This week on the Tuesday Tune we're going back to basics to look at some of the less obvious and less commonly discussed aspects of sag setup.
We aren't here to tell you what the "right" amount of sag is - no single number is correct, and what works best will vary according to the frame/fork/shock/rider/ability/terrain variables. For this reason, discussing specifics needs to be done in context; 15-percent sag on your Pike is fine, but that's extremely stiff on the back end of your downhill bike, for example. This video is aimed at those who already have a basic grasp of sag, so we aren't going to show you how to measure it, but if you want to learn more about that, DVO have a
short and helpful guide to sort you out.
What we are looking at, however, is what the relevance of sag is, why it's useful as a transferable and comparative value even between different riders on different bikes, and how to make sure your measurements are consistent. We'll also go over what the practical limitations of sag are, both in terms of measurement and relevance to performance. Although it's far from being the be-all and end-all of proper spring rate setup, sag is very useful as a starting point and a baseline indicator of spring rate relative to body weight.
MENTIONS: @VorsprungSuspension
I'm curious if you can deconstruct their motivation behind this: Why do they feel a RC rider needs a firmer tune than a RCT3 rider?
In the RC they don't have that adjuster (cost) and then felt the need to increase the comp Shimstack to ultrastiff (via thicker shims (0,15 ->0,2) and huge amounts of preload in the stack (RCT3 stack is preloaded as well)), to achieve enough LS compression with the needle fully in / lockout function (as Steve said a week ago, your max amount of LS compression is limited by the amount of HS compression.
This results in a too stiff HS damping and is a common problem. The massive preload in the stack does not make it better.
But ultimately the RC is the better damper with more potential, because it does not employ an adjuster, that might compromise oil flow. One suggestion would be to get rid of the preload in the stack (ring shim plus 16mm centering shim) and adjust the amount and thickness of the remaining shims to your likings in HS compression. Good starting point would be to put the 16mm centering shim at the end of the stack after removing it from its original position after the face shim. But depending on rider weight and aggresiveness you have to find your own setup in the end. Hope that helps, good luck.
But that's minutiae. Overall, I think you're on to the right track. When you talk about removing the ring shim & the 16mm centering shim, are you saying because of the preload, you can just leave them out of the stack & things will still tighten down, or are you saying to move them to the end of the stack?
Also, anybody got a line on where to buy shims? I'm not finding a lot of good sources online. Currently, I'm leaning towards just replicating the stack in the RCT3, & I'll need to buy some stuff to do that.
But you can try the RCT3 stack and then compare it to a firmer stack but without preload and see which one works better for you. On a stack without preload you might need to run the LS adjuster a lot closer to fully closed, which is not a bad thing imo. In the end it is absolutely worth it to try and find a good compromise between a nice and supportive LS damping and a supple enough HS damping. But from what I hear the tuning pistons (Fast, mst, novy,...) make things even better compared to what you can achieve with stock parts. Especially in the compression curcuit. So, let's fiddle around with dampers, it's fun. A good, educated guess up front helps of course.
Now that I know what the problem actually is, I know where to focus my efforts.
youtu.be/FF3R0KG-yzA?t=114
The reason I mentioned that concept was simply to illustrate why it is that we can't just run super low sag and expect it to be usable, as well as how it is that softer setups result in lower forces required to bottom out and what the relevance is to bodily strength.
Thank god for bottom-out tokens these days. Even 5 years ago it was hard to find off the shelf trail bikes that ramped up enough for aggressive riders without bottoming harshly resulting in lots of broken gear.
i'm at a similar weight with the 2014/5.5NM spring and took me forever to set up properly , still if i change from a smooth trail with jumps to a more steep natural track i feel a few adjustment are necessary.
i run roughly 3 turns of pre-load , LSC 10 clicks from fully closed , HSC 14 from fully closed , LSR to your liking -- I run about 15 from fully closed , HSR - basicially in the middle ( i think about 10 clicks from fully open)
*** by "closed" i mean - slowest rebound // firmest compression
for steeper natural terrain - i go to faster HSR and firmer LSC - to avoid dive while braking
compared to the boxxer i was running previously - the marz. are running quite deep in their travel . . .
Be aware that all Marzocchi springs are on the soft side. Their firmest spring sits between the Medium and Firm spring that Fox offer. Running an overly soft spring pushes you towards either highly progressive setups or running a lot of compression damping, both of which are easy to overdo, so I recommend running a stiffer spring than Marzocchi themselves recommend.
According to @VorsprungSuspension it will be the appropriate spring for my weight. So it sounds like I will need to reduce the amount of pre-load and work with the compression more. So far I like the fork even though I don't have it completely set up right. Hopefully soon it will actually be set up right. haha. Thanks again guys for all your help!
Thanks!