Evomoto : a 235mpg streamliner
 

Embrace the wind.

Dr.-Ing. Wolfgang Bauer has built a 235mpg (@ 90 kph / 56mph) streamlined motorcycle.

evomoto125cc


It'll do 130 kph / 81 mph with the streamlining, only 92 kph / 57mph without.
Additional weight : only 8.5 kg / 19 lbs


Fuel log :
Details: Honda - Innova - evomoto 125cc - Spritmonitor.de
(Note : the spritmonitor site won't accept any input under 1L/100 km - 235mpg !)

Nice! The site is has lots of info and step-by-step pictures. Me wants!
Euro, do you know German well enough to invite Dr.-Ing. Bauer to check EcoModder out?

Is that enough to estimate the Cd (or CdA) improvement?

The first thing I did was to check if the Honda Innova 125i is available locally, and for how much, and I found another one modded for 200mpg. That article even mentions EcoModder and links to JanVos's Burgman mod thread.

While aerodynamic it doesn't look very comfortable for an extended ride. The neck bend is pretty tight, into oncoming wind and add in a helmet, eeesh. A head rest would transmit vibration and road shock directly to the helmet.

Good effort though. The lay-down position reduces the riders drag significantly. The rider in an upright position, appears (to me anyway) to be one of the largest contributors to drag.

Its good to see more of this stuff coming out, and I like the electrically adjustable seat back in the video, but where did that MPG figure come from?
Comparison with Alert Jacobs' version, would seem to show much less effecient aerodynamics and the same base vehicle. Alert clearly documented his test results and did well to reach 214mpg, so how does this beat him?

Hello,

I was made aware that there´s a post on the ecomodder homepage about my bike so I figured I take a look at what´s written here. It looks like I can give some answers to your questions.

Let me first answer the question how I got to this low fuel consumption, even though my bike is not as streamlined as Allerts bike and has for sure a higher drag coefficient. The simple background to it is: frontal area. When you view the bike from front or rear you will notice that you can see only a very small profile. Take a look at the attached picture and you´ll see what I mean. And this significantly decreases aerodynamic drag. I was stunned when Allert and me met with our bikes near Cologne two months ago. There is a big difference. He gets the extreme drag reduction out of streamlinig, while I focused more on reduction of frontal area. Overall we then end up at about the same fuel consumption.

One advantage of the only partial fairing is the lower aditional weight which saves you some fuel in urban driving conditions (stop-and-go) while it for sure has only little influence when driving at constant speed in flat terrain. Additionally the acceleration of the bike is still pretty good. Even though it has a slightly higher weight and a higher gearing compared to the original Honda Innova, it gives you a better acceleration at speeds above 50kph just because of the lower aerodynamic drag (as shown on the evomoto-website).

The evomoto indeed is very comfortable. Compared to my "regular" motorbike, a 2002 Suzuki SV650S, and also compared to all other motorbikes I rode so far, it is very relaxing and does not cause either of the pains you get on regular bikes: wrists, neck, knees, backbone, buttocks. All these body parts are not overloaded and therefore do not hurt. beatr911 has a point though with his remark about the head rest: I took me quite a while to find the right design to keep vibrations away from the helmet - in the end I succeded and I can say, that the noise level now is quite a bit lower than on regular bikes, especially due to the low wind noise.

I did a round trip though Germany last month: 2230km within one week. Visiting major cities and friends. During the trip the bike did not only prove its stamina, robustness and comfort. It also showed that even in often not ideal driving conditions (rain, heavy head and side wind, many traffic jams and urban stop-and-go traffic) it is able to give you an average fuel consumption of about 1,1 l/100km - it needed 24,65l of gas for this trip.

I hope, I was able to answer your questions. More comments are welcome!

Wolfgang

Evomoto, thank you for posting here:)
Your mods look so easy to do that I'm keep thinking about getting an Innova, even though I don't need one (at the moment). I went through your page a while ago and can't remember if you wrote how much time and money you needed for this project?

Wolfgang, Great job, Your mods are very interesting and have produced great results. How well did the bike handle in heavy sidewinds? I have started streamlining my 1982 Yamaha Vision ( 550 cc V-twin )and while I have reduced aero drag, the handling in strong winds can be pretty twitchy. I liked your video showing how easy it was to get your feet back down.
all the best, Low& Slow ( Vic )

Elegant design, a simple and effective solution.

You might be able to improve your fuel efficiency by extending the fairing behind your helmet and back.

How is the rain protection using your leg enclosure? Do you think you could increase the coverage to make a motorcycle that can be used in the rain without soaking the rider?

How do you shift gears?

Hello there,

sorry for responding late. I´m quite busy these days.

@Piwoslaw: If you intend to rebuild an Innova from scratch, be aware that it´s a lot of work. It does look simple but getting there is anther thing. I have spent many hours in the workshop especially on the aerodynamic parts (front and rear fairing) until I was satisfied with them. I think the front fairing is already the 5th stage in evolution. Overall, I have for sure spent well above 1000h maybe even more than 1500h to get the evo where it is now.
On the other hand I have thought about creating an Innova-evomoto conversion kit, since quite a lot of people were interested in buying an evomoto 125cc. I got in contact with a german company who could produce the parts and sell the kit. However, when I announced the cost for the kit (3500 to 4000€), most of these people reconsidered their interest and for the moment there are not enough left to start a small batch series. Assembly time for the kit would be about 3 days for a skilled worker, for sure more for a person who does this the first time and is only a hobby mechanic.

@low&slow: Side wind indeed was one issue I was very unsure about, when I started the project. And actually this is also one of the most-asked questions about the evo. From todays view and with the experience of about 14000km I can say, that riding the evo in side wind conditions is not much different from regular bikes except the sideways inclination is somewhat higher. I have layed out the bike according to some rules and got a quite good behaviour. It virtually automatically compensates for side wind, leans into the wind and keeps the straight line. My sensation is that I don´t have to do any intentional action when a side wind gust hits me. Even in winds up to 7 Bft it was safe to ride. The only time I skiped a ride so far was when the weather forecast announced 100kph (10Bft) winds and recommended people to stay at home. As for your bike I´d recommend to try out the behaviour without front wheel fairing - I bet side wind behaviour is much better then.

@sky4lrk: Extending the rear fairing further backwards could be an option, but unfortunately I need to obey the european regulations for the license plate, the rear lights and the turn indicators. With this in mind, there is not much left I can do, since the rear flat surface of the fairing has to have certain dimensions simply to enable to meet the regulations.
Rain protection is great. Basically, when in motion your body stays dry. Only from the chest upwards and on the back of your hands you will get wet. And, in really heavy rain, you will see some mist slightly moistening the rear of your legs. For example: during my round-trip through Germany with several hours in rain and on wet roads I never needed to use my raingear, even though my protection jacket is not waterproof.
Shifting gears is quite simple but different from regular motorbikes: you´ve got two levers, one for the left and one for the right foot. Depressing a lever on the first 20mm or so disengages the clutch and then on the remaining displacement the gear is shifted. Releasing the lever then reengages the clutch. Right foot is for upshifting, left foot for downshifting. The additional centrifugal clutch makes starts (e.g. at the traffic lights) very easy. Basically I used the regular semi-automatic clutch and gear technology of the original Innova and only slightly modified it and relocated the actuation mechanism into the front fairing.

Greetings from Germany
Wolfgang

No problem at all.

Thanks for joining ecomodder and building an inspiring project !

Congratulations Wolgang
Your detailed responses cleared up any doubts I had about the MPG claim, and the picture (of frontal area) was the perfect example of how you have achieved these results. I only wonder what would be possible with even more enclosed bodywork!
Your theory on the vehicle design (from your website) is excellent! I also believe in the importance of small aero-efficient single person vehicles, and how they can shape future vehicle design - you are very fortunate to be working in this arena.

I have a few questions I would like to ask:
Have you found a top speed for the evomoto?
Have you done any coast-down measurements in order to get drag figures?
Your website states about 10kg for additional weight, have you got a total weight figure?
Where does your instinct lead you for future developments?

From his German website : 130 kph / 81 mph

114 kg (250 lbs) with fuel
275 kg (606 lbs) all up - the innova can take rider + passenger

I wonder how much of the fuel efficiency gain is attributable to a prone riding position and how much is attributable to the fairing.

Good morning,

as euromodder already mentioned, weight is 114kg with fuel. Top speed is about 130kph (according to GPS). Concerning the weight, there are some reductions still possible. In fact, I did some redesign work on the seat undercarriage which has cut about 1kg. More could probably be done on other parts but I look rather for stability than for lowest weight, since 5kg less weight only help little with the fuel consumption at steady speed. During my round trip through Germany I had an additional weight of over 10kg and did not see significant influence to fuel consuption.
Concerning top speed, 130kph can be reached in flat terrain with no wind. Downhill or with tailwind you will see even higher speeds, however I don´t do this since I don´t want to overstrain the engine. Actually I limit my permanent speed to 110 to 115kph and use the rest only for overtaking. Oil temperature measurements have shown that at this speed I have optimum oil temperatures of 100 to 110°C. Running 130 kph at 32°C ambient temperature for 10min will kick the temperature up to almost 130°C which is more than I would like to see permanently. However mostly I keep a speed of 85 to 90kph and roll along with the trucks (not using the slipstream advantage - I keep a distance of usually 50m because I feel more comfortable this way).

I did do coast down and steady downhill slope coast speed measurements with the original Honda Innova and the evomoto. Results for cd x A are:
Innova: 0,57m2 for the upright rider and 0,42m2 for ducked down rider
evomoto: 0,23m2 for the seat in upright position and 0,21m2 for the seat in reclined position (which I use 99% of the time)
All results with rather tight fitting textile motorcycle protection wear.
I would love to go into a wind channel one day, but this is very expensive.

I calculated that there are pretty equal contributions to the improvement of the aerodynamic drag both from reduced frontal area and coefficient of drag. As a rough numer, it can be stated that both individual values (cd and A) dropped from 0,7 (original Innova) to about 0,45 (evomoto 125cc).

Apart from minor changes to the evomoto 125cc my thoughts for future developments go in different directions:
1. Go electric - it must be an incredible feeling without the sound of the combustion engine only with the humming of the electric motor. I do get an idea about this, when I let the evo go downhill with the engine in idle. It´s great especially on a windig road - uncomparable to anything I´ve done before. Hopefully, battery technology keeps on improving like in the last 5 years and we will see reasonable prices and capacities within the next 5 years.
2. Go for more power - I´d like to try out and use the good aerodynamics rather for top speed than for fuel consumption - of course the latter will still be good. My precalculations show, that with a bike with a top speed of 275kph you will still get a fuel consumption of about 100mpg at 130kph constant speed.
3. Go for more weather protection - this is what many people have asked for and suggested. From a motorcyclists view, I think weather protection is already great, but of course from the car drivers view it could be much better.

Greetings from Germany
Wolfgang

Weight is secondary to aerodynamics, and drivetrain efficiency is the key. Both this project and the Jacobs project, and Dave Cloud's Dolphin and The Illuminati 7, all demonstrate this.

Hello there,

Neil you´re right about both drivetrain efficiency and the weight. That´s why I chose the Honda Innova as the basis and, so far, did not bother about 5kg more or less. The latter is especially true for constant speed.
For acceleration, less weight is of course better, since the vehicle will be more agile when it´s light. And for deceleration it´s of course good to have less weight too, since you´re loosing less energy when braking. So weight is very important especially in urban traffic - for acceleration and fuel consumption.

There is another important influence of weight to fuel consumption which I think may not be underestimated. I got to this insight and conclusion yesterday during a 600km ride to my parents and back home. The autobahn was partially very hilly, partially absolutely flat and I got into several traffic jams. In the flat sections I thought about increasing gear ratio even higher but in the hills I was happy to have enough uphill-stamina.
So here´s my chain of thoughts:
1. For best fuel consumption, you want to run the engine with best possible efficiency.
2. This usually means you need to increase the engine load (torque) and reduce the revs.
3. You do that by increasing the gear ratio.
4. However, if you do that, acceleration of the bike will get worse.
5. Of course you can, for better acceleration shift down but it´s annoying and with only few gears (4 in the Innova powertrain) you will end up at high revs in the lower gear.
6. So if you want to have a certain acceleration level in the highest gear, you may not exceed a certain gear ratio.
7. This is where the weight comes into play: since acceleration is force at the wheel divided by weight, you will have more acceleration if you decrease the weight.
8. So if you decrease the weight, you will be able to further increase the gear ratio and still reach the desired level of acceleration.
9. The higher gear ratio will then run the engine with more efficiency and fuel consumption will be lower.

I hope I was able to explain.

By the way, you can find my fuel logs at the spritmonitor website ( www . spritmonitor . de ). Unfortunately I´m not yet allowed to post links, but you can find the evomoto 125cc quite easily by searching for the Honda Innova.

The values are in liters / 100km but it´ll give you an idea about my everyday fuel consumption. Overall fuel consumption so far is 1,12 l/100km which is equal to 205mpg. I have added comments (in German) about ambient temperature, wind speed / direction as well as the route - the most important "external" factors for fuel consumption. Lowest fuel consumption so far was 0,96 l/100km which is equal to about 244mpg. Please note that the spritmonitor site will not accept fuel consumption values below 1 l/100km, this is why I sometimes artificially increased the fuel data to meet the 1,00 l/100km limit.

Greetings from Germany
Wolfgang

I posted it in the first message of the thread, but here it is again for convenience ;)
Details: Honda - Innova - evomoto 125cc - Spritmonitor.de


Maybe you could ask them to lift that limit, certainly for small displacement motorcycles and mopeds.

Coming from people like you who really can get under 1 L / 100km (over 235mpg) they might more easily be inclined to grant such a request ;)



The Honda Innova / ANF 125 is clearly a nice machine.
About half its users are reporting 2 L/100km or less (117 mpg or better) !

Ups, indeed you did. Sorry that I forgot that and thanks for posting it here again.

I asked spritmonitor to allow also lower consumption values but got no response from them. Well, not a big deal, I can live with it.

The Innova is a very economic bike. When comparing the Innovas on spritmonitor to the evomoto, keep in mind that most users usually go much slower than I do. That´s how they get to consumption values of 1,8l/100km and even less. If they went 90kph on the autobahn , they would most probably get up to values of 2 l /100km as I did, when I tested my Innova in the original trim.

Evo, what driving (riding?) techniques do you use? Do you keep a steady speed, or pulse&glide? Do you kill your engine while coasting?
Do you have special tires? Are there even LRR tires for motorcycles?
Any instrumentation, like a vacuum gauge? I read that there is nothing like an OBD standard for motors:(

I believe the Innova has a transmission similar to the Honda Cub or CT70. There is no hand clutch, you just idle down and shift.

I have been looking at available used small cc motorcycles but they all have a hand clutch. Eliminator 125, GS 250, DR 350 are a few types that I have found for sale in my area. I have not seen a CT70 for sale for a long time. I guess one could replace the CT 70cc motor with a Lifan 125.

Is there a way to convert a bike with a hand clutch to a prone riding position? The challenge is that you have four things that need to be managed by hand:

throttle
clutch
front brake
rear brake

It would be nice to be able to ride and control the vehicle either upright or in the prone position.

In the upright position you could operate the rear brake as usual with the left foot. But in the prone position, how would you do it?

Front brake, rear brake, front deraileur, and rear deraileur are hand control on my bicycles. In many ways they are counter intuitive as well, but can be managed with practice (of course nobody dies if I screw up a gear change or braking...)

@Piwoslaw: I do not use special driving techniques and I do not pulse and glide. All I try to do is avoid braking and, on longer downhill slopes, I disengage the clutch and let the bike coast downhill, if the slope is steep enough to keep the speed.
Unfortunately there are no LRR tires for motorcycles (at least not that I know of) so I´m running the stock tires. On top of that, these are not tubeless tires but have inner tubes. This kind of tires has an even higher rolling resistance than a tubeless version would allow. So all I can do is increase the tire pressure. I run them with 3bar pressure and am quite satisfied with it.
I have no instrumentation but the stock instruments (odometer, speed, gear, remaining fuel). I did install an oil temperature gauge but removed it after these test were finished - it was quite bulky.

I guess it should also be possible to convert a regular motorbike with handclutch to a recumbent motorbike. I think it would be O.K. if certain functions are not available, if you have the feet on the ground. I mean that would be the same as on regular motorcycles - feet on the ground means no control of the rear brake and the gearshifting. However, all functions would need to be operable when the feet are in the riding position up front below the fairing.