Will shock dampening change when going from 7w to 5w oil?

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.

 

I'm not sure on your exact combination, but technically the answer is yes. Back when i was racing motorcycles we used slight changes in shock oils all the time to slightly adjust dampening curves. That being said I'm not sure if a 2w change on the truck shock will be at all noticeable even if it is technically different. I don't know of any differences in shock life if it's the same basic oil formula(seal compatibility). I would actually expect temps to be slightly lower with the lower viscosity since it would slip through the shim stack or orifices easier, but again maybe not practically enough to be noticeable.

 

right, fair fair.

 

in terms of percentages thats a large change

 

and so, what are you saying?

 

in theory you can expect a 21% reduction in viscosity

 

ah, and that will help with?
Will it smoothen out a ride at lower speeds? Will it cause signifiant temperature change?

 

What are you trying to accomplish?

 

Was hoping/thinking, that a thinner oil would be able to slip through falling faster enough to provide slightly more shock compression at lower speeds, making a large bump, or small bump, less jarring.

I was also curious as to whether or not a thinner oil (5w) would have less of a life span than thicker oil (7w).

 

Yes, but this will change both compression and rebound characteristics. Since you are opening the shock anyway it would be quite simple to just do a quick valve change to only effect compression damping. I dont see an issue with shock life, I say go for it.

 

Right, but isn’t quicker rebound better anyways?
I was thinking About messing with the valving, but I don’t really know how to go about doing it, ya know?

 

You should probably do some research on basic suspension theory

 

I just realized what I said doesn’t always apply and make sense. Quicker rebound is less controlled and you don’t want your rear end to shoot up, want to keep it planted.

 

You will barely notice. It will drop shock forces slightly across the board. Thinner oils tend to have a less drastic cold to hot viscosity change so less damping change with temperature but this is also oil specific. And it's damping.