Updated: Jan 21, 2019
As I write the rear of the car is nearing completion, with only a few tasks to finish, sadly there is still a significant amount of blogging to catch up on and so I am trying to mix up the new build work with the retrospective blogging. I will get there.
One of the most recent activities was the preparation of the rear wings and the fitment of the wing guards. Fitment of the guards was very easy, but I suspect this might be in part due to the fact mine are made from carbon fibre and not the metal type supplied in the S pack. R spec or black pack cars are supplied with a guard made from a shaped sheet of carbon fibre which easily bends around the curvature of the wing, I understand the metal type is more rigid and won't simply wrap around the wing. If you've got the metal type, sorry but I would recommend another blog.
Wing protectors are of course designed to protect the wings including their paintwork from stones fired from the front wheels. From discussions on the Lotus 7 forum, I understand the wings suffer a bit and so the protection is critical. Other owners even consider the guards as almost sacrificial due to the volume of debris hitting them. This made me think, just how sacrificial are we talking? I guess driving style and road surface would influence how much debris would be hitting them and you can't always control either.
What are we talking in terms of cost then? The answer £68.64 each, ouch, that isn't sacrificial in my book.
As someone who hates stone chips and bodywork damage I came to two conclusions, firstly I need to limit the damage or do something to protect the guards, secondly ensure that new guards can be refitted with ease.
Addressing the first conclusion was straightforward, paint protection film needed to be fitted to the guards to help limit the damage. The second was suggested to me on the Lotus 7 forum, instead of using rivets to attach the guards use an alternative nut and bolt instead, removing a nut and bolt is significantly easier than ~15 rivets per wing protector.
Before getting into the install itself, I'll quickly run through the additional components sourced to meet the needs of the modified installation. A paint protection film (PPF) was sourced from a brand called Foliatec, I'd used this to apply to the inside of my wheel arches on the Lotus Exige and it had performed very well. For the nuts and bolts, I sourced the following from Accu Limited.
x40, M3 x 12mm Socket Button Screws (ISO 7380) - Black A4 Stainless Steel
x40, M3 Hexagon Nylon Locking Nuts (DIN 985) - A4 Stainless Steel
The first step in the process was to thoroughly clean the guards using an IPA solution, as a car detailing nut I had this to hand. Next, apply the PPF to the guard. I suspect most PPF products come with their own application instructions, so I'd recommend you follow those supplied if you are doing the same. In my case it was the typical lubricant mixture applied to the guard and then lay the PPF over, followed by a squeegee to remove the lubricant to achieve the desired seamless finish. I then carefully ran a sharp craft knife around the edge to achieve a perfect fit. A small amount of heat from a heat gun also helps to achieve a good fit, especially around the predrilled mounting holes.
Next was the fitment of the IVA or rubber trim. Each of the guards needs to be trimmed with a rubber edging supplied by Caterham Cars in a fitting pack. The edging just sits underneath the guard and so requires some form of adhesive to hold in place. I used small dabs of Super Glue to secure in place. Working the trim around the curvature of the guard requires V-shaped notches to be cut into the rubber so that it can sit flat. Note you don't need to trim the inner edge of the guard, if you do make that mistake you won't have sufficient trim for both guards. This task is pretty straightforward and doesn't need too much explanation, just ensure you are consistent with the amount of visible trim.
Once I'd got the PPF and trim added to the guard I drilled through the predrilled holes using a 3mm drill bit. Doing so ensured the hole went through the PPF and the rubber which was now attached to the rear of the guard.
Finally it was a case of attaching the now ready guards to the wing. Each guard was held in place against the wing approximately 5mm up from the bottom and butted against the inner edge. Using the existing holes in the guard, one top hole and one bottom hole was drilled and a button screw immediately inserted and secured with a Nyloc. These initial two fixings ensured the guard wouldn't move whilst the remaining holes were drilled in succession. Once drilled each hole was then filled with the button screw and Nyloc as expected.
Caterham have a habit of changing specifications within their kits, so please check the size of the predrilled holes in your supplied guards. As stated mine were approximately 3mm, yours may differ.