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This isn't a 'constructor' forum, but I thought it might be good to see if their is any interest in diesel bikes in the US.

Britain has the http://www.dieselbike.net site, which is the center of english-speaking diesel bikers and the German http://www.dieselkrad.infoare the top sites to research.

Privately built diesel bikes generally use industrial engines and either single cylinder Royal Enfields for the smaller bikes and Harley's for the larger, mostly because they have separate 'pre-unit' transmissions. Later integrated (unitized) transmissions are tougher to use. The Enfields are back roads machines, whereas the V2 Harleys can run the highway.

Here is a german story on an Enfield converter named Sommer: http://www.myvideo.de/watch/1598469/Sommer_Diesel_Motorrad

Advanced builders are using small tractor or small automobile (Smart/VW Lupo) diesel engines.

Speeds are slow and the bikes are heavy. Few Ninjas will be impressed. Mileage begins at 80mpg for the monsters and goes to 300mpg for some of the smaller.

Many of the Enfields report 150-170 mpg. At that level, the use of home-made biodiesel is not only suitable but practical.

You'd never need to stop at a gas station, again.

There was a story hear on CleanMPG regarding a U.S. company that was building diesel bikes for military use.
http://www.cleanmpg.com/forums/showthread.php?t=8970&highlight=diesel+motorcycle

I would love an enduro diesel. Great mileage and stump pulling torque.

Yes, I like the civil model:

http://www.dieselmotorcycles.com/images/L_Black_flag.jpg

Hi Flatty:

___Like Reid pointed out, oh how I would love to ride the KLR650 Diesel conversion. After taking the XT250 out for a week last month, I think the XLR would be a great addition to any bike riders stable!

___Good Luck

___Wayne

I believe the military looked into diesel bikes. They wanted to use the same fuel for everything. A small bike specific diesel could work well for that application, but a manufacture needs to spend the $ engineering it.

IMO current diesels are a little heavy and tough to package for bikes.

I would like a diesel bike, but then I like all bikes.15-20 years ago I remember reading about an Indian produced diesel bike-15 hp,150 mpg,.It was stuffed in a knockoff of a Brit Bike frame, maybe using the same jigs the Brits used.

I don't have much hope that the motorcycle manufacturers will give us diesel bikes.Now,I do have hope that they will give us some light weight-400 lbs- HIGH MPG bikes. I think a 300-400 cc single or a 250cc twin 4 stroke with FI could easily get 100 mpg city and make 30 RWHP. Low tech(mid 70's) 500cc singles ( Yamaha SR500, Buell Blast) get 55-60 mpg,and at times they are spitting out almost raw fuel(SR500 has an accel pump). A purpose built 300-400 could easily make the same power(0-60 about 6.5 seconds, so plenty of acceleration to match current cars on on ramps and to give more experienced riders a bit of zip.

I would like to see a pure mpg diesel bike-15 hp,75 mph,150 mpg,350 lbs - but I'm not holding my breath. I have much higher hopes for a high mpg spark ignition beginner's bike.Maybe starting with the 250 cc 4 valve MX bike motors.Stroke them to 350, put a very,very heavy flywheel, and FI, gear them to turn 3800 rpms at 60 mph(hence the heavy flywheel) and turn them loose. You could start with the 450's, but they are more motorand valve area than you need.

Heres hoping,
Charlie

Hi All:

___I knew I had seen a recent 125cc review and finally found it. The Europeans are getting the good stuff although a top speed of 65 mph may be a non-starter for some here? It would suit me fine as long as the magic 100mpg was a guarantee. By the sounds of it, the Suzuki SM125, Yamaha XT125X and Honda XR125L would be a slam dunk in that department from anyone that reads CleanMPG for over 10 minutes ;)

Suzuki SM125: Quench the thirst (http://www.telegraph.co.uk/motoring/main.jhtml?xml=/motoring/2008/08/23/mfbike123.xml)


I rode the bike for 50 miles in a range of circumstances, across three busy town centres, along country lanes and with nearly half the mileage spent on fast A-roads (much of that dual carriageway). And I was riding it normally, which meant throttle against the stop for mile after mile on the A-roads to maintain its flat-out 60-65mph top speed, revving it heartily at the front of traffic queues to make sure I got away cleanly, and spinning the engine close to its red line. Fifty-four miles later the two-gallon fuel tank took only 2.46 litres to brim which, in units that mean something, was 0.54 gallons: 100mpg.
___Remember that that was British mpg, not US. 95.6 mpg was the actual. Not bad for a guy driving at or near redline which is something I for some reason cannot even fathom :rolleyes:

___Good Luck

___Wayne

I would never ride a bike that small on the highway. My Suzuki 450 was too scary at 65...

As for diesel bikes, when the military was looking buy diesel bikes, some retired guys from Harley started working on one. The military never bought (as they bought the Kawasaki based bike), but I'm sure there's a bit of info on the net somewhere.

HDT is building the KLR 650 bikes for the Marines and NATO countries. They care mostly about running on JP8. The 96 mpg isn't a bad attribute, either. Apparently, they're stuck trying to produce for the military contract and can't get the resources or time to get into civil production.

They probably won't be able to certify in California - no small engine certification process (and may need additional cat and PM trap). High hurdles to high MPG.

Another cheap gasser we can't get in the states is the CBR 125 honda. Neat little bike; alledged 100mpg.

Herr Altmann has a good site regarding diesel Enfield conversion to run on 'salad oil':

Salad Oil Enfield (http://www.altmann.haan.de/riding_on_salad_oil/)

The benefits of the little diesels is at 150 MPG, you can produce or buy all the biodiesel you need relatively easily. 78% CO2 reduction (carbon banked), no sulphur. Downside is a bit more NOX. It reaches the ultimate goal of not going to the gas station - now.

If you look there are older small bikes are still available- locally CL New Orleans. Guy has an electric start NX125(late 80's) , but he doesn't have the title,so it would be tough to make it street legal- just $500.
Another guy has an XL125 -1974 -wanted $500 - not bad.
" " XL175 -wants $1100-that is collector type money for a bike that will most certainly break soon.

The little Honda 250 twin - around for 30+ years - got 90+ mpg in the most recent Cycle World test. It is still just carbed.

I would buy the 100 mpg claim of the CBR125. At 45 mph I'm sure can do 100 mpg. I had a 1970 Kawasaki 90 2 stroke that got about 65 mpg at 60 mph-smokey and noisy of course. It would do an indicated 76 mph with me stretched over the frame like Rollie Free.It must have made an honest 10 hp.

If given the choice I would go bigger-250-350 and turn fewer RPMs, but make more HP. I can't see why 100 mpg- at a steady 50 mph- wouldn't be possible with a 350 lb 30 hp bike with a heavy flywheel so it could turn just 3500 rpms at 60 mph with the throttle mainly open. The 6000-8000 RPMs the 125's require in kinda annoying - lotta friction also.Like being attached to a giant Dremel Tool.

I wish my SR500 had an electric leg. It starts great in the winter, but 10 kicks in the summer. Aftermarket carb is jetted too rich, and can't take the start circuit in the summer. It is a 36mm flatslide Mikuni pumper carb. Stock is a 32mm VM Mikuni pumper-got great mpg with it. I can't easily reinstall it because the intake port was raised, and the 32 is too tall-frame is in the way now..Hopped it up when I was younger- a screw up I can't undo. The cam isn't too bad MPG wise ,the bigger higher compression piston won't hurt,the exhaust I changed back to stock, but the carb is the biggest mpg drag.
Running wide here-sorry.

Charlie

Guess what! We can get the CBR125 up here in Canada! It is a bike that I would consider, although the insurance rates are extremely deterring (in Manitoba at least).

Although it is kind of puzzling that it is not available down there seeing that compared to the US, we have a much shorter riding season.