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.
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
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
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.
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.
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.
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.
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).
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.
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.
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
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
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.
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.
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.
Demonstration can't get much clearer than that👏
Probably my favorite video on shock cavitation
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。
Cool. Great way to visualize cavitation
This is how I picture a bump generator!? And you can charge it with air…love it.
Enjoyed watching this ,very cool 😀👍
So it seems that beer foam from shocks could come from air leaking through the bladder, not bleeding properly OR not enough pressure
That was a cool video. Always neat seeing stuff you normally can't. Learning a lot from these comments 🤣🤣🤣🤣🤣 smh
感恩了解，謝謝分享！
So when the shock extends and sounds like "it's working" it was really failing due to cavitation. Great information.
Thanks
Wow! An interesting and informative video on TH-cam.
That's cool. You know it happens but really cool to see it
thats why pressurise shocks, but vaccumise oil at bleeding?
Hey friend, can you make this with difference 5wt vs 30wt oil?
Do you work for Multimatic per chance? That gold gas reservoir cap is VERY familiar..
I learned something today.
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
That a cool demo
You got "steady shot" on that thing? Pretty cool though👍
Aww yea, finally a tour of my man pump research facility
the ladies gonna love this
Yes I will after I install a full Ohlins setup on my CRF1000...
Has anyone checked at what psi it starts working and at what fluid temp?
"he is just a friend"
Looks like something that should be on the Hub
i have no idea on what it was, but my mind goes everywhere.. 😅
That is very pleasant and arousing to watch ❤
Very cool indeed.
What about using a spring instead of the pressure
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.
Nice good job
Didn't know what this was at first.
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.
wow..i'm shock 😱
Кавитация?
Shocking
This machine looks fairly familiar
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.
Super seal
Netflix : Hey are you still there?
Someone's daughter: .....
Wat
So that’s how a damper works.
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!
That's why it's expensive shockbreaker
What is this?
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
How did I end up here?
Your average cam girl would need a whole stream just learning to operate this
I feel like that rod needs to be pixelated out, lol
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.
i was thinking this is vodka
This looks like a modified version of a turbo encabulator
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's a cavitation?
Anyone else rocking their head in sync with the piston??
maybe u mom
what am i doing here?
Кто нибудь мне скажет для чего я это смотрю ночью? Я же ничего не понимаю...
I wonder what substance turned that Bud Light so cloudy?
woketard pressurization
Why yes, of course, forsooth this is the case.
Could this be converted for more personal intimate use? Asking for a friend
And for educational purpose
จำลองโช๊คแก๊สหรอ
Seneng denger suaranya... plok koplokbkoplok... cretcretcrete....
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.
Shock absorbers tech
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.
Very cool
Id love to run full Ohlins suspension on my CR500..
Idk what’s going on but I’d like to think some engineer is buggin out of this pump moving 2 inches every millisecond
I should call her..
Itu buat apa banh
The bike I like doesn't have gas charged monoshock 😭 only hydrolic monoshock
is this a piston or a artificial heart model lol
So thats how a mayonaise is done?
The science behind qeefs
Why mans touching it like that?
hello. How could I know at what distance to leave the separator piston of a Monotube shock absorber?
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).
Ohlins shocks and suspension.
The forbidden vibrator.
I though he was gonna whip out his peanuts or something
Last time I whipped out my peanuts I got arrested.
Magnetorheological WHAT?
Nice camera work🙄
very good video ... may i review the video again
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.
WHAT IS THIS
Woow
Why TH-cam?
Yeah that's great bartender but can I have my Pernod and lemonade now please?
....and there was ligth
oh yes daddy
there no Ohlin is good suspension until they install in my cars in my house, and I tested it by myself and drop some comments for review
2000.00 later.
what kind of machine is that test stand?
You know what kind of machine it is, don't play innocent
Shock dyno
Shock for motorcycle