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Squish sound on rear end of '06 FSR XC?

1041 Views 5 Replies 4 Participants Last post by  walkman
Just bought a used Specialized XC for my girlfriend. The bike makes a "squish" sound when I activate the rear suspension. I think the bike has less than 200 miles on it.

It sounds like air escaping through a valve or maybe a sliding rubber sound. Like I said, more of a rubber sound than a metal on metal squeak.

It uses an X-Fusion RLA Air rear shock.

Any ideas on whether I should start with the shock or the pivots to fix it?
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walkman said:
Just bought a used Specialized XC for my girlfriend. The bike makes a "squish" sound when I activate the rear suspension. I think the bike has less than 200 miles on it.

It sounds like air escaping through a valve or maybe a sliding rubber sound. Like I said, more of a rubber sound than a metal on metal squeak.

It uses an X-Fusion RLA Air rear shock.

Any ideas on whether I should start with the shock or the pivots to fix it?
Probably just the sound of oil pushing through the orifice while compressing and rebounding. Should be normal.
rebound sound

Have you checked your rebound?
Could be too slow...try opening it up (quicker rebound). Sounds like my shock when I have the rebound really slow. Is the shock performing abnormally?
Keep us posted.
xsl_will: It doesn't sound like a normal shock sound. A new bike in the same model didn't make a noise like it.

g-air: unfortunately, it doesn't have a rebound adjustment. It has a compression/lockout lever that makes no diff on the sound. Lockout just makes it less noticeable (shorter sound).



Should the piston be lightly lubricated? I'm wondering if it's the sound of the piston moving against the rubber lining of the case sleeve.
Likely air in the oil damper. Clean oil doesn't make noise when pushed through damping ports. Once you get air mixed with the oil, you get a squishing sound. Might need to be serviced.
problem solved

A sleeve maintenance on the shock took care of the problem. There is no more sound coming from the shock when I fully activate the rear suspension.

I can't say for sure what the problem was. I didn't find any debris or grit in the shock body. I'm wondering if the guy who sold it took a pressure washer to the bike and hosed all the lubrication off the piston so that the sound was the rubber seal on the dry piston.

-- here's the maintenance procedure in case any one does a search in the future --

Doing sleeve maintenance on the x-fusion wasn't much fun. On my shock I had to position the mounting bolt hole in a workbench wood vice and then use a strap wrench to untwist the shock body. It was hard to get the strap wrench to grap the cylinder body and loosen. And it felt like it would have been easy to damage the cylinder sheet metal if I wasn't careful.

I cleaned the surfaces and used TriFlow synthetic grease to lubricate. The former professional downhill racer that worked at the local lbs (who has about 8 lbs of metal in his body from crashes) said that he didn't care for slick honey because it is too thin. He also said he uses lizard skins to keep the dirt and grit out of his shocks.

Reassembly was also a bit of a pain because it took a lot of downward pressure on the piston to get the sleeve body to slide down far enough while twisting to try to get the threads started.

It wasn't technical and didn't really take long, it just required applying so much force that it seemed possible to damage the shock if there had been an inopportune slip.
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