting straps combined with longer shocks and regular length springs at a 50/50 droop or more/ less based on preference, to give a lower static ride height and keep tires from going too deep into the fender well because shock body bumps full compression. I use traxxas big bores with this setup and i get 58* incline angle, great sidehilling (proper spring selection crucial as well as COG) and have about a coke can of of articulation and roughly 3 inch of ground clearance. My only hinderance being non bent links in back for "scale reasons". Never have i used springs that dont fit shock throughout suspension cycle but if i did limit straps can help there too. Just my 2 cents


Sent from the clouds

Never understood limiting straps either except for aesthetics.

If you use the proper shock length then limiting straps aren't needed.

If you're running a long shock with short springs and limiting strap then aren't you just running short shocks? What is the difference between that and running the same length shock that the strap is limiting you to?

[TacoCrawler]

Originally Posted by DowntownScience

How does your rig sidehill with such soft suspension?

...better then many
but it also has more to do with how much the tires deflect (flex/roll) and chassis COG.

Firmer tire foam inserts and proper chassis weight distribution...
are more pertinent to side hill maneuvering then solely the suspension set up.
A properly tuned suspension will respond by maintaining a level ride to the body within reason.
But one should realize that gravity is always the opposing enemy.

If one might assume that my body flops excessively to one side during side hill maneuvering... they'd be mistaken.
It doesn't... the springs are not that soft... and my shock oil viscosity/damping is not overly restrictive to their response time.
My springs are able to maintain a fairly level ride most always
and irregardless of what side hill angle I'm traversing (within reason).

But no matter... if the incline is more then what a tire's traction will allow...
gravity would find anyone on the losing end.

Originally Posted by DowntownScience

How about steep climbs?

...better then many.
but has more to do with chassis weight placement/distribution/COG.
Great tire traction helps alot... but chassis weight distribution is equally critical IMO.

Originally Posted by DowntownScience

Do you get any front tire lift?

yes of course... But not unless I punch the throttle in a sharp 90* turn.
But I haven't (as of yet) mirrored/rotated my trans. either.
doing so would eliminate passenger front tire lift.

Tire lift can be compensated some without altering the trans. position...
by slightly pre-loading the opposing rear suspension(shock).

Realize that I am crawling... not bashing.

Originally Posted by DowntownScience

Not a fan of droop.

...too bad that's your train of thought.
droop helps when doing a break over angle.
But still allows for and maintains a low COG.

Jacking the suspension up high may clear that break over easier...
but the suspension will be less then compliant traversing over other obstacles.

Originally Posted by DowntownScience

To my knowledge droop is achieved by running a shorter spring on a longer shock body or by running a properly tuned shock attached using a droop kit.

Short springs in longer bodies leave much to be desired when there isnt constant force against the spring retainers. Slop isn't good.

Droop kits are better but just put your tires to far up inside the wheel wells at full compression. Can't use the extra stroke in that regard anyhow!

Just use the right sized shock for your height preference and tune the spring and oil weights to fit your driving style.

I'm not subscribing to your methodology.

Maximum droop is pre-determined by drive shaft angle...
and the over-all length of the shocks dictate/control the amount of droop.

Compression is usually limited by body interference/contact.
But IMO raising the body to clear is fubar from the start.

Both the shocks upward travel or droop can be controlled by
installing spacers on the shock shaft (internally or externally)
Limiting straps are not needed and are there primarily for the look see.
And if they are used... it's likely the suspension is not set up as it should be.

[DowntownScience]

Not at all implying I'm an expert just sharing my experiences. Maybe I really don't understand droop at all. I definitely don't want slop in my shocks though

Can you explain more about what droop is to you, how you setup droop on your particular application and what a break over angle is?

[DowntownScience]

Ok...just looked for some more information on droop and I definitely wasn't understanding it properly.

I wasn't aware of the main concept which is to keep the shocks closed using internal springs which are under the piston.

That changes things a bit. Still wrapping head around concept.

So then do you need special shocks for this or can you use a traditional adjustable coil over with a thin spring in side?

[TacoCrawler]

Originally Posted by DowntownScience

Not at all implying I'm an expert just sharing my experiences. Maybe I really don't understand droop at all. I definitely don't want slop in my shocks though

Can you explain more about what droop is to you, how you setup droop on your particular application and what a break over angle is?

...droop is not something I conjured up
It is a proper terminology and equally understood in the 1:1 world as well.

Maximum droop is the capability of the suspension's full drop potential
while maintaining the necessary drive shaft angle, without causing bind to that.

The maximum allowable droop is pre-determined
by the factory's established drive line angle(s) (stock chassis geometry).
The mfgr does not push it's own specifications/limitations...
But many of us do or will.

Over-all shock length is what controls the amount of droop capability.
Once determined...
shocks that are too long would cause more droop then what is sustainable
and could cause premature wear issues or bind to the drive shaft's universals.

I have found that 100mm shock lengths are the longest that can
be utilized on a stock scx-10 chassis without causing drive shaft bind.

Shocks longer then 100mm would require that the upper shock mount be raised in compensation.

A "break over" is the action of going over a crown or crest (berm)...
and obtaining tire traction needed/wanted on the other side
to assist in pulling the rig over that.
Yes you'll drag yer belly skid some... part of the game.

Many folk with taller tires or higher sitting static chassis
do not fully understand the need because the underbelly of their rig
clears the break over crown.

But the higher COG (center of gravity)...
is not advantageous to a crawler that needs maintain a lower COG.
And an excessively stiff suspension is less compliant on other obstacles.

Not sure if I was able to bring an understanding to you...
but you can yell at me or call me names if I failed !? Lol

or ask me to clarify a specific that I may have missed.

[DowntownScience]

So do you just use the pen spring like I've been seeing in videos? Do you have a pen of choice?

Do you fill your shock with oil still? If so I'm guessing lighter is better so that the droop can happen easier?

Ultimately you need a spring that is soft enough to be overcome by the weight of the axle and tire right?

No name calling! I don't know everything there is to know about setting up a good crawler and am willing to learn and try something new! Have a set of shocks that I'd like to experiment with.

[TacoCrawler]

Originally Posted by DowntownScience

So do you just use the pen spring like I've been seeing in videos? Do you have a pen of choice?

Do you fill your shock with oil still? If so I'm guessing lighter is better so that the droop can happen easier?

Ultimately you need a spring that is soft enough to be overcome by the weight of the axle and tire right?

No name calling! I don't know everything there is to know about setting up a good crawler and am willing to learn and try something new! Have a set of shocks that I'd like to experiment with.

I honestly don't have the answer for the shocks you're using.
I've have always used/prefer adjustable coil-over type shocks.

I have never used internal spring shocks because tuning them
the way I like... is probably not attainable.

Knowing what alternative pen spring is utilized...
is beyond my experience/knowledge.

I don't even know what valving the pistons might have...
or if an alternative piston is even produced.

I have read that some don't even put oil in them...
well except for maybe a drop to coat the shaft's O-ring seal with.

I'm sure that others here whom have used those type of shocks...
could offer better advice/opinion regarding tuning them.

I'll bet it's been discussed here before...
so a search pertaining to your particular shocks may net a proper answer.

[Captainkickass]

Originally Posted by DowntownScience

Never understood limiting straps either except for aesthetics.

If you use the proper shock length then limiting straps aren't needed.

If you're running a long shock with short springs and limiting strap then aren't you just running short shocks? What is the difference between that and running the same length shock that the strap is limiting you to?

I agree if you use side by side limiting straps its mainly to limit flex to where shorter shocks would make more sense but that also depends on how they're installed and how long they are in relation to the shocks. But If you set up the limit the straps to only control up and down travel and to pivot on a central axis it allows for the flex and ride height tune ability at same time. i was just posting what works for me effectively and economically, while sustaining tunability. To each there own i suppose


Sent from the clouds

[DowntownScience]

http://www.rccaraction.com/blog/2011...al-with-droop/

[DowntownScience]

http://www.autotrends.org/2014/05/02...rock-crawling/

[DowntownScience]

Originally Posted by DowntownScience

How does your rig sidehill with such soft suspension?

How about steep climbs? Do you get any front tire lift?

Not a fan of droop.

To my knowledge droop is achieved by running a shorter spring on a longer shock body or by running a properly tuned shock attached using a droop kit.

Short springs in longer bodies leave much to be desired when there isnt constant force against the spring retainers. Slop isn't good.

Droop kits are better but just put your tires to far up inside the wheel wells at full compression. Can't use the extra stroke in that regard anyhow!

Just use the right sized shock for your height preference and tune the spring and oil weights to fit your driving style.

It's funny to read what you wrote sometimes! What a difference a day and some knowledge can make. I was very confused about droop and saw it very black and white.

Still not sure about full droop though!