Which 20inch rear hub engine 36V+++

[DuncanDK]

Hi all

I am looking for a 250W 20inch hub engine in 36V-48V for retrofitting.
I ride a tricycle, - not a bicycle ;-) And I want the engine to run with assistance up to approx 35 km/h or above. In other word, - I want to ride without the restricter (25 km/h)

I have found this supplyer for retrofitting my self but I do not know anything about the quality:
Heinzmann DirectPower PRA 180-25- Type Pedelec 20”- top speed 38 km/h
However, this requires me to drill a hole in the frame, down by the crank.... not good!
http://www.ebike.heinzmann.com/en/systems/directpower/motor

Do you have any other recommendations, what other supplyers are out there?

I have no hills in my area, and I prefer a rear hub engine in a 20 inch for easy wheel swapping to non-electric in the week-ends. During the week I use it for commuting 2*25 kms to work on a daily basis, In the weekends I pedal on my own.

Please help me along here....

#1

 

[appyarry]

I'm interested how you are going to mount the wheel, is it a single rear wheel?
Ta,

 

[flecc]

Heinzmann are a German maker of superb quality motors so you should have no qualms on that account. They are also the oldest maker, their first e-bike electric hub motor being 1922.

Cyclezee are UK agents for Heinzmann.
.

 

[Deleted member 4366]

Heinzmann are a German maker of superb quality motors so you should have no qualms on that account. They are also the oldest maker, their first e-bike electric hub motor being 1922.

Cyclezee are UK agents for Heinzmann.
.

Do they do a 370 rpm version, which is what's needed for 35km/h in a 20" wheel?

 

[cwah]

I'd be interested by a high speed too for small wheels!

 

[flecc]

Do they do a 370 rpm version, which is what's needed for 35km/h in a 20" wheel?

I don't know, so I linked to John since he may have an answer to that and if not, he may have other options in the eZee or Ansmann kits.
.

 

[Deleted member 4366]

I've been reading their blurb. They do a direct drive one, but not the old geared motor.

 

[flecc]

I've been reading their blurb. They do a direct drive one, but not the old geared motor.

Yes I know, which is why I've no idea what range of speeds they offer for different wheel sizes. Since Germany has the S class they may have some quite fast revving ones for that market.
.

 

[Cyclezee]

With regard to Heinzmann electric motors, they make many for different applications, their electric drive product catalogue is 60 pages long and can be downloaded from here http://www.heinzmann.com/en/electric-motors-and-hybrid-drives


Briefly, the two most commonly used for electric bikes are PRA Direct Power direct drive and RN Classic hub drive.

The PRA range are 36v, 250w or 500w.

The 250w 210 RPM have the following speed limits according to wheel rim size: 20" 25 Km/h, 24" 32 Km/h, 26" 34 Km/h, 28" 37 Km/h.

The 250w 275 RPM and 500w 380 RPM: 20" 38 RPM, 24" 42 Km/h, 26" 46 Km/h, 28" 50 Km/h.

The RN Classic range are 36v 250w.
Performance figures are 25Km/h for both the 210 RPM in a 26" rim and 180 RPM in a 28" rim.

Both types are available for front or rear wheel.

 

[DuncanDK]

How do you translate motor RPM into KM/H?

370 RPM is equal to 35 KM/H in a 20" wheel
470 RPM is equal to 45 KM/H in a 20" wheel

What is the logic/math fomula behind it?

 

[Deleted member 4366]

Speed (MPH) = 15 x (motor rpm)/201 x (actual battery Volts)/(motor nominal volts) x (wheel dia)/26

so for a 370 rpm 36v motor in a 20" wheel with a fully charged battery, the maximum no-load speed will be:

15 x 370/201 x 42/36 x 20/26 = 24.8 mph

 

[DuncanDK]

With regard to Heinzmann electric motors, they make many for different applications, their electric drive product catalogue is 60 pages long and can be downloaded from here http://www.heinzmann.com/en/electric-motors-and-hybrid-drives


Briefly, the two most commonly used for electric bikes are PRA Direct Power direct drive and RN Classic hub drive.

The PRA range are 36v, 250w or 500w.

The 250w 210 RPM have the following speed limits according to wheel rim size: 20" 25 Km/h, 24" 32 Km/h, 26" 34 Km/h, 28" 37 Km/h.

The 250w 275 RPM and 500w 380 RPM: 20" 38 RPM, 24" 42 Km/h, 26" 46 Km/h, 28" 50 Km/h.

The RN Classic range are 36v 250w.
Performance figures are 25Km/h for both the 210 RPM in a 26" rim and 180 RPM in a 28" rim.

Both types are available for front or rear wheel.

What happens if I attach at 48V battery to the 36V PRA Direct Power direct drive setup? Do I blow a fuse in the controller or do I achieve a higher max speed? (Can the controller/setup handle it?)