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Get Plusher: drop IFP pressure, drop IFP volume, or drop main volume

Feb 13, 2002
1,087
17
Seattle, WA
I'm planning to fiddle around with my new monarch shock.

My usual strategy for suspension tuning is to leave compression wide open, rebound to taste, as soft as possible off the top without excessive bottoming -- simple.

On a DHX air I had in the past I got great results by just reducing the main chamber volume.

This time I am also considering other options to increase small bump sensitivity -- reducing IFP pressure and reducing IFP volume.

Anyone have experiences of what the practical differences are between these 3 options to increase small-bump sensitivity? I guess all 3 could improve plushness but have different side-effects?
 

kidwoo

Artisanal Tweet Curator
Just hit shit harder. Less oil on the garage floor.

Of those options, all I've done is cram spacers into a monarch, on a turner 5 spot, a norco range, and a new nomad because that is by far the easiest of the three and absolutely what you should try first. That was more bike attitude/pumpability based though, not small bump sensitivity. Which I guess you could say helps that if you stay higher in your travel and don't nomad to the end of it for every little ripple.

What bike is this?

Also, when you're online, your frog avatar has a green wart on his right eye. It's kinda freakin me out man.
 
Feb 13, 2002
1,087
17
Seattle, WA
The bike is a new Reign.

A bit more on my philosophy -- feel free to correct me if i'm talking crazy.

I know all the fast race bros run their suspension hard as balls -- what's the argument for balls-hard and linear? Am I really that slow, or is the whole thing a tough guy fashion show? In my experience running a progressive spring curve is a great compromise and there's no need to sacrifice too much cornering traction.

Another component of my soft off the top philosophy is that if you rely on the shock for cornering traction you can run your tires a bit harder and get less pinch flats.

Don't even get me started on compression damping.. dudes pay $$$ for low friction coatings like Kashima and then dial in 10 clicks of compression to add friction back in? Am I missing something? People of my religion believe anyone running 10 clicks of compression is on an incorrect spring rate, or is riding a dh bike in the skate park.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
A couple thoughts:

-Equating damping and friction isn't very accurate. Well implemented damping is speed sensitive. Coefficients of static friction (before anything starts moving) are always going to be higher than coefficients of sliding friction, so the effects of friction are going to be highest in trying to get the suspension moving initially and then drop off once it starts sliding. That's not what you want from a damper.

-Think about what suspension is meant to do- dissipate energy. Damping takes kinetic energy and turns it into heat. The spring stores energy (and then releases it on rebound). The faster you're going the more energy there is you need to deal with, hence the need for more damping and stiffer spring rates. Running more compression damping and riding a bit higher in the travel also means there's more energy dissipation capability left in the suspension, both because there's more travel left and because what travel there is is more heavily damped. Obviously this is a balancing act, rather than a MOAR = BETTERER situation but if you're running things set up soft up top, with a substantial ramp up to avoid bottoming out all over the place, you can very well end up with harsher suspension as you're just riding deeper in the travel and slamming into the spring ramp up all the time.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
Isn't IFP pressure tinkering just a proxy for spring tuning?
Sorta. But the spring effect of the IFP is generally more progressive than that of the main spring, so it does effect the overall shape of the spring curve some.
 
Feb 13, 2002
1,087
17
Seattle, WA
A couple thoughts:

-Equating damping and friction isn't very accurate. Well implemented damping is speed sensitive. Coefficients of static friction (before anything starts moving) are always going to be higher than coefficients of sliding friction, so the effects of friction are going to be highest in trying to get the suspension moving initially and then drop off once it starts sliding. That's not what you want from a damper.

-Think about what suspension is meant to do- dissipate energy. Damping takes kinetic energy and turns it into heat. The spring stores energy (and then releases it on rebound). The faster you're going the more energy there is you need to deal with, hence the need for more damping and stiffer spring rates. Running more compression damping and riding a bit higher in the travel also means there's more energy dissipation capability left in the suspension, both because there's more travel left and because what travel there is is more heavily damped. Obviously this is a balancing act, rather than a MOAR = BETTERER situation but if you're running things set up soft up top, with a substantial ramp up to avoid bottoming out all over the place, you can very well end up with harsher suspension as you're just riding deeper in the travel and slamming into the spring ramp up all the time.
Excellent points -- I wasn't considering static vs. sliding friction and I wasn't considering speed sensitive compression. Looks like my mental model needs updating.

I think consumers over-value 'pedaling platform'. Hence abominations like SPV and 5th element. Marketing materials always promise that you can have your DH bike pedal like an XC bike, but it never works out in real life. My experience is that dialing in some LSC to ride higher in the travel will still bork small-bump compliance -- it's impossible to completely separate HSC from LSC. All the more reason to have the spring rate soft off the top, so the inevitable small amount of HSC doesn't make your shock feel like a complete brick.

I've heard people claim that a shock with zero compression damping would be unridable. I still don't believe this is true -- I think it would be great for a fast course with lots of chundery off-camber turns.

I also still think tons of guys use compression damping when they should be playing with spring rate / ramp.

I'm looking forward to experimenting with this stuff on the new bike!
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
I've heard people claim that a shock with zero compression damping would be unridable. I still don't believe this is true -- I think it would be great for a fast course with lots of chundery off-camber turns.
That would very definitely suck.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
Same reasons stated above. You're going to blow through the travel if you hit anything at speed. I really don't think you're appreciating how much the damper is doing at higher shaft speeds.

I also think you're wrong to equate light damping with great traction. Plus, anything you hit mid corner is going to unsettle the bike badly if it's way underdamped, which is going to be counterproductive to your cornering.
 
Feb 13, 2002
1,087
17
Seattle, WA
Same reasons stated above. You're going to blow through the travel if you hit anything at speed. I really don't think you're appreciating how much the damper is doing at higher shaft speeds.

I also think you're wrong to equate light damping with great traction. Plus, anything you hit mid corner is going to unsettle the bike badly if it's way underdamped, which is going to be counterproductive to your cornering.
hmmm. I'm starting to see how you might want a small amount of compression damping to stop the wheel's upward momentum from blasting it past the point in the travel it really needs to go.

As I understand it, compression damping just applies force. The spring also applies force. But from a thread on mtbr I dug up:

a spring gives a force proportional to displacement (position), while damping gives a force (roughly) proportional to shaft velocity.
I guess that means all compression damping is biased towards high speed even if it says LSC on the knob?

That means that if you have a problem with blowing through travel and you solve it with compression damping your bike will end up relatively floppy under low-speed rider inputs like pumping and brake dive. That seems like the opposite of what you want.

Seems like it's still a better option to increase either the spring rate ramp, or the overall spring rate.

Thanks for taking the time to argue with me, btw. This is good stuff.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,580
2,006
Seattle
I guess that means all compression damping is biased towards high speed even if it says LSC on the knob?
Not really, no. It's of course impossible to 100% perfectly decouple HSC and LSC adjustments (nothing is 100% perfect in the real world), but it works pretty well. The damper is speed sensitive, the idea being that the LSC adjuster tweaks the lower shaft speed end of the curve, and the HSC adjuster tweaks the upper part of the curve. This really is how it works in practice.