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Discussion Starter · #1 ·
I've been trying to figure out how to adjust my SPV fork and rear shock. I have heard a few different recommendations from heresay, MTB Action magazine, and a Manitou tech. I can't tell a big difference other than the stiffness. None of my forks seem to bob with normal spinning, but all of them bob when I stand up. Anyway, I honestly don't know what is going on inside the SPV shocks and forks. It seems to me like both the red and black valves are adjusting stiffness. Specialized had a movie on their site showing how the Epic worked, but I have yet to see anything like this for SPV.
 

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Manitou has a video (or at least they did) explaining how spv works. BTW, it works hydralically and pneumatically more than mechanically..

Basically, you have this valve called the control valve (progressive speak) or the stable platform valve (manitou), it's all the same thing. This valve has an air pocket in it, that's around about one atmosphere of pressure. As you pressurise the IFP chamber, it closes. The more pressure you put in your shock (or fork) the more force there is closing this valve, increasing "platform".. It also increase the entire damping curve all across the board, not just platform. Traditionally, these types of shocks don't have ANY free bleed in compression or rebound, all oil flow is metered through a valve, and this increases low speed damping, which reduces pedal bob. When you strike someting hard enough to activate the shock, the valve blows open, allowing the wheel to freely absorb the bump. As you travel deeper into the stroke, the shock saft displaces oil, causing the IFP pressure to rise, thus increasing damping, and this is what give you your bottomming resistance or position sensitive damping. So, in a nutshell, that's how it works. There's more to it than that but that sums it up for the most part.
 

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How does a posi-track rear end work? I don't know, it just DOES!!


















Actually the pnuematic valve explained above is key and on the money :D
 

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Discussion Starter · #4 ·
Cool, yeah I'd like to see that video. I guess it was confusing me when you can adjust the red valve and that affects the spring rate and overall stiffness. I could understand if one valve was for stiffness and the other was like an adjustment for an Epic type of suspension, but it's not isolated like that. I wasn't real sure what exactly was being adjusted and why you would want to adjust it. Which leads to my next question...

Assuming you wanted to dial in the suspension to your own taste, how would you do it with somewhat of a scientific method? I mean, I could figure out the overall stiffness just by feel, but I'm not sure how to play around with the SPV part without messing up the stiffness that I just dialed in. Since it seems like it doesn't take as many pumps for the red valve to reach a high pressure, it's probably not a 1 to 1 ratio, but it may be a linear equation. I guess what I mean is assuming that you liked the fork's spring rate of 160 psi in the black and 100 in the red, but wanted to play with the SPV setting, how would you do so while keeping the same approximate overall spring rate, without just guessing and pumping the thing up a thousand times? Like if I wanted to try 10 PSI less in the red valve, what does that equate to adding to the black valve to keep the same spring rate, so I know that I'm comparing apples to apples?
 

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Coolhand said:
Thanks for the info and link- I just ordered a 2004 Manitou Black Super 80 SPV, as I have been wanting to play with this technology for a while now.

:)
Be sure to double check the oil level when you get the fork. The SPV oil level is critical and it seems Manitou has had some trouble shipping them with the right amount. Check the semi-bath oil too. This will ensure optimal performance.
 

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Discussion Starter · #8 ·
Thanks guys. I have been reading the link below, and it explains it pretty good, although a little complicated.

http://www.bikemag.com/gear/spv/

Yeah my biggest complaint was with the fork, maybe I should check the oil. Currently I have the black chamber on 165 psi and the red on 100 just to try it out. Basically this was the recommendation of an article in MTB Action on the Haro R7 which has the same shocks and frame as my Werx. They said 100% of rider weight in the black and 60% rider weight in the red gives you a good cross country race feel with good small bump compliance. They said that was for the rear, but they did the same for the front and it worked good. My thing is that most people are recommending alot less, like 25 to 50 psi for the red. I have mine set on 100 and it easily bobs while out of the saddle. Even off the saddle, I can press down on the handlebars, at any speed, and compress the fork easily. This particular setup makes the fork ramp up tremendously, but I honestly cannot tell that there is any type of platform resistance at work in any situation, even with a fairly high setting on the SPV chamber. I have tried 60, 80, 100, 120, and even 150 psi and cannot tell. If doesn't bob while spinning in the saddle, but I think that's mainly because I have the thing aired up so much that it's very stiff, and any fork will cease to bob if made stiff enough. You just get a crapola ride. I am sure the fork was installed straight out of the box.
 

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The red cap has just about nothing to do with your spring rate. Adjust the left leg until you have your sag where you want, I personally do this w/o any air in the red chamber, and then adjust the "damping" in the right leg until it feels good. Science schmience.... W/o expensive data aquisition and dyno charts to document changes, your are limited to the seat of te pants method of dialing in your suspension. I'd suggest (this is what I do) go for a ride, get a good feel for it, then make a change. I'm just getting started dialing in my Minute fork, and I've been on three rides now, and I can tell that it bottoms a little too easily so I'm going to run the red (volume or bottoming reisistance) adjuster in further.
 

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I've been following your posts re: oil level, and intend to get mine torn down and reassembled accordingly a.s.a.p. Given the thoroughness of the rest of the manual, I just figured the 120 cc's would be the correct figure...hopefully that will explain why I've been less than impressed with what is supposed to be "legendary plushness", and all the bugs will soon be worked out. With no air in my SPV chamber (on a coil Minute One), it's not half as nice as my Z1 SL, which is strictly air. Anywhoo, I'll give your findings a try, and sort out the proper oil volume (for the ~80 mm level) while I'm at it, and report back with my impressions.

On another plushness note, if you're reading this, Chris...any word on the Enduro seals for the Minutes? Thanks - S
 
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