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Another bike maintenance subject unfortunately.
I took my Rochshox Yari 29er 150mm to a local bike mechanic for a lower leg service plus new seals. I've not seen him for about 2 years but was just glad he was still in business as they were well overdue.
I got the forks back only to check the air pressure only to find it was 3 times higher than what it should be! I usually run these forks at 55psi and found they were running at 150psi.
I set the forks to their usual 55psi and they sagged into their travel by a huge amount. There was less than half of the travel remaining.
The forks run rough.
Anyone know what could have gone wrong with these Forks ?
Without knowing how much you weigh, it will be difficult to comment. What does the air pressure chart on the fork indicate for your weight ? Might be that there is a problem with equalising the positive and negative air chambers ?
Negative spring probably isn't equalised properly, if it has a higher pressure than the positive chamber it'll make the forks sit into the travel.
The 55 psi is right for my weight. When these forks worked properly they sagged 25% into their travel when I stood on the bike. Now when I put 55 psi in, the fork is sagging half way into it's travel and I'm not even on the bike!! I have to pump them up to 150 psi to get most of my travel back, which is 3 times higher than normal.
Is it a difficult job equalising the negative and positive air chambers on these forks ?
I think it can be done by extending the fork? Easist way is to take the front wheel out and refit the axle. Stand on the axle and pull up on the bars as hard as you can to force the air to equalize on each side of the air shaft.
I'll give that a try tomorrow morning.
I noticed today that the fork was incredibly hard to pull up unless there was near to 150 psi in it
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There's usually a little notch that helps equalise pressure to the negative spring, sometimes it can block due to over-eager application of grease. It's possible that the positive air has leaked into the negative and that's been plugged up with gunge.
That can possibly cause the issue you've encountered, personally I'd empty the fork of air from the positive chamber and try to cycle the fork. The overpressure in the negative chamber might then blast through whatever is blocking the small notch from equalising pressure by volume.
I have had an air spring burp on me a couple of times with a 2010 Revelation U-Turn Air (yes, I know). A wonky seal burped pressure into the left leg which in turn forced the stanchion seal out of the lower with an audible "Bang!".
Your stanchion seal looks okay I hope?
And as per previous correspondence, I sincerely hope that your new "local bike mechanic" is light years better than your old one.
Chances are he's simply compressed the lower legs fully when reinstalling the them as per people like mbr show you which is not how it's done.
The old grease In The port is hughely unlikely unless he's used lard the pressure alone will clear the port and dispite what the internet posts the blocked transfer hole is a bit of a myth.
Pulling on the lowers is a lottery 99% of the time it doesn't work as the force required is too great .
Best fix is to drop the lowers ,remove the circlip from the air shaft and pull it out and with caution as it will pop out audibly.
If your not capable of the lower leg service i wouldn't recommend tackling this yourself .
If you happen to be in the calderdale area I'd be happy to sort this for you in exchange for a small donation to our Search and rescue team .
Id inspect the quad seal too as this can get nicked in one area as it passed over the port .
Good luck
Mine did this, i did as above. The forks went bang as i pulled the air shaft out. Cleaned, regreased and put it all back together. Sorted.