"In this Special Series about the CSL carbon roof of The Phoenix, I document my unboxing impressions, required hardware, professional fitment and final aesthetics.
In this journal entry, I unbox the Karbonius roof and document the great, the good and the not so good."
First things first, Karbonius knows how to package. The carbon roof is a PITA to ship: it is a dimensionally enormous yet light product with surfaces sensitive to scratches.
To make matter worse, Karbonius uses DHL. They're good as a courrier / parcel service, but they're still just a parcel service. The courrier guys don't care: quantity over quality.
Karbonius packages the roof in the thick, corrugated cardbox box with an additional cardboard internal wall. Thick, dense foam is added on edges of the roof and across the carbon outer shell to have a fixed state of package: it doesn't move during transport.
The clear-coated carbon is protected with thin, scratch-resistant paper to ensure the clear coat remains pristine. Additionally, they label the package "FRAGIL" stickers all over.
I've documented at length BMW's use of pre-preg carbon fiber on the CSL and how all replica parts I've sourced for my build used this same process.
It's not for bragging rights, a roof is structural and the process matters. Many replica roofs on the market use carbon vacuum infusion processes as it is cheaper and doesn't require an autoclave.
Vacuum infusion can lead to visual shrinkage of the weave from heat exposure. This isn't a risk I'm willing to take on an expensive installation of product that's essentially a giant black solar panel.
The pre-preg and autoclave process uses a negative mold in which pre-impregnated carbon layers with a resin system. Once the necessary thickness and aesthetics are achieved, the pressure and heat of an autoclave are used to laminate the pre-preg carbon.
As a result, the prepreg carbon is ready to lay into the mold without the addition of any more resin. It ultimately produces a part that is both extremely strong, flexible, light with perfect aesthetics to boot*.
The Karbonius roof uses the same 1x1 weave pattern as the OEM CSL roof. BMW M has kept the weave pattern for all of its carbon roof production ever since.
Aesthetically, I find it looks better than 2x2 as well. 1x1 is tightly weaved, it makes it easier for Karbonius craft-mans to handle without creating distortions on larger surface applications.
The Karbonius CSL structural roof panel is a true 1:1 replica in its design and carbon manufacturing process.
Handling the roof is a weird experience, it's 3.3kg! It's light as a feather for the size and is very a flexible piece.
As a 1:1 replica of the CSL roof, the Karbonius carbon panel is compatible with the peripheral hardware required to complete the install.
It incorporates the brackets required to install the CSL black roof trims and the extended sections on which the front & rear glass will be bonded.
The inner shell has spacing required to fit the required cross-brace and bond it to the panel. As with anything aftermarket, proof will be at fitment.
The required hardware list.
As the roof is a 1:1 replica, you should source Genuine BMW parts to complete the swap.
I highly recommend you source the CSL roof rails as repainting your original moonroof or slicktop roof rails will not be ideal. They are different sizes.
- CSL Roof Rails
- Driver (51137897926)
- Passenger (51137897925)
- Roof Bow (41328242075)
- Euro headliner (51442699065)
- The Euro spec doesn't have a bump on the roof. It looks cleaner.
- CSL roof insulation
- Front (51488229733)
- Rear (51488229734)
The somewhat expected meh.
I've often discussed the requirement for professional paint & body installation on new body panels for these M cars for fitment and a perfect color match paint.
Sure, these are 1:1 replicas of OEM parts. They're still replicas of parts that were installed at the factory on brand new, perfectly assembled cars 20 years ago.
This CSL roof isn't any different - but for different reasons then you'd expect.
My roof's clear-coat popped months into storage.
My roof was delivered by Karbonius earlier this Summer and has sat in a temperature controlled garage away from sun light. Upon a quick inspection at delivery, the roof's clear was in perfect condition except one visible dust spec under neon lighting.
Notice the little dots? This is popping. It happens before clear coat drying time, conditions or chemicals were not perfectly selected and applied per the varying conditions of the environment.
What is this?
This is commonly called "outgassing". In short: 2-component automotive clear coats harden over time and continue evaporating solvents for over 30 days after application.
I've covered what clear-coat popping is with the 1:1 CSL diffuser unboxing here.
Why did I expect it?
Karbonius isn't any different to other aftermarket companies in this industry: their clear coats are sprayed by humans in not perfectly sealed environments with a necessity to get products out the door to keep the production flowing and customers happy.
Having spent hundreds of hours in paint booths chatting with world leading painters as we prepared SEMA show cars. I know what to expect when it comes to aftermarket paint & body. It's never perfect unless you're willing to spend sums of extreme diminishing returns.
How it'll be fixed.
The Phoenix is going through a complete paint & body restoration. It was my intention to have the roof re-cleared fo further protection and a perfect finish before the final PPF protection.
I'm not happy about this to be clear, but I understand it's part of the process. How these issues are fixed is what matters.
I will communicate with Karbonius to better understand what would be offered to you should you experience this. Karbonius backs their roof with a 2 year warranty.
Up next: later on this Winter, we fit the roof, document the process as part of the complete exterior CSL'ification.