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Coninsan
01 January 2011, 1026
Hi all

A "how it's made" episode involving a great big wind tunnel got me thinking, and I'm reviving this old bird from forum v1.0

http://www.exa.com/images/applications/K40-Multi-right-top-front.jpg

The title says it all, Disc Wheels, Dustbins, Cowlings, Lowering Suspension, Loosing Weight. Is this something the Elmoto community should look into?

EVcycle
01 January 2011, 1534
Being drag racer most of my life it is bred into my design and application of any project.
I would think most of the EVs Motorcycle guys do as well.


Ed

Skeezmour
01 January 2011, 1646
Depending on speed and terrain 50# of added weight on a motorcycle can easily add 3-5 wh/mile. So I have put my focus on dropping the first 50# off myself of a good 80# I am commited to removing. Need to look good for all those pictures and videos coming :)

miketyson986
24 January 2011, 2322
Depending on speed and terrain 50# of added weight on a motorcycle can easily add 3-5 wh/mile. So I have put my focus on dropping the first 50# off myself of a good 80# I am commited to removing. )


Nice approach regarding bike riding ,,,,,,,,,,,,,,

Skeezmour
24 January 2011, 2359
Thank you :) I have a set of racing leathers in my future.

EVcycle
25 January 2011, 0420
It has always been cheaper to take the pounds off of me, but so much harder to do.

Good luck!

Coninsan
25 January 2011, 0518
Well then you are screwed if you are already underweight haha

But what kind of effect do you think it would have if you molded you motorcycle to resemble the Ecosse ES1? http://www.ecossespirit.com/
Another 3-5 wh/mile maybe?

EVcycle
25 January 2011, 0619
Aerodynamics works best at a higher speed. The weight (and cost to the wallet) of the added fiberglass hurts the acceleration at low speed.

If this is a hop around town bike, I would look at the cost, weight of the panels and the brackets befor purchasing anything.
It would be interesting to see a "before and after" project with the added aero package.

Warren
25 January 2011, 0752
Oh! No! More pent-up nerd aggression! :-)

Seriously though, reducing frontal area doesn't add weight. Use a hub motor, run the batteries down low, from wheel-to-wheel, reduce frontal area 25%.

http://experimentalev.files.wordpress.com/2010/10/cmc2.jpg

The downside? Your lower leg is horizontal, rather than at a 45 degree angle. Same coefficient of drag, just 25% less area. On that boring simulation I mentioned here...

http://www.elmoto.net/showthread.php?819-MotoPod-In-Depth-Interview-with-Chip-Yates/page2

speed goes from 130 mph to 150 mph. Sure, at highway speeds the gains are not as dramatic, but you get the idea.

Warren

Coninsan
25 January 2011, 0832
Your right, at low speeds, there is next to nothing to gain. So if your running around town at speeds lower than 20 mph, Aerodynamic improvement are not the thing for you. If you wanna gain range at those speeds, lose some weight haha :)

I've actually seen real world projects with great results, most are based on extreme modifications though.. Like this one which I think is way cool: http://ecomodder.com/blog/diy-aero-fairings-honda-125cc-motorcycle-214-mpg/

Nerd attack sorry:
I've been toying with Lennong Rodgers excel sheet, which factors in weight, frontal area and drag coef. Based off my own project that is.

The sheet tells excactly what Evcycle has been saying, that at low speeds, there is nothing to come for, but at 20 mph it changes greatly!
These results factors in the added weight of the modifications (15 lbs at .5 drag coef. and 25lbs at .4) with baseline being at .65 drag coef. which is the average of most sports bikes. Ranges are calculated by stable cruise speed. Speeds go from 5 - 70 mph.
You can see my result sheet here: http://www.filehosting.org/file/details/197153/Aerodynamics_GSXR.xls

I'll quote selectively here:


Improvement over standard .65 Drag Coef.

@ .5 Drag Coef. Fair improvements, blocking off old ram air ports, double bobble windshield, such..
20 mph = 4%
35 mph = 10%
50 mph = 15%
70 mph = 18%

@ .4 Drag Coef. Great improvements, dustbin fairing, disc wheels, such..
20 mph = 8%
35 mph = 18%
50 mph = 25%
70 mph = 30%


Bare in mind that the average Cruiser motorcycle has a Drag Coef. of .8 to 1.1
And that these numbers are all theoretical

Warren
25 January 2011, 1009
Coninsan,

Yeah. That is the same calculator I have been using. Also a bicycle calculator where you can change all the parameters. They match pretty well. I am afraid talk of dustbin fairings, and kneelers goes over here about as well as mentioning recumbents on a typical bicycle site. Real men just add horsepower.

Warren
25 January 2011, 1017
EVcycle,

"It would be interesting to see a "before and after" project with the added aero package."

http://prometheussolar.com/Motorcycle.aspx

He had a more detailed analysis here, where he was planning to produce a big electric touring bike....very sweet prototype....but it appears to be gone now. One more casualty of the new economy. :-(

http://novakinetics.com/specialty-products.html

Warren

Coninsan
25 January 2011, 1040
Coninsan,

Yeah. That is the same calculator I have been using. Also a bicycle calculator where you can change all the parameters. They match pretty well. I am afraid talk of dustbin fairings, and kneelers goes over here about as well as mentioning recumbents on a typical bicycle site. Real men just add horsepower.

Why precisely are you afraid of with Dustbins?
And adding horsepower doesn't make your range go ^ ;)

Warren
25 January 2011, 1053
Coninsan,

Sorry. I forgot, English is not your first language. I am in total agreement with you. I was attempting to be funny. English speakers here don't find me witty either.

Warren

Coninsan
25 January 2011, 1110
Ah, it's ok. ;)

I'm just trying to stir up a discussion about wether Aerodynamic improvements are worth while.
I personally think so based on the improvements in range that can be achieved. Note that these improvements also should reduce stress on components, lengtening the life of the batteries as well as the Controller and motor. Making them worth while. :)

Warren
27 January 2011, 1552
Coninsan,

You may be the only other one here who will appreciate this.

http://peraves.wordpress.com/

Warren

EVcycle
27 January 2011, 1652
Coninsan,

You may be the only other one here who will appreciate this.

http://peraves.wordpress.com/Warren

Wanna Bet?

We saw one similar in Va.

Warren
27 January 2011, 1918
EVcycle,

Yes. I saw your bike there too. Very nice.

Warren

EVcycle
28 January 2011, 0209
Thanks, this next one will kick that ones .....well you know.

Coninsan
28 January 2011, 0255
@ Warren Thanks for the thought, but i've known about that for years now.

Personally I think the Monotracer is a neat machine, though VERY pricey. Almost half a mill DKK 450.000DKK, that's more than most pricey new cars, BMW, Mercedec the like.
But I would be scared driving that thing around town, with direct steering, the huge weight and that long wheelbase.. At that size I would prefer 3 wheels + aircon and a cup holder :p

I am personally waiting to find out how this fairs: http://www.flytheroad.com/

Warren
28 January 2011, 1049
Coninsan,

Yes. The Zero-Tracer fell over once in slow traffic, during an unexpected stop...and was knocked over once, by a curb jumping mountain biker...on its around the world trip.

Unfortunately, the Persu is also astronomically expensive. All such vehicles suffer from tiny production numbers, and EU wage rates.

Warren

moparren
03 February 2011, 1657
I beg to differ on this. Little to gain, maybe. Nothing to gain - balderdash! I have model aircraft that don't fly much faster than 35-40 mph that I have modified with retractable landing gear. Even with the added weight of the retract system, I fly higher, faster, and with less throttle than the same model with the stock gear.

Also, if you want to see what low power, low speed airo can do, look up Craig Vetter (sp?) and what he was doing in the '70s.

Now, ballancing gains with money spent, that's another issue.


Your right, at low speeds, there is next to nothing to gain. So if your running around town at speeds lower than 20 mph, Aerodynamic improvement are not the thing for you.

Warren
04 February 2011, 0740
moparren,

At speeds below 20 mph, weight, rolling resistance, and mechanical drivetrain losses are comparable to aerodynamic losses. There are many e-bicycles over on ES that will outperform any e-moto up to 30 mph. For example, Zero tested their S, with a 161-lb rider at a constant 25 mph, on level pavement. It went 49.1 miles on a 4kWh pack. A decent e-bicycle is 3-4 times as efficient at that speed.

Warren

Coninsan
04 February 2011, 0815
I beg to differ on this. Little to gain, maybe. Nothing to gain - balderdash! I have model aircraft that don't fly much faster than 35-40 mph that I have modified with retractable landing gear. Even with the added weight of the retract system, I fly higher, faster, and with less throttle than the same model with the stock gear.

Also, if you want to see what low power, low speed airo can do, look up Craig Vetter (sp?) and what he was doing in the '70s.

Now, ballancing gains with money spent, that's another issue.

Excactly, based on the base motorcycle the cost of improving the aerodynamics would differ greatly.

A already faired sports motorcycle, would realisticly look at 300-500$ worth of improvements if you decide to build up a new faring on top of what you've got with foam and fiberglass cloth. And a load of manhours of work too.
This improvement would probably be from a drag Coef. of .65 to .5 or even .45 depending on your dedication and level of modifications. Look up my earlier post for which gains could be achieved.

On the other hand, a cruiser or naked type bike would need alot more work: A dustbin style fairing or a custom molded one as well as the brackets to hold it. A hefty 500-1000$ wouldn't be unrealistic, capital B, But!
This is the type of bike which would gain most.

I did a simple calculation based again on the Lennon Rodger excel sheet and my comparative sheet. Given that a cruiser og naked bike often has a drag coef. of .8 to 1.1
As much as a 50% increase in range could be achieved! Going from a drag coef. of 0.9 to 0.45 not an unrealistic goal with a dustbin style faring.
Of course this would be an expensive mod, but think about it, this fairing would also reduce load on your Motor, Controller and Batteries, lengthening their life by 30% at least.

Then money spent would justify itself in the added life of the components.

teddillard
04 February 2011, 0957
i can haz windtunnlez?

http://lswt.tamu.edu/index.htm

http://lswt.tamu.edu/Downstream%20Test%20Section.jpg

http://www.arcindy.com/index.php?main=profile

Skeezmour
04 February 2011, 1025
I thought you had a wind tunnel after a beer and beans :)

teddillard
04 February 2011, 1030
I thought you had a wind tunnel after a beer and beans :)

yes. that's my own personal phase change material.

billmi
04 February 2011, 1140
It looks Craig Vetter is getting away from aerodynamics in some of his newer fairings...

http://www.craigvetter.com/pages/Other_Designs/Energy_absorbing_fairing.html

http://www.craigvetter.com/images/Other%20Designs/Energy-absorber.jpg

magicsmoke
04 February 2011, 1556
I thought you had a wind tunnel after a beer and beans :)

One of the local stunt team (purple helmets) trying out his own wind tunnel.

EVcycle
04 February 2011, 1614
Ted?????


Mmmmmmmm :)

teddillard
04 February 2011, 1616
oh now THAT's just wrong... :O

EVcycle
04 February 2011, 1653
On soooooo many levels too..... :)

moparren
04 February 2011, 1718
Aerodynamics are still in play. Aerodynamics is not just about farings. Think frontal area also. How wide is a bicycle tire? And a motorcycle tire? As thin as the Zero is, it is still wider than a bicycle. That big, round, flat headlight alone is creating a good chunk of drag at any speed. I don't think anybody would say the Zero is aerodynamicly gifted.

Areo may be less important at low speeds but it should not be dismissed. Why not make it as efficient as possible? An e-bike would benefit from aero work also, even if it is just putting a disk in the rear wheel to cover the spokes.

Dave


moparren,

At speeds below 20 mph, weight, rolling resistance, and mechanical drivetrain losses are comparable to aerodynamic losses. There are many e-bicycles over on ES that will outperform any e-moto up to 30 mph. For example, Zero tested their S, with a 161-lb rider at a constant 25 mph, on level pavement. It went 49.1 miles on a 4kWh pack. A decent e-bicycle is 3-4 times as efficient at that speed.

Warren

moparren
04 February 2011, 1720
For some reason I see Tina Turner riding this...


It looks Craig Vetter is getting away from aerodynamics in some of his newer fairings...

http://www.craigvetter.com/pages/Other_Designs/Energy_absorbing_fairing.html

http://www.craigvetter.com/images/Other%20Designs/Energy-absorber.jpg

Coninsan
05 February 2011, 0551
Frontal area is a bitch in my mind. There is really not much you can do about it, lower the bike, tug yoursef down to the tank and shorten the handlebars. The Ecosse ES1 had a entirely new gearbox and chain guide system designed just so the ride could tug in his legs.

And yes, aero should count just as much for an Ebike as an Emotorcycle. Defifnetly, though Ebikes are so efficiant in the first place, and if you ask a Ebike guy about eaero, they think Velomobiles most of the time..

Disc wheels entrigues me, looking at the piccture I posted in the start of this thread, the wheels are a Dead area of aerodynamics, discing them should bring a significant upgrade in aero. But many fear that it would compromise the performance in side winds.

Warren
05 February 2011, 0557
moparren,

As someone who has spent over 35 years riding bicycles, I am well aware of the effects of aerodynamics at low speed. In hilly terrain, I benefit from minimizing frontal area...aero bars, or recumbent position...but not at the expense of extra weight....Zipper front fairing, or disc wheel. The difference in rolling resistance of a 25x451 tire vs a 25x622 slows me down...even with less weight and frontal area!

If you are Lance Armstrong, and can cruise at twenty in the hills, instead of fifteen, the balance changes.

Warren

teddillard
05 February 2011, 0615
Good point... just the mention of that made me flash back to a century ride up the coast of New England - all into the tooth of a 30 knot NE wind. I hate wind. I think it's tempting to think about aerodynamics in terms of vehicle speed, but you're always... ALWAYS gonna be dealing with wind, too. (OMG the flashbacks keep coming. My forward speed up a hill- about 3mph. Wind gust hits. I stop dead. ...and fall over.)

Warren
05 February 2011, 1530
Ted,

Into a wind, a Zipper fairing paid big divdends. Back in the midwest, where I grew up, lowracer bicycles are popular.

http://www.recumbents.com/wisil/misc/nocom.htm

Not great up hills, but kickass into the wind!

Warren

Frank
07 February 2011, 2106
I still have a zzipper fairing on my bike - it's worth 2 gears i.e. I can go that much faster for same effort. Aero is good!

DaveAK
07 February 2011, 2143
Doesn't it all depend on size, weight and power? A freight locomotive going in to a 20mph head wind probably wouldn't benefit much from aerodynamics when it's pulling 40 fully laden freight cars behind it, whereas a bullet train doing 200+mph needs to be a slippery little bugger.

I don't see the point of comparing aerodynamics for bicycles and model aircraft with motorcycles. I can't see improved aerodynamics on my bike having anything more than a marginal effect. Maybe I'm missing what you guys are talking about, but I think you're missing the scale of things.

teddillard
08 February 2011, 0439
Doesn't it all depend on size, weight and power?
of course.

I don't see the point of comparing aerodynamics for bicycles and model aircraft with motorcycles. I can't see improved aerodynamics on my bike having anything more than a marginal effect. Maybe I'm missing what you guys are talking about, but I think you're missing the scale of things.
Yes, I think you are. Missing what we're talking about that is. We're talking about the relative benefits of reducing frontal area and aerodynamic drag at speeds of around 15-40mph, where conventional wisdom holds that streamlining may not be worthwhile. I'm beginning to suspect it is more so than I've thought before.

A bicycle has about half the frontal area of a motorcycle, maybe, and weighs, with the rider, 200lbs? A motorcycle weighs maybe 600lbs (and twice the frontal area). Maybe the effect isn't identical, but it's a useful comparison and illustration, more than that of a train, and one I can appreciate viscerally.

Add to your standing speed the speed of a headwind, and now you've pushed the metric to the 40-60mph level, where even skeptics (like you) will concede that a fairing pays for itself. :p

http://en.wikipedia.org/wiki/Reductio_ad_absurdum

DaveAK
08 February 2011, 0940
I'm happy to conceed that a fairing will pay for itself, if it can be shown how a fairing will pay for itself. By that I mean on a per charge basis what percentage what gains are made? If I get 50 mile range with my non faired bike in normal riding conditions, what should I expect with a fairing? I don't doubt that there will be an improvement, but how much?

It's not that I'm a skeptic so much as disinterested.

teddillard
08 February 2011, 0949
It's not that I'm a skeptic so much as disinterested.

So, I gather you won't be renting that wind tunnel. Dammit.

Coninsan
08 February 2011, 1005
I'm happy to conceed that a fairing will pay for itself, if it can be shown how a fairing will pay for itself. By that I mean on a per charge basis what percentage what gains are made? If I get 50 mile range with my non faired bike in normal riding conditions, what should I expect with a fairing? I don't doubt that there will be an improvement, but how much?

If you trust calculations, then as much as 40% longer range per charge. From 50 miles range up to about 70 miles. (Drag Coef. improved from .9 of a standard Naked bike to .45 same bike with a dustbin)
Sourced from Lennon Rodgers excel sheet.

EVcycle
08 February 2011, 1017
If you trust calculations, then as much as 40% longer range per charge. From 50 miles range up to about 70 miles. (Drag Coef. improved from .9 of a standard Naked bike to .45 same bike with a dustbin)
Sourced from Lennon Rodgers excel sheet.

I have my doubts it is anywhere near that much.

teddillard
08 February 2011, 1022
Dave? Trust calculations? HAHHAHAHAAAahaaa

Coninsan
08 February 2011, 1048
Dave? Trust calculations? HAHHAHAHAAAahaaa

I see that :p


I have my doubts it is anywhere near that much.

Then what do you think is a reasonable % gained from adding a Dustbin to a Naked bike?

teddillard
08 February 2011, 1109
I have my doubts it is anywhere near that much.

Well the only way I see it can go is to run some actual tests. With a big cafe bike. Nekkid, then with a nice retro fairing... hmmm. Now WHERE might one find such a bike? :D

DaveAK
08 February 2011, 1123
So, I gather you won't be renting that wind tunnel. Dammit.
See, you just don't understand me. I can't think of anything more fun than a wind tunnel. As long as you don't have someone standing there telling you it's not a toy. :D

DaveAK
08 February 2011, 1127
I have my doubts it is anywhere near that much.
This. And it's not that I don't trust the calculations, it's the input that I'm dubious about. 0.9 to 0.45 seems quite a dramatic change, and I have absolutely no experience to deny it's valid, but no experience to feel confident it's reasonable too.

DaveAK
08 February 2011, 1128
Well the only way I see it can go is to run some actual tests. With a big cafe bike. Nekkid, then with a nice retro fairing... hmmm. Now WHERE might one find such a bike? :D
I don't know, but I wish you'd hurry up and give us some real life comparisons. :)

Warren
08 February 2011, 1151
daveAK,

"I don't know, but I wish you'd hurry up and give us some real life comparisons."

You could just email Jim Corning. He used to have all the info up on his aircraft parts company site.

http://prometheussolar.com/Motorcycle.aspx

http://novakinetics.com/specialty-products.html

Or we could all just continue to talk. :-)

Warren

DaveAK
08 February 2011, 1152
I like talking. :D

teddillard
08 February 2011, 1200
I like talking. :D


http://www.youtube.com/watch?v=Eisa5AZ20W0

(too easy)

Coninsan
08 February 2011, 1216
This. And it's not that I don't trust the calculations, it's the input that I'm dubious about. 0.9 to 0.45 seems quite a dramatic change, and I have absolutely no experience to deny it's valid, but no experience to feel confident it's reasonable too.

I might as well reveal ma secret weapon to yo talkative fools ;)

http://www.schultzengineering.us/aero.htm

I'm basing most of my estimations of of this site, the guy is blabbering so much that he might know a thing or two about what he's talking about.

teddillard
08 February 2011, 1223
dude needs some serious photoshop instruction... :p

(thanks for posting that, I've been trying to find it again for about 2 years now.)

Coninsan
08 February 2011, 1227
dude needs some serious photoshop instruction... :p

(thanks for posting that, I've been trying to find it again for about 2 years now.)

Nope he needs to know his HTML, so the pictures don't scale with the browser window, damn annoying when you have a hd display, you can't see the pictures without moving 3 feet away from your computer haha.

And your welcome. :)

teddillard
08 February 2011, 1232
Nope he needs to know his HTML, so the pictures don't scale with the browser window, damn annoying when you have a hd display, you can't see the pictures without moving 3 feet away from your computer haha.

And your welcome. :)

no man, that is some serious JPEG uber-compression. well, too. along with what you said. and oversharpening, did I mention that? makes a grown man cry, it does...