7w oil to 5w oil, will it make a difference???

I was curious as to whether changing from 7w to 5w oil would significantly change the dampening of the shock. What would occur internally if the oils were switched? Would a thinner oil cause quicker rebound and compression, or even enough to make a difference? Would it reduce the life of the shock, or increase temperature inside?

For reference, I have Icon 2.5 CO.

 

A lower weight oil would cause for quicker rebound and softer compression, as the oil will move will less viscosity. This change would cause the shock to heat up quicker, as it is working harder potentially.
On trucks, I have not messed with enough variables to know if that change will be a noticeable impact.

 

Yep. This.

 

5wt is the most consistent, it you want better damping you need to change the valving. These fluids are made to operate at a temperature (cSt) and running a heavier oil will raise temps.

 

Ah okay. Why is 5w the most consistent? Would it be advisable to change the oil that is recommended for shock? I mean, if I switch from 7w to 5w, would it lower the lifespan of the shock since the oil would be heating up a lot more frequently than with than with 7w? I am not looking for better dampening, I was wondering if the change in oil would lead to a sightly softer ride due to decreased viscosity. And by softer, I mean more plush, I suppose, not exactly 'smoother' per say, since that would be dampening, no?

Would there be an increased chance that I would blow through my travel faster, or is it not that noticeable.

 

isn't quicker rebound desirable though, even for on road driving?

 

So running a higher weight ( vs a lower weight) would make shock temps higher?\If I understood your post correctly.

 

I think so, but there are limits.

Too slow of rebound will lead to packing of the suspension, and too high can make the end of the truck ride higher in the shock stroke than desired.
But too much rebound is only really an issue if you have bypass shocks I believe, where stroke zones are important.

 

yeah, I assume, logically, it would be the opposite

 

i see. Im thinking of placing 5w in just to see how it goes, but I hope it turns out alright, as I dont want to take it all apart after just to put 7w back in lmao. I hope someone who has done this or something similar can comment and enlighten me on this lol

 

This is where the water is muddy, Icon's/king/fox/ads etc all ride like shit and do not perform like oem Rubber mounted disposal shocks that you are use to, then boom heavy ass tires dont help the plush ride either.. you can mess with nitrogen pressure and also have a good suspension tuner re-valve for a softer ride. 7w oil is going to make it a more rough ride. 2.5wt will be softer if the CST rating is different. you hear 2.5w, 5w, 7wt, 10wt but different companies offer different weights that turn into the same viscosity rating at a temp. it takes a hydraulic fluid engineer to explain all this really.

 

My experience with motorcycle and mountain bikes is that different brands of the same weight will actually operate differently. One labeled 5wt will be like 2.5 in another brand. All that said, you may want to stick with a brand for consistency.
I like a lighter weight oil and quicker rebound on my bikes but it does allow more brake dive with the same settings. I don't know anything about trucks though.
Edit: didn't read the above post. He covered it

 

oh wow, interesting. Yeah I thought about a re-valve, but I assume that costs several hundred (I know its just shims but its also the knowledge you're paying for).

Realistically, my ride quality is not bad at all, in fact, its great, particularly at higher speeds. I was just looking to see if a lighter/thinner oil would change compression at lower speeds since it can flow more easily. Which would be nice for slower off road adventures.

It makes sense that they make oils of different viscosity that turns into the same rating at a certain temp (common chemical engineering trick).

 

that is annoying that its not consistent

 

You wouldn't believe how easy it is to rebuild/service these aftermarket shocks yourself. You can buy the shim kits and do it. most offroad shops that do service shocks will only charge you around $20 to fill it with nitrogen

 

No I know, I plan on rebuilding mine, and I’ve done it in the past. I don’t even need them to fill nitrogen. I was just saying that it’s probably expensive to get a new shim set. And I don’t think anyone makes shim sets for icon shocks either :/

 

Icon won't sell you them? Or less expensive kits than Icon you mean?

 

by the seat o yo pants

cheap beer drinking opinions

unless U have real sensitive butt cheeks .....................???

no U wont tell the difference

 

Other than icon. Other companies making shim sets for icon shocks. Sorry haha

 

Icon will sell you their shims direct if you email them. Their authorized distributors will also sell them to you. Just tell them what u have and what u what it to do and they will sell you compleat shim stacks for your shocks. It’s about 15 bucks per complete stack. so x2 for a pair and x 2 again for rebound and compressions = $60 pair or $120 for all 4 shocks complete rebound and compression stacks each.

You can also buy individual shims from them for like 15 cents each. Icon shims are just like any other shims with one difference that makes it hard to find substitutes. Their ID (inner diameter) of each Shim is 7/16” not 1/2” like everyone else shims. (I think some old school walker evan shocks were also 7/16”ID shims). I was just going to use my Fox shims I had laying around from years of rebuilding shocks but that would not work lol.
Also icons are digressive dampened shims stacks so keep that in mind . If you want less body roll or stiffer turnin make that first largest diameter shim thicker. If you want to control high speed dampening make the top smallest diameter shims thinker. If you want over all softness just replace all the shims with 0.012” thick ones. Icon 2.5”s come form factory with all 0.015” think shims.
It’s not hard to rebuild shocks with remote reservoirs (non remote resi shocks require a BS special tool
to recharge with nitrogen) , just watch a YouTube video and you are good to go.

I rebuild shocks so much and so often (for Mtn bikes , motorcycles, cars and off-road vehicles) I normally just run hydraulic fluid 7wt , “ISO 32 hydraulic fluid”. A 5 gal bucket is about 25 bucks. If I’m out of nitrogen gas at home I have recharged shocks with Welding gas (Ar CO2 mix) and regular shop air (which is 80% nitrogen anyways). Never had any issues with using the above methods in 15 years. If you think otherwise , I recommend you toss your internet PhD in the trash and actually work on something you no talent waste of space. JK , you guys are cool ...