work nice,was sold in three types of setup, soft medium hard...
what type of setup had your friend?

soft = for fun,bikepark....relax drive..
mid = dh race ready,..run to performance..
hard = only for expert..(World Cup level racers only)

the only flaw is that you can not do it yourself maintenance...
u can adjust only lsc/lsr....the valve stack of hsc/hsr is custom made by elka

www.pinkbike.com/news/ELKA-Stage-4-cartidge-initial-impressions-2010.html

 has a fairly progressive compression...

if u have an air kit (wc) u can adjust it finely

 Thanks a lot for that review. I hope it's a medium valved setup. I thought that you can change valving setup easly by yourself. Was it sold with 3 cartridges or you had to choose one ? Is it possible to refill the nitrogen in floating piston chamber at home or you have to send it to factory ? I mean, what kind of adaptor do you need to do that ?

Sorry for that amount of questions. I asked ELKA for some user's manual but they have not respond.

 1) the setup of each cartridge,pratically is made just customizing the valve stack...
2) you CANT hange valving setup by your self (!!!)
3) I think that elka have a custom adaptor to refill the nitrogen...that's because u cant service him by your self..
4) I've never done service it, I was thinking to do myself, but then I gave up ... to avoid doing damage
5) look that www.elkasuspension.com/elka-suspension-sells-its-bicycle-suspension-division-to-mrp


N.B. my weight is 90 kg,and i use a YELLOW spring (!!!)
This should make you realize how hard this kind of set-up