Noleens NR4 service.

FluffyChicken

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So I have the challenge of servicing a Noleens NR4, it looks pretty simple.

I have these instructions to follow I think came from a proflex forum some years back

Service instructions for a Noleen NR2 damper:

Remove the spring and spring base (if necessary, remove damper-bolts first).
On the upper side of the damper remove the plug screw of the pressure-filler-inlet.
Punch through the rubber-valve with the needle of the original Noleen Filler Kit and release the residual pressure.
Push the damper-piston-fairlead on the lower side of the damper-cylinder inside with a stub object, so you can see the lockring.
Remove the lockring with a scriber (Caution! The lockring might easily get lost while removing. Take care!)
Cautiosly pull the piston out of the damper cylinder and deplete the old damper oil and put it to the hazardous waste.
Losen the nut on the upper side of the piston and remove the damper unit (shims) from the piston. Store the shims in the correct sequence and do not turn it by 180 degree. Otherwise the damping characteristic would change. A variation of the shims should only be perfomred by a professional. This might be necessary to use a damper of a girvin fork on the tail. Another possibility is to vary the damper oil.
Replace the gaskets of the piston (Obviously there are various piston diameteres. My damper has a 10mm Piston, while my O-ring kit was for 9mm pistons)
Aply air pressure to the pressue-filler-inlet to remove the sliding piston wich is still inside of the cylinder. Intercept the sliding-piston and the rubber valve.
Replace the gasket of the sliding piston.
Clean the cylinder and the piston unit with a clean and lintfree cloth.
Put the rubber valve of the filler back to its position by using a punch or a similar stub object. This works easily if the valve is oiled.
Push the oiled sliding piston into the cylinder up to its end-bearing.
Fill cylinder with damper oil. For fork dampers SAE 5 or SAE 7,5 oil is used. For tail dampers SAE 7,5 or SAE 10 oil is used. For heavy riders SAE 15 oil can be used. The higher the number of the oil is, the more viscous is it. So you can vary the damping characteristics. To get the oil cheaper, go to the local motor bike store, because fork oil from motor bikes is cheaper than the original damper oil from rock shox or something. However it is the same type of oil.
Push the damper piston into the filled cylinder up to its end-bearing
Push the damper piston fairlead about 2 mm further into the cylinder than its supposed position (adapt the oil level according to the fairlead position) and insert the lockring (absolutely keep the damper in the fully retracted position. If the piston extends while there is no pressure on it, the rubber valve might get out of its position and you have to disassemble the damper again. Very pesky.)
Punch the needle of the filler kit in the rubber valve and aply pressure to the damper with a damper pump. Here the piston moves slowly to the fully extended position. The pressure should be approximately 8 to 12 bar (about 120 to 170 psi). I could not feel differences by varying the pressure so I chose to keep the pressure low to put load from the cylinder. The pressure is applied to prevent the oil from frothing and works as an additional airspring. Originally the damper is filled with nitrogen, but dry air pressure from a damper pump is possible, too. A premature aging by the oxigen is not to be feared, as the pressure reservoir is separated from the oil by the sliding piston.
Insert the plug srew in the filler.
Assemble the spring and the spring base and put the damper back to the fork or frame.


I have a big list of proflex spring rates in my collection of files to.

Now how different does the piggy back on the NR4 make it over the above NR2 instructions?
Anything to look out for. I'll be using air, not nitrogen. I could dry it a bit I suppose but that seems quite a hassle.

Anyway seals, o-ring if it needs them. Any hjints on them. Not seen it yet to check for any codes on it.

Thanks.
 
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