This has to be the one area of my build I have spent the most time on, researching / searching for solution to a problem I have with the standard build, especially now that my Caterham has carbon fibre rear wings.

The issue I have is with the fixings. The kit-supplied fixings are self-tapping screws which make a lovely crunching sound as they bite into the fibreglass and crack the gel-coat. So I tried to find an alternative, and problem is the surface the screw is mounting to the service at an angle. I came up with the solution to use rubber-backed washers (M5), with M4 flare screws and flare nyloc nuts. I chose M4 flare screws, because they cleared the factory pre-drilled hole in the rear wing, meaning if I ever wanted to use the kit fixings I still could.

The large washers allowed them to sit flat on the angle of the wing, and the flare on the nuts resolved the size difference.

Reading the IVA checklist published by Caterham, the wires need to be fully covered inside the rear wheel arch, but for some strange reason the sleeve supplied is too short and doesn’t cover the wire fully. As an alternative, I applied heat shrink to the wires. To do this, I needed to remove the connections from the Econoseal connector and refit them in the correct order. A photo helped to get the wires back into the right place. Before I applied the heat shrink I made sure the sleeving was as tight as possible on the bulb holders, I didn’t want this to slip. I have read the rubber blocks need to be sealed with silicone, but I am not sure why. I might do this before the IVA; personally I can’t see the point, because the lens isn’t fully sealed onto the rubber block.

Next it’s time to take a brave pill and drill into the rear wings. Caterham provide two holes, the large centre hole and a single mounting hole. Using these two holes you can locate the light, but you will still need to get the light level, before you drill the remaining three holes. This is easier said than done, because the rubber block isn’t exactly level, and you need to make sure the car is level to start with. I used two spirit levels and drilled through the light block to start. I then opened the holes out to 4mm, providing clearance for my fittings (and still being able to use the standard fixings if ever needed).

The electrical connection to the chassis loom was hiding between the tank and the side skin. Once found and connected, I could fit the grommet to the side skin. The wiring needs to be supported according to the new manual (v1.2 and v2.0); a P-clip works fine with my fixings. I was very happy with the new fixings, you can see how the rubber backed washers are compensating for the mounting angle.

Tools Used

  • Drill
  • Flat blade screw driver
  • Pick (Econoseal disassembly)
  • Small flat blade screw driver (Econoseal disassembly)
  • 2.5mm Allen key
  • 7mm 1/4” drive socket
  • 1/4” driven ratchet
  • Spirit level x 2