Frequently Asked Questions
Rear shocks
Illustration of the different rear suspensions

Description Progression - Degression – Linear Steering

Rear system “final drive ratio” calculation
a) Eingelenker (active and Antriebsschwinge)

b) 3-/4-Gelenker
b) Multiple Joint rear suspension
1. Step: Remove the steel coil spring or let all of the air out of the rear shock absorber
2. Step: Measure the movement between the rear hub and the saddle decompressed – compressed “a”
3. Step: Measure the maximum travel of the shock absorber itself "b"
4. Step: Calculate transmission ratio: ü= a/b
Comparison of shock systems

Comparison characteristic curve of air, air-negative and steel spring

Necessary pressure in the main chamber of Air-force 1 shock
Approximation:
P ~ ü * Fg * 4,3 / 100
P = [ bar ]
Ü = Transmission ratio
Fg = Driver’s weight [ kg ]
Calculation of necessary spring rate (stiffness) for a steel spring
r = Spring rate [ N/mm ]
FG = Driver’s weight [ kg ]
SN = Negative travel [ % ]
SV = Spring bias [ mm ]
S = Working stroke of the shock [ mm ]
Ü = Transmission ratio
What’s about Air-force 1’s reliability and safety?

Can I use every pump for pumping Air-force 1?
Yes, if:
+ schrader valve
+ pump can produce high enough pressures
+ use of adapter, for not losing any pressure when taking the pump away
I have leaking oil/grease- is the shock broken?
+ no, if oil or grease leaks after mounting
+ yes, if leakage is not stopping
The shock loses pressure – is it broken?
+ no, if valves are not tightened
+ yes, if it loses pressure within days, with tightened valves
+ Test: leakage spray
Shock (with a refill valve) is extremly hard to pump up
+ push together while pumping
+ for testing: pull apart and do a „sit –on“ test
The shock contracts when pumping up after being empty:
+ OK until the pressure difference between the two chambers is reached
+ if pressure to high: pull apart and test, before pumping up
My shock /my fork is defect- where can I send it to?
+ in general: to our contractual partners, meaning: where you bought it from
Encyclopedia Trekking bike
