It s for bikes. When u have a high speed(usually supersports bikes.... r6, zx10r,etc .) this helps u to have less shock,vibrating on handlebar and get the maximum speed in safe mode 🤣🤣😘
When a fluid reaches a pressure so low that it evaporates, it causes cavitation. Cavitation is when gas bubbles form inside of a fluid because this critical low pressure evaporates some of the fluid. The problem is, that when the bubbles get big enough and reach a higher pressure, the gas inside of the bubbles turns back into fluid form, so it leaves vacuum behind. The surrounding fluid rushes into the spot with the speed of sound, and this creates an implosion. Cavitation is really dangerous because it can literally eat metal over time.
I have Ohlins struts matched with custom springs on my Lexus SC300 and it's hands down the best suspension. I've bought installed then removed and sold several other kits all because the Ohlins is the best middle middle ground/overall for me.
Basically he adds enough pressure to avoid the cavitation even though system has to move oil back and forth quickly. The flowing oil experiences a pressure drop across it's path and if this drop is too high the oil in the cylinder experiences vacuum. The faster the system has to move, the higher the pressure he needs to avoid cavitation. Shouldn't be many bars, just a few, guessing 3-4?
For monotube damper pressure is usually around 20-30 bar, twintubes that have the bottom valve providing pressure increase in the compression chamber are usually charged around 3-5 bar
@@michail1963 honestly I have experience only with automotive shocks and those are the pressures used for cars, I guess motorcycles need lower forces and can use lower pressures
MotoGP uses them. And I think there's high end consumer superbikes that have them as well now. For example the ZX-10R since 2016. But I guess it may be less of a problem due to the longer stroke the forks make, not moving through the same oil as much as a result? Not sure though.
@@steveman1982 I think that's it. The increased pressures further down the travel from the longer stroke and relatively low dead space to stroke ratio help as well I'd guess.
amaizing movie. i service forks and shocks for years but it is really nice to see cavitation in transparent shock:) can cavitation permanently degrade oil?
I don't think so, what it can do is cause cavitation and hence pitting on some of the orifices. This can detach material into the oil and hence we can call it degraded.
Pitting is correct, this can happen when pumping fluids. Cavitation can damage the impeller and pump housing over time if allowed to continue. The excavated material becomes suspended in the fluid. In a small volume of fluid like a strut, the suspended material will damage seals.
What happened when it got foggy? Did the oil break down or was there a vacuum in the chamber? Considering one of these in the future but theyre extremely expensive.
Its cavitation, it moves so hard the oil creates bubbles, the reservoir on the side catches and compensates for some of the extra pressure and negates the cavitation
True cavitation occurs in pumps and marine propellers where the fluid flow over parts of the device cause low pressure areas that exceed the cavitation threshold. The trailing edges of marine propeller blades are quite susceptible to this and it can cause erosion of the metal the blade is made from. It's analogous to vapour trails that appear from parts of aircraft wings in humid air
How does the reservoir experience so much pressure change (shown with the up/down motion of the diaphragm on the right) if the oil is simply transferring from one side of the main piston/valve to the other? Is there that much expansion of the fluid due to pressure effects? Because in my mind there isn't air or anything replacing the low pressure space of the main valve as it moves through the stroke transferring oil through the compression valve into the reservoir. I'm trying to understand the mechanics of this better. thank you!
I had *exactly* the same question. Just couldn't make sense of it. Then, one of those "ah-ha" moments: the reservoir is accepting the oil which is displaced by the shaft! The answer is almost too simple.
The piston isn't a complete seal. There are holes in the piston with stacks of small thin washers which are usually adjustable. They control oil flow. Damping is controlled by how fast oil is allowed to pass from one side of the piston to the other. The oil on the negative side will have a slight vacuum if the oil on the compression side can't travel through fast enough to fill the void/vacuum so they pressurize the whole system preventing the cavitation.
What I want to know is once cavitated how is the cavitation cured just by repressurizing the res? Wouldn’t the entire system need bled again once the air was sucked past the shaft seal or separator piston???
There is no extra air that was sucked in, the cavitation is only "bubbles" created by the super fast movement (too fast for the fluid's thickness and its surface tension to manage "pulling itself back together") This is creating really low pressure zones, allowing space between groups of molecules of the shock fluid, and it isn't able to revert back into being homogeneous - that is until the pressure is applied (This is a bad explanation I'm sorry, not a physicist) look up other videos/explanations of cavitation if you want to know more, it is fascinating and can erode and destroy equipment such as boat propellers or even diesel engines
I call "Fake Demo" on this. The cavitation is happening on the rebound side of the shock chamber. The rebound damping is typically much less than compression damping, and the max rebound rate is dependent on how hard the spring pulls the damper apart. In this case, the demo shows a machine pulling the damper apart which I would suspect is much harder than a spring would. Without numbers, this is just a "magic" demo to help sell you something. MO.
Is that the purpose of those shocks with canister? I've always thought it was mor like a secondary suspension like when having maximum load or something. But int he demonstration they release the air and add the air back in, normally therea just a fix amount of air and vreasure in that canister right, or does it need topping up periodically or something to maintain a certain pressure for it to work against the cavitation?
The pressure in the nitrogen reservoir typically stays fixed until the sealing components wear out over a long time (possibly shorter under extreme use conditions). You don't want to try measuring the pressure in the cannister after it's pressurized since the amount of nitrogen that flows into the gauge will be enough to drop the pressure a good amount and require a refill. Shocks without the reservoir will typically still be pressurized, but the bladder is internal. Having the reservoir separate from the main tube is useful but for reason's I don't remember at this current time.
The piggy back or canister provides extra oil and surface area for cooling as well as giving the designers more space to add the valving and adjusters. An in-line shock with no canister still has a gas charge in it.
No. The piggy back canister is where the gas charge is. You need a gas volume because hydraulic fluid is essentially incompressible. Every stroke of the shock puts more or less of the shaft into the oil chamber, which will displace the volume of the shaft. If there were no gas chamber the body of the shock would explode under the oil pressure. The gas chamber gives the displaced oil somewhere to go.
The reservoir pressure is relieved prior to service, and recharged once the unit is reassembled. For a fork, the reservoir is just the top section of the cartridge, separated from the oil by a floating piston.
This is why you should always buy shocks and brakes from big brand name companies... Yes you pay for the name but you get a far superior product with genuine RnD $ spent on it
Wait so if I have a cavitated shock and I just add the proper PSI back in to the IFP chamber will the shock automatically readjust and fix itself as demonstrated in the video?? Any insight from anyone would be appreciated. I'm about to rebuild a DHX2 mtb shock with the same issue and wondering if pressuring the IFP with nitrogen will fix it? Thanks!
The answer is NO in case anyone is curious haha. I didn't use Nitrogen, just air, but it did not fix the issue and have since rebuilt the entire shock successfully. So in case anyone is wondering, this is a unique setup clearly for demonstration purposes and would NOT simulate real world scenarios. Cheers!
I know this is a late response, but you are correct, it won't won't fix airation. Cavitation bubbles, like in the video, collapse and go away because it's the fluid changing states from liquid to gas and back, not introducing air from outside sources. It's also that collapse that pits shims and other metal component's in your shock over time. That would be the issue with running a cavitating shock for too long (aside from probably feeling really crappy).
So the cavitation will occur inevitably during the usage of damper, right? Would this experiment provide any conclusion or just a show of this inevitable phenomenon?
@@isleofauto what's the model of your shock that you have cavitation problem with? For example, if it's Fox X2 then it woun't be managed by regulating air pressure in IFP chamber like in this video. The problem with X2 is air-leaking cause of seals (o-rings).
As the shaft is entering the chamber it takes up volume. The reservoir is pressurized against the piston but as the shaft enters its displacing the oil so the piston in the reservoir moves compressing the gas.
@randomotaku3283 no crap. I'm not talking about axial movement up and down I'm talking about wobbling. The correct answer is "the piston is a sloppy fit and loose in the bore, but it doesn't really matter because this is just a display/teaching aid" 🥱 do better. Of course I understand how a remote res. Shock works it's a simple thing.
This is absolutely bonkers! The pressure valve in combination the the cristaline supercunductors is aligned with the crankshaft of the hydrocarbolized extension sensors and thereby creates what is known as a Schliermann-Eibenbach-suction on the ventrical dome patch. Never seen that before!
doesnt matter from cavitation perspective, but does matter from perspective of shocks getting to very hot operating temps. Air pressure ramps up faster with increased temp compared pure nitrogen (difference is not drastically big but it is there). this is why nitrogen is used in gas chambers. Usual pressure is 10bar (145psi) at 20 C
@@michail1963 the main reason for pure nitrogen is the atoms are bigger than oxygen and will not permeate seals and leak as easily. You don’t want to have to charge your ifp all the time.
I have absolutely no idea what I'm looking at or what's happening but it looks cool
It s for bikes. When u have a high speed(usually supersports bikes.... r6, zx10r,etc .) this helps u to have less shock,vibrating on handlebar and get the maximum speed in safe mode 🤣🤣😘
When a fluid reaches a pressure so low that it evaporates, it causes cavitation. Cavitation is when gas bubbles form inside of a fluid because this critical low pressure evaporates some of the fluid. The problem is, that when the bubbles get big enough and reach a higher pressure, the gas inside of the bubbles turns back into fluid form, so it leaves vacuum behind. The surrounding fluid rushes into the spot with the speed of sound, and this creates an implosion. Cavitation is really dangerous because it can literally eat metal over time.
@@botondpirisa4052 wow thank man
😯😯
@@botondpirisa4052 It's also how Aquaman moves so fast in water.
Amazing this looks like the thing my wife got in the mail, never knew she was into cars!
She bought it for you as a present
Did it come with had cuffs too? You best keep your hands out of the cuffs.
Shot over my head, but I rebound
Hang on I’ve seen that machinery elsewhere...
I see, you are a man of culture aswell
I want to like this but dont want to fuck up the like count
u mean in japanese action movies? lolllllll
Maybe something starts with the letter P I dunno
Yes! and it works the same way lol
My wife has one of those.
Lol!
Lolllll
*was
😂
I hear this same noise from the bedroom every afternoon and I do not know what it is
Are you still watching?
Somebody's daughter :
😆😂🤣
@@HotClown The Shaft by Ohlins
I have Ohlins struts matched with custom springs on my Lexus SC300 and it's hands down the best suspension. I've bought installed then removed and sold several other kits all because the Ohlins is the best middle middle ground/overall for me.
Demonstration can't get much clearer than that👏
Basically he adds enough pressure to avoid the cavitation even though system has to move oil back and forth quickly.
The flowing oil experiences a pressure drop across it's path and if this drop is too high the oil in the cylinder experiences vacuum.
The faster the system has to move, the higher the pressure he needs to avoid cavitation. Shouldn't be many bars, just a few, guessing 3-4?
For monotube damper pressure is usually around 20-30 bar, twintubes that have the bottom valve providing pressure increase in the compression chamber are usually charged around 3-5 bar
@@8coibaf almost all offroad motorcycle shocks are pressurized to 10bar
@@michail1963 honestly I have experience only with automotive shocks and those are the pressures used for cars, I guess motorcycles need lower forces and can use lower pressures
Ha nice 1 mate.
Every day, really is a school day.
More for sure, doesn’t say warning high pressure for anything. Maybe 10-20 bar is a possibility.
Probably my favorite video on shock cavitation
i always thought shocks were pressurised for suspension.. not anti-cavitation.
mind blown and grown 👌🏼
Exactly, I thought it was like a secondary suspension for the hydraulic pressure.
Cool. Great way to visualize cavitation
Enjoyed watching this ,very cool 😀👍
This is how I picture a bump generator!? And you can charge it with air…love it.
So it seems that beer foam from shocks could come from air leaking through the bladder, not bleeding properly OR not enough pressure
凄い、圧力室のガスを抜くとあっという間にダンパー内にキャビテーション(空洞現象)が
発生して圧力を戻すとすぐに収まる。ガス封入ダンパーが優秀な訳だ。
That was a cool video. Always neat seeing stuff you normally can't. Learning a lot from these comments 🤣🤣🤣🤣🤣 smh
Wow! An interesting and informative video on UA-cam.
the ladies gonna love this
So when the shock extends and sounds like "it's working" it was really failing due to cavitation. Great information.
Thanks
thats why pressurise shocks, but vaccumise oil at bleeding?
Hey friend, can you make this with difference 5wt vs 30wt oil?
That's cool. You know it happens but really cool to see it
I learned something today.
i have no idea on what it was, but my mind goes everywhere.. 😅
You got "steady shot" on that thing? Pretty cool though👍
感恩了解，謝謝分享！
Do you work for Multimatic per chance? That gold gas reservoir cap is VERY familiar..
Has anyone checked at what psi it starts working and at what fluid temp?
That a cool demo
Aww yea, finally a tour of my man pump research facility
Very interesting. Thanks for posting. I wonder if front forks are as susceptible to cavitation?
MotoGP uses them. And I think there's high end consumer superbikes that have them as well now. For example the ZX-10R since 2016.
But I guess it may be less of a problem due to the longer stroke the forks make, not moving through the same oil as much as a result? Not sure though.
@@steveman1982
I think that's it.
The increased pressures further down the travel from the longer stroke and relatively low dead space to stroke ratio help as well I'd guess.
Yes, look up the reasoning for closed cartridge forks vs open cartridge
Netflix : Hey are you still there?
Someone's daughter: .....
Wat
Only knew bout propeller cavitation untill this..
Random sweating black dude: get me thosee ohlins
but sir! its a prototype!
@@itz_lexiii_ GET ME THOSE OHLINS!!
@@MEALIVEUDEAD gotta pay extra fee for "early acces"
Öhlins Öhmatrons hitting the market soon. Online order only, discreet shipping.
That is very pleasant and arousing to watch ❤
Very cool indeed.
"he is just a friend"
Nice good job
Looks like something that should be on the Hub
What about using a spring instead of the pressure
Shocking
wow..i'm shock 😱
This machine looks fairly familiar
Didn't know what this was at first.
Your average cam girl would need a whole stream just learning to operate this
amaizing movie. i service forks and shocks for years but it is really nice to see cavitation in transparent shock:) can cavitation permanently degrade oil?
Yes it's essentially boiling the oil.
I don't think so, what it can do is cause cavitation and hence pitting on some of the orifices. This can detach material into the oil and hence we can call it degraded.
I think it won't oil returns to normal.
Pitting is correct, this can happen when pumping fluids. Cavitation can damage the impeller and pump housing over time if allowed to continue. The excavated material becomes suspended in the fluid. In a small volume of fluid like a strut, the suspended material will damage seals.
Conn, Sonar, We are cavitating.
What happened when it got foggy? Did the oil break down or was there a vacuum in the chamber? Considering one of these in the future but theyre extremely expensive.
Its cavitation, it moves so hard the oil creates bubbles, the reservoir on the side catches and compensates for some of the extra pressure and negates the cavitation
@@thegiantgaming7592 thanks!
So that’s how a damper works.
Super seal
This is true cavitation. The pressure on the low side vaporizes. If a pump or prop sucks in air from the surface it’s not cavitation it’s ventilation.
True cavitation occurs in pumps and marine propellers where the fluid flow over parts of the device cause low pressure areas that exceed the cavitation threshold.
The trailing edges of marine propeller blades are quite susceptible to this and it can cause erosion of the metal the blade is made from.
It's analogous to vapour trails that appear from parts of aircraft wings in humid air
@@PaulG.x sure but many confuse ventilation with cavitation.
what am i doing here?
I feel like that rod needs to be pixelated out, lol
Very cool
How does the reservoir experience so much pressure change (shown with the up/down motion of the diaphragm on the right) if the oil is simply transferring from one side of the main piston/valve to the other? Is there that much expansion of the fluid due to pressure effects? Because in my mind there isn't air or anything replacing the low pressure space of the main valve as it moves through the stroke transferring oil through the compression valve into the reservoir. I'm trying to understand the mechanics of this better. thank you!
I had *exactly* the same question. Just couldn't make sense of it. Then, one of those "ah-ha" moments: the reservoir is accepting the oil which is displaced by the shaft! The answer is almost too simple.
So basically the piston on in the reservoir is only moving a certain amount based on how much fluid the shock shaft is displacing.
No es aire es vacío👍
The piston isn't a complete seal. There are holes in the piston with stacks of small thin washers which are usually adjustable. They control oil flow. Damping is controlled by how fast oil is allowed to pass from one side of the piston to the other. The oil on the negative side will have a slight vacuum if the oil on the compression side can't travel through fast enough to fill the void/vacuum so they pressurize the whole system preventing the cavitation.
The answer is... It's the rod's volume that pushes it!
What I want to know is once cavitated how is the cavitation cured just by repressurizing the res? Wouldn’t the entire system need bled again once the air was sucked past the shaft seal or separator piston???
There is no extra air that was sucked in, the cavitation is only "bubbles" created by the super fast movement (too fast for the fluid's thickness and its surface tension to manage "pulling itself back together") This is creating really low pressure zones, allowing space between groups of molecules of the shock fluid, and it isn't able to revert back into being homogeneous - that is until the pressure is applied (This is a bad explanation I'm sorry, not a physicist) look up other videos/explanations of cavitation if you want to know more, it is fascinating and can erode and destroy equipment such as boat propellers or even diesel engines
Кто нибудь мне скажет для чего я это смотрю ночью? Я же ничего не понимаю...
I call "Fake Demo" on this. The cavitation is happening on the rebound side of the shock chamber. The rebound damping is typically much less than compression damping, and the max rebound rate is dependent on how hard the spring pulls the damper apart. In this case, the demo shows a machine pulling the damper apart which I would suspect is much harder than a spring would. Without numbers, this is just a "magic" demo to help sell you something. MO.
Idk what’s going on but I’d like to think some engineer is buggin out of this pump moving 2 inches every millisecond
How did I end up here?
Is that the purpose of those shocks with canister? I've always thought it was mor like a secondary suspension like when having maximum load or something. But int he demonstration they release the air and add the air back in, normally therea just a fix amount of air and vreasure in that canister right, or does it need topping up periodically or something to maintain a certain pressure for it to work against the cavitation?
The pressure in the nitrogen reservoir typically stays fixed until the sealing components wear out over a long time (possibly shorter under extreme use conditions). You don't want to try measuring the pressure in the cannister after it's pressurized since the amount of nitrogen that flows into the gauge will be enough to drop the pressure a good amount and require a refill. Shocks without the reservoir will typically still be pressurized, but the bladder is internal. Having the reservoir separate from the main tube is useful but for reason's I don't remember at this current time.
The piggy back or canister provides extra oil and surface area for cooling as well as giving the designers more space to add the valving and adjusters. An in-line shock with no canister still has a gas charge in it.
No. The piggy back canister is where the gas charge is. You need a gas volume because hydraulic fluid is essentially incompressible. Every stroke of the shock puts more or less of the shaft into the oil chamber, which will displace the volume of the shaft. If there were no gas chamber the body of the shock would explode under the oil pressure. The gas chamber gives the displaced oil somewhere to go.
จำลองโช๊คแก๊สหรอ
What is this?
So thats how a mayonaise is done?
very good video ... may i review the video again
What's a cavitation?
Why yes, of course, forsooth this is the case.
Woow
That's why it's expensive shockbreaker
i was thinking this is vodka
Ohlins shocks and suspension.
Seneng denger suaranya... plok koplokbkoplok... cretcretcrete....
Id love to run full Ohlins suspension on my CR500..
This looks like a modified version of a turbo encabulator
Shock absorbers tech
I should call her..
Кавитация?
I'm sorry, but my mental map is drifting somewhere else. 😏
Hadehh siti2
Can you service pressurized forks like normal forks?
The reservoir pressure is relieved prior to service, and recharged once the unit is reassembled. For a fork, the reservoir is just the top section of the cartridge, separated from the oil by a floating piston.
Why mans touching it like that?
Anyone else rocking their head in sync with the piston??
maybe u mom
Could this be converted for more personal intimate use? Asking for a friend
And for educational purpose
I wonder what substance turned that Bud Light so cloudy?
woketard pressurization
The science behind qeefs
is this a piston or a artificial heart model lol
WHAT IS THIS
Nice camera work🙄
The bike I like doesn't have gas charged monoshock 😭 only hydrolic monoshock
The forbidden vibrator.
This is why you should always buy shocks and brakes from big brand name companies... Yes you pay for the name but you get a far superior product with genuine RnD $ spent on it
Itu buat apa banh
Yeah that's great bartender but can I have my Pernod and lemonade now please?
Boing, boing, boing, boing, boing, boing, boing. Sorry if I got to technical.
Wait so if I have a cavitated shock and I just add the proper PSI back in to the IFP chamber will the shock automatically readjust and fix itself as demonstrated in the video?? Any insight from anyone would be appreciated. I'm about to rebuild a DHX2 mtb shock with the same issue and wondering if pressuring the IFP with nitrogen will fix it? Thanks!
The answer is NO in case anyone is curious haha. I didn't use Nitrogen, just air, but it did not fix the issue and have since rebuilt the entire shock successfully. So in case anyone is wondering, this is a unique setup clearly for demonstration purposes and would NOT simulate real world scenarios. Cheers!
I know this is a late response, but you are correct, it won't won't fix airation. Cavitation bubbles, like in the video, collapse and go away because it's the fluid changing states from liquid to gas and back, not introducing air from outside sources.
It's also that collapse that pits shims and other metal component's in your shock over time. That would be the issue with running a cavitating shock for too long (aside from probably feeling really crappy).
So the cavitation will occur inevitably during the usage of damper, right? Would this experiment provide any conclusion or just a show of this inevitable phenomenon?
@biteat what if that does not help?
@@isleofauto Your shock? I guess the common problem is in seals (o-rings) leaking.
@@ka81alex sorry i don't understand what you said.
@@isleofauto what's the model of your shock that you have cavitation problem with?
For example, if it's Fox X2 then it woun't be managed by regulating air pressure in IFP chamber like in this video. The problem with X2 is air-leaking cause of seals (o-rings).
@@ka81alex sorry i was asking about the damper on the video, not my car's damper.
Magnetorheological WHAT?
oh yes daddy
I though he was gonna whip out his peanuts or something
Last time I whipped out my peanuts I got arrested.
Whats up with the reservoir piston wobbling around?
As the shaft is entering the chamber it takes up volume.
The reservoir is pressurized against the piston but as the shaft enters its displacing the oil so the piston in the reservoir moves compressing the gas.
@randomotaku3283 no crap. I'm not talking about axial movement up and down I'm talking about wobbling. The correct answer is "the piston is a sloppy fit and loose in the bore, but it doesn't really matter because this is just a display/teaching aid" 🥱 do better. Of course I understand how a remote res. Shock works it's a simple thing.
This is absolutely bonkers! The pressure valve in combination the the cristaline supercunductors is aligned with the crankshaft of the hydrocarbolized extension sensors and thereby creates what is known as a Schliermann-Eibenbach-suction on the ventrical dome patch. Never seen that before!
Yes
What kind of gas they're putting in the can?
I would guess its nitrogen
doesnt matter from cavitation perspective, but does matter from perspective of shocks getting to very hot operating temps. Air pressure ramps up faster with increased temp compared pure nitrogen (difference is not drastically big but it is there). this is why nitrogen is used in gas chambers. Usual pressure is 10bar (145psi) at 20 C
my farts. best kind of gas imo
@@auomauom lamo.
@@michail1963 the main reason for pure nitrogen is the atoms are bigger than oxygen and will not permeate seals and leak as easily. You don’t want to have to charge your ifp all the time.