GHEA pistons (which way up!)

[Bigbaddave]

This is probably a daft question but just got some GHEA pistons for my B44.1, which way do they go in tappered side up or down?

[Belsten]

tapered side down

[reflexuk]

Originally Posted by Belsten

tapered side down

Why?

[Wraggy]

Originally Posted by reflexuk

Why?

faster return

[Rebelrc]

Either way...

[reflexuk]

If I understand it right the spring absorbs the bump and it is the job of a damper to control the return. If a faster return was better then surely no damper would be 'best'.

I too understood (and read somewhere) that it doesn't matter which way up they go.

[grelland]

then you understand it wrong...

The damper works in both directions and its task is to dampen the movement/oscillations you would get if you had only a spring.

The Ghea piston is designed so that you have a slightly different damping rate in each direction.

[Rebelrc]

You also understand it wrong grelland
Cause they cannot return faster cause that's impossible! They are linear in or out
Cheers

[Dazzler]

This has been done to death previously, and the man himself (ghea) confirms from testing that rebel is correct..

http://www.oople.com/forums/showthre...830#post465830

[Rebelrc]

Cheers Dazzler

[Rebelrc]

Don't get me wrong, they defo make a difference but just not in the way people are stateing
Not sure what it is though! Lol

[moth898]

The taper is down to keep the piston from hydro-locking against the shock body when fully extended . By hydro-locking I mean temporaraly stuck to shock bottom. The taper leaves a little oil between the piston and shock. It makes for a smoother ride.

[Rebelrc]

Moth you are wrong ! Read the link above cheers
That already been suggested

[reflexuk]

Hehe, this has been fascinating.


So, that cleared up, what would be wrong with a shocker that had 'no' damping in upward wheel travel and only damped on downward travel? An extending spring with no damping would cause a chassis to bounce after a bump so there is clearly a case for damping in that direction but why damp the other way? Surely a wheel can move more fully up a bump with less damping, no?
For the purposes of an answer let's remove cornering from the equation.

[Rebelrc]

The only reliable way of getting two stage damping on a 1/10th is to valve the piston like Richard weatherley did with the pred years ago.
I have problem with Ghea and their excellent products and yes machined (not moulded) pistons are a great idea in my opinion and do make a difference in a good way. And their service and information is great
Would be nice to see people trying the valve method as it defo makes for a quicker return with pack as desired

[reflexuk]

So, is that the universal desire then, more damping piston going in than going out?

[moth898]

Originally Posted by Rebelrc

Moth you are wrong ! Read the link above cheers
That already been suggested

Thank god for you being right

[Rebelrc]

Thank god I was right about some thing once! And I am not letting go of it. Lol cheers

[smokes]

can we get a graph of tapered vs non tapered dyno test to see why they work?

[grelland]

Originally Posted by Rebelrc

You also understand it wrong grelland
Cause they cannot return faster cause that's impossible! They are linear in or out
Cheers

I stand corrected

At least I was right when I said the previous poster was wrong