mx5cartalk.com

Disclaimer - All of the information herein is completly wrong, so dont believe any of it.

Hi guys,

Thought i would make a new thread on this, instead of clutering up Lightyears FS thread for the hardtops (which can be found here - viewtopic.php?f=44&t=38225)

Ok, so I went in and asked my local MVR (equivelant of RTA or what ever else you might have down south) and they've basically directed me to this web site: http://www.infrastructure.gov.au/roads/ ... _ncop.aspx - In peticular this section - http://www.infrastructure.gov.au/roads/ ... eb2006.pdf (PDF file) to check on the legalities of these hard tops.

Now theres no section specifically about Carbon fibre, so im just going off the rules under fibreglass, which basically states (from my under standing), that if the fibreglass is replacing a panel, it should be no thinner then 3.5 mm and should use the same fixings. So going by that, theres no issues with running one of these hard tops on the road?

The only issue i can see is that the CF would have to be lab tested by the guberment, in a flat 600mm x 600mm piece to test for strength - which being carbon fibre, I would assume would pass easily due to being much stronger then Fibreglass?

Any other thoughts?

i can't see any legalities issues.
The fact it's not replacing anything.

Currently now, you are protected by pieces of metal and 1mm of vinyl.

And when you drop the roof down, you are protected by air.

Unless we are talking about CF doors and bonnets.. then that's another issue.

I was thinking more along the lines of they'll say its a replacement for the "OEM" hardtop - which again, provides no real protection any way.. just wanting to see what other people could make from those documents I linked. (Alot of this legal jumbo goes straight over my head! lol)

I agree with Philz, this is only relevant when replacing panels on the car, not an optional hard top.

At the end of the day carbon fibre is still reinforced plastic, just like fibreglass. I don't understand how some people baulk at a carbon fibre part over a fibreglass one. Saying things like you are going to dye if you have a crash because it's c.f.

From my under standing, the only reason to worry about it being CF, is that CF has more of a tendency to shatter, but still no real need to worry there - As its not really a structural piece, I'd imagine at worst the brackets would snap off, and have some small shards, with the top hiting you on the head on the way down?


Edit: So mostly every one thinks there shouldnt be an issue?

The carbon fibre roofs i make will not shatter as they have a soric layer in the middle. It stops it from shattering. That's not it's job, but it stops the part from failing. If you bend an offcut till failure it won't fall apart. It wil break, but not shatter.

Acquaintance of mine was building a Clubman in Qld.
He was required to submit a sample of the layup for approval before he could use the glass panels on the car.

Are you interested in buying one?
If not, this thread is pointless.

Actually, yes i am interested in buying one, and will hopefully be driving my new NA8 with CF hard top from Vic back up to Darwin within the next 2 weeks.

Cheers.

I say just buy one, fit it and enjoy the thing.

It is not structural and does not affect crash worthiness in the way a bonnet and front wings would. Unless you want to show off the CF weave get it painted and nobody would know the difference anyway.

I dont think it is worth asking the question to the authorities, it is obviously a bit of a grey area and they are famed for just saying no because it is easier than arguing the toss and having to invest money and man power in to amending the wording of a regulation.

The only area I could see you getting some trouble over would be either sharp protrusions and edges or the windscreen in it not having the correct constuction and safety markings embedded in the glass and also not having a demister.

Your insurers should cover the roof if you tell them about it.

I don't get the reference to Fibreglass, the OEM top isn't fibreglass, it's plastic.

miata wrote:I don't get the reference to Fibreglass, the OEM top isn't fibreglass, it's plastic.

To be 100% correct...the factory hardtops are FRP - fibre reinforced plastic.

Agreed. Have you ever seen a broken one?

lightyear wrote:Agreed. Have you ever seen a broken one?

Plenty....where people have either dropped them or had no idea how to remove them off a car. So they've either broken the front corners off or torn out the rear mounting brackets by rotating the hard top up instead of sliding it rearwards and then lifting.

Cheers,
Danny