Bought used bike with seized front air suspension - easy fix?

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bingobob

· Registered

Joined Nov 23, 2015

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1 Posts

Discussion starter · #1 · Nov 23, 2015

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Hey! I bought a used bike with a Recon Gold TK front suspension.

The suspension doesn't move at all, regardless of the position of the lock switch. I don't know whether it's stuck fully compressed, or if it's not compressed at all.

I have no experience with air suspension, but I found one valve on the top, and I tried to fill it to 120psi, but that didn't help. I was unable to remove the pump without air loss, so not sure how much is still in. Could too low/no pressure cause the suspension to be locked?

I have unscrewed a bunch of parts, see photos below - the lower part should slide right at this point, right? It's still stuck...

Anyone have any suggestions on what's wrong?

Photos: Imgur: The most awesome images on the Internet

 

Hermes475

· Flow

Joined Mar 1, 2007

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95 Posts

#2 · Nov 25, 2015

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It looks like it is stuck down. Possibly a result of the air leaking into the negative chamber. You need to let all the air out, then try airing it back up again. It is also possible that there is too much oil in either the damper or the lowers which can limit travel. If all the air leaked into the negative chamber and the damper was overfilled, then you would have a fork that is not fully extended but that also won't compress any more. I suggest removing the lowers, draining the oil and putting in new damper and bath oil. If the main air seal between the positive and negative chamber is leaking, then that will need to be replaced as well. See the service manual on the Sram's site for better instructions.

Also, when you remove a pump, the air loss is usually from the pump only, not from the fork or shock.

 

Acme54321

· Shortcutting Hikabiker

Joined Oct 8, 2003

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3,216 Posts

#3 · Nov 25, 2015

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Let all of the air out of the fork. Then stand on the front wheel and pull up on the crown to try to force it to extend. Pull with a smooth motion but as hard as you can and hold it for a second. The put air back in and see if the problem has been corrected. Either way the fork probably needs to be taken apart and cleaned because something is obstructing the negative chamber equalization valve between the positive and negative sides.

 

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keen

· Well-known member

Joined Jan 13, 2004

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10,426 Posts

#4 · Nov 25, 2015

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Download the service manual from Rockshox website. Plan on overhauling the fork if the service history is un-known. You can purchase a reseal kit online or through your LBS.