[buildyourown]

I have an older DHS (I think). It only has externally adjustable rebound, no comp.
Anyways, it was working great and then the bike sat, unbuilt, for about a year. I just built it up to sell it, and now the shock clunk on rebound. At exactly the point where the shock goes from comp to rebound, there is a muffled thump that can be felt through the bike.
It worked great when the bike was torn down and the adjustments still work. The only thing I could think of was that the NO2 charge blead down. Anyway to check this before sending it in. (Don't really have time to send it in)
Thanks

 

[vitox]

at the risk of labelling myself as an avy whore....

yes, most likely it has to do with pressure, pump it up with a shock pump see what happens, try 200lbs .

 

[buildyourown]

Sweet! That eliminated the clunk.
I had no idea what pressure to go to so I didn't just want to start pumping.
I know the whole idea of NO2 is to prevent oil cavitation. Will a weekend of riding with just air in there hurt anything? I can just go to a moto shop and have them charge it, right?

 

[Brian HCM#1]

Any Avy WILL lose nitrogen period. They should be recharged every 6 months and rebuilt once a year. Most likely you're out of nitrogen.

 

[ChrisRobin]

Any Avy WILL lose nitrogen period. They should be recharged every 6 months and rebuilt once a year.

That's unacceptable!!! It's an 'Avalanche' shock! It should last forever without touching it!

 

[koffee]

I can just go to a moto shop and have them charge it, right?

I sent My fork out Last Tuesday, regular shipping. I got it back fully rebuilt Last Saturday. You will not get a 4 day turnaround at a Moto shop.

 

[Cave Dweller]

I don't see why air wouldn't work fine. Its mostly nitrogen anyway, and the avy uses a rubber bladder so no worries about corrosion (from moisture in the air)

You use air in forks, and swinger/fifths use air as well. I think air would be fine, unless you are doing 30min whistler runs with it.

 

[vitox]

I don't see why air wouldn't work fine. Its mostly nitrogen anyway, and the avy uses a rubber bladder so no worries about corrosion (from moisture in the air)

You use air in forks, and swinger/fifths use air as well. I think air would be fine, unless you are doing 30min whistler runs with it.

exactly, if its ok on a shock with a way smaller air volume, and with air in contact with parts that could actually corrode (altough not likely given a rear shocks lifespan) then on an avy i cant see the major issue of using air.

minimum pressure for avoiding cavitation is 150 btw.

 

[vitox]

That's unacceptable!!! It's an 'Avalanche' shock! It should last forever without touching it!

hmm just figure it as "adjusting it"
anyway, i think every 6 months might be a good time to check on the pressure, but that doesnt mean it will have lost much at all.

 

[Cave Dweller]

minimum pressure for avoiding cavitation is 150 btw.

Something i have been wondering, can you adjust the air pressure to make the avy more or less progressive??

 

[dest]

Dont Put Air In An Avy They Only Take Nitrogen.....dont Make The Problem Worse Send It In......

 

[SKYWAYBUZZ]

Something i have been wondering, can you adjust the air pressure to make the avy more or less progressive??

Yes same as the DHX accomplishes.

 

[Sandwich]

A moto shop can do it....i had it done recently. Mine didn't bleed out, but I let it out by my own stupidity. Air shouldn't hurt it for a weekend, but if you can manage, change it.

 

[vitox]

Something i have been wondering, can you adjust the air pressure to make the avy more or less progressive??

well since the minimum is so high i dont figure you have much room to play with.

 

[jcook90]

heres another question about avys, i'm gonna buy a sinister r9 and it currently comes w/ a avy montie. is it worth the money to upgrade the montie to an avy DHS w/ hi/lo compression adjuster because i'm thinking of upgrading for the difference of the 2 ($300ish).

 

[vibiker]

I had no idea what pressure to go to so I didn't just want to start pumping.

Tyler,
The PSI of nitrogen depends primarily on your bike frame. Call Craig at Avy and he can tell you your specific setup.
Do use a moto shop. Don't use a shock pump and put air in. Per Craig, that is not a very good idea.

FYI, I have used Aurora Suz in the past. Even though they were amused at the smallness of it.

 

[Cave Dweller]

Dont Put Air In An Avy They Only Take Nitrogen.....dont Make The Problem Worse Send It In......

Do use a moto shop. Don't use a shock pump and put air in. Per Craig, that is not a very good idea.

Why is air not a good idea? My boxxers have air in it, and so do my tires, my old monster T's relied on oil and air with no floating piston to seperate the two.

Nitrogen has a theoretical temperature advantage over air. For all but the longest DH runs i don't thinbk you could tell the differance and wouldn't get any fade. Air is mostly nitrogen anyway, and the nitrogen charge in an avy is held inside a rubber bladder with no contact with moving parts.

 

[vibiker]

Why is air not a good idea?

I do not know. I just know that this is what Craig told me. And being an Avy whore, I trust him. I forgot to ask him why, but my guess is that it may be a long term/corrosion issue.

 

[Brian HCM#1]

Here is a link that may help.

http://dirtrider.net/forums3/text/topic/121146-1.html

 

[Cave Dweller]

Here is a link that may help.

http://dirtrider.net/forums3/text/topic/121146-1.html

Exactly.

You will feel no difference in a typical 5-10min DH run on a mountain bike. There is no way the pressurised gas would get hot enough to vaporise the water.

The top cap on the avy is aluminium, no corrosion issues either.

Sounds like most shops use nitrogen it as its cheaper then installing a dry air system.

 

[buildyourown]

Here is a link that may help.

http://dirtrider.net/forums3/text/topic/121146-1.html

That thread made it sound like using air from the shop compressor was the major no no.
I've seen some nasty wet/oily air come out of shop air lines. Definitly stuff I wouldn't want in a shock. I don't think a shock pump is going to introduce anything nasty. Definitly not anything a rebuild can't fix.

Thanks for all the help guys. It looks like the bike is running good now.

 

[Sandwich]

moto shop i used had a canister of nitro...kind of like a paintball gun tank.