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Discussion Starter #1
I recently took a lady friend for a ride on the bike. We bottomed out on every little bump. Neither she or I are unusually large. But even before that I noticed that the bike was very spong feeling in the back, and I would almost bottom out on even the smallest bumps while riding alone. I pondered the situation, then remembered the shocks are air assisted. Went to a garage, and tried to get a reading of air pressure in the shocks, but couldn't because the air would be let out of the shock as soon as I touched the air nozzel to the intake of the shock. Anyway, to get to my point, I was able to put air into the shocks. Now my question, how much pressure should I be running in them for a safe and smooth ride?
Wayne
 

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Search Goddess
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Good rule of thumb seems to be..
Rear shock air pressure (10% of total load weight)
 

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Discussion Starter #3
YIKES, that means that I'll have to ask the weight of every woman I take for a ride on the bike. Guess I getter get some cheek protection, might get slapped a few times :D Thanks for the advise

Wayne :)
 

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Search Goddess
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Just ask AFTER you put the full face hemet on. Of course that leaves other areas vulnerable. Best to do a silent estimate and I'm sure if you come close the ride will be a bit more comfortable.
 

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Now what
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I found a special low volume hand pump at a bicycle store. The mountain bikes use air springs. It cost $30, has a built in gauge and when I disconnect it from the shock, I lose hardly any air. The chamber for the air spring is pretty small. Everytime I checked the pressure with a regular air gauge, I lost about 5 pounds of pressure. You shouldn't try and fill them with an air hose at a garage. The maximum pressure is 43 pounds and overfilling can blow a seal. If you have a compressor at home, and can adjust the pressure to the 5 to 40 pound range with the built in regulator, you can use that to fill the shocks.
 

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There is no "stock" air pressure for the rear shocks.
The general guide is 1 lb of air per 10 lbs of rider/luggage weight.

So if you weigh 200 lbs you would put 20 lbs of air in each shock.

Do NOT use a regular air compressor to do this. Either get the special hand pump, or, get an air tank, fill it/bleed it to the pressure you need (e.g. 20 lbs) and give each shock a quick shot with it. The shocks only take a very little bit of air compared to what is in the compresor tank, so they will be even enough in pressure.

RB

RIDE A LOT said:
A quick question what is the stock air pressure?
So i'll know where to start
and thanks ahead of time!!!
 

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Thanks, RB. I just bought a 2001 VN750 Monday, and was wondering why I was getting jolted so hard with every bump in the road after all the magazines complained about the "mushy" suspension.

The shocks are loaded with SEVENTY PSI. :doh:

I'm 215 pounds, so looks like I'll set 'em at 23-25 PSI to account for my gear.
 

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Geek
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I have about 5 psi and the shock set to 4. With the wife on the back (we total about 275) the ride is pretty good.
 

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GusPorterhouse said:
The shocks are loaded with SEVENTY PSI. :doh:

I'm 215 pounds, so looks like I'll set 'em at 23-25 PSI to account for my gear.
I hope that your rear shocks are not really loaded with that much air. Putting in 70 PSI would blow the seals on them. :BLAM:

I have a Progressive air pump which I use for my shocks. On my VN750, I run Progressive rear shocks which don't have air-fittings but I have modified my front forks with a set of older VN750 fork tubes with the air fittings and run around 12 - 15 lbs up there along with Progressive fork springs. Very smooth. On my Nomad, I keep around 24 PSI in my rear shocks unless I'm doing some heavy duty two-up riding, then I go around 30 PSI. Never more...
 

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The shocks come at 0 psi from the factory. I have my shocks at 30 psi and rebound at 3. Works for me, im 230 lbs
 

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My shocks had air in them when new. Must have been the dealer.
 

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Umm, I've never checked mine !?
I've never thought it to be that uncomfortable. Maybe I can still get more comfotable !!
I know what I'm checking today.
 

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hyperbuzzin said:
Umm, I've never checked mine !?
I've never thought it to be that uncomfortable. Maybe I can still get more comfotable !!
I know what I'm checking today.
My bike is just over a year old and I never checked mine until just a few days ago. My shocks have 0 psi. Using a hand pump I tried to air them up and the pressure leaked back down to 0 psi almost immediately. I guess my seals are shot.

Either my dealer aired them up with a compressor before I bought the bike (ruining the seals) or they have just deterioted to the point they won't 'seal'.

My guess is that they have been this way since day one.

Should I be concerned about repairing this or just live with it. The bike rides the same to me--of course I wouldn't know the difference if they have in fact always been blown.

BTW, my owner's manual list 71 psi as max.
 

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Can you hear the air leaking anywhere?
Maybe it's just the valve itself needs changed. There is also an O-ring with the valve. Maybe it's that.
Ron Ayers lists the valve assembly & O-ring for $13.27 per side.

The owners manual also says for an average rider of 150lbs w/ no extra gear, atmospheric pressure is standard.
 

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Is there any oil leaking out ? If not you should be ok.
 

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Is there any oil leaking out ? If not you should be ok.


There is no sign of an oil leak on or around the shock itself. There was oil associated with the valve stem when I was trying to air them up. It was basically leaking out of the valve stem as was putting the air hose on and off. But otherwise, no oil leak.

How does that make it ok?
 

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The owners manual also says for an average rider of 150lbs w/ no extra gear, atmospheric pressure is standard.
That's interesting and opens up another can of worms. Atomspheric pressure is ~15 psi, which would correspond to the 10% theory for a 150 lb. rider. If I weigh 200, would it not follow that only 5 more psi would be needed?

Atomspheric (15 psi) + 5 psi = 20 psi for a 200 lb rider. Or should it be atomspheric plus another 20 psi?
 
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