ReX
TY 4 Stroke God
Here is the multi-stage valve stack I am using on my main shock:
16x210 Spacer (to make sure the nut doesn't bottom on threads)
16x110 Spacer
26x150 End of first rebound stage
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 First rebound stage
2 slit piston bypass ports
30x200 First compression stage
30x200 End of first compression stage
18x150 Space before second compression stage kicks in .
30x200 Second compression stage
30x250 .
30x250 .
30x250 .
26x150 End of second compression stage
18x110 Space before third compression stage kicks in
16x110 Space before third compression stage kicks in
Hard stop (large thick washer)
As you can see my first stage is only 2x 0.200 mm thick valves, when stock the first stage was an incredible 12x 0.200 mm thick valves. Just imagine how much smoother my sled rides over small bumps. My second stage, with 0.150 mm open already, ends up being softer than the stock 1st stage also. My 3rd stage is fairly aggressive for this sled and it is very difficult to bottom out. If you want a little softer final stage, you could use a 16x150 3rd stage spacer instead of the 16x110. Of course my center shock is definitely contributing to the damping also, but the main shock does more of the work on big bumps.
FYI, Mike Carver's center shock setup has a soft 1st and 2nd stage compared to stock combined with a fairly aggressive 3rd stage too. It works well.
Yesterday I rode a stretch of trail with 1-2 foot moguls for about 2 miles. It bottomed out twice when I totally missed some of the bigger doubles (jumping from one mogul and hitting the up-slope on another) and when I put my hands on the shocks to see how hot they were, both were comfortably warm and free of snow (I had been riding hard on rough trails before that very rough stretch for about 2 hours). Stock, the non-functional center shock was always covered in snow and ice and the sled would have been bottoming and kicking and bucking everywhere on that trail. Stock I would not have been able to travel that trail at that speed and stay in control. BTW, the stability problem, stock, is due to enadequate rebound damping on the center shock (making the sled kick and buck off bigger bumps). This is also why we keep breaking limiter straps (and don't after the center shock is revalved).
One thing I did not do was create a second stage on rebound. On this shock I actually went back to the stock rebound stack. Note that compared to the REV-XP, it has a 2-slit piston and this does provide something of a softer 1st stage in rebound, but not as much as the REV-XP. If I ride my sled and a REV-XP X back to back, I can feel a little rebound harshness over very small bumps (just after going over something like a 1" ripple in the trail). I was tempted to try a 2nd rebound stage, except, there is a portion of shock/suspension travel, right when the sled bottoms out, where the shock velocity drops right down on these sleds. A soft first rebound stage will quite possibly create kickback. The REV-XP on the other hand has more linear shock velocity WRT suspension travel (BTW, the FX Nytro has VERY nice shock velocities - virtually the same as the REV-XP). Based on this, I recommend a single stage rebound stack for the main shock.
Still, compared to stock, the ride is absolutely incredible - everywhere from small bumps to huge bumps and jumps. It is also very comparable to a REV-XP MXZ X now also (the softer seat on the RTX is the final touch to bring it in-line).
For the center shock, you'll need to go to Mike Carver if you want the same setup as me (he can probably improve on it further too - now that he'll know where I went on the main). A second rebound stage could probably be added to the center, but it is the compression stack that is critical and it also might be more important to match the main shock for the best ride quality.
Finally, as you all know these custom valve stacks are typically fine tuned for the rider. If you are an extremely aggressive rider (I am fairly aggressive) or are heavier than me (I weigh 208 lbs), you might want to stiffen up the various stages. If you are a little less aggressive or lighter, you might want to soften everything up a little more, including the 3rd stage. The reason you might prefer a softer 3rd stage is once the bumps get into the 6-8" range and you are travelling at speed, the 3rd stage starts to kick in with my setup (and I can feel it - it really kicks in...). I don't think it is harsher than stock until the bumps get to at least 7-8" and when the moguls get really big, 1-1.5 feet, it starts to make use of all of the suspension travel on every bump (when riding at the worst speed for hitting the bumps; if you are brave enough to speed up to skipping speeds over 1-1.5 foot moguls it doesn't bottom out). The other place where my setup uses close to the full travel is through a big valley where the suspension is compressed for a long time and the softer 1st and 2nd stage let it compress a lot. I haven't bottomed it through a valley yet, but it feels like it can get close.
16x210 Spacer (to make sure the nut doesn't bottom on threads)
16x110 Spacer
26x150 End of first rebound stage
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 .
26x150 First rebound stage
2 slit piston bypass ports
30x200 First compression stage
30x200 End of first compression stage
18x150 Space before second compression stage kicks in .
30x200 Second compression stage
30x250 .
30x250 .
30x250 .
26x150 End of second compression stage
18x110 Space before third compression stage kicks in
16x110 Space before third compression stage kicks in
Hard stop (large thick washer)
As you can see my first stage is only 2x 0.200 mm thick valves, when stock the first stage was an incredible 12x 0.200 mm thick valves. Just imagine how much smoother my sled rides over small bumps. My second stage, with 0.150 mm open already, ends up being softer than the stock 1st stage also. My 3rd stage is fairly aggressive for this sled and it is very difficult to bottom out. If you want a little softer final stage, you could use a 16x150 3rd stage spacer instead of the 16x110. Of course my center shock is definitely contributing to the damping also, but the main shock does more of the work on big bumps.
FYI, Mike Carver's center shock setup has a soft 1st and 2nd stage compared to stock combined with a fairly aggressive 3rd stage too. It works well.
Yesterday I rode a stretch of trail with 1-2 foot moguls for about 2 miles. It bottomed out twice when I totally missed some of the bigger doubles (jumping from one mogul and hitting the up-slope on another) and when I put my hands on the shocks to see how hot they were, both were comfortably warm and free of snow (I had been riding hard on rough trails before that very rough stretch for about 2 hours). Stock, the non-functional center shock was always covered in snow and ice and the sled would have been bottoming and kicking and bucking everywhere on that trail. Stock I would not have been able to travel that trail at that speed and stay in control. BTW, the stability problem, stock, is due to enadequate rebound damping on the center shock (making the sled kick and buck off bigger bumps). This is also why we keep breaking limiter straps (and don't after the center shock is revalved).
One thing I did not do was create a second stage on rebound. On this shock I actually went back to the stock rebound stack. Note that compared to the REV-XP, it has a 2-slit piston and this does provide something of a softer 1st stage in rebound, but not as much as the REV-XP. If I ride my sled and a REV-XP X back to back, I can feel a little rebound harshness over very small bumps (just after going over something like a 1" ripple in the trail). I was tempted to try a 2nd rebound stage, except, there is a portion of shock/suspension travel, right when the sled bottoms out, where the shock velocity drops right down on these sleds. A soft first rebound stage will quite possibly create kickback. The REV-XP on the other hand has more linear shock velocity WRT suspension travel (BTW, the FX Nytro has VERY nice shock velocities - virtually the same as the REV-XP). Based on this, I recommend a single stage rebound stack for the main shock.
Still, compared to stock, the ride is absolutely incredible - everywhere from small bumps to huge bumps and jumps. It is also very comparable to a REV-XP MXZ X now also (the softer seat on the RTX is the final touch to bring it in-line).
For the center shock, you'll need to go to Mike Carver if you want the same setup as me (he can probably improve on it further too - now that he'll know where I went on the main). A second rebound stage could probably be added to the center, but it is the compression stack that is critical and it also might be more important to match the main shock for the best ride quality.
Finally, as you all know these custom valve stacks are typically fine tuned for the rider. If you are an extremely aggressive rider (I am fairly aggressive) or are heavier than me (I weigh 208 lbs), you might want to stiffen up the various stages. If you are a little less aggressive or lighter, you might want to soften everything up a little more, including the 3rd stage. The reason you might prefer a softer 3rd stage is once the bumps get into the 6-8" range and you are travelling at speed, the 3rd stage starts to kick in with my setup (and I can feel it - it really kicks in...). I don't think it is harsher than stock until the bumps get to at least 7-8" and when the moguls get really big, 1-1.5 feet, it starts to make use of all of the suspension travel on every bump (when riding at the worst speed for hitting the bumps; if you are brave enough to speed up to skipping speeds over 1-1.5 foot moguls it doesn't bottom out). The other place where my setup uses close to the full travel is through a big valley where the suspension is compressed for a long time and the softer 1st and 2nd stage let it compress a lot. I haven't bottomed it through a valley yet, but it feels like it can get close.
