Spreading the cause, prepared for the flak... e-bikes

[velomaniac]

15mph is not the limit on the speed of the bike with the rider pedalling. It's the limit on the speed under electric propulsion only. Many commuter cyclists especially in cities seldom get above 15mph without power assist. Thus the chances of death are not greater than the risks many of us take for granted. I do believe that more power from the point of hill climbing would be useful but see no problem with the motor only top speed.

 

[careful now]

Re:

So a 250w assist is like having another person pedalling quite hard?

Sign me up.

 

[Skyfarmer]

15mph is not the limit on the speed of the bike with the rider pedalling. It's the limit on the speed under electric propulsion only.

Correct...you can still cycle it faster.

But from the many people I have spoken to, older people and commuters, having the extra weigh and cost of an electric, then not getting something that gives them a bit more advantage, is a downer for them. Yes, they do have some advantage, but the feeling it is not enough is quite widespread. No one is lookign for 25-30 mph...but 20...at least to a speed a little faster than the average joe commuter cyclist will pedal at.


I have built quite a fast bike, but limit it a bit now I have got over the initial blast with it. I now run it at 60 volts not 100.. At peak when tuned on the computer and run at 100volts, it peaked at 14kW...yes 14,000 watt and was still pulling at 55 mph...

I would hate to see lots of bikes like this on the road...it will be way to dangerous and would result in a massive clamp down, not to mention the deaths of idiots who have zero road sense.

 

[velomaniac]

The government had to draw a line somewhere. A moped is a 30mph vehicle requiring a licence, tax, insurance and compulsary helmet wearing.
If you dont wear a helmet, pay road tax or insurance or have a licence I'd say 15mph is a pretty generous allowance by 'the man'.
If you stay off road then do what the heck you like power wise but dont sneek up on horses with your silentish motor..that could be nasty !

 

[Skyfarmer]

I rie horses too, no way i'd do that.

See what you are saying about speed, but reckon to allow a powered speed a little bit above what average people cycle...but not as fast as every day road or hobby cyclists can do..25-30.

If government are trying got get people out of cars, then making e-bikes a bit more atractive speed wise..so people see more of an advantage of normal cyclin grill get more people out there.

Till I buitl mine, I had no real thoughts on the whole subject..it is only since seeing how many scrap e-bikes there are around in Jersey, who have bought them and found that they have a bike that is heavy, and actually generally than they can cycle a normal bike..eventually consigns them to the scrap pile..I have 10- 12 of them in my shed here to prove that,

 

[Rampage]

Re:

What sort of power is the one in the video?

 

[Skyfarmer]

probably 20,000 (20kW)or more.

i know when I first built mine it showed peaks of 14kw but max after first 2 seconds of about 10kw, and it was no way as mad as that.

I think some where on the video he is running it on a dyno.
Most of the standard Infinieon square wave controllers that are easily available, are programable. You can set a "Block Time" which is a time in seconds where all current limiting is ignored to enable better initial pull off. On any powerful e-bikes, this should be set to zero..but on my first build I did not know that

for the first couple of seconds it would pull unlimited current..so i would see 140 amps plus from the battery pack at 100 volts if I slammed the throttle open. Mine has down exactly like the one on the video has done, but not quite as dramatically.

I have since set the block time to zero and reduced the current limiting. and run at lower voltage. Also fitted a three speed switch and three speed current limiting. So at the flick of two switches, I can limit to about 18-20 mph and 20 amps, so down around 800 Watt. That is my every day setting for cycle paths etc.

I am well aware of the dangers of these things if used irresponsibly . Not sure if this link will work...but look at this tosser riding through a road full of pedestrians. Yes it is a road, but it is very urban and full of people...what a tosser... But riding like tho sis not confined to e-bike riders. .
On our local cycle paths, especially in the summer, I am often passed by normal cyclists...MTB'ers I am ashamed to say.. I actually witnessed a group behaving like c***s last summer. swerving through a group of kids and mums on a large wide shared use path along the coast. They passed me then blasted through the slowing walking group ahead. Caused one of the kids to fall over, but they did not notice, they were gone. I stopped, gave them my phone number and told them I'd get the riders details..caught them up on the e-bike and ...well they got phone call from police later that day.

https://www.facebook.com/photo.php?v=10152363672695199