- Pag. 3. -
2-2. Selecting air pressure, “zero-SAG” adjustment.
WARNING:
IMPROPER ADJUSTMENT OF REAR SUSPENSION SHOCKS CAN RESULT IN
UNSTABLE CONDITIONS OR LOSS OF CONTROL.
How to set up the rear shock correctly with “zero-SAG”, in order to maximise the efficiency, comfort &
control of an NRS
TM
bike.
Do as follows:
1. Try the air pump on the valves and make sure the air pressure opens the valves, air goes into the
air chamber and does not stay in the pump hose.
2. Try to find out your exact body weight including cycling gear (clothing, helmet, shoes, …….).
If you ride with luggage, don’t forget to check chapter 4 of this manual:
“riding with luggage” !!!
3. Check the following table (for Giant NRS
TM
travel bikes) to find the correct “positive” and “negative”
air pressures, depending on your weight:
Body Weight
Negative
air pressure
Positive
air pressure
50 kg. / 110 lbs.
50 psi
50 psi
55 kg. / 121 lbs.
50 psi
55 psi
60 kg. / 132 lbs.
50 psi
60 psi
65 kg. / 143 lbs.
50 psi
70 psi
70 kg. / 154 lbs.
50 psi
80 psi
75 kg. / 165 lbs.
50 psi
90 psi
80 kg. / 176 lbs.
50 psi
100 psi
85 kg. / 187 lbs.
50 psi
110 psi
90 kg. / 198 lbs.
50 psi
120 psi
95 kg. / 209 lbs.
50 psi
130 psi
100 kg. / 220 lbs.
50 psi
145 psi
4. Inflate the air chambers until the correct pressures have been reached.
Start with the negative spring (
LOWER VALVE
, on the small diameter of the shock) and next the
positive spring (
TOP VALVE
on the large diameter of the shock).
5. These shock pressures enable you to set up the shock 95% correctly. It is impossible to take into
consideration deviations in the air pump gauge and the rear shock. Therefore we suggest making
the following simple steps, which offer two more ways to achieve the 100% correct setting. The
finishing touch to get to the “zero-SAG” setting will give the optimal efficiency and the best
performance.
It is important to understand that the shock should be delicately set on the edge of “zero-SAG” and
not with too high positive pressure. Therefore this procedure goes from a little bit too low positive
air pressure to just enough positive air pressure to achieve “zero-SAG”.
6. Put the bike against a wall and make sure there is a zip tie or O-ring around the rear shock piston.
7. Sit on the bike (during stand still). Pull the zip tie against the stop of the rear shock piston. Sit still
on the saddle, without bobbing. Make sure you sit on the bike like you normally would. Push gently
one of the pedals, like you would do during real riding (while keeping the front wheel locked with
the front brake).
8. Shift your body weight gently from the saddle to the front fork and try to dismount without causing
too much movement in the bike.
9. Check the zip tie. Did it slide down on the piston? If yes, this means there is some “SAG”.
REMEMBER: FOR MAXIMUM EFFICIENCY THE NRS
TM
SYSTEM SHOULD ALWAYS BE SET
UP WITH ZERO “SAG” !!!
10. Increase the pressure of the positive spring in repetitive steps of 5 or 10 psi. following the points 7,
8 and 9 until “zero-SAG” is reached.
