CarbonKings Hard Top Roofs

Wiggie987 · Postby **Wiggie987** » Tue Jun 09, 2020 7:26 pm

Hi all, I've been looking around for a hard top for my NB8B and stumbled across the hard top CarbonKings have been doing with an acrylic window. I was wondering if anyone has previously looked at them or or had bought one themselves and had a bit more info or an opinion about them, mainly whether they meet Australian Design Regulations etc. I figure they would but it never hurts to be sure. I've dropped the link below. Cheers

https://carbonkings.net/collections/maz ... 8459610200

93_Clubman · Postby **93_Clubman** » Wed Jun 10, 2020 5:16 pm

Haven't heard of CarbonKings, but now note they're in Australia. Lightyear's CFFBs for the track are the most well known on here, plus I think someone in Greece has been mentioned, as well as someone in US. Lightyear was also making an CFHT, but not sure if he produced many. Not sure the acrylic window would comply with ADRs, as recall Lightyear making a point of saying his CFFBs were for the track as the rear window wasn't glass.
search.php?keywords=hardtop&terms=all&author=lightyear&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
&
viewtopic.php?f=44&t=74963

bruce · Postby **bruce** » Wed Jun 10, 2020 6:53 pm

Regards hardtops you can't go past OEM. Everything else is just a compromise (and dearer).

StillIC · Postby **StillIC** » Fri Jun 12, 2020 1:56 pm

The Carbonkings hardtop image is a straight steal from Carbon Miata...
https://www.carbonmiata.com/shop/mazda-mx-5/nb-99-05-mazda-mx-5/exterior-parts-nb-99-05-mazda-mx-5-nb-99-05-mazda-mx-5/body-panels-exterior-parts-nb-99-05-mazda-mx-5/hardtop/

Which might suggest that they are simply a reseller for Carbon Miata parts? Which, if true, makes the ~$1500 hardtop cheaper than buying and shipping from Carbon Miata by about $500-local shipping.

legume · Postby **legume** » Fri Jun 12, 2020 4:57 pm

bruce wrote:Regards hardtops you can't go past OEM. Everything else is just a compromise (and dearer).

Not anymore. $1600- 2200, seems to be the prices advertised. One eager seller had a poor condition one with a smashed window for somewhere around one and a half.

Perhaps getting a run of reproduction glass, might be worth it. Put it one of the better quality aftermarket tops

Mr Morlock · Postby **Mr Morlock** » Sat Jun 13, 2020 2:53 pm

broken rear was mentioned recently by a forumite . They are available on a make basis from Mazda Jpn but expensive. If one was buying a used h/top it would need to be in good cond and with a rear window not damaged -. Getting something like a window made here I reckon would be next to impossible - I dont think most would understand the process of sourcing an engineered product and volume would be single digits.

legume · Postby **legume** » Mon Jun 15, 2020 5:26 pm

https://www.vehglass.com.au/custom-auto ... oducts.php

Although I have never had a dealing with them. But can be done.

ralt · Postby **ralt** » Mon Jun 15, 2020 5:41 pm

Hi.
The company mentioned above who can supply curved glass screens I would suggest have a large stock of current and older screens and use a good screen the same as required lay it onto their stock find the right curve obtain the same as their stock cut it to size. This is the way it is done in America. I thought it was very smart particularly as screens are getting scarce for older cars.

legume · Postby **legume** » Mon Jun 15, 2020 7:05 pm

https://youtu.be/Sg92LDhHYuA?t=135
starting at 2:15 and
https://youtu.be/HH3fAyJrEYo?t=131
starting at 2:10
The Pilkington one shows the bucks used to make the frame. It also has arms that move as the weight is loaded up to bend to more complex curves.
I was told once by a classic restorer that with simple shapes/bends, a thin sheet of mdf cut to the size of the opening was all that was needed. I guessed he would use this to get the glass template, then reinforce the another to get the shape.

bruce · Postby **bruce** » Mon Jun 15, 2020 7:58 pm

If anyone was thinking - I doubt you could fit a glass screen to a carbon roof. You couldn't secure it properly with a rubber seal nor would it support the weight.

greenMachine · Postby **greenMachine** » Mon Jun 15, 2020 8:46 pm

bruce wrote:If anyone was thinking - I doubt you could fit a glass screen to a carbon roof. You couldn't secure it properly with a rubber seal nor would it support the weight.

Good spotto Bruce! Now we all know what a crap material CF is, we can look forward to, amonst other things, F1 returning to aluminium for their tubs, or even going back to spaceframes ... :lol:

legume · Postby **legume** » Mon Jun 15, 2020 8:51 pm

But the original are only fibreglass. They have 4 lugs glued to the glass to hold it into place while the sealant is bonding. Then the rubber T trim is inserted between the glass and hardtop.

It would only depend on how well a reproduction it is. That and the fact that the cost of the glass for a one off. But if a small batch was produced and OEM hardtop prices rise, sooner or later it will hit that balance point . Really, a mass produced windscreen for most cars could of been had for under $300 fitted a few years ago. I mean $2150 for a chipped hardtop on Facebook up from the average of $1500 for a pecfect condition 2 years ago.

I once collected vintage Tamiya rc cars. Kits were reaching over $2k until Tamiya hit on the idea of getting the old dies out and reproducing them. They also updated the fragile ones with a new chassis on the old shell. Original prices tapered off very quickly, even dropped considerably. Yet the reproductions held there price, albeit not soaring like the originals.

bruce · Postby **bruce** » Tue Jun 16, 2020 10:57 am

I doubt any of the CF tops were manufactured to support/accomodate a glass rear window, thus the asssumed inability to support one. It all comes down to quality (which is a big question). I would not want an insecure sheet of glass as you drive over a speed bump.

greenMachine · Postby **greenMachine** » Tue Jun 16, 2020 1:18 pm

legume wrote:But the original are only fibreglass. ...

No they aren't. I think the term is FRP.

Probably not relevant for the discussion of windows, but let's not feed the internet's vast store of incorrect and misleading information.

:mrgreen:

greenMachine · Postby **greenMachine** » Tue Jun 16, 2020 2:16 pm

bruce wrote:I doubt any of the CF tops were manufactured to support/accomodate a glass rear window, thus the asssumed inability to support one. It all comes down to quality (which is a big question). I would not want an insecure sheet of glass as you drive over a speed bump.

The factory hardtops flex, many reports of the noise as they rub on rollbars as the car flexes over bumps and undulations. And glass is a lot more flexible than most people realise.

I was (IIRC) one of the first purchasers of Lightyear's CF hardtop, and subsequently sold it to Guran (Bryan). A quick search doesn't show any clear pictures of whether they had the tabs, but then these were sold to people who wanted to pay for weight saving, so glass would probably not be on their shopping list. It wasn't on mine, which came with a plastic-of-some-sort rear window. I haven't looked at any other CF hardtops so I don't know about them.

If there were tabs, I wouldn't see any problem with installing a glass rear window. I'd use the factory seal or a sikaflex or somesuch and regard the tabs as secondary fixing, belt and braces if you like. I would also have a damn sight more confidence in the strength of the CF tabs than the plastic of the original too. That is making an assumption about the build quality, but then I wouldn't proceed to buy one without being satisfied with that.

Would a non-tabbed CF hardtop support a glass window? If you wanted to use the factory rubber seal, that would be entirely dependent on how closely it matched the factory shape and dimensions. Otherwise, how much overlap was available for an adhesive to provide a decent bond. In both cases, and certainly in the latter case, I would use external tabs to backup the adhesive in the event it failed.

:mrgreen: