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Thread: SPV Devolve

  1. #1
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    SPV Devolve

    This is for those guys out there with SPV forks who don't like the platform feel.

    I've taken the rebound check valve out of my SPV blacks and so far I like it. The fork is left without a platform but still has a useful amount of low speed damping which is tuned by the air pressure.
    My fork still doesn't have enough high speed damping, but I think this is a factor related to my machined down piston not displacing as much oil through the ports as a factory one would. I've got a few ideas I'm working on.

    This mod is easy if you know how to pull the lowers off your fork and it is completely reversable if you don't like the results.

    First depressurise the damper, then turn it upside down, remove the lowers (careful of any spilling lube oil) and remove the damper by removing the damper side endcap. Stroking the damper a few times with the fork inverted will reduce the amount of oil you lose when you withdraw it.

    The damper will look a lot like the one below. The rebound check valve and spring are inside the silver topcap, it simply unscrews and the valve with spring can be removed and put somewhere safe if you wish to reinstall it at a later date. Replace the cap, reassemble the fork and test ride.
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  2. #2
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    Quote Originally Posted by Dougal
    This is for those guys out there with SPV forks who don't like the platform feel.

    I've taken the rebound check valve out of my SPV blacks and so far I like it. The fork is left without a platform but still has a useful amount of low speed damping which is tuned by the air pressure.
    My fork still doesn't have enough high speed damping, but I think this is a factor related to my machined down piston not displacing as much oil through the ports as a factory one would. I've got a few ideas I'm working on.

    This mod is easy if you know how to pull the lowers off your fork and it is completely reversable if you don't like the results.

    First depressurise the damper, then turn it upside down, remove the lowers (careful of any spilling lube oil) and remove the damper by removing the damper side endcap. Stroking the damper a few times with the fork inverted will reduce the amount of oil you lose when you withdraw it.

    The damper will look a lot like the one below. The rebound check valve and spring are inside the silver topcap, it simply unscrews and the valve with spring can be removed and put somewhere safe if you wish to reinstall it at a later date. Replace the cap, reassemble the fork and test ride.

    i am interested in the ride report with this mod. i do like the feel of my SPV Minute but am always interested in hot-rodding my fork.
    Voltron

  3. #3
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    air pressures

    Quote Originally Posted by Dougal
    but still has a useful amount of low speed damping which is tuned by the air pressure.
    Are you still running air pressures in the same range as your stock SPV setup?

    Haven't done this to my fork yet, but I did the mod on my old SPV assembly (recently upgraded to evolve) to better understand your description. Was really easy and completely reversible as advertised.

  4. #4
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    Quote Originally Posted by AOK
    Are you still running air pressures in the same range as your stock SPV setup?

    Haven't done this to my fork yet, but I did the mod on my old SPV assembly (recently upgraded to evolve) to better understand your description. Was really easy and completely reversible as advertised.
    I'm liking the result much better than before hand. I've also modded the damper to give more high speed compression damping (this could be solely due to me machining it down in diameter earlier) and the result is almost pleasing. My last ride was at 50psi, I've dropped the damper pressure back to 40psi but haven't had a decent ride since.
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
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  5. #5
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    So I could get one of the 04 Minute Ones and end up with an adjustable
    travel fork WITHOUT spv? Hmmmm. How do these dampers compare to TPC
    and TPC+?

    patrick

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    What happens if you run <30psi SPV air pressure? I see that Manitou recommends >30psi I think, just curious if it's an option to use less air to reduce the platform.

    (I currently have an active rear shock, but considering an SPV fork on sale, so I want to balance the bike until I go platform rear)

  7. #7
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    Quote Originally Posted by fsrxc
    What happens if you run <30psi SPV air pressure? I see that Manitou recommends >30psi I think, just curious if it's an option to use less air to reduce the platform.

    (I currently have an active rear shock, but considering an SPV fork on sale, so I want to balance the bike until I go platform rear)

    No SPV pressure ==> no damping ==> damage.
    Long Live Long Rides

  8. #8
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    Quote Originally Posted by fsrxc
    What happens if you run <30psi SPV air pressure? I see that Manitou recommends >30psi I think, just curious if it's an option to use less air to reduce the platform.

    (I currently have an active rear shock, but considering an SPV fork on sale, so I want to balance the bike until I go platform rear)
    If you run no pressure, the compression circuit can't close itself. This means you've got no rebound damping either as the oil takes the easy way home.

    SPV without the platform still isn't as good as TPC+, but it's still good.
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  9. #9
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    TPC+ is opposite SPV

    Quote Originally Posted by Dougal
    If you run no pressure, the compression circuit can't close itself. This means you've got no rebound damping either as the oil takes the easy way home.

    SPV without the platform still isn't as good as TPC+, but it's still good.
    I haven't seen more than the Manitou diagrams and only demoed TPC+ and SPV. Manitou's web site may still have diagrams of TPC+

    From the diagrams it appears that TPC is about a 10mm range of no compression damping, or very fast/soft compression damping as the shock shaft begins movement before a normal slower shaft speed main circuit compression damping begins. The main circuit has shimmed blow-off valving for high shaft speed compliance for sharp hits. The initially freely fast/soft TPC+ damping range compensates for seal and bushing stiction that produces friction damping at the very start of shaft speed.

    In contrast, SPV restricts low shaft speed damping to rather slow/firm compression until shaft speed and hydraulic pressure blows open the main hydraulic port circuit. There is no shimmed high speed blowoff valving for sharp hits in the current SPV designs that I'm aware of.

    I have not ridden an SPV, Propedal, 5th Element shock that I liked for handling except with nearly 6 or more inches of travel. Others may like the firm handling for shorter travel.

    - ray

  10. #10
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    Quote Originally Posted by derby
    I haven't seen more than the Manitou diagrams and only demoed TPC+ and SPV. Manitou's web site may still have diagrams of TPC+

    From the diagrams it appears that TPC is about a 10mm range of no compression damping, or very fast/soft compression damping as the shock shaft begins movement before a normal slower shaft speed main circuit compression damping begins. The main circuit has shimmed blow-off valving for high shaft speed compliance for sharp hits. The initially freely fast/soft TPC+ damping range compensates for seal and bushing stiction that produces friction damping at the very start of shaft speed.

    In contrast, SPV restricts low shaft speed damping to rather slow/firm compression until shaft speed and hydraulic pressure blows open the main hydraulic port circuit. There is no shimmed high speed blowoff valving for sharp hits in the current SPV designs that I'm aware of.

    I have not ridden an SPV, Propedal, 5th Element shock that I liked for handling except with nearly 6 or more inches of travel. Others may like the firm handling for shorter travel.

    - ray

    Not quite right.
    The TPC compression damper works on displacement, because of this it isn't as sensitive to small impacts as a conventional monotube damper (think of a fox vanilla shock) due to needing a certain size impact to flow enough oil to physically open the shims.

    So manitou added a second floating compression piston (TPC+) which in my 00 year Xverts have 14mm of float. Because it's a displacement system, that 14mm of piston travel equates to 40mm of wheel travel. This gives a two stage compression damper with much better senstivity where each piston can be tuned individually throughout the speed range.

    On small impacts (less than 40mm from sag), the first piston floats with the moving oil and only the second (top) piston and shims are giving you damping. This is a far cry from no compression damping.
    After that 40mm, the lower piston hits it's stops, from this point the oil must flow throught both compression pistons and their shim stacks.

    The low speed compression adjuster on the top of a TPC fork controls the free flow of oil through the compression pistons. On a TPC+ fork it initally controls the oil flow between the pistons. Winding this up slows down the reaction of the floating piston, giving you more inital compression damping in addition to giving you more low speed compression damping.

    The shim stacks are not a high speed blow off (or blow open). They're actually proportional valves that open further depending on the velocity of the oil flow through them. The shape and size of the stack determines their behaviour to different oil flows (impacts).

    SPV is simply a pneumatic valve to hold a compression circuit closed. More pressure in the damper provides a firmer platform by placing more preload on the valve. SPV does blow open all the way to it's stop on fast hits, becoming yet another orifice damper.
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  11. #11
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    Quote Originally Posted by Dougal
    SPV is simply a pneumatic valve to hold a compression circuit closed. More pressure in the damper provides a firmer platform by placing more preload on the valve. SPV does blow open all the way to it's stop on fast hits, becoming yet another orifice damper.
    Does it mean that when the SPV valve opens, it operates like a FFD which has a shim-stacked rebound and orifice compression circuit? If that is true, doesn't that make it inferior to TPC?

  12. #12
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    Yea, what he said

    Quote Originally Posted by Dougal
    Not quite right.
    The TPC compression damper works on displacement, because of this it isn't as sensitive to small impacts as a conventional monotube damper (think of a fox vanilla shock) due to needing a certain size impact to flow enough oil to physically open the shims.


    So manitou added a second floating compression piston (TPC+) which in my 00 year Xverts have 14mm of float. Because it's a displacement system, that 14mm of piston travel equates to 40mm of wheel travel. This gives a two stage compression damper with much better senstivity where each piston can be tuned individually throughout the speed range.

    On small impacts (less than 40mm from sag), the first piston floats with the moving oil and only the second (top) piston and shims are giving you damping. This is a far cry from no compression damping.
    After that 40mm, the lower piston hits it's stops, from this point the oil must flow throught both compression pistons and their shim stacks.

    The low speed compression adjuster on the top of a TPC fork controls the free flow of oil through the compression pistons. On a TPC+ fork it initally controls the oil flow between the pistons. Winding this up slows down the reaction of the floating piston, giving you more initial compression damping in addition to giving you more low speed compression damping.

    The shim stacks are not a high speed blow off (or blow open). They're actually proportional valves that open further depending on the velocity of the oil flow through them. The shape and size of the stack determines their behavior to different oil flows (impacts).

    SPV is simply a pneumatic valve to hold a compression circuit closed. More pressure in the damper provides a firmer platform by placing more preload on the valve. SPV does blow open all the way to it's stop on fast hits, becoming yet another orifice damper.
    I was over generalizing.

    On a related topic, while researching better motorcycle suspension for my '02 ZX-6R I've run across what is termed "Gold-Valve Emulators" which are add-on valves for simple single port rod and shaft damping common in OEM oil bath forks (probably in mine, not sure). The add on valves are very much like SPV without using air pressure, actually more like Romic platform damping design, using an adjustable spring loaded ball check valve that opens more an more flow and less damping resistance as shaft speed increases. They apparently closely emulate shimmed valve port damper design for digressive resistance to compression travel speed, and are even more externally adjustable.

    Seems like Romic used "Gold Valve Emulator" type damping for platform combined with a type of shimmed valve for main compression damping.

    - ray

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    Quote Originally Posted by eastpeak
    Does it mean that when the SPV valve opens, it operates like a FFD which has a shim-stacked rebound and orifice compression circuit? If that is true, doesn't that make it inferior to TPC?
    Yes I believe SPV is inferior to TPC.

    Bear in mind that the piggy back rear shocks with SPV have additional compression circuits which may be shimmed (I don't own one to pull apart).
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
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  14. #14
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    New question here. Shim Stack

    i ride light and hate the feel of SPV over loose pebbles shale and rocks . I have been offered the option of removing the SPV and replacing with shim stack any thoughts,
    Love the single crown shermans and would hate to replace them

  15. #15
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    Quote Originally Posted by Mr Smith
    i ride light and hate the feel of SPV over loose pebbles shale and rocks . I have been offered the option of removing the SPV and replacing with shim stack any thoughts,
    Love the single crown shermans and would hate to replace them
    If you get TPC assemblies (compression and rebound) for a good price, then do it. If you keep your SPV assembly you can go back any time you choose.
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
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  16. #16
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    Hey Dougal-

    Any thoughts on the newer Intrinsic dampers? I've yet to ride one, but wondered if (theoretically) it's still inferior in ride quality to a TPC+ fork (like my current Travis).

    Tommy
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  17. #17
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    It does not act like a FFD, ever. The control valve will regulate oil flow as a function of the internal pressure inside the damper. With a velocity increase, the effictive "orfice" increases allowing more flow, like a shim stack would, the difference is that it's not as sensitive to speed as a shim stack. The idea is to make up for it with position sensitivity. It can be tuned to have less damping at 60in/sec at the beginning of the stroke than a shim stack, but have mroe damping at the end of the stroke at even a lower velocity.

    Let me try to explain it better. When we try to tune a set of CV/t shocks for a new application, we will take the OE shocks and dyno them, through the whole range of damping adjustments and speeds to find a baseline setting. Then we will tune our CV/t shocks to have less damping at the beginning of the stroke, about the same in the middle, and more damping at the end. The idea is, for the small bumps and ruts in the track where you are riding in your suspension, the compression damping is lighter, making the wheel be able to move out of the way of the small bumps more quickly and letting the wheel track the terrain more smoothly, but have the higher end travel damping to help absorb the larger impacts and landings.

    I can't comment on which is better, SPV or TPC+. I haven't ridden TPC+ very much. I will comment that I'm not satified with the performance of my Minute 2 fork. I can also comment that what has been done in MTB with CV/t technology is very crude and there's far more that can be done to improve its performance. It's very sad that I haven't been allowed to incorporate any new technology into the MTB shocks.

    BM
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    Quote Originally Posted by bmadau
    I can't comment on which is better, SPV or TPC+. I haven't ridden TPC+ very much. I will comment that I'm not satified with the performance of my Minute 2 fork. I can also comment that what has been done in MTB with CV/t technology is very crude and there's far more that can be done to improve its performance. It's very sad that I haven't been allowed to incorporate any new technology into the MTB shocks.

    BM
    What are your complaints about the minute 2? I rode a minute 1 and loved it. The only complaint I had was that it rode a little too high in the travel and was sketchy on jumps and drops.

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    I really didn't have any for the longest time. I rode in tight techy stuff where it's big bump absorbtion shined, and I didn't care about the small bump ride. The fast sections were pretty short and abrupt, less than one minute each. Then I went and started riding this fireroad climb, and on the way down the small chattery bumps are too harsh, where I could go as fast as I dared for 15minutes. It'd create a vibration in the bars that made holding on too hard, my hands would start to burn. On trails that have somewhat smooth sections in between rocks, step downs, waterbars and such, it works great. It definately pedals well. I think it suffers because the forks are 1:1 with the wheel, and directly in line with the handlebars, unlike a rear shock that levered 2~3:1 and the saddle/BB is in between the rear wheel and front wheel, to some degree.

    BM
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    Spv, Good And Bad ...

    [QUOTE=. I think it suffers because the forks are 1:1 with the wheel, and directly in line with the handlebars, unlike a rear shock that levered 2~3:1 and the saddle/BB is in between the rear wheel and front wheel, to some degree.BM[/QUOTE]

    Both my bikes have SPV front and rear and I can say that Im pretty happy with how well Swinger air shocks work on both back suspension systems. Interestingly, despite a big difference in suspension systems between my Giant Reign and my Vt ( shocks are identical and interchangeable ) Swinger shock does very well at letting these 6-ish inch travel bikes peddle well and soak up the bumps. On my Vt I have lots of sag (35%) and a high SPV setting while on my Reign I have 25% sag and a low SPV setting. After heaps of mucking about these settings seem to suit the suspension systems. This says a lot for the adaptability of the shock.

    Cant say the same for my forks, Nixon Platinum and Minute one. Bouncy on roots and rocks and quite unreliable. My Nixon packs down over multiple big hits. The SPV system has got a couple of of advantages on forks though ...

    1) anti-dive : under down hill hard braking both my forks seem to work quite well.

    2) The peddling efficiency ; five years ago who would of thought that we could trail ride a 6 inch fork.

    It would be great to be able to turn off SPV on the fly!!! (Like Rock shock pop-lock)

  21. #21
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    Quote Originally Posted by other aardvark
    2) The peddling efficiency ; five years ago who would of thought that we could trail ride a 6 inch fork.
    Your kidding right?

    6+ years ago.

    Funny, weighs the same as my current single crown fork...except the single crown has more travel and works far better
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    The good old days???!!!

    Quote Originally Posted by Jayem
    Your kidding right?

    6+ years ago.

    Funny, weighs the same as my current single crown fork...except the single crown has more travel and works far better
    Point taken !

    Oh, is it 2006 already.
    How about 10 years ago ?

    I can remember when Marzocchi Z 1 was the ultimate rough riding single crown fork. Ive still got my Z 1s (attached to my rocking chair as I ponder the good old days on the porch ). Funny how my Z 1s seem to soak up small and medium bumps better than my Nixon SPV forks...
    Last edited by other aardvark; 04-21-2006 at 11:59 PM.

  23. #23
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    Quote Originally Posted by other aardvark
    Funny how my Z 1s seem to soak up small and medium bumps better than my Nixon SPV forks...
    Well, there's no mystery there, the damping system in the Z1 is far better suited to absorbing impacts than SPV. SPV decreases suspension performance and ability to absorb impacts, becuase you're adding 100% compression damping to the "blowoff" point, and the harshness and lack of performance will always be there due to that fact.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

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    Could intrinsic be the answer???

    Quote Originally Posted by Jayem
    Well, there's no mystery there, the damping system in the Z1 is far better suited to absorbing impacts than SPV. SPV decreases suspension performance and ability to absorb impacts, becuase you're adding 100% compression damping to the "blowoff" point, and the harshness and lack of performance will always be there due to that fact.
    I hope to upgrade to the Intrinsic damping system soon as I can find some one to supply parts cause Ive read a review in an english mag on Nixon 06 fork and it seemed to compare favorably with other 6 inch forks, but I may try the "DEVOLVE" thing first.

    Do you know anything about "INTRINSIC"???

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    Quote Originally Posted by other aardvark
    I hope to upgrade to the Intrinsic damping system soon as I can find some one to supply parts cause Ive read a review in an english mag on Nixon 06 fork and it seemed to compare favorably with other 6 inch forks, but I may try the "DEVOLVE" thing first.

    Do you know anything about "INTRINSIC"???
    I don't know of anyone that's had the intrinsic damper open yet to see what's really going on in there (if it's really a form of SPV, or if it's more like a form of TPC).

    SPV is dying, it may never die due to some bikes that are inefficiant, but it seems like manitou is trying to fix something that should just go away. TPC+ performed far better than SPV, and ever since SPV came out, manitou has been trying to "fix" it...
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    The saga continues

    Quote Originally Posted by Jayem
    SPV is dying, it may never die due to some bikes that are inefficiant, but it seems like manitou is trying to fix something that should just go away. TPC+ performed far better than SPV, and ever since SPV came out, manitou has been trying to "fix" it...

    Tpc+ is certainly option Im considering but I think Intrinsic has a Spv effect without the high compression damping break away .

    Il will try and get a ride on Tpc + nixon but Nixon Intrinsic hasnt been released in Australia yet. Ive been Emailing a Texan who has had his 05 Nixon converted to Intrinsic and he is really happy.

    To see his review go to MTBR Nixon Platinum.2006. Sorry I dont have time to find the link for you cause Im going riding!!!

  27. #27
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    Quote Originally Posted by bmadau
    It does not act like a FFD, ever. The control valve will regulate oil flow as a function of the internal pressure inside the damper.
    In my experience the control valve spent a lot of it's time wide open against the stops. In this mode it behaves exactly like an orifice (FFD) damper. It's possible that running more air pressure will keep it off the stops more, but that will only make it flow less oil, making the ride harsher still.

    It's true that a wide open shim stack acts in a similar manner, but shim stacks seem to spend very little time that far open and have much stiffer intermediate stages where they actively meter the oil flow.
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  28. #28
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    Well, it doesn't. On an electromagnetic dyno it's easy to see that as the shock moves through the travel, the control valve gradually closes, creating a restriction which causes a pressure drop on the one side of the orifice resulting in a damping force (resistance force) that is a funciton of the internal pressure at that instant. If it were wide open, the damping wouldn't chagne. If it were wide open, whether at 50psi or 100psi, the damping would be the same. It's like a teeter totter- on one side you have the oil flow (velocity) imapcting the face of the control valve creating a force opening the valve, and on the other side you have a resisting force, internal pressure, holding it closed. In a wicked high speed impact, it might blow wide open. I don't know. I can't see inside of the damper to tell, and we don't have instrumented dampers with a limit switch to tell us if it blows wide open. Even so, it would never act like a FFD. An FFD has small orifices that create a restriction. The orifices in the piston (we call them ports, because they are pretty big) are really big. Wtih no control valve, your damping would be mostly a result of seal drag. The ports are too big to create any significant damping were it not for the control valve controling oil flow.

    Yes, shim stacks have more intermediate stages. A CV by itslef in the first half of the travel has almost no speed sensitive damping. the damping force at 1in/sec isn't much lower than at 30in/sec. Back in the day when the CV was introduced to the mtb market, this was a good thing, when platform (a word I've grown to hate) was a desired thing. The market has changed, and people don't want platform anymore, but that's another subject. The CV has more speed sensitive spread in the last half of the travel. For a shim stack to have as much low speed dmaping (5in/sec and lower, to filter out pedalling forces on older frames) its high speed damping would be far too excessive. For shim stacks, there is this compromise. Do I want high low speed damping or low high speed damping? In any damper, you can't 100% spereate them. The CV gives you this high low speed damping, which used to be desired, but also gives you low high speed damping for initial bump compliance. The wheel needs the accelerate to some velocity to get out of the way of a bump, doesn't it? So, there's far lower high speed damping, initially, to allow for this. If that's all you had, for instance if it werent' position sensitive, this low high speed damping would not dissapate enough bump energy and you would blow through your travel and bottom very harshly. the CV being postion sensitive, then builds damping through the travel, providing the necessary damping to absorb the bump energy, resisting bottomming.

    BM
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  29. #29
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    Quote Originally Posted by bmadau
    Well, it doesn't. On an electromagnetic dyno it's easy to see that as the shock moves through the travel, the control valve gradually closes, creating a restriction which causes a pressure drop on the one side of the orifice resulting in a damping force (resistance force) that is a funciton of the internal pressure at that instant. If it were wide open, the damping wouldn't chagne. If it were wide open, whether at 50psi or 100psi, the damping would be the same. It's like a teeter totter- on one side you have the oil flow (velocity) imapcting the face of the control valve creating a force opening the valve, and on the other side you have a resisting force, internal pressure, holding it closed. In a wicked high speed impact, it might blow wide open. I don't know. I can't see inside of the damper to tell, and we don't have instrumented dampers with a limit switch to tell us if it blows wide open. Even so, it would never act like a FFD. An FFD has small orifices that create a restriction. The orifices in the piston (we call them ports, because they are pretty big) are really big. Wtih no control valve, your damping would be mostly a result of seal drag. The ports are too big to create any significant damping were it not for the control valve controling oil flow.

    Yes, shim stacks have more intermediate stages. A CV by itslef in the first half of the travel has almost no speed sensitive damping. the damping force at 1in/sec isn't much lower than at 30in/sec. Back in the day when the CV was introduced to the mtb market, this was a good thing, when platform (a word I've grown to hate) was a desired thing. The market has changed, and people don't want platform anymore, but that's another subject. The CV has more speed sensitive spread in the last half of the travel. For a shim stack to have as much low speed dmaping (5in/sec and lower, to filter out pedalling forces on older frames) its high speed damping would be far too excessive. For shim stacks, there is this compromise. Do I want high low speed damping or low high speed damping? In any damper, you can't 100% spereate them. The CV gives you this high low speed damping, which used to be desired, but also gives you low high speed damping for initial bump compliance. The wheel needs the accelerate to some velocity to get out of the way of a bump, doesn't it? So, there's far lower high speed damping, initially, to allow for this. If that's all you had, for instance if it werent' position sensitive, this low high speed damping would not dissapate enough bump energy and you would blow through your travel and bottom very harshly. the CV being postion sensitive, then builds damping through the travel, providing the necessary damping to absorb the bump energy, resisting bottomming.

    BM

    You do realise I'm talking about an SPV manitou black? Not a 5th or manitou rear shock.

    I know the SPV valve spends a lot of it's time wide open because adding or removing shims to it's stop (changing the wide open position by 0.3mm at a time) creates an effect easily noticed while riding.

    Dished pistons in conjunction with shim stacks can create whatever opening force (platform) is necessary. I'm currently running this setup in the koni's on my range rover. It's not externally adjustable like a control valve though, a revalve requires a strip down.
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    Alright, you got me. I never dyno'd anything by Manitou, especially a fork. The first 1/2 of travel on my couple year old minute 2 doesn't seem to have any damping, and on small bumps it tops out with a slight clunk, which is annoying while climbing. I'm too lazy to take it apart and try to fix it, or even trick it out with custom tuning, partly because it's my only fork and I can't afford to have my bike down for any amount of time (main form of transportation, currently)

    IMO, for a fork, the control valve would be best located in a base valve assembly (like in the place of the TPC valve). Being a 1:1 rate, damping doesn't need to be much, and it'd be alot easier to regulate if you only metered shaft displacement oil, rather than the full piston area. Coming off the TPC+ idea, having a control valve that can float a mm or two would be interesting to see how it would affect the nose of the damping curve. And then, if the CV was in a base valve assembly, it'd be possible to have an adjustable bleed bypass for those who may want less low speed damping.... Oh the possibilites....

    BM
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  31. #31
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    spv replaced with tpc+ mystery

    Quote Originally Posted by Dougal
    If you get TPC assemblies (compression and rebound) for a good price, then do it. If you keep your SPV assembly you can go back any time you choose.

    Am I reading this right? I just got an 05 Minute 3 to replace my aged 01 XVert Super, and if I wanted to I could do a swap with the SPV for the TPC+? How is that accomplished?

  32. #32
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    Quote Originally Posted by pan
    Am I reading this right? I just got an 05 Minute 3 to replace my aged 01 XVert Super, and if I wanted to I could do a swap with the SPV for the TPC+? How is that accomplished?
    Manitou black TPC assemblies will fit that fork. But they changed the rebound piston size around 04, you'll have to make sure you get the appropriate rebound assembly.
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  33. #33
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    devolved sherman with blown seals

    Dougal, are you still riding your devolved manitou with success?

    The reason I ask is that I took the valve out of my Sherman per your instructions, feels much better by the way, but on my first ride out oil was seeping through the dust wiper on the damper side. I don't know if this is a coincidence, or because of the valve removal.

    Any insight here?

    thanks

  34. #34
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    Quote Originally Posted by goatboy001
    Dougal, are you still riding your devolved manitou with success?

    The reason I ask is that I took the valve out of my Sherman per your instructions, feels much better by the way, but on my first ride out oil was seeping through the dust wiper on the damper side. I don't know if this is a coincidence, or because of the valve removal.

    Any insight here?

    thanks
    Your stanchion endcap is either leaking damper oil into the lowers, or you have too much oil in the splash bath.

    I'd pull the lowers and check the stanchion endcap, it's highly likely that there is some crap stopping the endcap oring from sealing. If that is good, then check you haven't got too much lube oil (if you're using oil).
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    i just got some slider pluses and i love em. I have been thinkin of devolving them and using them as a downhill ace fork. is there any cons to this as opposed to running it with the chack valve in place. will i lose bottomout resistance.

    also this is a wier question but could i retrofit my 03 sherman breakout 6" tpc+ system to the slider plus with 170mm travel spv

    thanks a bunch

    dougal and bmadau seem to be the expert lol

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    oh yea and what will be the effects on the pressure and volume adjustments on bottom out and rebound with the valve removed

    thanks

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    Hey guys, I am going to de-evlove my sherman slider later this week so I will give you an update on how it feels.

  38. #38
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    Quote Originally Posted by bElliott
    i just got some slider pluses and i love em. I have been thinkin of devolving them and using them as a downhill ace fork. is there any cons to this as opposed to running it with the chack valve in place. will i lose bottomout resistance.

    also this is a wier question but could i retrofit my 03 sherman breakout 6" tpc+ system to the slider plus with 170mm travel spv

    thanks a bunch

    dougal and bmadau seem to be the expert lol
    It will give the fork a little less bottomout resistance. But increasing the air pressure a little will bring it back.
    The major benefit of this mod is the complete reversibility. If you don't like it then replacing the check valve is an easy job.

    Yes you could convert your fork to TPC. I have an 03 Slider with TPC, let me know if you need any measurements.
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    ok thanks, im gonna get some real ride time on it, then ill devolve it and give some reviews

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    faster rebound needed

    Even after changing my sherman to a lighter weight fork oil in the rebound, the rebound is still too slow for my liking. I've heard to drill a larger hole in the damper for quicker rebound. Could somebody please give me more detail exactly where in the damper? A picture would be great.

    Thanks all

  41. #41
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    Quote Originally Posted by Rocker T
    Even after changing my sherman to a lighter weight fork oil in the rebound, the rebound is still too slow for my liking. I've heard to drill a larger hole in the damper for quicker rebound. Could somebody please give me more detail exactly where in the damper? A picture would be great.

    Thanks all
    Rather than drill anything, why not remove some rebound shims to speed it up a bit?

    Just make sure to make notes of the original stack (don't ask why I mention this) then remove a couple and test it out.

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    sherman firefly........SPV

    Sorry, forgot to mention that the needed quicker rebound was on a sherman with SPV. Didn't know SPV's came with shimes or does it???

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    did you try the devolve, it is to my understanding that this will increase rebound speed as well

    one more question for you guys, the check valve opens more depending upon the hit? so if you landed say a drop to flat and blew the check valve wide open, then shouldnt it be the same as it removed in terms of bottom out, wouldnt the removal only affect the "low-speed" hits

    i may be totally wrong and probly am but i may as well try to get some clarification

  44. #44
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    Quote Originally Posted by Rocker T
    Sorry, forgot to mention that the needed quicker rebound was on a sherman with SPV. Didn't know SPV's came with shimes or does it???
    SPV manitous have shims on the rebound side. I removed one or two (can't remember) from the SPV assembly I originally devolved to speed up the rebound as well.

    Devolving an SPV fork will only have a tiny effect on the rebound speed. It'll make it a fraction faster as the oil doesn't have to work against the spring and cap to get through the centre port.
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  45. #45
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    Quote Originally Posted by bElliott
    did you try the devolve, it is to my understanding that this will increase rebound speed as well

    one more question for you guys, the check valve opens more depending upon the hit? so if you landed say a drop to flat and blew the check valve wide open, then shouldnt it be the same as it removed in terms of bottom out, wouldnt the removal only affect the "low-speed" hits

    i may be totally wrong and probly am but i may as well try to get some clarification
    The check valve is closed for the entire compression stroke. It only opens on rebound.

    Removing the check valve gives an SPV fork an internal oil bypass. This lets the fork move on small bumps.
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    Hope shims???

    Yup, removing the check valve in the SPV assembly only speeds up the rebound by alittle. Now I have to disassemble again to remove the shim(s). So exactly which part is the shim in the SPV assembly? Pictures would really help.

    Thanks again

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    ok thanks for clearing that up ithink i may have had it right just completely backwards lol

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    Ack, I can't get my silver top cap to unscrew. Anyone have any tips?

  49. #49
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    Quote Originally Posted by Rocker T
    Yup, removing the check valve in the SPV assembly only speeds up the rebound by alittle. Now I have to disassemble again to remove the shim(s). So exactly which part is the shim in the SPV assembly? Pictures would really help.

    Thanks again
    There are pictures 2 or 3 posts up of the assembly showing the shims. Its basically a paper thin washer.

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    Quote Originally Posted by Buzam
    Ack, I can't get my silver top cap to unscrew. Anyone have any tips?
    What silver top cap you talking about?

    If you're talking about a shraeder air cap, try pliers (you may want to turn the SPV volume adjuster in, out of the way first). For the fork top cap, the correct socket size does it best. An adjustable wrench works in a pinch, but it's easy to strip/round the flats on the aluminum cap.

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    It was the top cap in the picture above, I eventually got it off with the gentel help of some vice grips..

  52. #52
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    Dougal,

    I am planning to devolve my Minute 3, but will probably do it this winter since I just serviced the fork in the Spring and updated the damper assembly to SPV Evolve. In the mean time I have been experimenting with different SPV and main spring settings in an effort to improve the small bump compliance. My riding weight with gear is ~185 lbs. and I ride XC single track with no drops larger than about 2 ft. My bike is a Ventana El Saltamontes, with 5" travel and a Pushed Fox Float R rear shock. If you don't mind, could you comment on my current and planned settings:

    Current Settings: SPV pressure = 45 psi; SPV volume = full open; Rebound = 1/2 turn in; Main air spring pressure = 87 psi; Sag = 18 mm; Travel = 130 mm

    Proposed Settings: SPV pressure = 35 psi; SPV Volume = 2 turns in; Rebound = 1/4 turn in; Main air spring pressure = 90 psi; Sag = tbd; Travel = 130 mm

    Any feedback or suggestions would be greatly appreciated.

    Thanks!

  53. #53
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    Quote Originally Posted by FrankinMich
    Dougal,

    I am planning to devolve my Minute 3, but will probably do it this winter since I just serviced the fork in the Spring and updated the damper assembly to SPV Evolve. In the mean time I have been experimenting with different SPV and main spring settings in an effort to improve the small bump compliance. My riding weight with gear is ~185 lbs. and I ride XC single track with no drops larger than about 2 ft. My bike is a Ventana El Saltamontes, with 5" travel and a Pushed Fox Float R rear shock. If you don't mind, could you comment on my current and planned settings:

    Current Settings: SPV pressure = 45 psi; SPV volume = full open; Rebound = 1/2 turn in; Main air spring pressure = 87 psi; Sag = 18 mm; Travel = 130 mm

    Proposed Settings: SPV pressure = 35 psi; SPV Volume = 2 turns in; Rebound = 1/4 turn in; Main air spring pressure = 90 psi; Sag = tbd; Travel = 130 mm

    Any feedback or suggestions would be greatly appreciated.

    Thanks!
    I'm afraid commenting on other peoples setup numbers is a little like commenting on their shoe size. It's impossible from numbers to tell how well something fits someone else.

    But I did find from my SPV experiments that it took a rear shock with a prominent platform to make the bike feel balanced with an SPV fork on it. Even devolved my romic still felt softer.
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  54. #54
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    Quote Originally Posted by Rocker T
    Yup, removing the check valve in the SPV assembly only speeds up the rebound by alittle. Now I have to disassemble again to remove the shim(s). So exactly which part is the shim in the SPV assembly? Pictures would really help.

    Thanks again
    The rebound shims are on top of the piston, they come off when you've undone the silver topcap you see in the photos. They're circular metal discs about 0.1mm thick each.
    There's a conical stack of them, leave the largest one in place (it is needed to cover the piston holes) and experiment by removing or changing the position of the rest of them.
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  55. #55
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    So tell me more about the

    Devolved Romic. I havent been inside a coil/oil rear shock since you helped me rebuild my RS Deluxe 9 years ago. I love my Romic, had two replaced one with RP3 and is only marginally better, and much better than the Pushed Vanilla R I have. Cheers, Jim

  56. #56
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    Quote Originally Posted by FrankinMich
    Dougal,

    I am planning to devolve my Minute 3, but will probably do it this winter since I just serviced the fork in the Spring and updated the damper assembly to SPV Evolve. In the mean time I have been experimenting with different SPV and main spring settings in an effort to improve the small bump compliance. My riding weight with gear is ~185 lbs. and I ride XC single track with no drops larger than about 2 ft. My bike is a Ventana El Saltamontes, with 5" travel and a Pushed Fox Float R rear shock. If you don't mind, could you comment on my current and planned settings:

    Current Settings: SPV pressure = 45 psi; SPV volume = full open; Rebound = 1/2 turn in; Main air spring pressure = 87 psi; Sag = 18 mm; Travel = 130 mm

    Proposed Settings: SPV pressure = 35 psi; SPV Volume = 2 turns in; Rebound = 1/4 turn in; Main air spring pressure = 90 psi; Sag = tbd; Travel = 130 mm

    Any feedback or suggestions would be greatly appreciated.

    Thanks!
    FWIW I also have a Minute 3, and currently run:

    SPV pressure = 35-40psi, volume = full, rebound = fastest, main air spring = ~130psi, and I weigh ~160lbs, so I'm surprised your main pressure is so much lower! I am planning to drop mine a bit, but I'm using using ~100mm of travel on most rides, so it doesn't seem way too high anyway. Is yours the same fork? ('05 with 30mm stanchions)

  57. #57
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    Quote Originally Posted by jimbo2k
    Devolved Romic. I havent been inside a coil/oil rear shock since you helped me rebuild my RS Deluxe 9 years ago. I love my Romic, had two replaced one with RP3 and is only marginally better, and much better than the Pushed Vanilla R I have. Cheers, Jim
    Sorry that was just my badly worded post.
    I haven't devolved my romic, I was trying to say that with a devolved fork the romic was a better match.

    I've mainly been inside fox shocks recently. I have yet to tackle the romic, but it's day is coming as the rebound plays games (slow, slow, fast, slow etc).
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    Parking Lot Test:

    Iíve got to say I am stoked on this mod so far. The fork feels awesome, much more plush and forgiving. With about the same SPV settings as before (45psi and 1 turn of bottom out) the fork feels way more active when pedaling. Hopefully this translates into way better small bump feel. Also, it feels like I am using more of my travel when I bounce on the fork. I tried the fork with a higher SPV air pressure (85psi). It made a noticeable difference in the low speed compression dampening; the fork basically acted like it did with the platform (much firmer under pedaling). My only concern is that now the fork may blow through its travel on larger hits. I will test it out this weekend at Mt. Washington and see what kind of set-up yields the best results.

    Cheers
    Scott

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    i devovled my slider luses and they are sooooooooo plush, almost too plush and the bottom easily, what do you think of some 15wt oil to give some bottoming resistance

  60. #60
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    Minute 3 set up

    Quote Originally Posted by fsrxc
    FWIW I also have a Minute 3, and currently run:

    SPV pressure = 35-40psi, volume = full, rebound = fastest, main air spring = ~130psi, and I weigh ~160lbs, so I'm surprised your main pressure is so much lower! I am planning to drop mine a bit, but I'm using using ~100mm of travel on most rides, so it doesn't seem way too high anyway. Is yours the same fork? ('05 with 30mm stanchions)
    My fork is a 2004 with an upgraded 2005 Evolve damping assembly -- it has 30mm stanchions. Manitou recommends a main air spring setting of 50% of your riding weight when using the 130mm travel setting. Given that, my 90 psi is just about right (supposedly). I had been running my SPV air volume at full open and my SPV pressure at 45-50psi. When I dropped my SPV pressure to 35 psi I dialed down my volume 2 turns to prevent any bottoming. I used to run my rebound at full open (i.e. fastest), but cranked that down 1/4 turn recently and I like the overall ride better.

    My biggest problem is that I have never been able to get close to the 27-30mm sag that Manitou recommends for the 130mm travel setting. With my current settings I can only achieve 18mm of sag. I am not sure how to get to the recommended sag number.

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    Trail test:

    Fork feels great. I increased the BO by about 1.5 turns and off good sized drops it doesn't bottom harsh. On the trail the fork feels great, plush but not too plush. I really notice the change on a section where I had a short but fast descent on a rocky fire road before my front end would have jumped around but this time it felt smooth. There is a noticable increase in pedal induced bob, but not enough to make me want to ever reverse this process on my slider.

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    two thumbs up

    The devolve sherman and faster rebound works much better.

    Thanks guys for the help

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    Quote Originally Posted by Rocker T
    The devolve sherman and faster rebound works much better.

    Thanks guys for the help
    do you mean faster rebound from the devolve mod, or did you change out rebound shims too?

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    did both, devolve to get small bump compliance and removed the large shims for faster rebound.

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    Quote Originally Posted by bElliott
    i devovled my slider luses and they are sooooooooo plush, almost too plush and the bottom easily, what do you think of some 15wt oil to give some bottoming resistance
    Have you tried more SPV pressure and/or less SPV volume first?

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    Quote Originally Posted by Rocker T
    did both, devolve to get small bump compliance and removed the large shims for faster rebound.
    what about climbing, if you stand up and mash, how bad does the front end react? did you put in a heavier spring?
    "He can make even a global summit meeting seem like a kegger." M. Dowd, NY Times, 19 July 2006

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    plush.......

    Quote Originally Posted by adamantane
    what about climbing, if you stand up and mash, how bad does the front end react? did you put in a heavier spring?
    If you stand up and mash to climb then it'll bob big time. That's even when you do have SPV. Maybe unless if you max out the SPV pressure you won't get bobbing? But remember it'll be very harsh on small pumps. I've devolve because I prefer the small bump compliance for trail riding. I've learned to do short sprints by pulling up on the handle bars and or longer climbs by sitting and spinning to get less bob.

    "How bad does the front end react?" If you mean break dive, I haven't noticed to bother me. Maybe it's the way I ride or I'm nieve. No bads, I like what I've done to the fork.

    I've actually put in a softer spring and use the other leg as air pre-load. I'm <160 pounds and 2-3' drops haven't bottom out the sherman yet. When in my dreams, I do 10'+ drops I'll put the medium ti spring back in.

    SPV with an on/off switch like the other brands is the way to go.

  68. #68
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    Quote Originally Posted by adamantane
    what about climbing, if you stand up and mash, how bad does the front end react? did you put in a heavier spring?
    That's really a bad way to climb and any form of suspension is going to let you know that.

    If you can learn to pedal hard uphill without bobbing all over the place, then your riding (and climbing) will improve no end.
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
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  69. #69
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    Quote Originally Posted by Dougal
    It will give the fork a little less bottomout resistance. But increasing the air pressure a little will bring it back.
    The major benefit of this mod is the complete reversibility. If you don't like it then replacing the check valve is an easy job.

    .
    Assuming you do the Devolve mod. Does adding oil to the SPV air chamber have any effect on the tunablility of the bottomout? Or is it the same effect as increasing air pressure?

  70. #70
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    Quote Originally Posted by racerzero
    Assuming you do the Devolve mod. Does adding oil to the SPV air chamber have any effect on the tunablility of the bottomout? Or is it the same effect as increasing air pressure?
    Adding oil has the same effect as winding in the volume adjuster.
    It ramps the internal pressure up more towards bottom out.

    Too much and you'll restrict travel with the possiblity of blowing oil past the seals.
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  71. #71
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    Quote Originally Posted by Dougal
    Adding oil has the same effect as winding in the volume adjuster.
    It ramps the internal pressure up more towards bottom out.

    Too much and you'll restrict travel with the possiblity of blowing oil past the seals.
    Ok forget the oil.

    So for tuning purposes on a Devolve fork the Volume Adjust is to adjust for bottom out and former SPV air pressure is to adjust for compression speed. If the SPV air is now for compression adjustment, what range does the compression work in. High speed or low speed?

  72. #72
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    Quote Originally Posted by Dougal
    Adding oil has the same effect as winding in the volume adjuster.
    It ramps the internal pressure up more towards bottom out.

    Too much and you'll restrict travel with the possiblity of blowing oil past the seals.

    Another question about adding oil. I have a 5th Element 3-way rear shock that does not have the volume adjuster on it. It does have an SPV air valve. Can I add oil to the SPV air chamber to resist bottoming out?

  73. #73
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    Quote Originally Posted by racerzero
    Another question about adding oil. I have a 5th Element 3-way rear shock that does not have the volume adjuster on it. It does have an SPV air valve. Can I add oil to the SPV air chamber to resist bottoming out?
    Yes it should work in the same way. But there may be good reasons why 5th didn't include a volume adjuster.

    I'd send a message to bmadau on these forums about it, he does have inside knowledge.
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    ok i've devolved th eslider plus but ive found it bottoms out way too easily. so im thinkin of puttin the check valve back in with some lighter than stock oil. im also thinkin of foolin with the rebound shims as well. to do this i should leave the lrger ones on and take the smaller ones off as stated before right? if i remove thes rebound shims, it will lower compression dampening as well right?

    this is a sweet thread

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    Techno Overload

    Guys: The R7 is the right length and weight for me. Can I gather from this thread that the R& Super would be more progressive w/better comp/rebound damp? Would it also be the most adjustable? Lock out is a wash out for me. I want suspension that works. Can it be removed? I didn't mean to hijack the thread, I'm trying to pin this down before buying.

    Sorry

    Ricisan

  76. #76
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    Quote Originally Posted by bElliott
    ok i've devolved th eslider plus but ive found it bottoms out way too easily. so im thinkin of puttin the check valve back in with some lighter than stock oil. im also thinkin of foolin with the rebound shims as well. to do this i should leave the lrger ones on and take the smaller ones off as stated before right? if i remove thes rebound shims, it will lower compression dampening as well right?

    this is a sweet thread
    Rebound shims only affect the rebound damping. They have no effect on compression.
    It's also a good idea to only make one change to your fork at a time. Go to lighter oil <b>or</b> change the rebound shims, don't do both at once or you can easily go too far.

    Try running your fork with more SPV air pressure. Unless you especially like the platform feel it'll work better this way than with lighter oil and the check valve in.
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  77. #77
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    Quote Originally Posted by Ricisan
    Guys: The R7 is the right length and weight for me. Can I gather from this thread that the R& Super would be more progressive w/better comp/rebound damp? Would it also be the most adjustable? Lock out is a wash out for me. I want suspension that works. Can it be removed? I didn't mean to hijack the thread, I'm trying to pin this down before buying.

    Sorry

    Ricisan
    You can remove the lockout, but you need to find a compatible compression assembly to put in it's place.
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    i think iim gonna put heavier weight oil in it as is. the if the rebound is too slow ill remove some shims.

    like i said small first when takin the shims off right? ive tried puttin more pressure in it but it like to bottom. how many shims can i take off, as in whats the limit

  79. #79
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    Quote Originally Posted by bElliott
    i think iim gonna put heavier weight oil in it as is. the if the rebound is too slow ill remove some shims.

    like i said small first when takin the shims off right? ive tried puttin more pressure in it but it like to bottom. how many shims can i take off, as in whats the limit
    Hm, mine had one small, and two large shims, so I removed one of the large ones. I wasn't sure if removing the small shim would stress the large ones?
    Is this what most people have? (1 small, 2 large rebound shims)
    What's the recommended shim to remove to speed up the "real" (trail speeds) rebound range a bit?

    Dougal?

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    Hi there. Hi have a Manitou Sherman Breakout Plus I bought 1 month ago. I'm satisfied with the fork except for the very slow rebound. Do I have to remove the oil if I remove the rebound shim ?

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    you will have to remove and replace the semibath oil, but if you flip the fork upside down, you can leave the dampening oil

  82. #82
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    Quote Originally Posted by fsrxc
    Hm, mine had one small, and two large shims, so I removed one of the large ones. I wasn't sure if removing the small shim would stress the large ones?
    Is this what most people have? (1 small, 2 large rebound shims)
    What's the recommended shim to remove to speed up the "real" (trail speeds) rebound range a bit?

    Dougal?
    You need the largest one to cover the holes in the piston.
    You need the washer to go under the nut.
    The rest of the ones in the middle can be thought of as "for tuning purposes".

    Yes it does stress a large shim more if it's mostly unsupported. But shims don't break very often so it's unlikely you'll have a problem.

    I cannot remember which ones I removed, I have photos but they are blurry and I don't know if they were before or after shims were removed.
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  83. #83
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    Quote Originally Posted by bElliott
    you will have to remove and replace the semibath oil, but if you flip the fork upside down, you can leave the dampening oil
    Manitou damping oil is completely contained in the stanchion. You don't need to worry about losing it by removing the lowers.
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  84. #84
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    do you think if i greased the spv valve every time i switched the semibath oil it would help?

  85. #85
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    I'm totally confused....so there's two differente oils ?? If I turn the fork upside down won't that make de oil split ?? Do you guys know a place where I can find a step by step with pictures ?

  86. #86
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    Quote Originally Posted by bElliott
    do you think if i greased the spv valve every time i switched the semibath oil it would help?
    Dunno, try it and tell us.
    Your results will probably depend highly on what grease you use.

    Yes there are two oils in a semi-bath fork.
    5wt oil in the damper.
    16cc of oil in each lower cavity to lube the seals and bushings. I can't remember what manitou recommend for this, but motor oil works well.
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  87. #87
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    Quote Originally Posted by flyingrider
    I'm totally confused....so there's two differente oils ?? If I turn the fork upside down won't that make de oil split ?? Do you guys know a place where I can find a step by step with pictures ?
    yes there are different oils.

    If you remove the SPV top cap, and turn the fork upside down, the damper oil will drain out.

    If you unbolt the lowers, and pull them down, the semi-bath oil will drain out. It has to be refilled into the bolt holes, which is easiest with a syringe, but can be done by careful pouring from a measuring cup.

    This is one place to get instructions:
    http://www.enduroforkseals.com/id10.html
    Click on the link for your fork (R7, Minute, Nixon etc)
    www.answerproducts.com has factory manuals too.

  88. #88
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    I wasn't very happy with my sherman breakout plus. but I did the SPV devolve thing and removed the 2 small shims and now it works a lot better. I also put in 2.5W oil.

    the compression damping can only be altered bij changing oil wheight? except for machining down the piston( what do you mean by piston dougal?) or are there other possibilities?
    I bottom out quite easily even with a smaller air volume.

    Is it possible to run the pressure on 0psi or lets say 10 PSI, atleast lower then the recommended SPV pressure. Will it damage anything?

    What is the spring actuated blue cilinder for?

    How bad is it to use mineral oil for the semi bath?

    Our supplier of Manitou in the Netherlands said that if my rebound was really slow it would mean it is broken. What could be broken? I doubt it because both my shermans where awfully slow.

  89. #89
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    Quote Originally Posted by djamgils
    I wasn't very happy with my sherman breakout plus. but I did the SPV devolve thing and removed the 2 small shims and now it works a lot better. I also put in 2.5W oil.

    the compression damping can only be altered bij changing oil wheight? except for machining down the piston( what do you mean by piston dougal?) or are there other possibilities?
    I bottom out quite easily even with a smaller air volume.

    Is it possible to run the pressure on 0psi or lets say 10 PSI, atleast lower then the recommended SPV pressure. Will it damage anything?

    What is the spring actuated blue cilinder for?

    How bad is it to use mineral oil for the semi bath?

    Our supplier of Manitou in the Netherlands said that if my rebound was really slow it would mean it is broken. What could be broken? I doubt it because both my shermans where awfully slow.
    By "piston" I mean the cylinder that seals against the inside of the stanchion.
    The blue cylinder underneath the piston is the SPV valve. The spring effect you feel is air trapped inside it (that's how it works).

    The air pressure you put in the SPV valve on top works against the air in the SPV valve to hold it closed against the piston.
    If you run very little (or no) SPV air pressure then the piston will not close and the oil will take the easy way on the return stroke (back through the open compression holes) leaving you with no rebound damping (very fast fork).

    On a SPV fork more air pressure = more compression damping. But it also gives more of a platform feel which the SPV Devolve helps to reduce.

    You can add shims under the blue SPV valve so it cannot open so far. This gives you more high speed compression damping, It will help with bottomout resistance but will make sharp edged bumps feel harsher.
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
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    even when I ride with little to no pressure I still have rebound damping. somebody has "tuned the SPV for me a long time ago so I could ride without SPV pressure, could that mean that he altered something else with the blue cilinder in stead of taking out the spring and plastic cap?

    my plastic cap had a hole in it that even though the spring kept the cap in place there still could flow oil trough it. Does the hole in the cap come standard?

    When I put my fork in the 130mm setting I have no rebound damping is that normal? always has been that way.
    Last edited by djamgils; 10-28-2006 at 03:18 AM.

  91. #91
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    Quote Originally Posted by djamgils
    even when I ride with little to no pressure I still have rebound damping. somebody has "tuned the SPV for me a long time ago so I could ride without SPV pressure, could that mean that he altered something else with the blue cilinder in stead of taking out the spring and plastic cap?

    my plastic cap had a hole in it that even though the spring kept the cap in place there still could flow oil trough it. Does the hole in the cap come standard?

    When I put my fork in the 130mm setting I have no rebound damping is that normal? always has been that way.
    The SPV Evolve (2nd generation SPV) has that hole in the cap. The first generations didn't.
    Removing the cap lets a whole lot more oil through.

    Because the SPV valve works on a trapped bubble of air, it's highly sensitive to differences in air pressure between where you are now and where it was assembled.
    This is affected by not only altitude, but also atmospheric pressure changes due to weather patterns
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    I have removed the spring and plastic cap 2 weeks ago. I still haven't got enough rebound so I took it appart again yesterday. But now I also removed the piston to take a good look at it. To my surprise I found a broken compression shim.



    I have replaced it with a rebound shim but the inner diameters do not match. I will change it to a correct size shim as soon as possible.

    The guy who tuned my damper isn't very clear about what he has done but the result is damping even without SPV pressure. He describes it as follow: I have drilled a hole in the compression check valve(plastic valve). adjusted the rebound with a check valve so it will work with low SPV pressures( this isnt standard in manitou forks).

    I have no clue of what he is talking about. He says it isn't standard, does it implies that it is available trough manitou?

    I am ashamed of it but I can't remeber if it is spring and then cap or cap and then the spring?

    What is the slot under the blue cilinder is for? I can't see the use of the blue cilinder, in the rebound stroke it closes the compression circuit?
    And how does the rebound adjustment work?

    The chassis of the sherman fork is the best freeride fork there is but the internals suck.

  93. #93
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    Quote Originally Posted by djamgils
    I have removed the spring and plastic cap 2 weeks ago. I still haven't got enough rebound so I took it appart again yesterday. But now I also removed the piston to take a good look at it. To my surprise I found a broken compression shim.

    I have replaced it with a rebound shim but the inner diameters do not match. I will change it to a correct size shim as soon as possible.

    The guy who tuned my damper isn't very clear about what he has done but the result is damping even without SPV pressure. He describes it as follow: I have drilled a hole in the compression check valve(plastic valve). adjusted the rebound with a check valve so it will work with low SPV pressures( this isnt standard in manitou forks).

    I have no clue of what he is talking about. He says it isn't standard, does it implies that it is available trough manitou?

    I am ashamed of it but I can't remeber if it is spring and then cap or cap and then the spring?

    What is the slot under the blue cilinder is for? I can't see the use of the blue cilinder, in the rebound stroke it closes the compression circuit?
    And how does the rebound adjustment work?

    The chassis of the sherman fork is the best freeride fork there is but the internals suck.
    In a stock SPV assembly there are no compression shims.
    Did your "tuner" place a large shim on the compression side of the piston between the SPV valve and the piston?

    If so I can see how your fork will then work (in a way) without SPV pressure. But you'll get cavitation issues which prevent the damper making any useful compression damping force with the air pressure above it.

    I can also see why the "compression" shim has broken. A single shim like that is unsupported and will bend back too far, eventually cracking and breaking from fatigue.

    The plastic check valve goes against the top of the piston with the spring above it to hold it closed.

    The "slot" is the entry for oil on rebound, the rebound then goes through the middle of the piston and out where the check valve is.
    The "devolve" mod lets oil flow through this passage on compression.
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    So if I remove the compression shim I am back to the "need minimum pressure" spv configuration. Or I should use multiple shims for the compression.

    If I leave the compression shim in place en start using a minimum pressure of 35PSI will I still have cavitational problems?

  95. #95
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    Quote Originally Posted by djamgils
    So if I remove the compression shim I am back to the "need minimum pressure" spv configuration. Or I should use multiple shims for the compression.

    If I leave the compression shim in place en start using a minimum pressure of 35PSI will I still have cavitational problems?
    Yes removing the shim will revert you to normal SPV operation, needing air pressure to keep the SPV valve shut.
    Running multiple shims will help the breaking shim issue you currently have, but you will still require air pressure to prevent cavitation.

    With 35psi you shouldn't have any problems.
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    i hate to keep bringing this thread up but im excited for a new idea.

    what do you guys think of installing the check valve up side down?

    initially the compression will feel "devolved" , but on hard hits it will start to close over those two ports on the side of the cap holding the springin, i think?

    again this is a slider plus which im try ing to use as a race fork

    do you think this will work as a speed sensitive compression damper, or will it just cause spiking?

    thanks

  97. #97
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    Quote Originally Posted by bElliott
    i hate to keep bringing this thread up but im excited for a new idea.

    what do you guys think of installing the check valve up side down?

    initially the compression will feel "devolved" , but on hard hits it will start to close over those two ports on the side of the cap holding the springin, i think?

    again this is a slider plus which im try ing to use as a race fork

    do you think this will work as a speed sensitive compression damper, or will it just cause spiking?

    thanks
    I don't know if it'll work. It would rely on enough oil taking the "hard way" down through the top of the aluminium cap to force the check valve down against the spring. I think most of the oil will take the easy route through the side ports.

    But it'll be straightforward to try, let us know how it turns out.

    I'm amazed this thread is still going strong after over 2.5 years.
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    it should be stickied

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    Another vote for a Sticky!

  100. #100
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    Quote Originally Posted by Relayden
    Another vote for a Sticky!
    So how do we contact a moderator to make it happen?
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