Electric Velomobile

[lava]

I'm having fun fantasizing about an electric velomobile. Fully enclosed, of course, so I could ride in any conditions. I currently have an Amped Bikes 36V 500-750W direct drive kit on a single speed diamond frame bike. I get like 22 mph max w/no pedaling. If I put a rear-wheel kit of the same power on a tadpole trike velomobile, generally how much faster do you think I'd be? There would be some added rolling resistance from the extra wheel, but overall with the improved aerodynamics do you think I could hit 30 mph w/no pedaling? Help a brother dream here...

 

[John in CR]

I've been fantasizing about a leaning delta velo for 3 years. 0-50mph in under 3 seconds and then mountain roads here I come.

 

[Drunkskunk]

the unloaded speed of that motor is about 26-27mph. Thats the speed it turns when held up in the air. Nothing will make it faster than that unless you increase the voltage.

What will happen is a small increase in speed, maybe 23-24mph, but a major decreas in amp draw at speed. You might be pulling 400 watts at full speed now, and the velo might only need 250watts to go 24mph.

What you need to feed your greed for speed is voltage. 60 volts will get you up over 30mph

 

[lava]

the unloaded speed of that motor is about 26-27mph. Thats the speed it turns when held up in the air. Nothing will make it faster than that unless you increase the voltage.

What will happen is a small increase in speed, maybe 23-24mph, but a major decreas in amp draw at speed. You might be pulling 400 watts at full speed now, and the velo might only need 250watts to go 24mph.

What you need to feed your greed for speed is voltage. 60 volts will get you up over 30mph

Thanks! So it sounds like if I bumped up to a 48V battery I might hit 27 mph?

 

[JennyB]

I don't think an over-volted hubbie is the best fit for a velomobile, since it's a lot slower than a bike on hills and accelleration. Better would be something that runs through a wide range of gears so that it can assist where you really need it and also when you feel the need for speed.

There's an interesting report here

The eWAW that I drove has everything that the WAW has, plus an electric motor of 250 watts and a surprisingly small battery of 288 Wh, which takes you 60 to 130 km further (37 to 81 miles). The battery and the motor add only 5 kg, bringing the total weight of the vehicle to 33 kg .... Because the driver always provides the main part of the total power output, the speed of the vehicle will depend on the power that he or she can deliver. There is no better illustration of this than my test drive. Over a period of about an hour and a half, Brecht and I managed to reach an average speed of 40 km/h (25 mph) -- I was in the eWAW and had the regular assistance of the electric motor, Brecht was in a WAW without pedal assistance.

The eWAW does not increase the cruising speed or top speed of the unassisted WAW, although it does increase the average speed because it speeds acceleration. This is a different approach from the electric bicycle, where pedal assistance is continuous at normal cruising speeds. With regards to efficiency, the concept behind the eWAW makes much sense. A bicyclist needs less energy to accelerate than a velomobilist does (because of the bike's lighter weight) but more energy to keep up speed (because of its weak aerodynamics). In contrast, a velomobilist needs more energy to accelerate than a bicyclist does (because of the vehicle's heavier weight) but less energy to keep up speed (because of its excellent aerodynamics).

Because it takes more energy to accelerate in an eWAW than to drive it at a constant speed, the engineer's choice to assist the driver only during acceleration is smart; it increases the range of both the cyclist and the battery. The electric motor supports the driver during peak efforts, so that his or her endurance will increase spectacularly. (Peak efforts have a detrimental effect on endurance, while pedalling at a steady pace can be done for hours.) Meanwhile, the driver offers the same service to the battery. Because the electric motor is shut off at cruising speed, the battery range increases considerably.

 

[dogman dan]

Just depends on what your uses might be, and if you gave a damn about efficiency. If the goal is just to go fast, volt up and let er rip.

Direct drive motors really perk up with 72v, and with a velomobile fairing cutting your wind drag, you could very likely cook along at a nice speed quite efficiently on the flats. I recall one nice recumbent velo with a 5304 or 5303 running it that performed very nice.

But yeah, gearing really shines when you have to climb a hill.

Go to 48v, and you oughta see pretty close to 27 mph without the fairing.

 

[Lebowski]

Watch out with Velomobiles, a friend has one (Quest ?) and it has a single sided rear wheel...