Setting up an e-bike?

[ericmark]

First e-bike came from Halfords who did all the settings so my wife could simply ride it, nice mid motor step through frame with hydraulic disc brakes, 7 speed derailier gears, but slightly on the heavy side, no longer on sale think around 22 kg.

Seem to remember bike rack rated at 40 kg, it was selected as it allowed us to carry bikes and tow a caravan, there was a plate that fitted behind the tow ball.

Also hard to secure the bike when on a bike rack and can only carry with the one car, so seemed a good idea to go for a folding e-bike for me, a little heavier at 25 kg, but can carry in the boot, so when a second hand one was advertised it seemed a good idea, so got one of these or very like that one, controller not mounted in same place, but it seems it is a standard frame.

However it showed km/h and clearly would prefer MPH, nothing in the manual to show how to change it, however some playing and I found pressing up/down at same time goes into a menu, and there are 17 settings, the km/h to MPH was clear as number 2, but the rest were just numbers.

An internet hunt found USA sites where they seemed to know what they all are, and it seems similar but not the same as mine, there is no ID number on the display so can't hunt for identical model. Seems in USA allowed up to 750 watt on the road, maximum speed of 20 MPH but in UK 250 watt and 16 MPH, and it seems mine is set to 350 watt so needs to be set to 250 watt to be legal. Also needs to be set to pedal assist only, at the moment it is both pedal assist and twist grip.

It seems likely below is the way mine is set, hence I say possible as not tested, but some of the values don't seem to make sense, 350 watt at 48 volt is 7.3 amp, but where I think is amps it says 12, if it said 7.3 then dropping to 6.2 would make sense.

Also it says speed limit if sensor fitted, can't see one unless built into motor.

So I am loathed to play in case I damage some thing. So wonder if anyone has already played with the settings and what was the result?

 

[mattylad]

What?
You mean you don't just buy an e-bike and press a button/twist a grip to control them??
Eeeek!

 

[ericmark]

For me whole idea was to get exercise, so want to pedal, but that means want to pedal not take my bike for a walk, and living in mid Wales that is exactly what happens, I walk with bike up the hill and free wheel back down.

The 250 watt of my wife's bike mean it was still a lot of effort, but I could remain seated on the bike. I know we call them push bikes, but I want a pedal cycle. I am not sure of age of my new bike, and the law is not it seems retrospective, so early e-bikes with thumb or twist grip controls and over the 250 watt limit, may still be legal, depending on age, it should stop non pedal assistance at 4 MPH (called walk assist) and pedal assistance at 16 MPH. One can pedal faster, but motor does not help, as a result wife's bike good for around 100 miles range, so even if the law does allow the assistance to get the range one wants the motor to stop assisting.

Technically if the bike does not follow the rules it is not an e-bike, it is a motor bike or moped. So needs rear number plates and registering, and a licence to ride it. I was unaware it was 350 watt when I bought it, it was advertised as an e-bike. Selecting mode 1 there are 0 - 5 to select from, it seems the assistance only comes in up to 4 MPH, so keeping it in one of the low modes I am sure both legal and and the battery will last, and it does what I want, it means not used as a push bike, I can ride it up most of the hills, but would be nice to know what all the settings do.

 

[mattylad]

TBH I'd like one myself, I need to lose some weight and cycling to work will do it well.
There are hills between me and work, I could cycle there but the return journey would mean walking it up a long hill so I'd like to use electric power for that.

However I cannot afford one so I'll just have to think about losing weight

 

[Keithmac]

Some people have a knack of taking the simplest of things and stringing them out into a long, drawn out process.

 

[ericmark]

Some people have a knack of taking the simplest of things and stringing them out into a long, drawn out process.

It seems you may be right. I was worried it was not legul but it seems the 250 is a continuse rating. So it seems I should have just looked at CE marking and accepted that means it's legul.

 

[Avocet]

It seems you may be right. I was worried it was not legul but it seems the 250 is a continuse rating. So it seems I should have just looked at CE marking and accepted that means it's legul.

That's odd? It is CE marked?! You're right, 250W is the maximum for an EU (UK) approved bike. Also, I'd be a bit surprised if it's an American bike but all the units in its setup are metric? What make is it? I take it there isn't a forum for users of that make of bike that you can ask the question on? Also, I wonder if one of those settings is for torque? Although the power of an e-bike is capped at 250W over here, as you say, there's no limit on torque. That varies enormously. Mrs Avocet has a (European) e-bike which is maxxed-out at 250W, but has three settings to control the torque. 40Nm is the most it will manage, but there are e-mountain bikes on the market with double that. What this means, is that the bike can help you up steep hills much better. The problem is the legal 250W cap, and as power = torque x RPM, if you keep the power the same and increase the torque, the RPM (AKA speed) has to go down. This leads to quite complex algorithms in the control unit so that at (say) 5 MPH, grinding your way up a steep hill, it can give you loads of torque to help you up there, without exceeding its 250W cap. However, at (say) 15 MPH, it has to limit the torque that it is providing, to avoid going over the 250Watt cap.

 

[ericmark]

It seems common to have laws which are not clear, the court cases refine the law.

Little words can completely alter things, in this case continuous, one is allowed peaks over 250 watt. As said CE marked so assuming OK.

What seems odd is the ability to change things without a tool, the mobility scooter and wife's e-bike need a PC plugging in to alter things. So the user has no option, but with my bike I can swap between pedal assist only and motor assist only, and both by simply pressing both the up and down buttons together.

I find around 6 MPH is the lower limit, once under 6 MPH the motor starts to loose torque, between 6 and 12 MPH it goes well. Balance wise 3 MPH is the lower limit, below that start to wobble, if I rode a tricycle then there would not be a lower limit, but under 2 MPH it is get off and walk, this makes me wider so more likely to have problems with other traffic.

I remember working out horse power from torque 2πNT/33000. Stuck in my brain, but hardly helps when working in watts. Know the metric system should be even 10, 100, 1000 etc. but also know they got it wrong with 4.2 Joules in a Calorie, and 980 instead of 32 in imperial but no idea how I could set up a dynamometer, used a rope one in the past, but long time ago when I was in collage.

 

[Avocet]

It seems common to have laws which are not clear, the court cases refine the law.

Little words can completely alter things, in this case continuous, one is allowed peaks over 250 watt. As said CE marked so assuming OK.

What seems odd is the ability to change things without a tool, the mobility scooter and wife's e-bike need a PC plugging in to alter things. So the user has no option, but with my bike I can swap between pedal assist only and motor assist only, and both by simply pressing both the up and down buttons together.

I find around 6 MPH is the lower limit, once under 6 MPH the motor starts to loose torque, between 6 and 12 MPH it goes well. Balance wise 3 MPH is the lower limit, below that start to wobble, if I rode a tricycle then there would not be a lower limit, but under 2 MPH it is get off and walk, this makes me wider so more likely to have problems with other traffic.

I remember working out horse power from torque 2πNT/33000. Stuck in my brain, but hardly helps when working in watts. Know the metric system should be even 10, 100, 1000 etc. but also know they got it wrong with 4.2 Joules in a Calorie, and 980 instead of 32 in imperial but no idea how I could set up a dynamometer, used a rope one in the past, but long time ago when I was in collage.

I couldn't do it in horsepower! (Well, I'd have to cheat and do it in metric and then convert back to horsepower)! Power (in Watts) = Torque (in Nm) x RPM (in Radians per second). That's the bit that catches everyone out! To convert RPM to Radians per sec, 1 RPM = 0.10472 rad/s.