Shock Rebound

[MatJohnson]

Whilst racing last night I noticed that as my car came off the jump it hit the ground and bounced back up (rebounded off the ground).

Now, I would say that this is due to the damping not being too effective, as in the shock packs up too quick or doesn't 'hold' the piston enough. So, am I correct in thinking I need to go for a more viscouse shock oil in the rear and a bigger piston hole? or have I got the wrong end of this and its not damping?

Car is a 2wd on a grass/astro/concrete track, its an old double x I just want to know if my theory is correct.

[bigred5765]

if its hitting the ground sounds like it slightly under damped,

[MatJohnson]

So I would be right to go for thicker oil and bigger holes?

[Lee]

You have described 2 things there, you have said that the car is hitting the ground but also about the shock packing up, if the shock is packing then the chassis is unlikely to be hitting the ground.

You should be able to tell the difference.

Depending on what is happening and what you are already running determines what you have to do next ;)

If the shock is packing then go to a bigger hole, viscosity has nothing to do with pack, if it was 10wt in there or 100wt it would still pack the same as it is about getting volume through the holes.

If it is slapping down then thicken it up until it feels right, you should know when your getting close ;)

[MatJohnson]

Cheers Lee. I think I'm trying to change too much at once really, I will give the oil a tweak and check that out before changing the pistons.

[Nick Goodall]

Losi XX - All you needed to ever run in that car was 30wt 556 Pistons (Red piston with two holes drilled to Orange) in the rear and 35wt 556 in the front.

Pink rear springs and either blue or green front were ideal - That should still work :-)

[Chris Doughty]

strangely enough, running the car 'high' will actually make the car double bounce more, your springs will have more pre-load on them.

ride height has nothing to do with landing a jump, your shocks will extend to full droop in the air no matter what your static ride height

[MatJohnson]

Losi XX - All you needed to ever run in that car was 30wt 556 Pistons (Red piston with two holes drilled to Orange) in the rear and 35wt 556 in the front.

Pink rear springs and either blue or green front were ideal - That should still work :-)

Ace, I don't want to go down the drilling route just yet, I would like to try and get a feel for what changing current bits are before doing that method but its good to have a backup :)

I've always wanted to know how people just knew to change bits and this time around am just changing them to see what happens and then work out why really so I might end up putting a few more threads up like this one.