[db3266]

is this really how you set rebound? (you can skip to about 5m30s to get to the meat of it)

 

[tbmaddux]

It worked for me on the Fox Float Evol DPS shock on my Santa Cruz 5010 v2. I found the maximum damping value and then backed off one click. That number of clicks matched the middle of the recommendations from Fox for the air pressure I set based on what Santa Cruz recommended at my sag.

 

[db3266]

yeah, just found this, which suggests leaving settings at critical damping is a bad thing to do resulting in packing, so backing off 1 or 2 clicks would get better results

 

[One Pivot]

In short, no that's not how you set damping.

A port orifice damper is set differently than a normal shimmed damper, which is also set differently than a highly preloaded damper, and on top of all that there is a considerable window to adjust all of them according to your trails, or just preference.

This video comes up occasionally, but it's really not useful.

Generally, you have to set your damping to work best most of the time. You get to choose which end you sacrifice on. Most shocks and forks don't have sufficient damping circuits to work properly always, so something has to give and there's no rule as to what gives.

 

[294037]

The Vorsprung Video explains it the best, critical damping is far too slow for a mountain bike. Even most race cars aren't critically damped

 

[Dougal]

Hell no. That's too slow and dead for anything except catching falling elevators.

70% of critical is the most rebound damping you'll ever want. But even that is massively overdamped for almost all bike applications.

 

[tbmaddux]

The Vorsprung Video explains it the best

Here it is: Tuesday Tune Ep 19 - What Your Rebound Damping Does.

Critical damping is the black line on Steve's plot. He starts talking about it at 3:10 and moves on to the "medium" green line about a minute later.

 

[Nat]

I don’t have any idea what he said, not because of his accent but because I was transfixed by his shirt.

 

[Lone Rager]

FWIW: I put a black mark on my rebound knob so it's easy to verify where it is and can also change it a few clicks one way or the other depending on conditions and to experiment with it and not lose where it's at.

The curb test is like a lot of other cycling rules of thumb. It's a decent starting point from which you start experimenting and see what works best for you in different situations. DH pros, despite may years of experience, technical know-how, data-logging, and analysis software still test and modify based on feel as well as data.

 

[Erotomania]

I've been told this method forever, and it always results in a super slow setting that packs up. Bounce around in a parking lot and get it as fast as you can without getting tossed, then hit some trails and adjust from there. Adjust both front and rear at the same time and keep them balanced.

 

[Dougal]

I've been told this method forever, and it always results in a super slow setting that packs up. Bounce around in a parking lot and get it as fast as you can without getting tossed, then hit some trails and adjust from there. Adjust both front and rear at the same time and keep them balanced.

My method is to slam your rear down on the seat and set rebound so the return doesn't kick you back off: https://www.shockcraft.co.nz/technical-support/setup-guide

But you need to set spring rates first. Otherwise it's useless.

There is also a big difference in how rebound behaves depending on how good the shock valving is inside. A good high speed rebound setup will enable the suspension to recover quickly when unloaded but still provide chassis stability.

This is because suspension has two different frequencies it works at. The frequency of you bouncing up and down on top (the slow frequency) and the frequency of the wheel up and down on the ground (the fast frequency).

Crappy rebound dampers cannot satisfy both.

 

[Jayem]

In short, no that's not how you set damping.

A port orifice damper is set differently than a normal shimmed damper, which is also set differently than a highly preloaded damper, and on top of all that there is a considerable window to adjust all of them according to your trails, or just preference.

This video comes up occasionally, but it's really not useful.

Generally, you have to set your damping to work best most of the time. You get to choose which end you sacrifice on. Most shocks and forks don't have sufficient damping circuits to work properly always, so something has to give and there's no rule as to what gives.

This x1000.

It should be noted that most rebound dampers are either orifice dampers, or they act like orifice dampers due to insufficient circuits/pistons/shim tunes. Because of this, they usually offer piss-all stability when set to not pack up on repeated quick impacts. You are usually tuning the LSR rebound to allow enough flow to make up for this, which usually results in far faster rebound than would be optimal, but something has to give due to the insufficient high speed circuits.

 

[minimusprime]

While watching the new fox racing series "dialed" on youtube... I noticed that Jordy tests forks rebound by jumping on it both lightly and with a significant weight, to activate the different rebound circuits (low and high). Since rebound speed is dictated by air spring, you can essentially think of hsr and deep stroke and lsr as beginning stroke rebound (NOTE YOU CANNOT THINK ABOUT COMPRESSION IN THIS WAY AS IT IS NOT POSITION SENSITIVE).

I digress, what he's doing is getting a feeling for how fast it rebounds. He's doing this by feeling if he can pull his hands away from the bars as it rebounds or if it stays with his hands. He's also looking at the wheel and seeing if it hops off the ground.

I use this method as a constant for checking my rebound settings. While rebound is slightly subjective (the last .5 - 1 click of adjustment in either direction) there is an optimum. Over time, I've honed in on what I feel like the right return speed and tire hop is for my riding, and I use the above method to validate it.

While it's not the exact answer, look at this is some one running through the particulars of how to fish. It's on you to figure out what sort of fish that you like.

 

[db3266]

I like that series. He is one clever dude.
All the bikes he bounces on look super stiff relative to how I think mine is.
I also use the technique he is using, especially on the fork. I normally set it super fast so the tyre bounces, then start to add rebound compression until it stays on the floor.


Sent from my iPhone using Tapatalk

 

[127.0.0.1]

I learned a while back andrextr information is 50% horseshit.

 

[Erotomania]

While watching the new fox racing series "dialed" on youtube... I noticed that Jordy tests forks rebound by jumping on it both lightly and with a significant weight, to activate the different rebound circuits (low and high). Since rebound speed is dictated by air spring, you can essentially think of hsr and deep stroke and lsr as beginning stroke rebound (NOTE YOU CANNOT THINK ABOUT COMPRESSION IN THIS WAY AS IT IS NOT POSITION SENSITIVE).

I digress, what he's doing is getting a feeling for how fast it rebounds. He's doing this by feeling if he can pull his hands away from the bars as it rebounds or if it stays with his hands. He's also looking at the wheel and seeing if it hops off the ground.

I use this method as a constant for checking my rebound settings. While rebound is slightly subjective (the last .5 - 1 click of adjustment in either direction) there is an optimum. Over time, I've honed in on what I feel like the right return speed and tire hop is for my riding, and I use the above method to validate it.

While it's not the exact answer, look at this is some one running through the particulars of how to fish. It's on you to figure out what sort of fish that you like.

I'm not so sure the high and low speed rebounds really work this way on the grip 2. My local trails are nothing but roots, and I have noticed faster HSR smooths out even smaller impact chatter. Initially I was running a slower HSR and faster LSR, but was still packing up in the first 1/3 travel even though the fork felt fast overall. Now I'm @ 5 clicks of both and it feels better.

 

[Nat]

In that Dialed series I watch Jordi listening to the pro racers trying to describe how their bike feels ("It feels too far in front of me.") and I wonder how often he thinks to himself, "Mmm hmm. Mmm hmm. I see. Just change something, anything." [click] "There. All better!"

I know an operating room technician ("scrub tech") who in the past when a surgeon complained "These scissors aren't sharp" she'd take the scissors, put them down on the back table, rifle around in the instruments, then pick up the same pair of scissors again and hand them back to the surgeon who would then go about using the same pair of scissors completely satisfied.

 

[Dougal]

I'm not so sure the high and low speed rebounds really work this way on the grip 2. My local trails are nothing but roots, and I have noticed faster HSR smooths out even smaller impact chatter. Initially I was running a slower HSR and faster LSR, but was still packing up in the first 1/3 travel even though the fork felt fast overall. Now I'm @ 5 clicks of both and it feels better.

Lots of HSR damping and little LSR gives the worst possible rebound damping.

It behaves like orifice rebound damping. Like a Fox CTD EVO shock or RS Moco fork.

 

[nmxtrdr]

Lots of HSR damping and little LSR gives the worst possible rebound damping.

Completely disagree with this. Steve from Vorsprung appears to as well.

Care to elaborate on why you feel this approach is incorrect?

 

[ghostbiker]

Completely disagree with this. Steve from Vorsprung appears to as well.

Care to elaborate on why you feel this approach is incorrect?

steve explained why he recommends this way of setting rebound up on twin tube shocks in that vid, that doesn´t make it right for every other shock or fork or even the best way of doing it for those exact shocks, it´s just the fastest and most simple way to get close. a lot HSR means it won´t be able to recover from deep in the stroke fast enough so it will be packing up on repeated hits. A little LSR means it won´t be stable around sag point and will be bucking you on jumps.