And steering dampener No 2

griff851

This black one is for the 888 sp griffy. A lovely little Italian dampener made by some company called Active, it's from some time in 90's.
In case anybody has ever wondered what the cylindrical thing attached on the side of the main body is, it's a surge dampener. Basically an air cavity with a piston and a spring in it. rather than put ginormous load on the seal, the little piston moves.
If you ever pull one apart that cylinder assembly slides over the wasted end section of the main body. There are 2 o rings inside. There is a hole in the main body and a groove between the orings in the bit that slides over the body to allow oil and pressure to act on the little piston.

freqrider

Hi Griff,
I have one of those Active dampeners that has been leaking a little for some time now. Still dampens though? Is the rebuild/oring replacement pretty straight forward? Wonder what weight oil it uses? I have some 7wt laying around?

griff851

I got the seals made up out of viton, with a extra lip to prevent sucking air. Seals were $9 each. I used one of those CNC seal making companies. There is also 5 O-Rings. One on each end cap and 2 that sit inside the surge dampener bit that slides over the main body, and one for the surge dampener screw.
I'm using 3 wt push bike shock oil. I tried 7 weight but it seemed to heavy with the dampener off the bike. ( I've felt a few over the years playing in the bike shop)

freqrider

Thanks Griff, I guess I'll attempt to recondition it, at some point. Having rebuilt Showas, Marzocchi and Fox forks, on mc's and pedal bikes, I'm sure it can't be that complicated. I will try to source the seals out here in the states. There surely must be some off the shelf seals that would work?

griff851

Let me know if you can't and I'll get them made up for you. I used 2 SRBM -010019-035VM Seal size 10x19x3.2/3.5mm
The company here in Brisbane is https://sealteam.com.au/
Cost $19.80 incl tax
If you have a look at the web site you can see the profiles. I did try the red plastic stuff( forgot name), but there was way to much drag. I would suggest putting a ting Bevel on the shaft ends. I tried without the Bevel and the shape edge trashed the seal on installation.

freqrider

I went ahead and took it apart and gave it a good cleaning. Boy was it grungy! Refilled it with ATF, lol. At least it's red and will match my fairings when it leaks! I'm hoping the clean fluid will help the seals work better. I know... hopefull! 😉

Thanks for the encouragement. Wish I would have done it 10 yrs ago! Lol

griff851

I have one spare seal if you need it.

freqrider

It seems to be holding oil after a good cleaning. Went for a spirited ride Sunday and no weeping. Dry as a bone! I wonder if the ATF's slightly heavier weight has anything to so with it? I run it on softest setting, for the most part anyway. Thanks though! BTW, I noticed some bicycle suspension cartridges have the same type of seals in them. May have to go that route. Still researching.