CF Roof Decision — RKP vs Karb

[bavarian3]

Projecte46m3

-Since you DIY'd, did you notice any ill fitment when test fitting? Check this vid (timestamped already) https://youtu.be/Bny08_GKhNk?si=r6WnHw-dM3iI2qfS&t=1353

[0-60motorsports]

From the homework I have done for my build:

RKP

1. Fit is perfect, requires no trimming
2. Made more for CSL rails. If using original roof rails, you will need to add CSL specific spacers (they call them fixing clamps 51137898131)
3. Purchase from IND, ships instantly with no import costs

Karbonius

1. Fit is too long in front, the expectation is that you trim to size (approx 7mm)
2. Fit in rear requires trimming corners at an angle to clear factory roof guides (or cutoff the factory roof guides and leave roof as is)
3. Can reuse original roof rails since it comes with clips just like factory roof.
4. Can purchase from IND directly or from Karbonius with delay and import costs.

Quality wise, they both seem really well made. If you search around in the slicktop thread and member’s build journals, you can see that people have installed both with good results. Since you already have the CSL roof rails, I’d probably go with RKP. Just throw it on with no fitment type modifications then add the rails.

Do you have any pics of where the spacers 51137898131 go? I am guessing 6 ae needed, 3 for each side....

[Avedis]

Disclaimer: I have yet to do my roof, so this is based on homework I have done.

Each CSL roof rail has 7 spacers, 3 of them have double sided adhesive, 4 of them do not. There is so little information on the part number themselves, so I have no idea if they come with adhesive or not.

If I were to order these for my car, i'd order 14 total. You can see better photos here LINK

[bavarian3]

Disclaimer: I have yet to do my roof, so this is based on homework I have done.

Each CSL roof rail has 7 spacers, 3 of them have double sided adhesive, 4 of them do not. There is so little information on the part number themselves, so I have no idea if they come with adhesive or not.

If I were to order these for my car, i'd order 14 total. You can see better photos here LINK

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These don't appear to be readily available. So if CSL rails are NLA, and these clips cost $1-200 to source, RKP doesn't seem to be a viable option.

With that said, the "clips" in the Karbonius piece seems to be an easily 3d printable part, then one could panel bond them on. Paging heinzboehmer since we've been chatting about this.

Karbonius roof is $280 more. Which isn't nothing, but solves this, and from my research seems to be a more trusted solution.

[bigjae46]

These don't appear to be readily available. So if CSL rails are NLA, and these clips cost $1-200 to source, RKP doesn't seem to be a viable option.

With that said, the "clips" in the Karbonius piece seems to be an easily 3d printable part, then one could panel bond them on. Paging heinzboehmer since we've been chatting about this.

Karbonius roof is $280 more. Which isn't nothing, but solves this, and from my research seems to be a more trusted solution.

I bonded my original roof rails onto the roof.

[0-60motorsports]

Disclaimer: I have yet to do my roof, so this is based on homework I have done.

Each CSL roof rail has 7 spacers, 3 of them have double sided adhesive, 4 of them do not. There is so little information on the part number themselves, so I have no idea if they come with adhesive or not.

If I were to order these for my car, i'd order 14 total. You can see better photos here LINK

OK great, thank you. I think i really cant be bothered though after the recent shit show of a fiasco ive just been through with CSL roof rails.

I ordered new CSL roof rails and once they get here i'll try my best to 3M install them but if that doesnt work out comes a bit of silicone........

[Bimma360]

Why does that make a difference? Prepreg makes it harder to screw up but a post cured infused part is just as strong as part cured in an autoclave. The properties are in how the part is post cured according to the specific resin matrix formulation.

While kind of true, this is only half the story. The strength is determined by the carbon to resin ratio. Prepreg fabric has the optimum ratio for strength. A resin infusion process, while totally capable of reaching the optimum ratio, leaves room for error.

Regarding post curing vs oven curing with precise ramp up and cool down intervals (regardless if its an auto clave, or a composites oven where you can pull vacuum from an outside source), the post cured part is a compromise even if the resin is formulated for that exact process. Depending on the use case, this is probably fine for a good bit of parts you'd install in a car. But I wouldn't go as far to say that both processes produce the same results.

And for clarity, when I am talking about post curing I am talking about the part fully curing at room temp and then being post cured at a specific temp for a specific length of time (for example say 120*F for 9 hours).