Gmade RSD Suspension?

[gbean]

I swung by RPP yesterday and snagged a couple pair of the 90mm piggybacks.

Will build tonight and report back.

[redemon]

My non reservoir 90mm's came in last night.
What weight oil comes with them? I have some 30wt from the kits I have built, that prolly wont be enough will it?

[Rjohn929]

I have some 90mm piggy backs on my SCX cherokee. It's not a II but I like them. They seem to hold oil well and are very smooth. I'm only running 20wt with 3 hole pistons as its not fast at all and I want it to absorb as much as possible to look more "scale" when running. So far so good.

[monster 550]

Mine were scheduled for tomorrow, but are here at the post office so should get them today. Hopefully they're waiting for me when I get off work. I might try 55wt til the spring kits are in stock.

[redemon]

Junfac's site has the springs in stock.
Can get soft medium and hard

[JatoTheRipper]

Originally Posted by redemon

My non reservoir 90mm's came in last night.
What weight oil comes with them? I have some 30wt from the kits I have built, that prolly wont be enough will it?

30 - 40 weight is often a good start.

[Big Daddy]

What is everyone using for the top mount bushing?

[andrewd]

Originally Posted by Dbx

The piggyback adjustment will allow for tweaking spring rate progression near the end of the stroke, but is't going to do anything for the damping force.

Are you sure about that? By adjusting the piggy back volume, you are changing the pressure of the damping oil in the shock chamber, which should effectively give the same result as changing the weight of the damping oil.

[MUF DVR]

Originally Posted by Big Daddy

What is everyone using for the top mount bushing?

I wonder if the DLUX BB standoffs will work? I love those things.

[Dbx]

Originally Posted by andrewd

Are you sure about that? By adjusting the piggy back volume, you are changing the pressure of the damping oil in the shock chamber, which should effectively give the same result as changing the weight of the damping oil.

Pretty sure. The pressure on the oil won't change it's viscosity, so cannot change it's damping effect. Adjusting the piggy back screw will apply more pressure resisting the damper rod being pressed in, hence increasing the overall spring rate.

[monster 550]

Originally Posted by Big Daddy

What is everyone using for the top mount bushing?

Just got home from work and got my shocks. I just happen to have 4 of the aluminum top mount bushings from a sawback that match the plastic ones that came with the shocks so that's what I'm gonna try.

[monster 550]

Originally Posted by Dbx

Pretty sure. The pressure on the oil won't change it's viscosity, so cannot change it's damping effect. Adjusting the piggy back screw will apply more pressure resisting the damper rod being pressed in, hence increasing the overall spring rate.

I think you're correct here. I just built 2 off my shocks with the 3 hole pistons and 35wt oil. I bench tested them side by side in my hands with one screw all the way in and one out. I even switched hands til feel the difference. Dampening felt pretty similar, but the one with the screw all the way in felt like it had a harder spring rate. I'm gonna try 55wt in the other 2.

[Odd-M]

I'd rather have a dummy piggyback than this useless system with inversely proporsional compression to rebound dampening ratio.

Those regular RSD's looks very interesting though.

[redemon]

The springs on the normal RSD's are insane stiff.

[monster 550]

Originally Posted by Odd-M

I'd rather have a dummy piggyback than this useless system with inversely proporsional compression to rebound dampening ratio.

Those regular RSD's looks very interesting though.

I wouldn't say useless. Maybe with the stock stiff springs, but with softer springs I think they'll work great to fine tune.

[andrewd]

Originally Posted by Dbx

Pretty sure. The pressure on the oil won't change it's viscosity, so cannot change it's damping effect. Adjusting the piggy back screw will apply more pressure resisting the damper rod being pressed in, hence increasing the overall spring rate.

Ok fair enough. I am tring to extrapolate my understanding of how motorbike damping adjusters work. These seem to adjust the pressure of piggy back or external chambers. However I guess the design is more complex than what can be achieved in a 1/10 scale shock.

[andrewd]

Originally Posted by monster 550

I wouldn't say useless. Maybe with the stock stiff springs, but with softer springs I think they'll work great to fine tune.

Can anyone confirm if the RSD piggybacks come with the stiffest (red) springs as standard? If I order some I will probably order a set of mediums (white) and softs(green) at the same time to allow future tuning options.

[monster 550]

Put my second pair together with 55wt and the 3 hole pistons. This feels much better to me for the rear end on my truck. While setting everything up to build them I glanced over and noticed my rc4wd rock krawler shocks on my mud truck and had a thought... ...After building the rsd's I pulled a spring off my rk's and it fit the rsd's bodies, collars, and cups. Next I searched my spare parts for a stock cup and the rk springs fit them too. Point there is that the beef tips for scx shocks will work. I searched for spring sets and the 110mm rk springs are 44mm long and since they're a dual spring setup you'll only need one set. Here is a side by side of my rsd's with the stock springs and rc4wd springs from 90mm rk's.
Sorry for the long write up, but this might help others...
[IMG][/IMG]

[monster 550]

Hopefully I can get it out tomorrow for a decent test, but I can tell on the bench the springs are too stiff. Also I'm almost wishing I would've went with the 80mm's. I don't have stock shocks anymore, but these 90's are taller. I'm running scx10 limiting straps and depressed the shocks a little otherwise it would sit higher.
[IMG][/IMG]

[triggerhapy]

Too bad those shocks aren't threaded further so you can back the preload off more. That has always been a turn off for me regarding these shocks.