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Many articles, videos, shops recommend drilling holes in the ICS Piston.
Enzo recommends it, among others.
My question is if drilling holes in the ICS piston or using an upgraded piston that is completely open, also without the upper o-ring changes the SSS speed sensitive circuit in any way?
Thanks in advance.
Has about 5-10 hrs on it all since new.
I can be reached @
Langhammx@sbcglobal.net
The Shop
Do the holes or having the piston have completely open sides like most of the aftermarket pistons com affect the speed sensitive circuit? I'm wondering why KYB doesn't sell the pistons with pre-drilled holes.
Honestly, I spent a lot of money upgrading my 2005 to SSS and I want to make sure that I'm getting the full advantage of SSS.
I'm wondering if one of the engineers from KYB would have the answer. There's a lot of confusion out there about this topic.
Thanks again!
Radical
This will only work on the newer SSS not the older they are to thick on the top..
Stock clamps work but you need a 0.4mm thick shim in the bottom clamp (Or X-trig from Technical Tutch)
For using Original Ktm wheele
Use 2000 wheel spacer that you grind down one of the lips and slot into the original wheel spacer
Original right side spacer needs to be shortened.
For break you got 3 Options
1.Drill a Extra bolt hole in original Brake adapter
2.Custom Brake adaper
3.Honda/Yamaha Front Brake
In stock form the solid free piston with both o rings seals the ICS chamber from the outer main spring chamber and that's where you run into problems with the plastic piston breaking under the pressure rise of the fork compressing the the air space. When you relieve that pressure by drilling holes in the piston you now have a situation where the outer spring chambers pressure rise is equalized into the ICS chamber area. With that, like the outer spring chamber, you will now have a bit more pressure backing the free piston as it compresses the ICS.
Technically, you will now have a bit more inner cartridge pressure as the ICS compresses, but that would be more of a "position sensitive" change since the pressure rise is related to how much the fork has compressed in the stroke. You would have to run the fork on a dyno to graph the changes, but I have never once heard anyone with the free piston mod say they felt it change the way their fork worked. In other words, it's not anything worth worrying about.
What about using a free piston where the sides are completely open, and without a upper o-ring?
I definitely noticed a difference, but there were other factors after the rebuild that could have caused the change.
My suspension guy recommended running less oil on a 125. He set it up with 300cc (and would've liked to go lower) rather than the stock 335 or the 350cc the forks came with.
While he was in there, he replaced a broken piston with one that has completely open sides, and no upper o-ring.
On the good piston he drilled the relief holes and removed the upper o-ring.
Before adding oil, the forks washed out easily and just felt soggy. It seems these forks really need the oil to perform.
When I brought the oil up to 325 they're way better, but not like they were before the free piston changes. It seems softer. I've added another 10cc, and will gift that a try. Hopefully what I'm experiencing is from simply not having enough oil.
I appreciate your and ML's advice.
Thanks!
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