Electric Bikes - 36v v 48v system..... 36 is my choice

http://www.ebikehub.com/forum/download/file.php?id=361

52 mph... with only 48 volts!

I'll get back to the banter later...

Just the first speed run:

52 mph on the flat with only 48 volts.

Previous BEST for 48 volts was 48 mph.
Previous BEST for 72 volts was 52 mph.

...I'll see if I can break my old speed record later today. (at 52 mph the wind resistance makes it hard to get going much faster)

The motor did not even get close to overheating... it was very, very cool.

The Triple is an enormous success. (which is good)

The Theory of parallel winds allowing more current (more top end power without heat) works:

"Somehow"

(Litz wire?, Inductance?, Parallelism?)

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58 mph... at 72 volts!

Damn that was fast. :twitchy:

(flat land, no wind, held for about three seconds)

Output is estimated as 2800 watts. (3.7 hp)

The range dropped to near nothing. :lol:

The Triple was able to deliver that much power without overheating, so as far as raw power is concerned it certainly beat my old Double wind. The old Double could manage about 52 mph on the flat and it produced a lot of heat in doing it.

In principle the concept of switching from Double to Triple works for peak power, but the range is naturally going to go way down. Overall efficiency remains good, but the simple fact of using all your battery so quickly means that there is less to spread around. One cannot ride the Triple and get the same range as you could with the Double because the Triple needs to be fed a lot of amps to make it function. The best argument for the Singles and Doubles is that the range is better. (they run better when batteries are more limited)

What do you want? Power or Range?


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Note: I managed 58 mph while only in fourth gear out of six while in 72 volt mode. The last two gears were essentially worthless. In 48 volt mode the sixth gear matches up perfectly with 52 mph, so from a practicality standpoint it makes more sense to ride the bike at 48 volts.

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Very cool, and I know this is slightly OT but I have a question.

How do you calculate output?

I know how many watts input I plan to put into a motor, but I don't know what the output will be and I'm told that those silly laws are based on output, not input.

If I should have started another thread I apologize, I generally frequent forums that are quite relaxed in that regard but I know not all are.

Well, there<s a simulator at ebikes.ca, if you know what unloaded top speed to expect at a given voltage for your motor, then matching it with something similar on the simulator should give you a reasonable idea what power out to expect. Power in isn<t indicated on it, but it stays at max amps until the lump in the curve where it gradually drops to nothing.
http://www.ebikes.ca/simulator/

You can compare that for power use at given speeds/slopes on kreuzotter simulator to get an idea what it would yeild in real life.
http://web.archive.org/web/20050408065837/www.kreuzotter.de/english/espeed.htm

OK, thanks. I have been using the one at ebikes.ca but was told that the output was different somehow. Maybe I was confused.

In Missouri they have something called the "Missouri Moped Law" and my bike fits into that when it's running below 3 hp and I keep the speed down. (below 30 mph)

This 58 mph bike is just for testing purposes... I'm working on another that is more of a true "ebike" with a 750 watt power output.

Nearly 4 hp is a bit much for an ebike. :lol:


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I've writtedn my own spreadsheets for simulations, modified simulation that have been posted online (GNU language) and also I've matched my results in real life with the simulations.

When I made the 52 mph run my simulation projected 51.7 mph.

For the 58 mph run my simulation projected right about 60 mph.

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Hehe, yeah, I'd still like to have it though. I'm in BC Canada and our law for a Limited Speed Vehicle is 1500W and 70Km/hr. (44 mph)

Wow, it would be a lot easier with a 44 mph limit. The cars around here travel really fast and I need all the speed I can get to stay ahead of cars and keep from getting passed. The roads here have no bike lanes... so it gets scary when you can't keep up.


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My problem is that I'm a very heavy guy. I hear the biking term is Clydesdale. So to keep the motor under 1500W and still make it up to that speed is posing a challenge.

Right now I'm considering a 48V 48A Crystalyte 5303 but that just barely goes over the 1500W limit and finding a battery pack that can take that abuse is looking pretty expensive too.

48V 48A Crystalyte 5303 is a good start.

Going up to 72 volts would be better.

Batteries are the weak spot with so much power. This Triple wind produces amazing power (for what was normally a small motor) and for short speed runs it's great, but now I'm trying to figure out how to make the range longer. (the Triple prefers to run with a lot more current than the Double or Single)

$$$ is the easy way to solve the problem... just buy those expensive batteries.

There is no easy answer. :(


http://www.ebikehub.com/forum/download/file.php?id=265

In the American marketplace the manufacturer is limited to roughly 750 watts for ebikes, so the more creative solutions are going to be focused on that power level. The Crystalyte hub motors are the only motors (that I know of) that are built from the start to produce large amounts of power without overheating. But the negative of the Crystalyte hub motors is their weight... 25 lbs trapped in the insides of your rear wheel. My home built bike with gears locates the motor in the bike (which only weighs 10 lbs) while producing (with the Triple) high power levels.

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That looks pretty cool. 70Kph is the Limited Speed Vehicle limit, I'm not sure I want to go the ebike route at 32kph (20mph) because finding anything with enough power to make the 10+% grade hills we have here with my body mass is even more of a challenge.

You might look at the Cyclone motors and then get some low gears to use with it. Hub motors are really poor at dealing with non-optimal conditions like hills.

I'm actually starting to look into long range as an area to investigate next. 58 mph is enough top speed... no need to search for more.

At 24 volts my range could go all the way out to 30-40 miles, but the top speed will have dropped to 30 mph.

It's all about "trades"... power, range, hill climbing...

http://www.cyclone-usa.com/sc_images/products/291_image.gif

http://www.cyclone-usa.com/store.php?crn=199