Quote:
Originally Posted by 3-Wheeler
I would think that 13° is enough clearance for most driveway aprons.
Jim. |
I'm not Robert, but................
The clearance isn't just a rear issue. It is an issue with the whole car. The correct way to analyze the clearance is by use of triginometric methods which consider both the wheelbase of the car, 94.5", and the boattail extension.
The sum of the wheelbase, and Robert's boattail extension forms the long side of a right triangle, whose length is 171". The short side of the triangle is the proposed tail clearance of 18". A similar triangle can be drawn, with the same apex angle, inside the first triangle. The second triangle has a long side of 94.5 inches and an short side of unknown length. The short unknow side is the amount of allowable drop of the rear wheel before the tail drags. This unknow length can be found by using the law of proportions and in Robert's case is 9.9 inches. This is the amount within a 171" span that the rear wheel can drop before the tail drags.
The clearance issue is not just one's driveway. There are numerous other hazards encountered by street vehicles. There are numerous other driveways to consider. There are entrances to malls, gas stations, and other business locations. And perhaps the most devious of all, there are some intersections in older cities which have been repaved so many times that the crown of the road alone is enough to drag a long extension. I don't say these things out of lack of experience. For many years I have driven motorhomes which have significant rear overhangs. It is very common to drag the rear, but fortunately motorhomes invariably have a massive steel trailer hitch to take the abuse.
I'm not against boattails - in fact I would like to have one myself. And, I'm finding the discussion very, very interesting. But I just don't want to see you nice folks put lots of money and time into something which is going to be easy to damage. We can all learn to drive with constraints, like learning not to pull the first gen up to a curb and damage the front strakes, but a long overhang is gonna take even more "training".