A number of members here have commented that this thread has the opportunity to open up an interesting dialog, what I believe would be suspension components and their independent roles and how they work together, as well as suspension set-up. I think there is some confusion in what each component does, for example springs are not a compression dampening adjustment and likewise a shock is not for ride height / sag adjustment. I think having a better understanding of what each component does allows everyone to have a discussion on how adjusts work.
for example one of the first things any suspension manufacture recommend is the importance of setting ride height or sag with the machine fully loaded. sag is very important for absorbing terrain features and reducing damage to the vehicle and person. if during this process one finds they can not achieve proper sag/ride height one would need to increase spring rate (change springs). springs do a couple of things they set the ride height, they return the vehicle back to that proper height. if one finds they require heavier springs one would then need to think about how this affects compression dampening (increasing the effect but not the dampening) and rebound (decreasing the effect but not the dampening) which would typically require shock adjustments to the dampening. Doo dampens their set-ups very lightly and as such any increase in spring rate will feel like an increase in compression damping or resisting bottoming out and on the other end rebound will feel like it's been decreased pogo stick effect. If one really wants to fix bottoming out compression dampening is required and this is weight related, the heavier one is the more dampening is required, to think that a shock set-up with fixed compression damping would work for me (5'7" 140 lbs) would also work for anyone 6'4" 260lbs is misleading. Rebound damping is not quite as critical but also requires attention to function properly, it plays an important role in insuring the suspension returns to proper ride height/sag quickly enough for the next hit however too quickly and it'll pogo stick on you and too slowly and the suspension will not recover for the next hit and eventually one could pound the suspension flat due to continuous compression impacts.
now I'm no expert, guys Like Andy at GSR, or Kevin from Kmod would be ideal to get into the conversation....I know there are lots great people with great information out there to share so please join in.
Nice comment! I dig it.
Few thoughts...
1) I do agree sag is very important for a number of reasons. I would really like to post a video of a trophy truck through gnarly terrain but will abstain
I know, mountain sled riding is not the same thing as rallying a truck through the desert, but there are plenty of excellent skids out there that run a fair amount of sag and still control transfer very well. For a variety of reasons, running some sag is going to be a good thing (front and back).
Part of me wants to get into the idea of transfer, instant center and antisquat, but I'll leave a lot of that alone for now.
2) Yes, the system has to work in harmony. One of the best videos out there is that Skinz Shock Therapy video. One can learn a LOT from this.
3) The way you are explaining damping isn't quiet right. Damping is speed sensitive control over the shock package. Some damping is also position sensitive. This means when the shock cycles, it is able to control the speed at which the shaft is compressing (or rebounding). In certain cases damping can change depending on the position of the shaft.
Yes, damping can help control bottom out, but so can your spring rate.
As far as needing a revalve for heavier springs or heavier riders, no argument. However, in practice its not always true. Depends how much one is bumping up in spring rate (and to some degree, what their preference is and if the - most importantly - the rebound damping is suitable/matches the other dampers)
To add, for those that jump, rebound damping is incredibly crucial, especially if one part of the sled is rebounding at a different rate than another (say the front is slower than the back...good way auger in that front end!)
The really trick part is a lot of this kind of goes out the window with respect to mountain riding. Or rather, it doesn't but your suspension's ability to track the smallest bump while still maintaining its composure while sending a huge double isn't quiet as important as say, Snowcross.
What we are really looking for is a sled that can control weight transfer well, EG: Keep the skis down, unless the rider wants to be able to lift them for one reason or another (there are plenty of reasons)
So having a way to control AND adjust this transfer is crucial. There are a number of variables in play, including how your FTS is sprung, how much preload you are running here (or sag), how your rear track shock is sprung, damping, the shape of the front/rear arm etc etc. As many have pointed out, lots of ways to skin the cat.
Obviously, suspension up front has a lot going on too that'll impact not just the way the sled rolls over (or doesn't roll over) but how the sled transfers weight. (more sag vs less sag)
So yeah, it gets complicated, but its also really cool, as you can have a pretty dynamic machine.
Finally, like most things in the sled world, taste impacts this immensely. Funny thing is, "feels good" is often not what we are after when it comes to control and best setup for a certain condition.
The point of suspension has less to do with comfort and more to do with control. To me anyway...
...yeah that got long.
