Best way to upgrade a Dillenger D5 ebike top speed

[Evolk]

Hello ES community,

Please share your help and wisdom with me. I've recently purchased a Dillenger D5 ebike but I'm finding its top assisted speed to slow.
http://dillengerelectricbikes.com/featured-products/d5-by-dillenger.html

I'm about 84kg in weight, I want to ride it 40km between charges over fairly flat terrain and I'm looking for a top assisted speed of approx 40kmh or better on flat ground.

I've bought the PC programming cable and have fiddled with the controller settings. I'm currently running a "Limited Current(A):" of 14. I've adjust the settings so that it doesn't speed limit me to 26kmh but I'm finding the motor RPM maximum is about capping my assisted speed at about 30-31kmh.

I really like the bike I just wish it had a higher top speed so it can keep up with my peddling a bit more as I feel I'm not much better off than riding my plain old road bike at the moment.

What do you think my best approach would be for increasing the top speed of this ebike? I'm happy to speed up to $400USD to improve this bike.

Should I run more current through the controller than 14A?

Should I purchase the larger Bafang 500W 36V CST rear hub motor to replace the Bafang SWXH6 250W? . If upgrading to the Bafang 500W CST would I also need to get an upgraded controller too that can output 500W?

Any help with this would be very much appreciated

Here are the main electric specs that can be taken from the product website:-
BATTERY
Battery Chemistry: LiMn2O4 Lithium Ion
Nominal Battery Voltage: 36V
Charged Battery Voltage: 42V
Battery Capacity: 10.4Ah
Nominal Battery Energy: 374.4Wh
Battery Cell Type: 18650


MOTOR
Motor Brand: Bafang rear hub motor
Motor Model: SWXH6
Motor Voltage: 36V
Max Motor Power: 450W
Drive Type: Rear hub drive
Motor Sensors: Hall sensor

CONTROLLER
Controller Brand: Bafang
Controller Operating: Voltage 36V
Controller Max Voltage: 36V
Controller Operating Amps: 7A - 18A
Controller Nominal Power Output: 250W/350W
Controller MOSFET Tubes: 6 Mosfet
Controller Sensors: Hall sensor

 

[Chalo]

Not only will the modifications you're talking about make your bike illegal, but they'll destroy its range. Plan on having a much heavier, much less pleasant bike if you want to go the same distance at 40+ kph as your bike does at 26.

A quick power calculation will show that you'll need quite a lot more than the Australian legal limit of power to hold 40 kph. So if you want to do that, expect to build your bike yourself, because no reputable manufacturer will provide a bike whose intended use is illegal.

 

[Evolk]

Thanks for the reply Chalo. The change in weight will depend on what modifications (if any) are done. I am aware of the legalities.

I'm planning on making the modifications myself and not looking for an off the shelf complete bike. I've worked in bike shops in the past and know my way around bicycle mechanics.

In the current setup my bike will do about 70km range with a 31kmh top speed. But I'm after that higher speed more so than the extra range. I'm more than happy to supply some of the wattage needed to get to 40kmh by pedaling. It's just that my current setup can't rev higher enough to stay with me above 31 kmh speed mark.

From what I've read on the ES wiki a 500w motor may give me that bit extra speed I'm looking for and the weight differential between the bafang 250w and the 500w motors is 700 grams. Fairly minimal.

Sure if I upgraded to a 1000/1500W+ motor I'd probably be looking at quite a bit of extra weight but I don't think my budget would allow for that as it would require changing everything (motor, controller, battery, electric wiring).

 

[d8veh]

Change to a 48v battery and controller to get a 33% increase in speed and torque. A 15A controller should be fine, but you can go a little higher if you want as long as you keep the speed up. You can get batteries from Aliexpress if you can't find one locally.

 

[Chalo]

What d8veh said. If all you want is more RPMs, those are proportional to system voltage. Your actual top speed (no pedaling) will be somewhat less than that because of the nonlinear increase of resistance with speed.

 

[craneplaneguy]

When I converted my 350 watt 36 volt Bafang hub drive to a 52 volt system, besides a new battery I also installed a new controller. My top speed before was 20 mph, now it's over 30. Part of this was the higher voltage, part was the old controller that had a built in limit of 20 mph.