20mph or Bust(ed) - USA "Legal" eBike Speed

[DrkAngel]

3 eZip choices for 20mph legal
22.2V w/13T Mod
25.9V w/16T Mod and
Coming soon ...
33.3V w/22T Mod.



33.3V w/22T mod - Specifically for hillers or hefties.

Last eZip (planned) project, will be a 22.2V ... 44.4V switch.
Planning on 20mph w/22.2V and 30mph w/44.4V.



"Legality" is good ... but should be taken in moderation!

 

[DrkAngel]

Ordered up 2 - 22T LHS (Left hand Screw) freewheels.
- $11.22 + shipping
Estimates indicates as being ideal for turning eZip into 20mph (LEGAL LIMIT) with much improved acceleration and torque - w/33.3V battery.

Will rebuild 2008 eZip Trailz that neighbor sold me ... after being hit by texting woman.
Ran over front wheel-fork.

Bike needs:
front wheel - found one being tossed out = flat tire
suspension fork - whole bike tossed out = bent wheel
36V controller - had for long time = been waiting for project
Rear wheel re-spoked - broken spoke = needed "proper" lacing with better spokes anyhow!
22T freewheel - already shipped

22T freewheel is the "cheap" Dicta, without removal notches.
I intend on greasing hub threads ... hoping that non-destructive removal might be possible ... if ever needed.

I plan on maintaining multiple quick swap motor-wheel combinations.
Motor - Wheel
9T ....... 20T = oem 15-16mph@24V ~23mph@37V
9T ....... 16T = 16T mod 20mph@24V, 21mph+@25.9V, 27mph@37V
13T ..... 20T = 13T mod 20mph@22.2V, 22+mph@25.9V, 30mph@44.4V
9T ....... 22T = 22T mod 14mph@24V, ~20mph@33.3V

Combined with my various battery packs:
22.2V 30.24Ah LiPo
24V SLA 2 - (new) never used, charged monthly
25.9V 2 - 26Ah 1 new 1 3+ years old
33.3V 31.2Ah 1 very used building 1 with new cells
37V = none at present
44.4V = plan on 44.4V 21.6Ah LiPo & Lipo 22.2-44.4V switch pack but future project ...

I will have a variety of speed and economy choices!

Not sure what to do with it ...
Someone threw out a 26" full suspension mountain bike with bent front wheel.
Will put new rim on disc hub and fork and convert bike as my mid-drive project?
USES same 258 & 260mm spokes as eZip ... I have WheelSmith 14ga SS and 13ga SS spokes in proper sizes!
Shopping for better quality wheels! 26 x 1.75 36h alloy ...

 

[Ithanul]

... The bill removes low-
speed electric bicycles from the definition of ``motor
vehicle'' within the jurisdiction of the Department of
Transportation ... "

I would really really like that to be stated in my home state of Alabama. Basically anything with a motor is considered a motorized vehicle and has to be registered.

 

[John in CR]

I would really really like that to be stated in my home state of Alabama. Basically anything with a motor is considered a motorized vehicle and has to be registered.

Not possible. I believe you are mixing "motor vehicle", a legally defined term, with "motorized vehicle", anything with a motor. I'm sure electric wheelchairs don't require registration despite being motorized vehicles.

 

[Ithanul]

Well, my home state is one of those that considers a moped and motorcycle the same dang thing. In their view point, if it got a motor and two wheels it one of those two.

Traditionally, vehicles with pedals, two or three wheels and a motor smaller than 50 cubic centimeters are considered mopeds. The state of Alabama views mopeds and motorcycles as similar vehicles and requires licensing, insurance and abidance of motorcycle laws for any persons operating mopeds within Alabama state lines. Another kicker, you got to have motorcycle license to ride one too.

I usually don't complain about my home state to much, but sometimes they are slow on the up take about new tech.

 

[DrkAngel]

Hot damn!
Just realized something ...
At 48V 10A controller this current regulated motor outputs 350w at the optimal point for 20mph USA "legal".
At 48V 20A controller this current regulated motor outputs 750w USA "legal" max motor output.
A simple PAS sensor and module could either limit controller amps or throttle signal strength.
Either, could limit a 20A = 750w motor output to 10A 350w motor output.
This could qualify as USA "legal" meeting the "20mph limit from motor only" and "750w maximum motor output".
Just turn the pedals around (No longer "motor only" = Turbo Engaged!) and hit near 30mph ... 30mph+ with just a minimal effort applied.

"Load Line" (Black) is for a mountain Bike ... Race bike, recumbent etc., would require PAS adjustment to meet "legal".

 

[gogo]

With the appropriate control and capable equipment you could put 750W to the ground at any speed. It wouldn't be too difficult to program the controls to only allow that 750W beyond 20MPH on condition of the pedals moving.

Most commercially available ebikes don't exploit the legally allowed limits. 750W off the line and then continuously will leave most other vehicles behind for a good distance.

 

[DrkAngel]

With the appropriate control and capable equipment you could put 750W to the ground at any speed. It wouldn't be too difficult to program the controls to only allow that 750W beyond 20MPH on condition of the pedals moving.

Most commercially available ebikes don't exploit the legally allowed limits. 750W off the line and then continuously will leave most other vehicles behind for a good distance.

Pedals moving = 750w motor output "legal" at any speed.

At peak, motor is outputting 750w @ 75% efficiency.
So, 1000w input.
This would be true for the full 20A chart.
At 2mph the 100w output from 1000w input = 10% efficiency, at that speed - full throttle.
So ... 750w output at 2mph would require 7500w input or 200A controller and compatible battery.

.

Most impressively, for me, is that current limiting at higher voltage increases efficiency throughout the output curve and broadens maximum output portion of the power curve.

 

[gogo]

At 2mph the 100w output from 1000w input = 10% efficiency, at that speed - full throttle.
So ... 750w output at 2mph would require 7500w input or 200A controller and compatible battery.

Yes, and that's why equipment capable of that performance is rare. The great thing about electric drivetrains is that they can do crazy strong torque like that yet still be reasonably efficient throughout the rest of the operating envelope.

Most impressively, for me, is that current limiting at higher voltage increases efficiency throughout the output curve and broadens maximum output potion of the power curve.

Yes, modern electronic controllers rock!

 

[DrkAngel]

10A controller 350w output motor
Well, in high gear, 11-36 sprockets, motor outputs 19lb of torque at 0 rpm
In low gear, 36T sprocket, that is 62lb of torque "off the line"

20A controller 750w output motor
Well, in high gear, 11-36 sprockets, motor outputs 38lb of torque at 0 rpm
In low gear, 36T sprocket, that is 124lb of torque "off the line"

That should be better than .5G initial acceleration! = enough torque to be capable of climbing a 45º grade-hill.
........................ (50 lb bike and 198 lb biker = .5G) .........................

Better hold on!
.5G would be equivalent to 100 lb of force trying to pull a 200 lb'er off the back of he bike
Only weigh 74 lb? Hold on for dear life! True 1G initial acceleration!

 

[friendly1uk]

I think the ebike speed limit should be the same as the speed limit for cars on slow roads (past houses, through neighborhoods etc..)

in the uk the ebike limit is 15mph

slow/normal road car limit is 30mph


the bigger the gap between your speed and the speed of the cars passing you the more dangerous it is for those cars to pass you

if you're doing 30mph... cars aren't in such a hurry to pass you, and when they do they're only a few mph faster than you... so they don;t rush past and take you buy suprise

We are having a shake up. Non arterial roads are becoming 20mph. So you can drive in and out of town at the usual speeds, but if you deviate through estates and side streets it's a 20mph limit. My area is already done. They are putting the cycle routes along the 20mph roads or giving them their own routes. On most arterial roads there are bus lanes and if buses don't respect us they are disciplined. There is slow but definite change upon our roads.