what is the typical pressure to run in a rear (air) shock? (manitou radium)

I believe you're looking for sag.

Sag is the ammount of compression the shock takes just under the riders weight.

You want the sag to be about 1/5 of the total travel of the shock. Adjust it until you get it there.

Also, a friend helps when trying to get it perfect.

Personally, even on my full suspension bike it always feels better (especially in turns) to have it pretty firm with some give.

I have a spring rear suspension with damper, so I just took the travel of the fork after sag and cut a third off of it.

I can't think of a better way to explain it, but this makes it pretty firm without transforming it into a hardtail.

their is no ideal pressure.

it depends on the shock, the frame, the rider weight, and the conditions you want the shock set up for.

reitterating the preveous statment, your looking for 20% sag as a rough estimate, guess your pressure, sit on the bike, bounce, let the suspension push you back up, and then measure how far the shock is compressed via the o-ring, adjust air pressure untill its just right.

if your still none the wiser, find somone who is, best place to look being your lbs.

fixed But seriously 20-30% of the total stroke of the shock with your static weight on the seat.

I run my TALAS R at body weight + 5% and that works great for me but thats a FOX not a Manitou.
check their website. they should give you a formula as a starting point.

Not so much. The most common advisory is 20% and that is 1/5.

But yes, 30 percent (or 33.33333333333333333 etc) is 1/3.

We're both mathematically correct, but you don't need to correct posts based on your opinion.

I have a Fox and it's actually much less than that. It is different for every frame as well as shock manufacturer. I think I'm running 160 PSI and I weigh 185 lbs. I get right @ 15% that way.

5,000,000 pounds

Whatever manitou recommends.

I guess you were absent on significant figures day, but thanks for the math help nonetheless.

So is that 20% number your opinion or, as you wrote, "the most common advisory"?

Everything I've ever seen recommended has been in the 25 to 40 percent range.

100 BILLION psi

I said thats what I RUN, not that it is the only correct way. is yours a TALAS?

Use the pump and put in as much as you can. Then take a little out at a time until you hit the "sweet spot".

Is this the advice you give at your shop**********??

Gastro, do you really run 40% sag?

Yes.

tftunedshox

How much travel does your rig have?

The bike with the 5th Element has 6", my trail bike has 5" with a Fox Float and I run that one around 35%.

I subscribe to the school of thought that says a perfectly set up shock will bottom out once per run.

There we go, thanks! That's what I was looking for. I needed to know what type of PSI we are dealing with so I know how powerful of a compressor is needed. A lot of smaller compressors max out at about 100-120 PSI. It's my first bike, I had no idea what range of pressure these shocks take.

Thanks!

Wooooah there, buddy. An air compressor isn't neary accurate enough to fill a shock. The volumes are so small and the pressures are really high that a standard compressor or chuck gauge isn't going to do much good in setting suspension. What you need is a real shock pump that is accurate and can fill/relaease tiny volumes of air so you can set things precisely.