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Discussion Starter · #1 ·
somebody said there are no dumb questions so here it goes

what's the difference between compresion and rebound? does the former works when the suspension is being compressed, and the later when the suspension is recovering from the compresion? That is at least what I understand, but something tell me I'm missing something
 

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Bandolero
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ritopc said:
somebody said there are no dumb questions so here it goes

what's the difference between compresion and rebound? does the former works when the suspension is being compressed, and the later when the suspension is recovering from the compresion? That is at least what I understand, but something tell me I'm missing something
to my knowlege,it goes something like this.compresion dictaes how much travel you'll have,the more compresion you put in the fork or shock the less travel you'll have to your self(suspension will feel stiff)and viceversa the less compresion in the suspension the more travel youl'll have.
Rebound control's the speed at which the suspension returns to its normal posion after been compressed,the higher the rebound the faster the suspension returns to its normal position and viceversa.hope this help.later.
RCC.
 

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Bike to the Bone...
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As far as I understand, you adjust rebound damping to regulate how fast the fork/shock will return to 'normal' after being compressed. If you put it too fast, it will kick back at you after each bump, if you put it too slow, if you come up to a series of bump, it won't have time to return when the next bump comes up.

Compression is how hard a bump must be before moving the fork. If you put too much compression damping, the fork will be firmer, while less compression damping it will be more plush.
 

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Mexican e-rider
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I beat Warp to this reply! :D

Compression damping: The resistance offered by the shock to your weight and bumps from the road. It slows down the shock when you hit something, like rzozaya says, the more you have, the firmer the shock feels. This is usually controlled by an air spring or normal coil spring.

Rebound damping: After you compress a spring, it wants to regain its original shape, but the speed at which it does so can bee too fast. Rebound damping slows down the rebound and prevents it from launchin you from the bike

Some other terms:

Sag: The amount of preload you put on the suspension, its what RCC explained. You want to have some sag so when the wheel comes in to a depression, it still follows the terrain.

Stiction: The resistance every suspension has to start moving

Platform or slow speed damping: Its an artificial resistance the shock offers to start moving. This is usually incorporated so the suspension does not move when pedaling.

Hope I got it right
 

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Discussion Starter · #5 ·
elmadaleno said:
I beat Warp to this reply! :D

Compression damping: The resistance offered by the shock to your weight and bumps from the road. It slows down the shock when you hit something, like rzozaya says, the more you have, the firmer the shock feels. This is usually controlled by an air spring or normal coil spring.

Rebound damping: After you compress a spring, it wants to regain its original shape, but the speed at which it does so can bee too fast. Rebound damping slows down the rebound and prevents it from launchin you from the bike

Some other terms:

Sag: The amount of preload you put on the suspension, its what RCC explained. You want to have some sag so when the wheel comes in to a depression, it still follows the terrain.

Stiction: The resistance every suspension has to start moving

Platform or slow speed damping: Its an artificial resistance the shock offers to start moving. This is usually incorporated so the suspension does not move when pedaling.

Hope I got it right
So If I understood correct I was in the rigth track. They both work very similar to each other, the only difference being which direction of the stroke they affect. They're both related with the speed at which the suspension moves. The compression affects the compression stroke (duh!) so it makes the suspension feel stiffer when hitting something. Neither of them affect sag.
 

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"El Whatever"
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18,889 Posts
ritopc said:
So If I understood correct I was in the rigth track. They both work very similar to each other, the only difference being which direction of the stroke they affect. They're both related with the speed at which the suspension moves. The compression affects the compression stroke (duh!) so it makes the suspension feel stiffer when hitting something. Neither of them affect sag.
Yeah, you were right from the start and so did all the others.

Mada... nice suspensions skills!! :thumbsup:

Now... damping is a force opposing to the movement of a body. Damping is always realated to two parameters (this may sound simple, but it gets really complicated to calculate... actually, not even F1 teams calculate dampers and they rely more on practical testing)... that's speed and viscosity of the damping media. Commonly oil, but air can be used as well as water or else.

In a fork or shock, damping is achieved by a piston with orifices in either fixed or variable size that move thru an oil media. The oil can not be compressed (substantially, it's considered incompressible in engineering) and hence, trying to move an object across it will cause a force opposing to the input movement (Newton's 3rd Law). This force depends on the size of the orifices on the damper and these orifices may variate in size depending on the force generated by the pushing oil... and things get more complicated from there on.

Fixed size orifice dampers are SSV, SSVF, Fluid Flow, the Rebound of TST and Motion Control, etc. These are just a pushrod with a piston that has holes in it.

Variable size orifices dampers (called Speed Sensitive dampers) are HSCV, TPC, the Fox dampers, TPC+, TST Compression, RC2X, RC2, Motion Control's compression, Magura's Phaon and Albert Plus dampers. All of these have a piston with fixed size holes, PLUS a device closening or opening the orifices to allow more or less pass of oil... hence variating damping according to speed (force) input. This can be achieved by shims and in a more promitive way, with spring loaded "floodgates" (a very thick shim that is held closed by a spring and opens with the oil input.

Being viscosity equal (in a fork) for all conditions, that leaves damping as a function of speed. This means damping variates with speed. In a fork it means that depending on how the damper is designed, damping can cause to slow down the movement of the fork in several ways.

Damping can be separated into two ranges: low speed and high speed.

Low speed is when the shaft of the damper moves slow (it's not tied to the speed of the bike)... high speed the opposite.

Low speed compression examples are pedaling inputs, brake dive on the fork, and going over small stuff (ripples or whoops)

High Speed compression is when taking a big hit or sucession of big hits.

Low speed rebound is when the suspension rebounds after going over ripples, whoops, curbs, washboards or when exiting turns (have you felt how the bike moves when going out of turns?).

High speed are again, mostly after big hits... mostly landings.

Fixed orifices dampers have to be tuned for a narrow range of speed... that is, they feel good over small or big stuff and they feel like crap on the other. Most common problem with them is "spiking"... which happens when the speed is so high that the oil can't get thru the damper and kind of locks up making the fork feel harsh.

Variable size orifice dampers (speed sensitive) don't have problems with spiking. They're tuned to open more as speed increases... there may be a limit, but not easily reached by mere mortals.

Sorry for the delay... I have a job to attend :D
 

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moaaar shimz
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9,125 Posts
Warp said:
Yeah, you were right from the start and so did all the others.

Mada... nice suspensions skills!! :thumbsup:

Now... damping is a force opposing to the movement of a body. Damping is always realated to two parameters (this may sound simple, but it gets really complicated to calculate... actually, not even F1 teams calculate dampers and they rely more on practical testing)... that's speed and viscosity of the damping media. Commonly oil, but air can be used as well as water or else.

In a fork or shock, damping is achieved by a piston with orifices in either fixed or variable size that move thru an oil media. The oil can not be compressed (substantially, it's considered incompressible in engineering) and hence, trying to move an object across it will cause a force opposing to the input movement (Newton's 3rd Law). This force depends on the size of the orifices on the damper and these orifices may variate in size depending on the force generated by the pushing oil... and things get more complicated from there on.

Fixed size orifice dampers are SSV, SSVF, Fluid Flow, the Rebound of TST and Motion Control, etc. These are just a pushrod with a piston that has holes in it.

Variable size orifices dampers (called Speed Sensitive dampers) are HSCV, TPC, the Fox dampers, TPC+, TST Compression, RC2X, RC2, Motion Control's compression, Magura's Phaon and Albert Plus dampers. All of these have a piston with fixed size holes, PLUS a device closening or opening the orifices to allow more or less pass of oil... hence variating damping according to speed (force) input. This can be achieved by shims and in a more promitive way, with spring loaded "floodgates" (a very thick shim that is held closed by a spring and opens with the oil input.

Being viscosity equal (in a fork) for all conditions, that leaves damping as a function of speed. This means damping variates with speed. In a fork it means that depending on how the damper is designed, damping can cause to slow down the movement of the fork in several ways.

Damping can be separated into two ranges: low speed and high speed.

Low speed is when the shaft of the damper moves slow (it's not tied to the speed of the bike)... high speed the opposite.

Low speed compression examples are pedaling inputs, brake dive on the fork, and going over small stuff (ripples or whoops)

High Speed compression is when taking a big hit or sucession of big hits.

Low speed rebound is when the suspension rebounds after going over ripples, whoops, curbs, washboards or when exiting turns (have you felt how the bike moves when going out of turns?).

High speed are again, mostly after big hits... mostly landings.

Fixed orifices dampers have to be tuned for a narrow range of speed... that is, they feel good over small or big stuff and they feel like crap on the other. Most common problem with them is "spiking"... which happens when the speed is so high that the oil can't get thru the damper and kind of locks up making the fork feel harsh.

Variable size orifice dampers (speed sensitive) don't have problems with spiking. They're tuned to open more as speed increases... there may be a limit, but not easily reached by mere mortals.

Sorry for the delay... I have a job to attend :D
WWWWTTTTTFFFFF:eekster: :eek:

You should copy all that into Wikipedia dude, as well as all the other articles you've made!
 

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Me hates pinchflat
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Warp said:
Yeah, you were right from the start and so did all the others.

Mada... nice suspensions skills!! :thumbsup:

Now... damping is a force opposing to the movement of a body. Damping is always realated to two parameters (this may sound simple, but it gets really complicated to calculate... actually, not even F1 teams calculate dampers and they rely more on practical testing)... that's speed and viscosity of the damping media. Commonly oil, but air can be used as well as water or else.

In a fork or shock, damping is achieved by a piston with orifices in either fixed or variable size that move thru an oil media. The oil can not be compressed (substantially, it's considered incompressible in engineering) and hence, trying to move an object across it will cause a force opposing to the input movement (Newton's 3rd Law). This force depends on the size of the orifices on the damper and these orifices may variate in size depending on the force generated by the pushing oil... and things get more complicated from there on.

Fixed size orifice dampers are SSV, SSVF, Fluid Flow, the Rebound of TST and Motion Control, etc. These are just a pushrod with a piston that has holes in it.

Variable size orifices dampers (called Speed Sensitive dampers) are HSCV, TPC, the Fox dampers, TPC+, TST Compression, RC2X, RC2, Motion Control's compression, Magura's Phaon and Albert Plus dampers. All of these have a piston with fixed size holes, PLUS a device closening or opening the orifices to allow more or less pass of oil... hence variating damping according to speed (force) input. This can be achieved by shims and in a more promitive way, with spring loaded "floodgates" (a very thick shim that is held closed by a spring and opens with the oil input.

Being viscosity equal (in a fork) for all conditions, that leaves damping as a function of speed. This means damping variates with speed. In a fork it means that depending on how the damper is designed, damping can cause to slow down the movement of the fork in several ways.

Damping can be separated into two ranges: low speed and high speed.

Low speed is when the shaft of the damper moves slow (it's not tied to the speed of the bike)... high speed the opposite.

Low speed compression examples are pedaling inputs, brake dive on the fork, and going over small stuff (ripples or whoops)

High Speed compression is when taking a big hit or sucession of big hits.

Low speed rebound is when the suspension rebounds after going over ripples, whoops, curbs, washboards or when exiting turns (have you felt how the bike moves when going out of turns?).

High speed are again, mostly after big hits... mostly landings.

Fixed orifices dampers have to be tuned for a narrow range of speed... that is, they feel good over small or big stuff and they feel like crap on the other. Most common problem with them is "spiking"... which happens when the speed is so high that the oil can't get thru the damper and kind of locks up making the fork feel harsh.

Variable size orifice dampers (speed sensitive) don't have problems with spiking. They're tuned to open more as speed increases... there may be a limit, but not easily reached by mere mortals.

Sorry for the delay... I have a job to attend :D
Wow........thats a great explanation :eekster:
 

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Registered
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Warp said:
Yeah, you were right from the start and so did all the others.

Mada... nice suspensions skills!! :thumbsup:

Now... damping is a force opposing to the movement of a body. Damping is always realated to two parameters (this may sound simple, but it gets really complicated to calculate... actually, not even F1 teams calculate dampers and they rely more on practical testing)... that's speed and viscosity of the damping media. Commonly oil, but air can be used as well as water or else.

In a fork or shock, damping is achieved by a piston with orifices in either fixed or variable size that move thru an oil media. The oil can not be compressed (substantially, it's considered incompressible in engineering) and hence, trying to move an object across it will cause a force opposing to the input movement (Newton's 3rd Law). This force depends on the size of the orifices on the damper and these orifices may variate in size depending on the force generated by the pushing oil... and things get more complicated from there on.

Fixed size orifice dampers are SSV, SSVF, Fluid Flow, the Rebound of TST and Motion Control, etc. These are just a pushrod with a piston that has holes in it.

Variable size orifices dampers (called Speed Sensitive dampers) are HSCV, TPC, the Fox dampers, TPC+, TST Compression, RC2X, RC2, Motion Control's compression, Magura's Phaon and Albert Plus dampers. All of these have a piston with fixed size holes, PLUS a device closening or opening the orifices to allow more or less pass of oil... hence variating damping according to speed (force) input. This can be achieved by shims and in a more promitive way, with spring loaded "floodgates" (a very thick shim that is held closed by a spring and opens with the oil input.

Being viscosity equal (in a fork) for all conditions, that leaves damping as a function of speed. This means damping variates with speed. In a fork it means that depending on how the damper is designed, damping can cause to slow down the movement of the fork in several ways.

Damping can be separated into two ranges: low speed and high speed.

Low speed is when the shaft of the damper moves slow (it's not tied to the speed of the bike)... high speed the opposite.

Low speed compression examples are pedaling inputs, brake dive on the fork, and going over small stuff (ripples or whoops)

High Speed compression is when taking a big hit or sucession of big hits.

Low speed rebound is when the suspension rebounds after going over ripples, whoops, curbs, washboards or when exiting turns (have you felt how the bike moves when going out of turns?).

High speed are again, mostly after big hits... mostly landings.

Fixed orifices dampers have to be tuned for a narrow range of speed... that is, they feel good over small or big stuff and they feel like crap on the other. Most common problem with them is "spiking"... which happens when the speed is so high that the oil can't get thru the damper and kind of locks up making the fork feel harsh.

Variable size orifice dampers (speed sensitive) don't have problems with spiking. They're tuned to open more as speed increases... there may be a limit, but not easily reached by mere mortals.

Sorry for the delay... I have a job to attend :D
HAHAHAHAHAHAHAHA DAMN MAN! YOU'RE INSANE!!!!
AND HERE i PRESENT YOU THE ALL MIGHTY SKILLS OF OUR UNIQUE PROPHET! YEAAAAAAAAAAAAAAA
 
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