Hi
@raschaa
What I finally did, and with the "parking test" works great, is this. (this weekend I will do a real test)
I put a coil spring inside the air chamber. The coil comes from an old marzocchi and it fits just perfect. The correct lenght. I covered it with termo retractile stuff so it doesnt make any noise and also protects the inside of the chamber. Also use a plastic top end.
At first, with this configuration, I still had to put like 40psi of air to compensate the negative spring (it is really strong). With this configuration I had coil feel the first 110mm of travel and then progresiveness just ramps up to infinite (pressure of air adds to spring resistance), being almost imposible to get more than 130 of travel and being too progresive at this point, so I had no sense of having a suspension fork.
I knew the problem was the excesive air I had to put to compensate the negative spring (if I put no air, the negative springs eats like 30mm of travel) and I didnt want the fork to be 130m (I use it a 160mm). So the solution (in my mind) was to eliminate this negative spring and leave the top out spring (so I took off the big spring). I was able to do it without breaking anything at all. And it is totally reversible.
Right now I have been able to get 150mm of travel (jumping from stairs that are no more than 1m high, I would say like 0,75m) and Have coil feel during all the travel up to 140mm where it gets progressive thanks to the small amount of air I put in the air chamber (around 10psi) and also the spring makes this chamber smaller. Now I can use air as a precharge and I can play with the compresions to leave the fork just the way I like.
So I guess I will be able to get full travel in case I need it and have a coil fork that works just they way I wanted to.
Obviously I was all the time in touch with a professional suspension specialist in order to not to do something crazy, I had too many ideas and he guide me through the whole process, actually being him the one who did some of the work.
Hope this small guide can help anyone else thinking on doind some crazy stuff to the fork.
PS: This would have been imposible for me to do it without reading you all, I dont speak german but google translate was a big help
that sounds like a pretty cool setup! let us know how it rides.
