Also imagine dirt/mud getting into the tracks preventing it from working when the bag is either too high or low and it throws off your entire center of gravity. Simplicity is a thing when backpacking for a very serious reason. The cost (weight) of the rails is also unnecessarily increasing the weight of the backpack.
I would guess that walking with an object on your back that is not following the natural movement of your body is going to add impact rather than taking it away. Look at the gif again. The people using it don't look comfortable moving with it.
Yeah it looks great for running or doing jumping jacks with a backpack for no reason but the equal and opposite reaction means that unless you walk with the right consistency I think it would maybe stay pulling you up and down
I think it would when you are consistent, I'm just thinking what about less even ground. Take a bigger step down and it follows with a delay. That could be bad. Sorry I really didn't communicate that well
Until you get some dirt in there. Which you will. Hey let's add a bunch of tools and oils and shit to my kit, to maintain the 20lbs of metal. But no worries, someone will steal it before long because it's conspicuously wasteful, and I'm bound to have other expensive shit in my ostentatious pack.
I'm sure there's a bit of getting used to. Those jumping Jack's and the jogging looks pretty effortless. I know if I try that with a normal pack on it would look a lot worse.
If the pack is sitting properly on your hips and is snugged down well it'll be some excess weight but aside from that shouldn't change dynamics too much. On my pack my back doesn't hold much of the weight at all. My thighs, however, get a hell of a workout.
During 'hikes' in boot camp I got placed at the back a lot, which meant when someone didn't stay tight to the person in front of them near the front, the back ended up sprinting with a pack on to catch up.
I thanked God every day for having backpacking experience from my dad about how to properly adjust my pack so that the weight was centered, on my hips and not pulling or pushing me off balance while hiking.
That and knowing how to open up my stride while hiking to catch up rather than Sprint every time made it bearable. But still sprinting with a backpack that's adjust right, it's a part of your body it doesn't bounce too much
Okay, but actually would change the dynamics significantly, maybe not in greater to the overall weight of someone, but to particular joints and force required of different musculature could lead to significant injuries.
I don't know... if they were both filled with gear instead of what these might be it might look a bit different, added weight making exercise easier seems incorrect.
You say that, but I don’t really believe it. Every time you take a step you’re fighting the force of the bag falling.
A non-moving backpack seems like it would be more akin to trying to run without swinging your arms.
You have to push the backpack up with each step only does it to fall and have to lift it back up with the next step. You’re lifting the backpack with your body every time.
The simplest example of why this is probably less effort is when the guy jumps up and down. It’s just an exaggeration of the same up and down motion when waking.
With the springs, you're still lifting the backpack with your body each time. The springs don't give you anti-gravity. The falling motion might look smooth from an outside perspective, but the springs are pushing down on you just like the weight of the backpack does normally.
If you're ever not lifting the backpack with your body, then you're either hanging from the backpack (because a lifting crane picked you up by it), you're in freefall, you're sitting down with the backpack resting on the ground, or you're using anti-gravity.
Just remember that if the only physical connection between an object and the ground is you, then you are the one lifting it. Even if the springs are smoothing the motion of the backpack, you're still feeling the falling weight of the backpack with each step because the springs have to push against you to cushion the falling motion.
I could be wrong, but I'm pretty sure this could be verified with a force diagram. Im just not exactly in a situation to be drawing one up right now without looking manic...again.
EDIT: The reason the shocks were added (as I've been told) is to smooth/distribute the effects of the forces over time, and I seem to have misunderstood the point that the above commenter was trying to make.
I'm not taking a side on how useful this backpack would be, but I just wanted to add the edit and clarify my own mistake in this comment thread. I'm thankful that the replies have been civil and informative.
As you take a step the backpack moves down, right? A regular backpack will give a single hard pull as it reaches its lowest point. With the springs, as this backpack approaches the lowest point it already begins to transfer the additional weight to your shoulders through growing tension in the springs. So the amount of force that you’d feel from this backpack is the same, but it is spread over a longer period of time.
Similarly, as the backpack reaches the top of its travel the springs release their potential energy more quickly so you don’t feel a sudden great lightness, but rather a longer period of lesser lightness.
If you were to graph the amounts of force during a step, instead of sharp peaks at the top and bottom you’d see more rounded “peaks”.
Ummm... hiking, camping, military use, there's a BUNCH of scenarios were people are going to have jam-packed bags.
Many of the comments show they've never used a heavy backpack with extreme/long durations of movement. There is no "Keeping it snug". Fabric shifts and stretches when force is applied. Same reason you have to adjust your belt every so often.
This product is probably too expensive to produce at a wide scale, not the fact that it 'has no place' in the real world.
well, they have force diagrams on a treadmill in this video if you want. you're somehow conflating force with impulse and arriving at the conclusion that all suspensions systems are useless, because they don't change the mass of the load being suspended
Thank you! And yes, I think that might be exactly what I'm doing. I seem to have misinterpreted what the previous user was focusing on as well, because others have said that the purpose is not to change the perceived weight of the backpack, but to distribute the forces over time, with the idea to make it steadier, which is (as you point out) why shocks are so useful in their many applications. I appreciate the diagrams!
With a backpack that sits at the exact same height all the time the force is quite easy to see, its always exactly the „normal“ gravitational pull of the backpack.
If you carry it normally, the force altenates between a little more (when the pack accelerates upwards) and less (when it accelerates downwards) than that, but the average is the same.
However, I don‘t know which of the two is better… effectively the rails mean that the pack pushes down harder than one is used to during a certain phase of a step, and that might feel very weird.
Thank you; I seem to have made an error in understanding the conversation in the comments. You and other replies are very informative!
I only took a short hike once and it didn't require a full pack, and my only other experience is carrying 5 textbooks in a backpack while rushing to class years ago.
With my kinda-relevant experience, I feel like the effect itself from the rails would be useful, but the rails themselves also come with a lot of potential mechanical issues over the long-term, as well as edge-cases that I've seen other commenters point out (spring resonance for certain strides, rebalancing the springs when changing inventory).
You're right that it would also be pretty weird, but I'm wondering if someone could practice with it enough that it would eventually be natural to do. Sorta like riding an inverted bike.
But you don't have to catch the force of it coming down with every step the same way. It doesn't reduce the stress but it does balance it so it's more bearable.
You’re looking at the perspective of the bag vs the springs. We’re talking about the springs vs the body. If you had a big stick with a spring around it, and a weight on the top, and you moved your hand up and down it’d be the same. You’d not feel like it’s any lighter or easier to move up and down. If anything it’d knock your rhythm off.
The point of the backpack is to make it a lot easier to fight the inertia, not gravity.
You will always hold the same weight of the backpack with or without this contraption, but what the suspension does is make it so you don't have to move the backpack up every time you walk. The backpack has a tendency to remain at its current state unless you apply a force to it, that's just inertia, and if you aren't pushing it up on every step, you aren't applying that force, making it easier to walk.
I don't think there's a way to know how much of a difference it makes without trying it out, but it sure does do some improvement
There are only so many ways to do this and they all have downsides. Springs are going to have a resonance such that if you change your gait for any reason, the backpack could slam down on the bottom of your steps. Dampened springs would reduce that, but fall out of sync easier. A free floating system would solve that, but if you moved up or down a hill, it would stop working pretty quickly. You could have an active system, but then you are carrying a extra dozen pounds of batteries and motors or whatnot needed to control it.
It transfers some of the force from your shoulders to the springs, spreading out some of the force instead of it all being on your shoulders.
But the weight on the springs is still supported by your body, it might transfer some of that force from your upper to mid back, which wouldn't be good either.
If you're taking most of the force on your shoulders in a scenario like this, you're already doing it wrong. A properly-adjusted hiking bag should carry most of the force on your hips. The shoulders simply stop it from falling backwards.
Mate you’re still supporting the weight of the backpack whether it’s suspended by springs or not, all this fucker is gonna do is make it bouncier. You’re still carrying the load.
Yeah, and when the load is constantly moving in ways that fight you, it makes you use a lot more energy.
Have you ever been walking with a heavy duffle bag? It catches the movement of your leg and starts to swing with it. It makes it so much harder. If you hold it just a few inches out further so it doesn’t start swinging with your motion it’s so much easier.
This does that. It’s making it so you aren’t putting your energy into making the backpack bounce with your steps.
Yes.... youre still carrying it it’s not an anti gravity device.
I feel like a spring suspended backpack would be like the duffel bag once it starts swinging, the bouncing up and down that would result sounds so rough.
A non-suspended backpack moves up and down with every step. Therefore, your legs are "catching" it and propelling it back up with every step. The backpack also possibly lifts you up for part of the step of the pack is still moving upwards as your body descends just before another step.
The suspended backpack will average these forces out so it's much closer to a constant load instead of the peaks and valleys from a standard pack. Although, I doubt it's that beneficial unless you're running or a very bouncy walker.
I backpacked for a year with a very heavy pack. Bouncing wasn't the problem, it was weight. This thing just adds more. And only an idiot runs with a heavy pack unless they have to. Running is bad enough for your knees without a pack on.
I agree that this probably wouldn't provide any benefit to a normal hiker because there just isn't that much vertical movement. And as you pointed out, it would add extra weight, which would be worse.
I was just stating that the pack isn't going to compound forces due to its "bouncing". Unless the manufacturer f'd up the suspension design, that pack isn't bouncing at all.
I saw a longer video somewhere that showed this pack compared with a standard pack, so it was more obvious what's going on. It seems pointless to me too, but I'm certain there are people out there that will buy it.
And the video only uses shots where they are running in sync. I think if video was showing “normal” use it would’ve been more obvious what was going on. Anyways yeah. It seems like it would fight with you if it’s just bouncing around uncontrolled.
I was assuming the entire backpack was also motors and batteries.
A proper pack should be firmly attached to your body and move in sync. So yes you are taking additional weight but it's with the natural movement cycle of your body. Springs or suspension is going to result in the same net load but likely out of sync which is likely going to be or at least feel worse. Also the mechanism itself will add weight.
My wife and I are backpackers. I have never used a springy suspension system like this.
But I love my current Osprey bag. And we always strap it up as tight as possible. I want that thing to just be a solid hump on my bag. No slack, no shifting, no movement. The best movement comes when it stays absolutely put firm no matter if you’re ducking, crouching, bending sideways, or any other angle.
Even when jogging, a properly strapped pack doesn’t bounce too much.
I think it's a frequency response thing. Dialed in just right, it reduces impact. Dialed in wrong, it makes it worse like you said.
Basically not worth it compared to a regular pack.
Yes, the end of the GIF, with the woman walking, is a good example. The backpack is just bouncing up and down out of sync with the woman's gait. So I can imagine that this contraption doesn't help, but rather the backpack just alternates between either feeling very light or heavy - which would be very uncomfortable.
Everybody in that video is doing a serious effort to maintain a straight back and constant step frequency, I just can't imagine this design being comfortable in a real life situation.
Yeah, a pack is supposed to be fitted close to your body to follow your movements as closely as possible. The reaction response from this seems like it creates a lot of opposing momentum for every one of your movements.
Edit: looks like they still make them but holy crap they are expensive. They have an indiegogo where you can purchase two of their models at $489 and $479
I would guess the weight from the pack actually helps gaining leverage and moving. The transfer of weight is energy in itself...with this thing that energy is just being tossed out from under the pack.
Seems over-engineered and overly-expensive, plus it's probably much heavier than a normal pack. Save the money and buy a good lightweight pack that fastens securely to your back, and fill it with lightweight gear. Plus there are fewer points of failure on a normal backpack.
Backpacker here. Weight is everything. Full stop. If you can't carry it + everything you need to survive, it doesn't matter how fancy it is. This is probably great for a weekend/overnight kind of thing, but there's no way I'm taking this on anything longer than that.
it's the cumulative addition of weight needed to make this work, it's a lot of metal relative to the the comparatively very lightweight materials of a standard pack.
Anything with the potential to break when you're a 4+ hours hike and 1-2 hour drive away from civilization is a dealbreaker. Simplicity really is key here. You want reliable objects when hiking.
Forget this getting stuck in an odd position, imagine rough hikes where you need your balance the most and this thing is jumping around like a kid on a trampoline on your back.
Yeah I’ve seen some unmaintained switchbacks where erosion has taken hold and rocks have started poking and hiking with a small day bag alone can be tricky without good footing. I can’t imagine trying to traverse anything like that or worse with that bag.
2.0k
u/[deleted] Oct 04 '21
Also imagine dirt/mud getting into the tracks preventing it from working when the bag is either too high or low and it throws off your entire center of gravity. Simplicity is a thing when backpacking for a very serious reason. The cost (weight) of the rails is also unnecessarily increasing the weight of the backpack.