3 Wheeler Pedals
Due to physical size constraints with the height of the bonnet, standard pedals from a donor car could not be used. Most pedals are quite a bit higher than the pivot point which would have stuck out of the bonnet in this vehicle. Also the correct leverage for the motorbike engine was required. This meant it was easier to start from scratch and design the pedal system ourselves.
Measurements were taken from the chassis with the seat in place to get an idea of the pedal position. The mock up shown below was then used to try and calculate the correct height for the pedals and the pivot. A wooden pedal was then made up and tried in the chassis with the seat in place to get the correct pedal position. A mounting bar was welded at the correct height and position for the pedals.
The correct ratio for the pedals also needed to be calculated. The maximum movement of the clutch was measured from the engine end. The same was done for the accelerator and brake. Then the amount of pedal travel on a standard car was measured. Therefore by calculating a ratio between the two the pedals should feel the same as a standard car. As it happened all ratios required were 2:1 which made the building of the pedals easier. Pivots for the pedals consisted of a metal bush and Allen key bolt. This pivot was attached to the mounting bar by using 1.5mm angle iron. The 3 pivots were tacked in place. The actual pedals were made out 4mm thick, 40mm wide steel strip. It was welded together in a Z shape. One end accommodates the pedal, the other the cable end. The pedals were put in place and tested for height and spacing. Legally pedals have to be at least 50mm apart between the pads. These pedals were positioned 70mm apart including room for pads. It was soon clear that the Angle iron brackets for the pedals were not strong enough because they flexed when pressure was applied to a pedal. These brackets were replaced with 4mm angle iron instead. This was much better and reduced lateral movement of the pedals.
One of the main problems with the pedals was actually finding a suitable way of clamping the cable to the pedal without it slipping. Nipples that clamped the cable were made and tried but slipped and frayed the cable under heavy load. This was deemed not suitable. To solve this problem the cable ends were silver soldered to the cable and longer cable adjusters added to take up any slack. Extra slots had to be added to the mounting brackets to make the cables removable.