What constitutes a desert sled when we’re talking about dirt bikes? Some consider a desert sled to be any heavyweight motorcycle 500 cc’s and up, modified for desert riding with a skid plate, a big gas tank, along with assorted tools and spare parts tucked into every nook and cranny on the bike.
Desert sleds were a breed unto themselves, since nothing looked like a desert sled, or rode like one. Sleds usually reflected the personality of the rider, and were gussied up with any number of good luck charms, like four leaf clovers, rabbit feet, St. Christopher medals, or any other talisman that might ward off an evil rim destroying rock, or mine shaft hole that would end a ride prematurely. 
1963 P-11 Norton with trick up-pipes (stock high pipes exited on either side)
The first desert sleds were built up around the venerable US built street bikes of the late 40’s, stripped of unnecessary street stuff and fitted with trials tires and skid plates. 
Early OHV Sporty set up for desert. Forward mounted & laid down shocks too! Who says Sporty's weren't before their time?
These machines were not so much about going fast through the mighty desert, but just finishing the ride without a major break down, or crash. Harleys and Indians made up these first desert sleds, with a few English bikes thrown in for fun, since they were the next big thing in the “lightweight” movement that was a few years up the road. 
The second-generation desert sled was the 650cc twin cylinder British bike, stripped of its street bike essentials and modified for off road riding and racing. Sled riders being ingenious types modified the bugs out of these machines, and the British sled became a reliable tool for high-speed desert work. Still, the most important accessory a sled could have was a tow-rope wrapped around the top triple clamp. Or handlebars. Never could be too sure. 
Bruce Olgivie's dad on some kinda thumper
The British double-knocker ruled the desert from the middle nineteen fifties to the early seventies, and some die hard sled riders still rebuke the two-stroke (ring-ding) as a passing fad, and ride them today. These sleds are modified down to the last nut and bolt, with lightweight frames, modern suspension, and equipment that wasn’t available back in the heyday of the big twin. But as time goes by, the riders pass on, and the bikes get sold, or end up in a collection, or a museum. The chapter is slowly closing on these machines, an innocent period of open pipes with no green sticker or BLM to worry about. When you leaned your 650 up against a yucca tree, and drained the oil into the desert sand. 
Mitch Mayes on his Dad's Velo
The third generation of desert sled was the open class two stroke. Beginning in the early seventies, and still alive today (if you can get an off-road sticker that is) the big two stroke shared none of the fragile nature of the Brit bikes, and soon eclipsed them in handling and reliability. 400 Husqvarnas, 360 Pursangs and 360 Yamahas soon out numbered the four-stroke crowd, and the golden era of dirt bikes was on. Everyone seemed to have a dirt bike, knew someone with a dirt bike, or wanted one. This was the heyday of the desert race scene in the Southwest, and legendary races like Corriganville/Hopetown, Barstow to Vegas, The Moose Run, Elsinore GP, and others captured a time that will sadly be no more. The desert sled had evolved into a light weight open class two stroke machine with Curnutt rear shocks, a Don Vesco tank, and six ply knobby tires on alloy rims. Speeds increased, with bikes reaching eighty-ninety miles an hour in some of the faster sections of these races. Not to say the bikes were un-breakable, since a tow-rope still made its way on most bikes as an afterthought. 
Jeff Wright on a Micro Metisse, Terry Clark on a factory Baja, and someone on an AT1MX with Van Tech forks. Dinky bike are sleds too.
The fourth and latest generation of desert sled is once again, a big four stroke. Modernized with water-cooling, 12 inches of suspension travel and reliability the old Triumphs and Beezers could only dream about, these new sleds are winning everything from Baja to Tecate and SCORE alike.
It’s ironic that the two stroke replaced the big four stroke, only to ultimately be replaced by a four stroke dirt bike again. But this time the new sleds are complicated high-strung machines that get about 30 hours out of a motor, before it has to be totally rebuilt, by a factory trained tech.
It seems to me, the desert race community is growing smaller, into a specialized sport where you have to have big bucks to play. The days of a privateer with an old pickup truck campaigning a home-modified desert bike are gone, or so it seems. Innocence lost? And with the population boom causing towns to spring up where races were once held, it’s only a matter of time before the desert sled is relegated to the history books.
A sad ending to a desert lifestyle that spanned sixty years? Let’s hope not. I guess all we need are a few hundred more twelve-year-old kids on mini bikes, a few hundred more vacant lots, and it’ll start all over again. We can only hope. 
1966 BSA Spitfire Hornet 650cc sled. I can't imagine hitting any rut at speed on this machine. Or whoops.
