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Zip-Out Rear Window on a BN-7 Top?

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M

mrunci

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Many years ago I found one of the many joys of owning a BJ-8 was the possibility of driving with the hood (top) up while leaving the rear window open. Great air flow on hot summer days!
I now own a BN-7 which as we all know does not afford that possibility in stock form.
Has anyone heard of modifications being done to an original-type roadster hood that would offer that same feature? If not is custom manufacture of a hood modified in this way even possible and if so does anyone know of a source?
 
No, but I can not think of a reason why it can not be done - at a price of course, I know of a BJ8 that has had the soft top and rear shroud modified to allow the fabric to cover the frame like a BT7, because the owner some times uses a hard top and then changes to a soft top at the drop of a hat. I suspect but do not know for sure that the hard top may be for a BT7 and hence the soft top had to be removed in total to get it to fit.

:cheers:

Bob
 
I had a zipper installed in my BT7 by a shop that did car upholstery and top installation. It was a long time ago and i don't remember the cost. Be sure to make sure they will put the zipper 'slider' on both side to meet in the middle like on the BJ8. One is workable but a hassle sometimes.
You are correct, it is great for highway driving on hot summer days.
 
Ken Rocke has built at least a couple of 2-seater tops (maybe 3 - 4) with zip-out rear windows - from scratch. He told me a stock top can't be modified this way. He may have told me why (long forgotten), but I took him at his word. No contact info.
 
A Souther California club member has one. It may be that this is one of the tops made by Ken Rocke


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I have tops for the BN1 and BN2 with zip- out rear windows. The source was AH Spares and this request was not an additional charge. Just specify the modification required.No other sources for tops would accept this modification !!!
 
Guys, I appreciate your responses. The photos are particularly helpful for me because they bring into focus perhaps the one continuing problem with this arrangement, i.e., if the wind remains attached along the bottom seam, it must remain rolled or somehow folded on the rear shroud deck. It cannot be folded downward into the cockpit as is the case on a BJ-7 or BJ-8. As a practical matter this would mean poor aerodynamics as the window portion would flop around in the wind at speed. This would obviously risk compromising the paint surface on the deck, not to mention the structural integrity of the window itself. Somehow I hadn't been able to anticipate this as I stared at my top. The photos were really of great help.
I will consult with an upholstery and top specialist to be sure but I'm a little more skeptical about modifying an existing top than I was when I first posted this note.
Building a new one from scratch may be the better solution.
Thanks again very much.
 
Hi Mat,

I have spend many hours repair-sewing the zip-out rear window on my BJ8 and have learned a number of things relating to its construction and support. Your BN7 top substantially depends upon its in-place rear window to maintain all-round rear support as air passes over the top and then blows in a forward direction at the window. With door windows not in place (open), air coming through also acts to push on the window to add a counter force to the forward pressure provided by the outside air flow.

If I were doing the window modification you are looking to do, I would consider having the rear window unzipped and completely removable to be stowed separately. Additionally, consider having the rear top frame support completely wrapped to provide additional support and secured and detachable with a lengthwise zipper, similar to the BJ8. Also, with the window removed, I would make sure there is ridged support and attachment across the bottom of the window opening and added body contact support at each end of the rear window opening.

I very much appreciate your objective and do appreciate the effort and chance of experiencing unexpected conditions that would need to be addressed. However, I often drive during a hot summer day with the top up and rear window folded down and appreciate the benefit you are looking to achieve.

All the best,
Ray(64BJ8P1)
 
Matt, we put many, many miles on two lanes and interstates with the window zipped down. We just laid it on top of the 'luggage' that was in the back seat. When there was no luggage, it just laid over the back seat. Never had any problems with the top driving that way. If the side curtains were mounted on the car, the back window was zipped up. We rarely ever used the side curtains unless it was really cold or we knew we were going to hit heavy rain for an extended period of time. We had the side mounted air deflectors that normally made driving bearable if not enjoyable.
 
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