New Hardtop

[Simon_P]

After many years of thinking about it I have finally decided to get on with making a hardtop for my car.

To cut another long story short! We have decided to go into productiion!

Here is the desing brief so far
1.Must be easily removable (preferably by one person)
2. Will be similar in shape and line to the soft top
3. Have a glass, heated rear screen
4. Not leak!
5. To be priced at arround £1000
6. To keep cost down it will require completion by the buyer.

I've sourced the heated rear screen and had an initial chat with a fibreglass expert.

Let me know your thoughts!

Simon

[GeoffSmith]

I guess you've seen the Wiki. I still think the Lotus prototype looks the best.

[Bolsom]

Have you looked for a source for the window seals? This was the main problem for NTC. I visited Norman there a couple of times over a two year period and
he was unable to find anything that worked without leaking. He even tried some electronics that lowered and raised the window when the door was opened.
Sadly I eventually gave up waiting and bought the SPC one.

Colin

[Simon_P]

Geoff,

I have compiled as much information as I can over the years - Most of it from LEC and the wiki - Thanks Guys!

I agree the Lotus one does look good. I think this is mostly due to the rear screen and theirin lies a problem. Bending perspex screens isn't really an option. Finding a suitable screen becomes more difficult as the curvature in the screen increases (wrap around) as the curvature dictates the shape of the rest of the hardtop. After a stiff neck and some funny looks from looking at just about every car I saw I came across a screen that is reasonably flat, heated, obtainable and within our price range. It is however more in the style of the soft top. I'll bring the screen I have to Malvern.

Colin,
Yes this is going to be a difficult one to crack - No surprise that lotus didn't manage to stop them on the soft top. There was, either on the old LEC site or the BBS site, a sort of leaks register (anyone happen to have a copy?). I reckon I have a seal that will stop all of the leaks around the window, which leaves the top of the screen and the joint with the a pillar seal. I'll know more when I start prototyping!

I also looked at the electronic drop a few mm method like on the Porsche Boxter. Feasable but would require a lot of work.

Will you be at Malvern? Do stop for a chat.

Simon

[Jackonicko]

The curved rear screen of the Lotus roof improves the external appearance, the visibility for the driver (hood up, or with the kind of hardtop you seem to be describing, visibility from the Elan is poor), and light in the cabin and would give a compelling reason to buy a new hardtop - without one, why not just buy an SPC hardtop?

I don't really see why a perspex screen shouldn't be curved - the glider/kitplane fraternity have moulded canopies with complex double curvature, after all.

I'd echo Geoff's sentiment that the Lotus original design looks best - by many, many miles. It also looks as though it would address all of the visibility issues.

[ashm]

I also looked at the electronic drop a few mm method like on the Porsche Boxter. Feasable but would require a lot of work.

I think this is now pretty much the accepted method for new cars. The BMW convertibles, Alfa, Porsche etc all seem to have settled on this solution. I agree though, it'd be tricky to implement - you'd have to put switches in the doors and a control box hooked into the electric window controls. Not insurmountable though, and it should allow a really good seal with no leaks and draughts.

I was vaguely thinking of trying this approach with the soft top and replacing the seals accordingly.

Adam

[Bolsom]

I agree the light in the cabin is poor with the soft top and it is desirable to have as large a rear screen as possible. One of
the most noticable improvements with the SPC top is the great rearview plus the increase in light within the cabin.
My hardtop has about 6 saucer sized depressions in the roof. I am going to see if I can find a supplier that can fit a popup
sunshine roof. This will give even more light in the cabin and reduce the amount of work required to repair the roof
contours.
I will not be at malvern as I have not long returned from the States via the Uk and in any case I managed to impale my calf muscle
with a sickle two days ago so cannot currently drive. (Stupid boy!)

Colin

[Monty]

This will be an interesting project and i wish you all the best of luck


I would give people the option of glass and plastic screen

also if you can keep the roof so it`s seperate from the hood storage cover all the better

[bobbrown]

Getting glass bent is not as difficult as you may think and it can be tempered or laminated and it is even possible to get it heated, you only have to look a little outside of the box like the marine industry but cost may be an issue but it is a numbers game.
1 offs are typically very expensive but as you go up the numbers the price comes down.

The B post or rather where it would be if the soft/hard top had one is pain at times as the visibility at some junctions can be reduced particularly "Y" junctions and I think the Lotus design is the best as it follows the cars overall shape, SPC's is a bit Toyota. Also SPC's requires the hood lid removed more pain, I would prefer one that clips on at the front and rear retaining the original hood lid even if it meant putting a couple of fixings in it.

Bob

[Simon_P]

Yes looked at both Perspex and Glass screens made to order - difficult/ very expensive. Perspex isn't really practical as it scratches easily and can go cloudy in sunlight.

It will be separate from the hood stowage cover.

See you at malvern!

Simon

[petezipp]

Good to hear someone else is going the hardtop route.
Mine is proving just as hard as i was told it would be, and work is very slow.
First it was too cold for the GRP , then too hot for me.

I have used an MGF shell which is the closest I could find. Then reshaped the front( as you say quite a curve on the lotus),I have an Aluminium sheet attached to the top & fixed with the standard clips. just a bit concerned about lifting at speed.
Next I will move the window shape back to suit.

Honeyborne mouldings have a screen which fits this Top but i don't know what it is off, it is heated though.
The seal does look tricky but surely I can equal the factory effort. It looks like the large round seal should touch the window when closing the door,& squash up when winding up with the door closed ?

I intend to fix mine to a spare Hood cover so to remove the top I can Tilt up the whole assembly and unbolt it.
Wish you the best of luck with your top hope you will keep us informed of progress.

Peter

no 2.jpg

[steve matthews]

I myself like the look of the spc hard top.
If a choice had to be made.
I might also buy that version.
Steve across the pond ever closer to oil slick.

[kevin31157]

Hi, just out of curiosity, i noticed your post on hardtop manufacture. Did you ever make one in the end and/or go into production, or even sell some. If so how much and are u still doing it.
KEVIN

[Simon_P]

Hi all,

Sorry for the delay in replying.

Progress is slightly slow as I have had several holidays (in the US at the moment).

I have tried several screens and looked at modifying both the MX5 and MGF hardtops. Pretty much settled on the MGF rear screen as it is big enough and heated (considering comments above) also it is easy enough and cheap enough to buy both the screen and rubber.

Will post some pictures when I am back in the UK.

Simon