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 Post subject: Rumpler fenders
PostPosted: April 25, 2011, 2:31 pm 
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Joined: March 30, 2011, 7:18 am
Posts: 1615
Location: central Arkansas
The other day I saw a drawing of a Rumpler automobile in a book I was perusing. I tried finding a picture on the web, but the best I could some up with is the Rumpler Tropfenwagen, which isn't quite the same thing, and it isn't as easy to see as the side view drawing.

The Rumpler was "aerodynamic." The fenders are just straight wings. If you look just behind the front wheel you'll see a little stub wing. The drawing I remember showed a third bottom wing, a bit longer, sort of like a stubby running board.

What I finally realized was, the "extra" stub fenders are rock deflectors. All of them are horizontal for minimum drag, and no rock has a direct path to a window opening.

Even knowing what is going on, it still looks funny... but it sure would be simple, effective, and easy to build...


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 Post subject: Re: Rumpler fenders
PostPosted: April 25, 2011, 3:09 pm 
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Joined: April 23, 2006, 8:26 pm
Posts: 6410
Location: SoCal
I get what they're doing, but I'd think that the tires themselves generate 99% of the drag, with close-fitting fenders adding another 1%... probably a bit more I suppose.

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 Post subject: Re: Rumpler fenders
PostPosted: April 25, 2011, 3:54 pm 
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Joined: July 26, 2010, 10:37 am
Posts: 752
Location: Tennessee
So, my question is, do these wings produce lift or downforce? Would the reduction of weight due to lift be of any value, considering the extra drag, or would the added downforce be cancelled out due to drag. The shape may just be a marketing ploy, even though the benefit of reducing rock hazards is real. Interesting.


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 Post subject: Re: Rumpler fenders
PostPosted: April 26, 2011, 7:12 am 
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Joined: November 7, 2008, 4:48 am
Posts: 1097
Location: snow city - it's wet!
I have to agree with Kurt's assessment. I also think that while the fenders may work for deflecting rocks or other solid objects picked up from the ground, they are probably not very effective at keeping water spray or gravel dust from being lifted into the air stream and then passed back into the passenger area of a low sitting car like a seven. Conventional fenders at least keep the level where small particulates get passed into the air stream fairly close to the ground.

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