Shock Rebound

[Lowie]

some ideas here, I might as well pass them on.

I was looking for some left-over O-rings in my tool-tray and got an idea of using something else as a spacer.
I just took a silicone of plastic tube (might be a fuel-tube for gas-engined RC-cars) and cut of some pieces with a Stanley knife.
I made them of several lengths and wrote down the length in mm on them, using a permanent marker.





I then cut them over the length.



It's now very easy to snap them on the shaft and use as a spacer ...





and then using the same spacer for the next shock, to obtain equal rebound amounts.

Now, it's at this point that I noticed that I did something wrong when previously building my shocks. ... well, wrong in my book.
I assembled them, as described in the manual and placed the bladder when the piston was fully extended.
With the piston fully extended, it became clear to me that the volume of my shocks when I make them the way I did, had to be under presure, and even getting a higher presure when mounted into the car and when driving. Also this must certainly have an effect on the performance or efficiency of the shock-springs as the higher shock-oil-pressure must react as a spring itself.
I noticed, when trying to obtain 50% rebound, that I had to almost fully push the piston in before putting on the bladder... and it's then that I recalled that my mates had told me before, this was a better way of mounting them.
So I was trying with my spacer, nr4 (see photo 2) and still got full rebound, spacer nr 3: full rebound ... and I realised the nr2 had to be OK ... or as is described higher on: the thickness of a simple O-ring

[lynx75]

Hi Thard,

Could you post some pics about rebound setting, please?

Following your rebound setting explained in July 2008 concernig the use of O-Ring, it's very useful following these steps through pictures.

What do you think, please?

Regards

[TryHard]

I'll try and get some this weekend, but if you have a look at Lowie's pic's above, they give the idea on how it is set (push the shaft in until touching the spacer, then screw the cap on).

HiH
Ed

[lynx75]

Hi Thard,
thank you so much. After I pushed the shaft until touched the spacer and then screw the cap on, Do I need to filled shock woth oil, doesn't it?

Apologize for stupid question, maybe

Regards,
Lynx

[Lowie]

i'm sorry, Lynx, but I don't understand your english.
It seems that you ask if you have to fill teh shock with oil after closing it, which is impossible.

What you have to do is this:
open the shocks (unscrew the cap and remove the bladder)
extend the shockshaft (make the shock as long as possible).
fill the shock with oil until like 2 mm from the top of the shock-body.
push the shaft half way in, leave it like that for a couple of minutes and then extend the shaft again, so that any possible bubbles might seep through the piston-holes.
Leave the shocks for about 10 minutes or even longer so that all possible airbubbles have come out
(or use a device that uses vacuum to get the bubbles out, like this:)


Now, here is the trick I described higher: add the "washer" to the shaft. I used a piece of green silicone tubing as you can see on the pictures.
Make that washer like 2mm thick as a starting point.

Then push up the shaft, very gently so that the piston doesn't sucks up new air-bubbles, until the washer touches the shockbody ... and the shaft can not be pushed in more.
There might seep some oil over the edge of the shockbody. That's ok and can be cleaned later.
Tilt the shock a tiny bit. Gently put the bladder on the shockbody, starting on the lowest side of the shockbody (as you tilted it a bit).
The bladder will push out some more oil, that's ok. Just take care that there are no airbubbles traped under the bladder.
That is also why I tilt the shock slightly. Airbubbles are pushed out, on the highest side of the shock.
Now screw on the cap.
As you do this the shockshaft will extend again, but that's ok .. unless it extends to the maximum lenght again. This should mean there is too much oil in the shock. If the shock extends like 100mm, that would be ok.

Done. Just clean up the oil you messed.

I hope this explains things a bit.

[lynx75]

Hello Lowie,
apologize for my English , now I understand the correct way to set the shock rebound.

Thank to you and Thard .

My brand new TRF416 WE is coming, I'll let you know.

Stay tuned.

Lynx

[Lowie]

glad that I could help