Build spec by committee, might that include you?

[saneagle]

Okay, no point in ignoring advice I've asked for, and even less sense ignoring someone with practical experience. I hope I'm not heavy/heavy at 13st (though I'd like to weigh less), and I won't be towing or doing extreme climbs.



Wheel rolling circumference will effect the required rpm of the motor to achieve the planned model speed of 8-9mph with a 700c wheel...

"Smaller" motors, I assume mean 250w ones? When you say manage 600w, is that continuous or peak? I thought I'd read peak was somewhere in the 700w range?

I haven't spent many hours looking, but I've seen very few motor specs that mention optimum or maximum spin speeds, though I have started to notice when sellers mention "geared". Not noticed any obvious mention of gearing ratios though. Possibly I should be trying a bit harder.

I was only talking about geared 250w motors. Say small are 100 - 120mm, medium 120 - 140mm and large are bigger.

If you want 8 to 9 mph, you need an extremely slow motor. In that case 145 rpm would be ideal, but I've never seen a motor that slow. Bafang sometimes have speed codes written on them. You'd need code 15 or higher. Code 15 is 201 rpm. The higher the better. Occasionally, you come across 180 rpm motors. You can always get 201 rpm from Chinese suppliers. Most UK suppliers sell motors around 260 rpm.

BPM code puzzle

I'm going to order a BPM hub for my next build, but i'm having a spot of bother determining which code motor to order. I've just recieved an email from Michael at evassemble which states details of the hubs they stock and sell: EVassemble 36V BPM is code 10 48V BPM is code 13 Both european...

www.pedelecs.co.uk

You can often see the reduction ratios on the manufacturer's website. Some Chinese suppliers mention them in the listings.

Why are you so rude to the people trying to help you? They offer their time and help for nothing.

 

[guerney]

Two Bafang mid motors! (Cardiff crackdown post #60)

No front hub motor in sight:

 

[Nealh]

Looks like a good few fastfood menaces being taken off the road, maybe next time they will stick to legal type kits.
The last pick looks like a normal rear geared hub but like most of these bikes they will have a twist and go throttle or simply no speed limit.

 

[StuartsProjects]

The bottom picture is the entrance to the Queen street pedestrian zone, its where the Ninjas congregate for pickups.

 

[guerney]

"Over the course of their operations, the council and police have pulled over and spoken to 1,300 people, 70% of whom were riding illegal electric bikes. "

Illegal e-bikes seized as police and council launch crackdown

Ted Peskett, local democracy reporter A clamp down on illegal e-bikes involving Cardiff Council and South Wales Polices has resulted in the seizure of bikes with an estimated value of over £22,000. The majority of the e-bikes confiscated had defective brakes. The council and police, which...

nation.cymru

The bottom picture is the entrance to the Queen street pedestrian zone, its where the Ninjas congregate for pickups.

That's a lot of Rinjas.

 

[StuartsProjects]

That's a lot of Rinjas.

It is, I recall mentioning on here some time back that catching the Ninjas is easy, the Police just needed to hang around the take-a-ways in a city centre and that was the exact location I was on about.

So now we have evidence that the Police might be reading the Pedelecs forum, maybe some should take a bit more care about what they post ..................

 

[saneagle]

So now we have evidence that the Police might be reading the Pedelecs forum, maybe some should take a bit more care about what they post ..................

You think the police are going to contact Pedelecs admin to find out the real details of the people posting, and posters gave admin their real details? Or are they going to put their best detectives on the case to geolocate forum members from their photos?

 

[FastFreddy2]

If you were to choose that controller, then yes.
The principle is that the maximum amperage of the battery is equal to, or preferably exceeds, the maximum rating of the controller. This way you avoid battery strain and degradation.
Of course you may never use the maximum assist setting so never draw the maximum current. Or you buy a lower rated controller.

This morning I was racking my brains to try and remember a time when the opposite is true. Had an appointment at the dentist this afternoon, which is usually a pleasant experience thanks to a lovely man who tries to help look after my teeth, but remains something I worry about... Anyway, what was the thing I was trying to recall?

Many years ago when I used to a drive a 'passion wagon' (in my mis-spent youth) my car was always decked out with 4 decent speakers, and a proper hi-fi system that allowed ear-splitting volumes of very melodic music. Back then, you were NEVER to have more amps, than your speakers could tolerate, even if it meant the higher volumes would have more distortion. (1% distortion at 20% volume was less likely to to be heard than 1% distortion at 80% volume. In theory....)

So having more energy in the battery than the hub would likely tolerate, seemed odd to me, although I now understand the controller is the gatekeeper to that extra energy. This 'learning stuff' is good!

 

[soundwave]

like a voice coil in a speaker if you give it to much power it starts to distort keep going and you burn out the voice coil and blow the driver.

electric motors are the same but the voice coil as a stator permeant magnet and a coil winding.



the more power you dump in to it will result in distortion/heat if you keep adding more power you can demagnetize the magnet or blow the winding/ blown speaker.



my roof will fall off b4 i blow a driver

 

[FastFreddy2]

I was only talking about geared 250w motors. Say small are 100 - 120mm, medium 120 - 140mm and large are bigger.

I don't often enjoy being talked to like I'm a child, but this is one of them.

What relationship is 100-120mm to the motor? Motor diameter? Do 250w motors come in various diameters for example? At the moment the motor I have in mind is a Mxus XF08, because it seems popular, and likely, through being popular, probably reliable?

If you want 8 to 9 mph, you need an extremely slow motor. In that case 145 rpm would be ideal, but I've never seen a motor that slow. Bafang sometimes have speed codes written on them. You'd need code 15 or higher. Code 15 is 201 rpm. The higher the better. Occasionally, you come across 180 rpm motors. You can always get 201 rpm from Chinese suppliers. Most UK suppliers sell motors around 260 rpm.

That 8-9 mph is an averaged off-road speed. "Modal" speed? There are times when I move at twice that speed, and sometimes less, when dodging between trees for example. Which I don't always miss.....

Why are you so rude to the people trying to help you? They offer their time and help for nothing.

I hope that isn't aimed at me? If I appear rude, I apologise. I don't think rebuffed anyone that I'm aware of?

 

[FastFreddy2]

like a voice coil in a speaker if you give it to much power it starts to distort keep going and you burn out the voice coil and blow the driver.

electric motors are the same but the voice coil as a stator permeant magnet and a coil winding.

View attachment 53161

the more power you dump in to it will result in distortion/heat if you keep adding more power you can demagnetize the magnet or blow the winding/ blown speaker.

View attachment 53163

my roof will fall off b4 i blow a driver

And now we know why the moniker "soundwave".

I'm not a fan of your cycling habits, but I sure am impressed with that studio! If you have them, I bet your neighbours aren't.

 

[soundwave]

well i have had my bike for ten years now and still not dead they was the rear speakers for town house studios in london from the main studio with the 5.1 setup.

60kg each

 

[FastFreddy2]

So now we have evidence that the Police might be reading the Pedelecs forum, maybe some should take a bit more care about what they post ..................

I very much doubt the police are interested in anything going on here. Their job, is to keep a lid on communities, not stir things up without a reason. Let me give you a couple of examples.....

Some 20 or more years ago when the internet was a lot less monitored than it is now, the police were given some 3000 account details of buyers who had made purchases on child-porn sites with their credit cards. That was likely, 3000 potential court cases, convictions and prison sentences. Apparently, a half-dozen of those were actually prosecuted.

Numerous city grooming gangs (Rochester being the best known perhaps) were advised to the police over a number of years. What happened? Not until one of the officers in the know, (a woman) made herself a PITA to her colleagues and bosses, did anything get done.

Ironically I saw a food delivery rider on a main road this evening. Rear hub motor and a huge square bag on his back. 3 months ago I might not have noticed anything unusual, but tonight, I realised he was riding an electric moped. No pedalling at all, but was moving uphill at a fair speed. Same road, but different rider and again a food delivery worker, I have seen several times in the past, with front and rear hub motors. As long as the police don't get complaints about them, they'll be left alone.

 

[Woosh]

I select the hub motors so that they don't exceed 21mph even when derestricted and get twitchy everytime someone is interested in running those motors at 48V instead of 36V to give themselves 30% extra speed.
Cardiff police confiscated 17 bikes, they are all capable of 30+mph. Let that be a warning.

 

[FastFreddy2]

I select the hub motors so that they don't exceed 21mph even when derestricted and get twitchy everytime someone is interested in running those motors at 48V instead of 36V to give themselves 30% extra speed.
Cardiff police confiscated 17 bikes, they are all capable of 30+mph. Let that be a warning.

I'd be very happy with 21mph. I'd be happy with 15mph. I want the grunt for hill climbs, not speed.

A mate derestricted his Levo which I tried out on a flat/level road. Speed was ridiculous. Okay you had to peddle, but it was so fast ..... Acceleration was incredible.

He burnt out that motor, so didn't derestrict the replacement. And burned out that one too, which is why I am reluctant to buy anything "integrated".

 

[soundwave]

I select the hub motors so that they don't exceed 21mph even when derestricted and get twitchy everytime someone is interested in running those motors at 48V instead of 36V to give themselves 30% extra speed.
Cardiff police confiscated 17 bikes, they are all capable of 30+mph. Let that be a warning.

its a token effort like all these things they take a few bikes yet in reality they will be replaced in 24hrs it just cost you in sales like ebike shop selling dongles with bosch motors and honors the warranty.

even curry's sell e scooters now and will sell them to anyone that walks in the door same as halfords yet nothing saying they are not road legal.

i have a dongle on my bike and know what laws i am braking selling something like this to someone thinking it is road legal when it is not is just wrong and could land them in prison for being told a lie to sell a product.

 

[FastFreddy2]

well i have had my bike for ten years now and still not dead

I hope it stays that way, but riding drunk at the speeds you can travel.... You are stacking the odds against.

they was the rear speakers for town house studios in london from the main studio with the 5.1 setup.

60kg each

I've just done some reading up on Town House Studios. Them speakers must have had some very famous people listen to them over the years. I still wouldn't want to be your neighbour.

 

[soundwave]

A mate derestricted his Levo which I tried out on a flat/level road. Speed was ridiculous. Okay you had to peddle, but it was so fast ..... Acceleration was incredible.

He burnt out that motor, so didn't derestrict the replacement. And burned out that one too, which is why I am reluctant to buy anything "integrated".

brose has the worst reliability of every ebike motor bar shitmano dongles dont destroy motors there made not to last in the first place.

all the new gen 4 smart motors are going bang atm at 1000 miles i have one job try and blow my motor up, and if i do i get it fixed for free

 

[soundwave]

 

[Benjahmin]

I'd be very happy with 21mph. I'd be happy with 15mph. I want the grunt for hill climbs, not speed.

So you pick a motor with the rpm to get you that speed (+ about 10%), in your sized wheel, under no load conditions. That way, when loaded, it should give the legal requirement but still give enough torque to climb.
If you can maintain 50%+ of top rpm when climbing then the motor remains efficient enough not to overheat. So that means climbing at 7-8mph.
My own Ezee motor has a top speed of 19mph on the stand (if the cycle computer is anywhere near accurate). It has done many years up and down the hills of west Wales without issue. I have had the controller thermally cut out on hot days though.