John_S

Many thanks for your detailed responses guys. It's clear from your helpful advice that the controller and LCD both need to be changed. Therefore, I think I'll go with the 35a KT torque-simulation square wave controller and the KT-LCD3 display, both of which I happen to have in storage. I'll reduce the current using the LCD to something around two thirds of the 35a in order to protect the DGW07 Shengyi motor from overheating. I understand this is a decent motor and is possibly a clone of the Bafang SWX02; itself a powerful motor although slightly less powerful than the old Bafang BPM which is now hard to find. I'll keep you updated on how it goes with the adjusted setup. Many thanks guys!

Hello. I've got a bike with the 36v Dillenger road-legal front hub kit that has a 15a Lishui controller (product no.: LSW1155-19F) and Bafang C965 LCD display. I'd like to upgrade the controller to one with more current to give more of a boost going up hills. It would need to be an external controller as it wouldn't fit in the tiny enclosure designed for the current controller. I'm wondering if anyone can suggest a compatible controller that has greater current (preferably 20a or more)? Many thanks

I understand about the current, but I also gather that there are other variables too that make some motors inherently more suitable for hill climbing than others. The old Bafang BPM motor (which I have one of in storage) was regarded as exceptionally good for managing the hills, for instance. I'd prefer not to change the voltage of the Wisper bike, as I think 48V would make the bike's default speed too fast (33% faster, AFAIK), and above the legal limit. My bike was bought by the original owner in October 2021. Older official descriptions that I've seen of the Wisper 806 describe the SE version's motor as "high torque" but the Torque version's motor as "ultra high torque". I think my bike is a later one than the point in time when this distinction was being made, although I cannot be sure. Either way, I don't doubt that the bike has a good motor.

Thanks Wisper / David for your reply. Just to clarify, you're saying they have exactly the same torque? The bike I have might be a few years old (not sure, but potentially as much as five). Would it still have been the same motor on the two 806 models at that time? I only ask because I'm fairly sure I saw a post from a few years ago by a Wisper representative on here saying the Torque model had a higher-torque motor. Cheers. John

Thanks for your responses. I purchased the bike and an 18ah battery, the latter from AliExpress. I've read that the Wisper 806 SE has a lower-torque motor than the Wisper 806 Torque. I live in a hilly area and need a high-torque motor. Anyone know if it might be an option to swap the motor on my SE bike with a motor from the Torque model, whilst keeping everything else (i.e. cadence mode of power delivery) the same? Cheers

Hello. I'm pondering whether to buy a used Wisper 806 SE that someone is selling. It needs a new battery, but the seller has said that everything else is working. A new battery for this bike is costly. I'm wondering if an alternative option is to look for a compatible third party / generic battery. Would this be an option, and if so, is there something specific that anyone can suggest? Many thanks guys, appreciated

I'm from Llandudno and am interested in the idea. I don't know of a pedelec club nearby.

I certainly hope the new bill will result in throttles becoming legal. However, the user Flecc (who is clearly very knowledgeable) believes it is highly unlikely.

Would it be legal to have a throttle limited to 4mph until you pedal, to help with starting off from a standstill? I read something suggesting that 4mph throttles are legal, but only in walk mode (i.e. you have to be physically off the bike).

Interesting. So does this mean that the rules applying to twist-style throttles might not necessarily apply to lever-style throttles?

Thanks. That sounds like good advice. My main concern is if I was to get involved in an accident, and my bike was to be inspected. I assume the existence of a throttle could get me into legal trouble. I realize its very unlikely to happen, so perhaps its a risk worth taking.

Thanks for this information. Is the legislation banning throttles completely unambiguous in that DIY conversions are definitely included in this law? I guess it doesn't matter anyway if DIY pedelecs are illegal on other grounds by default. Do you know if there's a straigtforward process I could follow to make my DIY ebike legal (with a 15mph throttle)?

I see. I'm very much hoping for a change in the law regarding throttles, as I struggle a lot with hill starts, or setting off quickly at the entry to roundabouts or crossroads. Not to get off topic, but am I right in saying that 15mph throttles on DIY ebikes are also illegal, just as they are on store-bought bikes? What if some of the electric components of the conversion were manufactured before 2016 (perhaps meaning that grandfather rights could come into play)? I've read some posts on here that have implied that throttles on DIY conversions are legal, although its a bit confusing. This is of interest to me, as I've recently converted my mountain bike to electric. My bike has a throttle which I've currently deactivated.

If e-scooters become legal, does that mean twist and go 15mph throttles on e-bikes will probably become legal too?

I see. So in my case, the nominal voltage is actually just under 47V. If I were to get a 14s battery in the future, I figure that my bike would go very slightly faster (perhaps 1mph faster) than it does currently, although as I'm keeping my bike legal, the result would just be that the bike would keep cutting power more frequently. I'm glad that you've found my advice useful in your decision to order a BPM yourself. Its a great motor.

Yeah I've checked that the speed reported is correct. I've compared the speed with a GPS speedometer on my phone, and it is accurate. I'm not sure of those details unfortunately. All I know is that it is listed as 48V. This is the battery: https://www.dhgate.com/product/ebike-lithium-battery-48v-20ah-lithium-ion/384948639.html I bought it four years ago, and its still running fine and doesn't seem to have lost any range yet (at least, not that I've noticed).

Well, a small update. I've been using this motor now for around three weeks, and it has been very impressive. I've not noticed it to be in any way different from my old 500w version. It runs just as well and with as much torque. The only difference is that this motor is legal, which to me matters a lot. I've also bought another of this motor which I can use after my first one gives way. As its a slow wind (code 16), I've been running it at 48V (in a 26" wheel with a normal sized tyre), and it has decent speed, doing 16-18mph on the flat when unrestricted. However, I've set the cutout at 27kph (17mph), in line with the 10% of leeway allowed above the 25kph limit. One of you mentioned that you're also interested in getting hold of a BPM motor. BPMs seem to be extremely rare now, even moreso road-legal ones. This seller only has a few left in stock, and I don't know if they're available anywhere else, so this would be your chance to get hold of one.

Thank you for your detailed reply, and the effort you went to to find out this information for me. As far as I can tell, my motor is genuine. The model number JS-033 is clearly one that comes from Bafang themselves. I looked at some photos of a couple of other BPM motors. The motor I have looks the same, other than the fact that 37V is written on it instead of 36V, and it also has different connectors at the end of the three motor wires. Its serial number is 1603027264, which as far as I know looks normal. I don't have a weighing scale, but the motor does feel more like 4.5kg than 3kg. I'll buy a scale tomorrow to weigh it. As mentioned, my guess is that the 37V stamping is just a spelling error. I'll limit the controller current to under 25a, as instructed by the user manual. I assume that the motor I have is several years old. As long as its unused (as advertised) and has been stored okay, its lifespan from when I begin using it will not be shortened due to its age, right?

Yes code 16 is a very slow wind. That's why I'm running it at 48V, and the wheel has a 2.4" thick tyre to make its diameter larger (larger wheel = faster motor). I've calculated that it should do around 19mph on a full battery. The controller I'm using is a 35a one from PSWPower, which I believe is compatible with this sensorless BPM motor. Yes that would be my guess too. Its hard to say for sure, but my guess would be its just a spelling error. I would hope that my motor is an original Bafang one rather than a copy. Do you know if there's a way I can check this?

Thanks for the link. I'll take a look at that thread. I bought the motor from a German retailer on Ebay, described as "new other": https://www.ebay.co.uk/itm/184322065430

From what I've heard, the 500w version of the BPM is more powerful than the 250w/350w version, as it has thicker wire in the windings. The old forum member D8veh, who'd had experience with both versions, would mention this in some of his posts. I'd like to supply around 26a of current to my 250w BPM. Would you say it could handle that when running at 48v? Thanks

Hi guys. I've not posted on here in years. Hope you're all doing well. I'm building an e-bike with a 36v 250w BPM code 16 motor running at 48v in a 26" wheel . The battery is 48v 20ah with a 30a BMS, and I'm using a 48v 35a controller with adjustable current. Is anyone able to let me know what the maximum current is that I can supply to this motor at 48v without causing damage to the motor? My last setup had a 48v 500w BPM that I ran at 30 amps. However, I now want to switch to a road-legal motor. Am I right in saying that the 250w BPM should be run at a lower current than the 500w version? If so, what current would you suggest? Many thanks.

As they are two totally different motors that just happen to have the same arbitrary 250w rating, they are likely to vary vastly from each other in terms of their power and torque. An internally geared motor will be much better at climbing hills than a gearless (direct drive) one. Are you sure its not the Halfords one that is geared and your current one that is gearless? In order to be able to tackle the hills well, a hub-driven bike needs to have a slow-wind internally geared motor running at a decent current. The motor also has to be sufficiently large enough to handle this current without overheating. My bike has a 48v 201rpm BPM motor in a 24 inch wheel, paired with a 26a controller. It pulls me up all the steepest hills effortlessly, and can still reach a top speed along the flat of over 19mph. I recommend you replace your current motor with a slow-wind BPM-type one similar to mine.

Thanks guys. Wouldn't 10g spokes be expected to be stronger and at less risk of braking than 12g or 13g ones?

Is it the exact same motor, or is it a different one that just has the same rated power? Even if its the same motor, the winding speed could be different, or the wheel size may be different. Also, the controller current could be less on your current bike, or the battery could have weak cells. All these things affect pulling power.