When Im trying to get a good nights sleep, I sometimes find myself tossing and turning, thinking about what I could do to improve a motorcycle. Some of my ideas have been downright stupid, like cramming a 670cc Predator V-twin from into the frame of a tiny Honda Ruckus. However, one persistent idea has been to take an old beater of a motorcycle, remove whatever boring engine resides in the frame, and drop in a diesel. Apparently, I am not alone with this idea. A number of manufacturers have put diesel motorcycles into production, though youll be lucky to find any of them for sale.
(Published 10/30/2020. Updated 4/11/2022.)
Those of you familiar with military equipment will be quick to point out an obvious (well, to nerds) motorcycle that runs on diesel. Its a fine example to start with:
The HDT M1030M1 was an off-road motorcycle based on the Kawasaki KLR650 and built by Hayes Diversified Technologies of Hesperia, California. Like many military vehicles, it can run on multiple fuels. Why? Well, as the National Motorcycle Museum notes, many NATO nations decided that everything should be able to run multiple fuels:
Many armed forces around the world associated with NATO (North American Treaty Organization) have determined that all of their vehicles should be capable of running on multiple fuels, specifically diesel and biodiesel in peacetime, and JP8 aviation fuel and kerosene in time of war. The U.S. Marine Corps joined together with Cranfield University (in the United Kingdom) and Hayes Diversified Technologies of Hesperia, California to develop such an engine.
It runs on JP-8 jet fuel or regular old diesel, and sometimes you can even buy these bikes once the military is done with them. However, as these are no longer being produced, finding them on the market is becoming harder by the day.
What about civilian diesel production motorcycles? I launched a search to see if I could maybe buy one.
Disappointingly, I found staggeringly few production machines out there. My favorite is the EVA Track T-800CDI. This mishmash of characters is a low-volume adventure motorcycle by EVA Products BV Holland from the Netherlands. How low volume? I couldnt even find a website for the manufacturer and came across only one review for this thing.
To quote that Motorcycle News review from Chris Newbigging:
Bizarre
Starting the Track T800CDI gives an unusual experience it clatters into life like a tractor giving rumbling vibration and the disgusting-smelling exhaust gases rising from the small forward-facing silencer in front of the right footpeg will be familiar to anyone whos ever got stuck behind an old school bus. You cant blip the throttle either doing so will engage drive and send you shooting forward.
Crude
It doesnt get better with speed vibration subsides a little but its still enough to be intrusive, and the CVT means the engine is always at the same revs giving a monotous tractor-like noise, which even on MCNs short test ride became tiresome. Even with an open mind theres no getting away from the fact is just isnt quick or refined enough to be compared with petrol rivals on riding enjoyment.?
I think I can see a potential reason why these werent so popular…
This motorcycle was meant to compete with the likes of the KTM 990 Adventure, but it does so with an 800cc common rail diesel engine sourced from the Smart Fortwo CDI. However, with only 45 ponies being transmitted through a CVT and a shaft drive, you really arent going many places quickly.
Yes, you heard that right, this motorcycle sports an engine used in a little unicorn Smart diesel.
Royal Enfield was the only manufacturer I could find that managed to put diesel motorcycles into mass production for civilian use.
The Taurus was essentially a Royal Enfield Bullet with its engine replaced by an industrial diesel. According to auto news site DriveSpark, these were 325cc models made by Greaves Lombardini in Italy. The bikes reportedly remained in production from the 1980s until emissions laws pushed them out in 2000. They definitely werent for riders with a need for speed, as they pumped out only a heart-racing 6.5 horsepower and 11.06 lb-ft of torque.
Some German brands also took a shot at diesel as well. The Sommer 462 is a particularly obscure example. As Bike Exif notes, this bike is the brainchild of Jochen Sommer, and while Sommer is a one-man operation, hes managed to crank more than 200 of these out.
Power comes from a 462cc HATZ diesel making 11 horses and 20 lb-ft torque. Adding to this motorcycles quirks is a four-speed transmission with controls on the right side. That power gets delivered to the wheel through a belt drive.
Sommer is still around and its site advertises a Sommer 512 model. Amusingly, the specs indicate no real increase in power.
If you were a rider with a need for speed, Neander Motors out of Germany produced a turbodiesel cruiser with 112 horsepower and a claimed 4.5 second 0-62 mph run. Like the Track T-800, the Neander venture was so short-lived that only a single review for it turned up. Out of all the diesels built by a company on this list, this one is reportedly the most normal in terms of performance. Most of the diesels in this group were slow and clattery, as if someone strapped a tractor engine to a motorcycle frame.
The Motorcycle Cruiser review by Alan Cathcart suggests the Neander is a bit of a hoot, unlike the others on this list:
But maybe the biggest surprise once youve adjusted your mindset to accepting youre riding an oil-burning powerbike, is how fast this diesel motor gains revs. Coupled with the relatively short span of power and especially torque, this means youll find yourself using the six-speed Aprilia gearbox much harder than you might have expected with a supposedly humble diesel, if you ride the Neander like the sport-cruiser it undoubtedly is. I regularly saw 100 mph/160 kph at just 2820 rpm during my afternoon road rumble around Bavaria, and thanks to a reasonably rational riding stance I wasnt blown off the back in achieving it, so figure this is a genuine 240 kph/150 mph turbodiesel mile eater in real-world riding.?
Sadly, it does appear Neander Motors will not be producing more anytime soon, instead deciding to focus its development on diesel outboard motors. It seems to me that powering a motorcycle with a diesel engine may be somewhat of a novel concept that lacks a whole lot of interest. Riders may enjoy the thumping of a Harley V-twin, but perhaps not the clatter of a diesel
This is hardly an exhaustive list of diesel motorcycles, but the ones above are the ones that you could in theory find for sale somewhere in the world. But as those reviews seem to suggest, your experience will likely be disappointing unless youre really into diesel.
Other bikes include the Star Twin Thunder Star 1200 TDI, which never went into production. Theres also Axiom Diesel Motorcycles, a startup that promises to put diesel motorcycles into production someday.