I went to pump up my rear shocks this evening. They would pump up to 17 psi, and no higher. When I let go of the compressor button, I heard the telltale hissssss of a leak in the pneumatic system, and all the pressure bled out of the system.
"Oh darn, not again," I said, (or words to that effect).
This is the third time I have fixed this problem with my Progressive 416 shocks since I installed them. Hopefully it will the be the last.
The problem is that the shock casing tends to rotate over time as the shock compresses and expands, no doubt due to the spring inside. Looking down at the shock from the top, it rotates counter-clockwise.
On the right side of the bike, this isn't a problem, because the air inlet contacts the inside of the saddlebag, which prevents it from rotating any further.
However on the left side shock, the air inlet rotates until it jams up against the inner fender, compressing the air line at a 90 degree angle, and eventually shearing the air line, at which point the system will no longer hold air.
- Air inlet jammed against inner fender
- Closeup of air inlet (and air line) jammed against fender
Rotating the shock outward (easily done by hand), you can see how the air line is bent at a sharp angle.
- After rotating shock outward
When you remove the inlet cap, the air line falls apart, as it has been completely sheared.
- After removing the screw cap, the air line falls apart, completely sheared
This is easily fixed - pull out the rubber O-rings and compression fitting from the inlet fitting, cut the air line square, insert it through the cap and compression fitting, slip the O-rings over the end, and reinstall.
- Cut the air line flush and reinstalled into inlet
I decided that I am not fixing this problem again, and figured I'd try to solve the problem with some lockwire.
- Lockwire and lockwire tool
After the shock was rotated into proper position, with the fitting facing the back of the bike, I wrapped lockwire around the inlet and tightened it. The other end I wrapped around the air compressor mounting bracket.
- Air inlet lockwired to frame
Now when the shock attempts to rotate inward, it will be prevented from doing so by the lockwire. The amount of torque trying to rotate the shock housing is negligible, so fingers crossed this should be a permanent fix.
