Valk is 1940's technology developed by Harley and BMW?

[LaMonster]

Well sort of. :roll: I couldn't believe it either. Check it out.
http://www.conansclassics.com/harxahis.html

"The XA is one of the rarest Harley-Davidson production bikes that is well-documented and is considered a coveted piece in any Harley-Davidson collection. The US Government drew up a specification for a horizontally-opposed, shaft drive motorcycle in 1941 and asked Indian, Delco, and Harley-Davidson to compete for the contract. At the time, the U.S. was engaged in the war in the deserts of Africa, and it was thought that a bike of the XA design would be more efficient and durable under the extreme desert conditions. As well, the Army thought a bike designed like the XA with 2” more ground clearance would be more versatile than the WLA. A drive shaft would be more reliable than chain drive in the desert sand and mounting the cylinders and heads out in the air stream would allow for 100 degree cooler motor temperatures."

[Cruisin Dave]

I believe the XA was developed as a "copy" of the BMW boxer that was used by Germany in WWII. Japan also built military bikes based on the same design.

[sarge]

Blame the Jeep http://jm.g.free.fr/smileys/non-smileys-animated/smiley_abzz.gif

That’s why this bike never made it into full production -- and why, incidentally, military motorcycles of any kind fell out of favor during World War II. But that’s getting ahead of the story.

http://www.ama-cycle.org/museum/1999/images/classfeb.jpg

Mechanically, the large cooling fins stuck straight out in the breeze, reportedly keeping the XA’s oil temperature 100 degrees cooler than a standard Harley 45. At 4,600 rpm, the side-valve engine put out a claimed 23 horsepower.

While the army dragged its feet on picking a winner between the Harley and the Indian, the H-D factory looked for other potential uses for the XA motor, including sidecar rigs, snowmobiles, and even powering a 1,000-pound mini version of the Jeep called the Peep. None of the projects worked out.

Eventually, the army finished its testing, and decided that neither new bike would be built. Instead, they bought several thousand more Harley WLAs. Mostly, though, the U.S. military decided to hitch its hopes to a vehicle that could go through anything, didn’t tip over, and required very little training to operate -- the Jeep.

The XA motor, despite its workable design, fizzled.

Thus ended the Harley XA project -- and the idea of a tactical military motorcycle.

more at http://www.ama-cycle.org/museum/1999/classfeb.asp

Thanks LaMont for the history, lots of things that I never knew and love to watch the History Channel, Discovery, Biography, etc.

[Cruisin Dave]

Wait...maybe that was Great Britian that built boxer replicas, not Japan. I was at a car show about 12 years ago that was hosted by a gentleman with an extensive military vehicle collection, tanks, jeeps, armoured personnel carriers, etc. He also had various military motorcycles, Indian, Harley 45's, the Brit bike and I think an XA. At first I thought the Brit bike was a BMW, that's how close a copy it was. I don't remember what company built it.

[Cruisin Dave]

Here is a Chinese boxer...Chang Jiang CJ750

Quote: The bike is a present day, Chinese-built copy of a design that dates back to the pre-war BMW R71. It has a few modern-day refinements just to make life easier, but which aim to keep its original character intact.

http://www.realclassic.co.uk/bemw03100602.jpg

[Cruisin Dave]

And the Ural...
http://www.realclassic.co.uk/ural03101502.jpg

[sarge]

Better Photo of the XA

http://ulyssesnb.netfirms.com/classic_old/1942_hd_xa.jpg

http://jm.g.free.fr/smileys/non-smileys-animated/smiley_abzz.gif

I Like the Thompson addition :wink:

[solo1]

Great post! Thanks Lamont, Sarge, and Cruisin' Dave. Very interesting.

[Coot]

Very interesting. Thanks for the history lesson.

I saw a Harley Vertical Four in Atlanta in 2003 at the show. Do any of you know about it?

Thanks,
Coot

[Maddog]

There was also the ABC twin that produced an oppossed twin in 1912, fact of the matter it set a new record for class at 74mph. It had a chain drive, and the cyclinders ran fore and aft. Then Franch copied the R12 & R71 BMW after the war and called them the Cemec. Also the Zundapp which was first built in 1917 had an oppossed twin.

Lamont, check out a 1907 Boss Hoss called the Curtis