Bicycle Mechanics - pessure troubles with manitou black elite air

hi folks!

this is a call for help from vienna, austria (where a. schwarzenegger, the terminator came from!). so pease excuse my poor grammar.

two weeks ago my baby (trek stp400) was completed with a brand new manitou black eite air. but now i have some troubles with the setup.
the user manual recommends an air pressure of 75% of the riders weight! 75% of what? cheeseburgers?
i think what they mean is 75% of the riders weight in psi.
this would be (my weight is 70kg) 52,5psi.
if i fill the air chamber with ~55psi, the fork will be very, very soft.
so i tried to increase the pressure up to 150psi and could not feel a real difference.
what could be the reason for that????

if anybody could give me an helpful hint....i would be very glad.

thanks from a sunny day(30°C) in vienna,
soulman

Sorry - not a fork expert but I seem to recall www.angryasian.com was the place to go for fork information.

Richard

I'd suggest you convert to weight to pounds first. Since Manitou is an American company, I'll bet they didn't think about metric conversion.

70kg * 2.2 lb/kg = 154 lbs * .75 = 115.5 psi.

If there is not difference in feel between 50 psi and 150 psi are you sure you're inflating properly? Are you using a shock specific pump or a regular floor pump? You WILL need a shock specific pump to get the desired high pressures needed.

Hope that helps!
L8R

@ a2psyklnut !

yes, i used a shock specific pump (cane creek = same as rs).
and i tried it more than one time whith a special adapter. this adapter avoids the loss of pressure when you screw off the pump from the air valve.
i filled the air chamber with 150psi, screwed off and screwed on again, to see the amount of air loss when screw off. this was max. 25psi!
so i can guarantee myself, that the indicated air pressure is correct! but it seems that the difference i feel is not correct, because it feels nearly identical!

Let's start with air pressure, for you it should be about 115psi, 120 if you're hard rider. This is to adjust for sag. what the positive and negative travel of the fork is.

The other ajustments are rebound, damping and spring rate. Rebound is how fast the shock will return to its original position, you should be able to feel that . (If I remember right it's the bottom of the right leg) In the right leg is also a spring that may be changed if it is always too soft for you. The last adjustment is damping which is how fast it will compress, this is controlled by oil weight and an adjustable HIGH SPEED valve. In other words, you won't feel the difference in the shop, but you will feel it on the trail.

Take it for a ride, you'll see what I mean. Good riding.