Thursday, October 02, 2008

The Lonely Wiper Blade

Outside of the realm of supercars, vehicles with single front wiper blades are a rarity. My first experience with these one armed bandits was with my first car, the Isuzu / Holden Impulse / Piazza. It was a royal pain in the ass to drive to one auto parts store after another to find just one 5' long (maybe an exaggeration) wiper blade insert.

The single blade design was also used in the Mark I Volkswagen Scirocco...

...and the Jaguar / Daimler XJ40.

But the most ingenious and sophisticated implementation of the single armed wiper design was by none other than Mercedes-Benz. This illustration from How Stuff Works describes the mechanism perfectly. With the Isuzu, VW, and the Jag, it's just a single arm sweeping simply back and forth in one, uninterrupted stroke.

But the Mercedes "monoblade" system, also known as a controlled single arm system, is much more complex. Remember, the Mercedes of the 1970s and 1980s was overengineered to death.

With the monoblade system, the blade extends outwards during the sweeping motion in order to cover the windshield's top corners. The blade pulls in at the ends and middle of the stroke.

This is the best, and only, video I can find of the monoblade mechanism in action.



Blogger said...

I have had the pleasure of driving my folks' C-class, and that wiper is superb. It also LOOKS robust, as the base is thick.

However, I have a mono-blade on my Lotus Esprit SE too, and the things is awful. More like a fragile scraper than a blade, it still does the job, but looking at it you won't think it would.

Maxichamp said...

Interesting observations.

By the way, do you have the 4 or 8 cylinder Esprit? What are your thoughts on it, versus the other version? Do you see the 8 cylinder version as necessary to compete with Ferraris and the like, or a marked (and unfortunate) departure from tradition?

Blogger said...


I own a 1990 SE which is the charge-cooled four cylinder.
I had a discussion about this before on the Lotus Esprit Forum.

The problem is not one of performance, but of perception. Despite being cheaper, but much faster to a 100 and, in some cases, a higher top speed than its rivals, it just never could compete in the minds of sports-car afficianados with less cylinders. This is a pity, the Esprit's genius is in fact the 4 cylinders, but only owners and real fans will discover this. I also somehow feel it could have been a novel differentiation, and a continuation of the tradition. But the 4 cylinder reached the end of its development, anything larger than 2.2 liters would've required a whole new engine, and things like balancing shafts as found on the large capacity 944 and 968.

I haven't driven the V8, but I have heard it is much more expensive to maintain. There is very little difference in top performance, but obviously the V8 has much more flexibility as a driving machine due to low-down torque.

Despite changing to a V8, Lotus didn't develop the engine fully, and the sound from the V8 is disappointing, so it was too little too late for the Esprit.

There is talk of a new Esprit in 2009 or 2010 with a BMW-sourced engine.

Maxichamp said...

You, my friend, just gave me an idea for my next blog entry. Thanks!

Blogger said...

You are welcome - looking forward to it!