Just listen to that sound.
Peering back through the veils of motorcycle history, it’s fascinating to contemplate what could have been. Take the Harley-Davidson XA. Short for “Experimental Army,” just 1000 of these bikes were ever made, as the U.S. Army invited both Harley-Davidson and Indian to compete for a potentially lucrative contract.during WWII
At the time, the Motor Company was already supplying the Army with its much more well-known WLAs, but the Army wanted a little something with shaft drive for some of the rough terrain they were covering. It also wanted a horizontally-opposed engine that could stay cooler, and would of course be easy to work on in the field.
So, Harley got to work reverse-engineering the sturdy, hardworking, battle-proven BMW R71. One of the many interesting things about motorcycle history as you dig into it is, just about everyone copied something from someone at some point. Most of the time, the copier took someone else’s design and iterated upon it to make it better (or at least different) in some way. Incidentally, the R71 design also went on to form the basis of Ural and Dnepr machines, as well.
When all was said and done, the XA’s air-cooled design reportedly produced oil temperatures that were an entire 100 degrees cooler than the WLA could manage. The 738cc engine made 23 horsepower, could handle a top speed of 65 mph, and had a full seven inches of ground clearance. The throttle was mounted on the left-hand side of the bike, with Harley’s first hand-operated clutch on the right, and Harley’s first foot shifter on the left. The kick-start was also on the left, and was more of a step-start, which you can see in the video. You also get to hear an XA fire up and run in this video, which is a huge treat.
Between 1942 and 1943, Harley-Davidson built 1,000 of these bikes. Only 10 had disc wheels like the first one in this video, while the rest had spokes. Sadly, the U.S. Army ended up passing on the XA, choosing instead to go with a vehicle that wasn’t a motorcycle at all: the Jeep. It was a lot easier to get soldiers trained to drive Jeeps around than riding and operating a motorcycle for the first time, and the WLAs were a lot less expensive than the XAs would have been.
Existing XAs were sold off as military surplus, leading to civilians purchasing some remaining stock and making them their own, as the video illustrates. According to a Bike-Urious writeup from 2018, around 60 working XAs still exist. It’s unclear how many in any condition exist in 2020, but they’re incredibly rare and interesting pieces of motorcycle—and Harley-Davidson—history.