Jost

Technical Specification

Hitch and towing eye size

• Hole pattern in the crossbar of the towing vehicle 
• Hole pattern in the hitch flange 
• Pin size of the hitch 

Characteristic values

• Value of the hitch
• Values of towing vehicle and trailer (see vehicle registration certificate)
• Values of the towing eye

Truck and trailer: D-value

Calculation

• Theoretical horizontal force between towing vehicle and trailer 
• The D-value can only be calculated with the permissible total weight of both truck and trailer 
• Calculation of the D-value (kN):

 

T : total weight of the towing vehicle in t 
R : total weight of the drawbar trailer in t 
g : gravitation acceleration 9,81 m/s2 

The calculated D-value can be equal to or lower than the D-value of the hitch and of the towing eye.

D-Value calculation

 

Towing vehicle and central-axle trailer: Dc-value

 

Valid only in connection with the V-value 
• Theoretical horizontal force between towing vehicle and trailer 
• The Dc-value can only be calculated with the permissible total weight of both truck and trailer 
• Calculation of the Dc-value (kN):

 

T : total weight of the towing vehicle in t 
C : sum of the axle loads of the central-axle trailer in t 
g : gravitation acceleration 9,81 m/s2 The calculated 

Dc-value can be equal to or lower than the Dc-value of the hitch and of the towing eye.

Dc-Value calculation

 

Central-axle trailer: V-value

 

Valid only in connection with the Dc-value 
• Vertical force for central-axle trailer 
• Dependent on the rear axle suspension of the towing vehicle 
• Calculation of the V-value (kN):

 

a : an equivalent vertical acceleration in the hitch point in m/s2 
a = 1,8 for vehicles with air suspension 
a = 2,4 for vehicles with other suspensions 
l : theoretical drawbar length in meters 
x : length of the loading area in meters 
x2/l2 : at least 1,0

V-Value calculation

Central-axle trailer: Static vertical load Valid only in connection with the V-value

 

• Vertical load of the central-axle trailer on the hitch point 
• The vertical load depends on the size of the hitch and the maximum is 10% of the gross weight of the trailer or 1000 kg (whichever is less). 
• When using a central-axle trailer the vertical



CONTACT

Gümaş Otomotiv Sanayi ve Ticaret A.Ş.
Taksim Cad. No:33/A 34437,
Taksim - İstanbul

t: 0212 254 78 05
f: 0212 256 17 86 e-mail: info@gumas.com.tr