New to Everything

[WrickM]

Really interested in a diesel motorcycle. I already have a Land Rover 109 with a 200tdi engine so perhaps I have a British heart pumping diesel. Unfortunately i need something that can manage a regular 70mph for my commute and that eliminates a lot of the simpler and lower cost options. I am here to research and learn, so a lot of reading before you hear much from me again. Thank you for posting all this information!

[Eddy Wane]

Welcome to the forum and a Landy owner to boot. You would be hard pushed to find a home built diesel bike that will cruise at 60 mph let alone 70mph. If you read through old posts the average performance is cruising at low 50's but with a very good fuel return of well over 100 mpg (UK).

Most of the manufactures that produced diesel bikes have gone to the wall. It appears that the big boys (at the moment) do not think dumping their petrol models is the way to go, nor do they want to produce a military spec diesel machine because of the reality of low volume sales.

Having said that more and more people (old) are coming round to the conclusion that speed isn't everything and are looking for an alternative and diesel may be the answer.

[WrickM]

I have been seeing what you mean about the top speed. I live in the country here so it is all 70mph highway to anything. Hopefully i will be able to find something in time. With so little weight and so much torque it seems the only issue is finding a gearing and rpm combo. I have set the Landy up to cruze at 75mph and that was a bit of a trick with the stock 4.11:1. i can get by with 65mph for a bike.
anyway just rambling at this point. I'll find something i can turn into a bobber and tinker with the ratios to get some higher limits

[Diesel Dave]

S'all about power and perhaps a little about aerodynamics.

If you were to draw a graph of power vs speed it's a logarithmic scale after 55 mph, so whilst 10-12 hp will get you to 55, 70 requires 20 hp.

Worse still of you go down the adventure bike route as it turns your upper body into a parachute, 80 on the Tiger can get quite uncomfortable and tiring after a while.

Gearing is simply a matter of choosing a setup that allows the motor to JUST rev out in top gear, if you go too high the bike will become rather thirsty as the motor will go to max fuel inject trying to reach the required rev's - in essence this is over injecting and should only be used for brief periods.

If you look at the typical power graph below (in this case a Lombadini 15LD440) note curve C - this is the fuel consumption and see how fast it rises at the tip:



So although max torque is at 2200 rpm, at this speed only 6.5hp is available and this would be about the same as an original Taurus Enfield and they were good for 38mph on a good day.

[Eddy Wane]

http://ecomodder.com/blog/diy-aero-fair ... e-214-mpg/

The above link shows just what you can achieve. Very modest motorcycle with streamlining.

[Diesel Dave]

Hmm doesn't show you what happened after he got blown off in a sidewind though.......

Only 2 weeks ago I got blown into the oncoming traffic lane in Wales on a 250 scooter, my Enfield would have shrugged it off without any ill effects

[UAofE]

If you were to draw a graph of power vs speed it's a logarithmic scale after 55 mph, so whilst 10-12 hp will get you to 55, 70 requires 20 hp.

Not really. My Rebel's gas engine had only 16hp (less at my high altitude) and it could cruise 70mph with throttle left to get up to 75mph.

[WrickM]

Thanks for the discussion. I had already been thinking that something in the 20-30hp range would be required to both go that fast, and get there is a reasonable time frame. Again, i know i am eliminating some of the easier option out there with my demands, but I love to tinker and tune and adjust all things diesel so i am all in for a bike that is a hobby in and of itself.Finding that for a built bike it might be more ecominical to actually get one shipped in from the UK. Just not near as much interest in diesel motorcycle here is the U.S. ( though clearly there is some) Seems like people here want 3-5k for an unfinished project, whereas in the UK that's a pretty finely finished bike. (£2000-3300) Shipping can be had for ~£625-800. . .

[WrickM]

http://ecomodder.com/blog/diy-aero-fair ... e-214-mpg/

The above link shows just what you can achieve. Very modest motorcycle with streamlining.

That is so not what i want, and yet still so awesome LOL

[Diesel Dave]

Well there must be loads of Harley rolling chassis about in your neck of the woods that are ripe for a motor transplant.

[WrickM]

LOADS but probably not quite as cheap as you are thinking. Also building from scratch is a bit intimidating. Not saying that wont be the way i end up going, just that the amount of work on top of all the other stuff i do. . .

[Diesel Dave]

Well there's plenty of advice hereabouts, pity your not more local as you could have had my Tiger.

[gearhead1951]

https://www.youtube.com/watch?v=Dbl5sJwYAG4 is very good example of a FAST diesel bike !!

[WrickM]

https://www.youtube.com/watch?v=Dbl5sJwYAG4 is very good example of a FAST diesel bike !!

Awesome! I am not as into the fuel economy of diesels as some here. I just enjoy diesels in general and the rarity would be fun. So juicing one up to be a smoke bellowing turbo monster is not out of the question.

[WrickM]

Well there's plenty of advice hereabouts, pity your not more local as you could have had my Tiger.

We could arrange shipping. since either way that is gonna be part of anythign i do. If you're serious send me details.

[coachgeo]

https://www.youtube.com/watch?v=Dbl5sJwYAG4 is very good example of a FAST diesel bike !!

actually the maker if that bike is in I think Louisiana and if Im not mistaken will make you (as he has done others) a custom bike.

[gearhead1951]

He is actually in Montgomery NY (you might have been thinking of Montgomery AL) and you can find him on facebook at " Dethmachine Fabrications "

[WrickM]

Both bikes i was looking at taken off my radar on the same day. A sad day. I am sure i will find a new bike to obsess over soon.

[coachgeo]

He is actually in Montgomery NY (you might have been thinking of Montgomery AL) and you can find him on facebook at " Dethmachine Fabrications "

yep..... I was thinking Montgomery AL. Interesting that he is in NY... hmmmmmm.

[WrickM]

I think i have decided to undertake the very long learning process of building m own bike. I am sourcing bits now, and i have a few more experienced bike guys who have said they will help with details. Probably an older Harley Sportster. Thanks for the welcome and knowledge.

[gearhead1951]

Deth machine is still a good source of info and even parts that are unique to the shop that you might struggle to create for yourself !!

Another good place to look if you are intent on making it all yourself is www.choppercompendium.com ! They have a library of frame , frontend and engine mounting plans ( proper blueprint ) and all the dimensions for creating the steering geometry !