Cable Retraction – (The Smart Question)

If you press the pedal on the Driver’s Side will the Dual Control pedal on the passenger side move as well? Or stated differently: When a pedal gets pressed on the driver’s side does the cable retract back to the passenger side? This is the smartest question customers have asked.

FAT kits are unique in that cable retraction can be setup according to the installer’s preference.  The driver’s side parts on these kits were designed such that the cable slag doesn’t necessarily need to retract back to the passenger side and the springs on the instructor’s side, main unit, can be configured to provide a zero static cable tension (see table below).

The “ideal installation” is one where there is very little bend in the “cable housing path” allowing for an installation with only a little tension in the cable. The cable then retracts to the passenger side each time the drivers pedal is pressed and because there’s little tension in the cable, there’s no need to supplement the vehicle’s pedal spring back.

The “cable housing path” is the major thing to look at when determining how a cable instructor brake kit will work in your vehicle. Cable operated Dual Controls were designed to be a universal type of system but too many bends in the cable housing is going to lead to a poorly operating system. On some vehicles, you’ll be able to see right through from the passenger side to the drivers, but more typically things will look solid with no way through. Take a really close look. Pull off some panels if you have to. You’ll just need a small opening to snake the cable housing through and hopefully you can find a fairly straight route.

(Item #: txiss) Installation Spring, Strap and Screw This is used to supplement the vehicle’s pedal spring back. One end of the spring is attached under the vehicle’s dash and the other end is attached to the vehicle’s pedal using the strap and screw

Presidents Note:  7B kits come with a spring arrangement that will keep the cable from retracting when the driver’s side pedal is pushed (zero static cable tension).  I’m not a big fan of this and feel that the best way to do this installation is to disengage these springs.   This will however require a straight cable housing path that allows for a free moving, friction free, cable,  see note,  the “cable housing path”

FAT: Cable Tension Specifications

Left Coil Torsion Spring, Item # fsp-L (shown on left)

 Right Coil Torsion Spring, Item # fsp-R (shown on right)

To aid in providing or reducing static cable tension, two torsion springs are available for the main unit on FAT kits. One is a right coil spring and the other is a left coil spring. Notice in the picture that the left coil spring starts on the bottom left and that the right coil spring starts on the bottom right.

The options for changing the static cable tension on FAT kits are as follows:

  • Use no spring
  • Use a right coil spring ( fsp-R ) on the left side of the frame (increases cable tension)
  • Use a left coil spring ( fsp-L ) on the left side of the frame (decreases or eliminates cable tension)
  • Use a left coil spring ( fsp-L ) on the right side of the frame (increases cable tension)
  • Use a right coil spring ( fsp-R ) on the right side of the frame (decreases or eliminates cable tension)
Presidents Note, Definition of Static Cable Tension: The tension in the cable when the dual control unit is at rest, i.e., not being used by the instructor.
Pedal Type And Location On Frame Spring Being Used Specific To Kit Type And Pedal If Applicable Tension with Pedal Installed Tension with Pedal Removed
Brake, right side None FAT1 and FAT2 , Brake .308 kg .679 lbs 0 kg 0 lbs
Brake, right side fsp-R 0 kg 0 lbs 0 kg 0 lbs
Brake, right side fsp-L .713 kg 1.57 lbs .375 kg .826 lbs
Brake, left side fsp-L FAT7B , Brake 0 kg 0 lbs 0 kg 0 lbs
Brake, left side fsp-R .713 kg 1.57 lbs .375 kg .826 lbs
Brake, left side None .308 kg .679 lbs 0 kg 0 lbs
Accelerator, right side fsp-R FAT7B , Accelerator 0 kg 0 lbs 0 kg 0 lbs
Accelerator, right side fsp-L .604 kg 1.33 lbs .375 kg .826 lbs
Accelerator, right side None .216 kg .476 lbs 0 kg 0 lbs
Clutch, left side None .246 kg .542 lbs 0 kg 0 lbs
Clutch, left side fsp-R FAT3 , Clutch .661 kg 1.46 lbs .375 kg .826 lbs
Clutch, left side fsp-L 0 kg 0 lbs 0 kg 0 lbs
Accelerator right side add on *** Doesn’t Apply *** FAT2 , Accelerator *** .138 kg .304 lbs 0 kg / 0 lbs (cable unhocked ***)

*** The accelerator pedal on FAT2 kits can be immobilized by unhooking the cable from the pedal.


Notes: The angle that the unit is mounted at and where the pedal is in the stroke, is a significant factor in providing the cable tension. Tensions given in the table above are for the units mounted at a 30 degree angle with the pedal in the middle of its stroke. Pedals on FAT kits are removable with the exception of the accelerator pedal on FAT2 ***. The weight of the pedal is a significant factor contributing to Static Cable Tension. Cable Tensions are provided for both the pedal installed and the pedal removed. A value of “0” means that there is no tension on the cable. If the driver’s side pedal is pressed, the cable slag will remain on the driver’s side because there’s no force to pull it back to the passenger side. FAT kits come with the spring configuration as specified in the table above. If you plan on making a change, you will need to order the spring and acquire snap ring pliers. You also may have the option of simply disconnecting the stock spring and leaving it hanging loose on the frame. If you choose to make an installation with a high cable tension, you will probably need to supplement the vehicle’s pedal spring back with a supplementary spring. See the web page: Springs and Cable Retraction.