Power to weight and speed .

[Sibbo]

I was doing a couple of calculations the other day .

The car I drive is a 1980 Mercedes 240 D, a diesel 4 cylinder with 65 hp and weighing 1.4 ton .
The power to weight ratio is the same or worse than an Enfield mit 10hp diesel weighing 230 kg with rider.The Merc will do 130 km /80mph ,a clone in standard sit up bike form ,50 to 55mph .80 to 90 km .

The only real difference is the drag of the standard bike versus a car ,even a boxy 30 year old one .

Fairings with real aero form are the way to go if you want to ride on a highway safely .

[Sibbo]

I guess the diesel bike crew like going slowly .

[Sibbo]

Comments ?

[Stuart]

Fairings with real aero form are the way to go if you want to ride on a highway safely .

Granted, they'd make a difference but I'm finding my Smart Tiger has fairing & power enough to ride safely with the traffic. If you go for all round fairings you'll end up with something akin to a big tourer and would that be suitable for use as a day to day commuter bike? I think the half fairing set up with more power from a modern engine is about the right balance for a safe and fuel efficient ride.
The Tigers 500 mile range and 100-120MPG figures are surprising even me and I've ridden diesel bikes for over a decade now. The large tank is the icing on the cake making the bike seem even better. I do not under estimate when I say the Tiger is game-changer. Fairings may get you better MPG but, in my mind anyway, I have to balance them off against practicality. When you have a little more power on tap then you don't need quite so much aerodynamics. If you ride a bike with a mechanically injected diesel engine then yes, you may need to look at the fairing a bit harder.

Motorcycles fitted with modern, medium sized, electronically controlled, diesel engines will one day rule the road. They are just too good not to

Sibbo, you are right - it's all about numbers It just depends on what set of numbers you want to aim for.

[Sibbo]

You are right of course Stuart but I live in the dreaded NSW...I'm sure Andrew has explained our regulations !
I very much doubt my ability to get such a modification to a modern bike through the inspectors ...even if I could afford the components .A 1966 RE is a different matter ! Practically no regulations for a bike that old although I would love a bigger engine than the miserable 9.5hp the Yamnar clones provide ! 20 would be bliss !

Here's an interesting tool to play with ... http://ecomodder.com/forum/tool-aero-ro ... stance.php

For me getting the drag coefficient to within the range of an old car is my best bet ,say .5 ? A modern Japanese small car is around .35, a standard bike is 1.Plugging those numbers into the calculator is enlightening .I'd very much like 110 kmh and 1.5l/100 on biodiesel .Such is the plan !

The Smart Tiger would be brilliant and congratulations on owning her! Will she run on biodiesel ? It's my fuel of choice but a friend with a Peugeot 307 HDI seems to think the modern common rail diesels can't use bio .What do you reckon ?

[Stuart]

Ah, regulators, you have my sympathy Maybe you need to lobby at a higher level argueing it's stopping you making bikes 'greener'?

I'm told the Tiger won't go too well on bio- diesel and so haven't put any in. We have some (5-7%?) mixed with pump fuel for slipperiness. I guess it doesn't cope with the pressures well? Maybe that's the next thing, development of a more stable Bio-diesel? Onward and upward

[Sibbo]

The new NATO bike , the diesel that we seem to read about but never see is supposed to run on bio,apparently that is one of the design parameters . That one I'd like !

[Stuart]

Yes, that truly is a multi-fuel bike. It might happen next year. I keep hearing things that lead me to think that it will certainly happen.

[TedV]

Common rail engines are more demanding of fuel quality than older style mechanical injection pump motors. They all need the lubricity, or slipperyness, which bio definitely has. Bio will attack various rubber and plastics. From what I understand most manufactures won’t state their parts will use bio fuel since the bio fuel varies from manufacture to manufacture and the engine manufacture doesn’t want to warranty their parts damaged by substandard biofuel. Even tho it actually will run on bio.

I think for NSW, a Royale Enfield with diesel conversion topped by reproduction of the streamline body work would be a cool project. You might be able to show them pictures from the books and magazines “ see they did it back then”

[Sibbo]

Ted , you might be referring to the Royal Enfield ''Dreamliner'' fairing ? A strange looking thing but it reduced fuel consumption by 25% and increased top speed by 10mph on the original 350cc 13 hp Bullet it was trialled on .The trial was a long and complete one ...I've managed to chase up 2 issues of Classic Bike with articles and photos of it .I seems that it might even be possible improve on it a little although despite it's looks the old one worked well .

If the 25% fuel improvement carries across I could expect a normal 1.6 litre /100 km figure and 100km top .A bit of weather protection would be nice too!

[andrewaust]

I read a report years ago that the coalition of armed forces wanted most if not all vehicles to run on Jet-A fuel , not sure my chinese clone bike would like that somehow.

Worst thing for me to run bio now, being crook and not riding the bike much leading to the fuel going off

Algae bio diesel was also mentioned on a show I listened to a year or so ago, not sure how that has come along. Big push here for electric cars and now the latest dirt bike magazine in OZ has done a small article on electric MX/SX bikes, I just cannot see many liking that.

Direct injected two stroke petrol motorcycles are now coming on line, now how good would it be to see some kind of bio direct injected two stroke diesel bike .

So many different varients if you let your mind wonder.

Now for what the post is about, working power to weight and speed depends on the bike being streamlined as stated in previous posts or like the Enfield, a brick in the wind . If you can overcome the drag effect which increases substantially - keeping the weight down, the faster you go, producing a faster machine. If you watch the worlds fastest Indian, that gives you a clue.

Sibbo! Sorry mate I have not been able to give you more of a hand - as I'd really like to, still crook mate, and yes I have mentioned how bloody stupid our rules are, here's how crazy it gets. If I were to either put a diesel engine in a newer bike, turbo my old 95 Enfield, it would require pollution certification, one problem !! The NSW RTA has such a place to do it, BUT !! It will not facilitate a motorcycle WTF ??? including the facial expressions. I'm sure kindergarten children have more active brain cells then the idiots who come up with rules. To personally get a bike pollution tested outside the RTA would cost big $$$$$.

Cutting the frame I know is a do not do here in NSW, modifying the original configuration "fairings etc" of the bike might also see you go through more hoops !!

Id wanted to get an old BMW or similar frame and put a turbo 3cyl diesel in it, when looking at the $$$$$ I just gave up the though, not that it probably couldn't be done, but my income = or now very lack of, would never get the project started.

I'll PM you Sibbo and let you come down and see my old girl when it is suits you, I'm taking it off the road later next year to renew the clutch, duplex chain and front sprocket along with a few other things, due to such a great hospital system I have not been able to do any substantial work, so funding to keep the ole thing running continuously has to be halted. Still a few more thousand K's in the bike before this maintenance needs doing.

We should also tell the other guy's on the forum how much it costs to register and 3rd party "greenslip" a bike here mate, you don't get much out of $500.00 once you pay for inspection along with the other B.S. If you own a bike over 1000cc's, your parting with just about the same as the cc level !!. It's the most over taxed state in Australia, and probably a lot of the world, it's only family that keeps me here.

I have to admit I'm fairly light "75kg" so I guess it's no surprise I can get my old thing to do 100khr without much effort, I've even sat up the ass of a semi to achieve approx 115, don't try it unless you have a spare engine, you'll be doing 4200rpm - 400rpm more then the nominated maximum rpm.




PS: There feel better now, got the RTA frustrations out of my system




A

[Sibbo]

Hi Andrew ,
I've found a 1966 Enfield, an Indian import originally a 350 but converted to 500 and the nice bloke on the phone from the RTA inspectors office said they didn't mind what I did to it ... no regs at all for a bike that old .So I can cut the frame to have an electric start which if I build a really enclosing fairing would be necessary as kicking would be restricted .It looks like an old one is the go here .



(I haven't bought her but the owner is holding her for me in case I decide to go ahead with this game .)

The BMW road is a bit of a hard one , the engine opening isn't very high and with the fixed transmission ratios she would be slow . That's using the numbers from an R65 cos they're cheap .The big ones are a more suitable ratios but they are very pricey .
Chain is best I reckon ,as flexible as you'd like .

I hope you're getting better and I look forward to your PM !

[Sibbo]

I just came up with an interesting number .At 55mph / 90 km 92.4% of a bike's hp output is going into air resistance .
7.6% into rolling .That's on flat ground .

http://ecomodder.com/forum/tool-aero-ro ... stance.php