[Electric_City]

This is going back a couple years, but I'd still like an explanation I guess.

A buddy's bike sat dormant for 2-3 years until we finally went to Creek. When he took the bike off the rack and dropped the wheels on the ground, I heard a loud clunk. Pushing down on the seat, the thing just kicks back and topped out with that clunk again. I turned the rebound up all the way, but no luck. As he messed around in the parking lot jumping on it, the rear went down and stuck there. We figured he'd have to rent. But I turned the rebound knob and the shock returned and the damping was working again. Why?

As the day went on the shock went back to clunking with no damping. We figured it was shot at that point, but he insisted on riding it. Others told him that he had blown out his shock too.

I get the fundamentals of suspension and the fluid traveling thru ports and valves. But what happens that it works or doesn't? Did an o-ring disintegrate or something?

Anxiously awaiting for useless replies with one or two serious ones!

 

[kickstand]

air in fluid, not enough fluid, bad seal, sat on shelf for two years there's countless explanations

 

[jonKranked]

air in fluid, not enough fluid, bad seal, sat on shelf for two years there's countless explanations

air in fluid is my first guess. perhaps from a bottom out piston in a reservoir? hard to tell without even knowing what the shock in question is

 

[Jeremy R]

Sounds like the Rux capacitor went out.

 

[jstuhlman]

Maybe Chewie can fix it?

 

[cecil]

same thing happened to me somehow Iost my nitrogen charge

 

[Electric_City]

Manitou swinger.

 

[jonKranked]

Manitou swinger.

might be the SPV valve as well, as this is a platform damped shock. ie no shimz.

 

[Jm_]

Try it now

 

[daisycutter]

http://www.mtbsuspensionexperts.com/mtb-suspension-services

 

[Electric_City]

I think he sold the bike. I'm just wondering what makes it go from so smooth on compression and rebound to slamming up and down. It doesn't gradually get worse. It either works or it doesn't. Ya know? Not to mention how his didn't work, then it worked, then it didn't. I didn't mention the make or model cause I've seen this on Fox, Progressive, Manitou and Rockshox over the years and figured it would turn into a "Manitou sucks" type thread. . Thanks, EC

 

[Sandwich]

maybe the heat caused the air pressure to expand and then re-fill the reservoir, where it was previously empty? I've had similar things happen on clapped out shocks. Best to send it to a pro, but my bet is something happening with the air. Maybe it leaked out, was squished around a few times mixing in air into oil, then refilled which kept air in the damping circuit?

 

[kickstand]

#manitousucks

 

[dcamp29]

could be some debris getting stuck in a shim/valve/somewhere and causing the thing to be stuck open (ie no damping) and then getting blown out and letting the shock return to normal.

 

[toodles]

might be the SPV valve as well, as this is a platform damped shock. ie no shimz.

My money is on this. Loss of nitrogen charge somewhat causing the SPV valve to not operate correctly. They used to use a small air bubble in the valve body to operate open and shut and the loss of air/nitrogen charge would prevent it from cycling.

 

[Steve M]

My money is on this. Loss of nitrogen charge somewhat causing the SPV valve to not operate correctly. They used to use a small air bubble in the valve body to operate open and shut and the loss of air/nitrogen charge would prevent it from cycling.

This is pretty likely. Check the pressure in the reservoir and make sure it's up over 100psi (I think they claimed you could run 50psi or 75psi or something absurd like that, but it doesn't work very well at those pressures!).

 

[herbman]

Those swingers needed 75pis? in the reservoir to make the rebound damping work. With out it they were a pogo stick.

Still rate my old 4way air better than the fox RP3 that replaced it.