The Tuesday Tune Ep 19: Rebound Damping - Video

 Yes! and with a better sound quality! (I can now understand every word!)

 @faul: we finally took the internet's advice and got a microphone

 @VorsprungSuspension: i like very light rebound compression , but hate the associated pogo effect. would a top out compression damping solve the negative side fast rebound aka pogo effect ? If so is there such a shock with this type of compression circuit ?

 @trauty: the only way to stop the pogo is to increase rebound damping!!! Was that a joke question.

 @mikelee: i mean you could realllllly underspring the suspension and it wont feel pogo-y because you just stay bottomed out.

 Don't all try to be some Steve here. With pogo people often seem to imply a continuous oscillating motion (unlike a real pogo stick which is supposed to catapult you up in the air). So if this is what @trauty is aiming at then yes I do think compression damping could help some. The classical spring-damper theory typically considers compression and rebound damping equal which obviously is not what he have on bicycle suspension. If you have very quick/light rebound damping and very slow/heavy compression damping you'll end up with something that resembles the critically damped curve. But it is still not ideal, especially for rear suspension. Because usually after having absorbed a big hit, you don't want the (rear) suspension to raise near top out again. A big top out bumper would help some but then it would also keep the suspension from extending properly when going through a depression as it is position sensitive and not speed sensitive.

Either way I think it is a valid question and I'm interested in what Steve has to say about this.

 @VorsprungSuspension: thats great! Thanks for the lesson. If you want to make te sound even better to listen to, you might want to consider hanging some curtains / extra furniture in your room. You an also add a simple de-esser as a audio plug-in in your video editing software so your sssh is not as harsh

 @VorsprungSuspension: The internet will NEVER steer you wrong!

 @trauty: I'm not entirely sure what you're asking there - a top out compression damping circuit? Compression damping is what happens when the suspension is moving away from topout so I'm not sure exactly what you mean, though as @vinay mentioned compression damping does help dissipate energy as well, which contributes to reducing unwanted bouncing around. I'm also curious - when you say you like very light rebound/compression but hate the pogo feel, what is it that you actually like about it?

 @VorsprungSuspension: great vid, how does high speed and low speed play a role in the move vid. when setting your dampening to regain the little over sag recovery is that more low speed or high speed adjustment oe a it of both? cheers

 @adrennan: but then you’d be permanently bottomed out!! Why would you want that? The rebound controls the rate that the spring returns. There are no other forces on the rebound other than spring force. The reason there Is a wide range of rebound damping is to componsate for the many spring weights.

 @vinay: so you’re saying run really fast rebound but really heavy compression so the spring returns fast but can’t pogo back and forth due to the heavy compression setting? This would feel awful. So on small hits the bike would feel rigid losing traction and that set up would work for one big hit. If you only have one big hit then what’s the rush to get the spring back? Also the spring retuning un damped from bottom out will defo buck you up,maybe over the bars. You could always set up the Shock as it’s desighed for. To control all movements over rough terrain

 @trauty: do you mean more like a position rebound damping that slows rebound more once during extension you reach/are near to your sag position?

 @vorsprung
Topnotch as ever!

 @mikelee: What I was saying is that if you don't want the oscillation but don't want the rebound damping to aid stopping that, you'll need more compression damping. But I also mentioned it is not ideal for reasons I mentioned in the same post.

Now I do think I get what @trauty is aiming at and it is something I'm struggling with too. I ride a steel hardtail most of the time. Lots of feedback from the trail obviously, lively ride. If I get on the fully it feels a bit dull. Running less rebound damping gets more life back into it. And it goes great for most riding until I land a bigger drop and bottom out the rear suspension. Maybe it is because it is a (progressive) air shock but it rebounds much, much faster than anticipated and either bucks me over the bars or at least makes me more concerned about absorbing the rebound stroke than absorbing the actual hit. Safest is probably to run more rebound damping than I'd like for the majority of my ride. But experimenting with how fast I can run it (that is, how little damping I can get away with) is scary business because it requires me to bottom out the suspension and find out where I can no longer compensate for it. Obviously this feels like this misses the purpose of running suspension in the first place. So for technical or harsh stuff I'd rather ride the hardtail. Hits will be harder but at least they're predictable.

 @VorsprungSuspension: sorry if my question seemed badly formulated. You are correct. I meant a top out compression damping circuit ( sorta negative lsc tha would work in first 30% of travel and only when the shock extends) . Fast rebound makes my bike super agile , poppy and also (and that is super important) makes wheel traction better for me. the wheel seems to float over bumps without loosing speed. What I especially mean is that fast rebound helps me to pop ever terrain. If i set the shock the way its meant to be - medium rebound , then bike feels lazy. Maybe my shock would perform better with custom rebound circuit perhaps.

 @trauty: I think you mean a hydraulic topout circuit (which is a rebound circuit not compression) from what you're describing? It could also be that you might prefer a more progressive spring rate and/or a more digressive rebound curve.

 @VorsprungSuspension: Now you just have to control your sound's rebound...echo
Love theses vids though.

 @trauty: I too like very light rebound settings. One thing that NEVER gets discuss in the "light rebound damping" discussions is that when the rebound circuit overshoots sag point and nears top out, the bike will then start activating the compression circuit as it starts heading back to sag. Run more compression in combination with less rebound and the bike will ride higher in the stroke. The often overlooked feature of riding higher in the stroke is less pressure in air shocks and less spring force in coil shocks, which makes for a way more supple ride, no packing down.
To tune steering feeling, use rebound settings to control ride height at either end to get the desired HA for steering.. Lower in the back, monster truck... Lower in the front, quick and nimble steering...
The suspension system is always about all the settings, not the sum of parts..

 Entertaining? I thought the wall behind me had more screen personality than I do, but hey thanks, I'll take that

 One thing we come across quite commonly is people running rebound faster and faster trying to get more grip, or slower and slower to try to prevent themselves getting kicked around. Most people are aware there's a happy medium for sure, but if there was one main point to be taken away from it, it's that beyond a certain point, faster rebound actually decreases traction rather than increasing it.

 @VorsprungSuspension: couldn't agree more. I find if my feet are getting tired or I feel the trail is rougher than normal if I just do 1-2 clicks slower on the rear shocks rebound things get so much better.

I do tend to ride my front fork pretty quick but will have the rear be on or two clicks slower.

 I’ve read/heard that for the vast majority of riders, the stock suspension is tuned right in the middle, that is, if you’ve got 22 clicks of rebound or compression and your sag is set properly, you should be living between 9 and 12...or something. Do you have thoughts on that?

Thanks!

 @jeremiahwas: rebounding damping is proportional to spring rate, so higher PSI or heavier coil = more damping required to keep the rebound force in check. Steve explained this in a TT episode last year, so there's a useable range of clicks of rebound damping for a given spring rate and going way outside that results in poor performance (pogo stick no traction, or packing up if too slow).

 @VorsprungSuspension: A fast rebound sets up the shock quicker for the next compression.
This is to prevent the fork packing up too much.
Too fast of rebound is another matter.

 @VorsprungSuspension: you reckon there will be an electronic automatic rebound system implemented in shocks in future ? perhaps even on the go dynamic rebound adjustments ?

 @VorsprungSuspension: So aim to make rebound as fast as possible without having it feel out of control?

 @ibishreddin: Not necessarily "as fast as possible", but if you are looking for the best possible grip it's more like looking for the speed at which the wheel stays on the ground as much as possible. In some cases that can be slower than you might expect, but it does vary quite a bit depending on the terrain you ride. Slower steeper/techier stuff can benefit from slower rebound, but if you're moving faster then the wheel has less time to move in order to track the terrain, so it needs to be allowed to extend a little faster.

 @VorsprungSuspension: so basically slow rider ride slower rebound and faster rider ride faster rebound and fast trail rides fast rebound and slow trial rides slower rebound, yes?

 Agreed. It kinda missed the "here's a few ways you can find the perfect rebound for you" part of the lecture. But otherwise good presentation. I have this one section of trail (has lots of chatter) that is probably an ideal place to test rebound because you can really feel when the wheel breaks loose.

 Haha, there are definitely many similarities!

 I was thinking the same thing.

 haha yeah, too bad suspension doesn't have auto tune... at least for now.

 That one is a good test to give you an indicator of what definitely is overdamped - no overshoot in rebound when seated and riding off a kerb is guaranteed to be more rebound damping than you actually want. That is the critical damping point for a (nearly) rigid mass spring damper system, but when you're standing on the pedals, the rebound setting that test gives you is distinctly slower than it needs to be.

 He explained in the video, "rebound back to the sag point". So the fork shouldn't use any sag travel unless you hit a hole. Overall with a full suspension bike you'd get an optimally comfortable ride with his set up, because the tires will always be in contact with the ground. It is the business way to set up a bike, say if you were racing downhill.

 Isn’t the test that you should get one over shoot and then stabilize at sag with just minor oscillations?

 Possibly - HSR/LSR have even more overlap than HSC/LSC. Worth discussing, we might cover that in a future video.

Dual rate air springs are what I was referring to regarding complicating setup (systems with more than one positive air valve). Progressively wound (sometimes referred to as "dual rate") coil springs I have very little interest in, they're heavy, expensive and units currently on the market make *very* little difference to bottoming force.

 Bumps are never truly sinusoidal per se, but some bumps such as stairs or braking bumps do have a fairly consistent input frequency. For that kind of input, yes you can come up with a setup that is quite optimised for that particular section of trail - but it may lead to considerable compromise elsewhere too.

 Oh my, I've been granted!

 I find it funny how this is like my #1 program out of anything I could watch. It just seems so quirky, like kids yelling, "if you like suspension so much, why don't you marry it?"

 Measured my stancions today with a caliper, they were 1.375" which is just a hair less than the 35 millimeters they're supposed to be.

 Check out some of our previous videos, this has been covered in some depth.

 Just a heads up, but you're going to need #alltheeggcartons to solve this particular problem.

 Screw the egg cartons! First you'll need some walls #awalldontcomeforfree

 Coils are nice, having the option is good for sure. Air springs are not as good as they could be just yet, but I believe the potential is there to make air springs outperform coil springs overall, irrespective of weight. In some applications (rear shocks on some frames) they already do.

 How to solve problems, negate them entirely. Doesn't sound wrong, but if I was bad at say running, improving would be better than avoiding it altogether.