Looking for a decent ebike to buy, on a bit of a 'budget'

[Mr. B Ikeman]

Thanks for all of the responses so far.
I've found used converted bike online, looks to be in good condition from the pics. Price isn't too bad either at £550 for the bike, meaning I'd have money to spend on a new battery, controller, spares and so on.
Has an AKM350 kit on it, 36V, 350W geared hub motor.

Would this be suitable for my needs; as I've said, I just want more range than a traditional bicycle can afford me and at least some assurance that if I overdo it, I can get back to my place.

One more old woman nag from me too.. Other road users dont expect pushbikes with large lads sat on em to zip about at 20mph+ so even if seen by a motorist they could easily mistake you for a slow bike and judge actions accordingly.

I'd quote the entire post, though I'm trying to keep the thread easy to follow. It gives a lot of excellent advice. One thing I will say however, is that in my experience, some drivers just seem to not care regardless. Long before ebikes were a thing I nearly got killed, twice, by two different drivers in the same spot because they didn't think that someone could cycle at 30+mph, it was a 40 zone and I'd regularly overtake (not undertake) cars in the inside lane. However cars would usually chance it and try and pull out in front of me. First time it happened it was dry and the brakes stopped me, second time it was raining and the bike slid out from under me, luckily I didn't have traffic behind me to run me over. Driver who tried to pull out just drove off like nothing happened.
Was wearing hi-vis and using lights, it wasn't a blind junction either, both drivers definitely saw me and decided to chance it.

 

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[saneagle]

Thanks for all of the responses so far.
I've found used converted bike online, looks to be in good condition from the pics. Price isn't too bad either at £550 for the bike, meaning I'd have money to spend on a new battery, controller, spares and so on.
Has an AKM350 kit on it, 36V, 350W geared hub motor.

Would this be suitable for my needs; as I've said, I just want more range than a traditional bicycle can afford me and at least some assurance that if I overdo it, I can get back to my place.


I'd quote the entire post, though I'm trying to keep the thread easy to follow. It gives a lot of excellent advice. One thing I will say however, is that in my experience, some drivers just seem to not care regardless. Long before ebikes were a thing I nearly got killed, twice, by two different drivers in the same spot because they didn't think that someone could cycle at 30+mph, it was a 40 zone and I'd regularly overtake (not undertake) cars in the inside lane. However cars would usually chance it and try and pull out in front of me. First time it happened it was dry and the brakes stopped me, second time it was raining and the bike slid out from under me, luckily I didn't have traffic behind me to run me over. Driver who tried to pull out just drove off like nothing happened.
Was wearing hi-vis and using lights, it wasn't a blind junction either, both drivers definitely saw me and decided to chance it.

48v is always better if you're heavy and/or unfit. Quite often, the 350w motors are wound for a higher speed than the 250w ones, so the hill-climbing isn't as good.

Don't think that the watts mentioned has anything to do with actual power or climbing ability. The motor is just a transducer. How much power you get depends on the controller and battery. It makes no difference whether the motor has 250w, 350w, 500 or 1000w written on it. For hill-climbing, you need a motor with good efficiency at its climbing speed and a controller that gives the power to provide the torque you need.

 

[Mr. B Ikeman]

48v is always better if you're heavy and/or unfit. Quite often, the 350w motors are wound for a higher speed than the 250w ones, so the hill-climbing isn't as good.

Don't think that the watts mentioned has anything to do with actual power or climbing ability. The motor is just a transducer. How much power you get depends on the controller and battery. It makes no difference whether the motor has 250w, 350w, 500 or 1000w written on it. For hill-climbing, you need a motor with good efficiency at its climbing speed and a controller that gives the power to provide the torque you need.

Thanks for your input.

I'm a little confused however, you're right that the motor rating doesn't matter if the controller isn't able to supply the rated wattage (I assume this is what you mean) and therefore it may be wise to increase the current to the motor.
I'd be hesitant to increase both the voltage and current (though again this depends on the controller and the voltage*current making it to the motor) but, from what I've read, wouldn't starting with a geared hub motor like this (so a gear reduction rather than direct drive) be better than going for a standard hub motor that is direct drive.

I'm going off what other people have said which is, paraphrasing, if I've got it wrong, let me know "Get a 36V kit, a 48V battery and a controller able to handle more current to allow the motor to achieve more than it's continuous wattage rating" also "A geared hub motor at a lower wattage may be better, if you're not looking for a bike that achieves extremely high speeds without pedalling"

So would a 350W geared hub motor, with a 36V battery pack (and mystery ESC) alongside a decent bike frame be a bad first purchase, given the listed price of £550? Used, but looking at the pics, in reasonable shape.

 

[Peter.Bridge]

Thanks for your input.

I'm a little confused however, you're right that the motor rating doesn't matter if the controller isn't able to supply the rated wattage (I assume this is what you mean) and therefore it may be wise to increase the current to the motor.
I'd be hesitant to increase both the voltage and current (though again this depends on the controller and the voltage*current making it to the motor) but, from what I've read, wouldn't starting with a geared hub motor like this (so a gear reduction rather than direct drive) be better than going for a standard hub motor that is direct drive.

I'm going off what other people have said which is, paraphrasing, if I've got it wrong, let me know "Get a 36V kit, a 48V battery and a controller able to handle more current to allow the motor to achieve more than it's continuous wattage rating" also "A geared hub motor at a lower wattage may be better, if you're not looking for a bike that achieves extremely high speeds without pedalling"

So would a 350W geared hub motor, with a 36V battery pack (and mystery ESC) alongside a decent bike frame be a bad first purchase, given the listed price of £550? Used, but looking at the pics, in reasonable shape.

Short answer, I think it will be fine.

Slightly longer answer, the Yosepower kits used AKM geared hub motors, the "350 w" motor has a higher top rpm (and hence worse hill climbing ability) than the "250 w" motor. The manufacturer just used 250w and 350w as a proxy for the top speed, in reality there was no difference in the power you could supply to them.

The stamped wattage on motors has very little relationship to anything, regulations have created an incentive to certify them as 250w and a lot of Chinese manufacturers have used the wattage to signify the top speed

If you bought it and felt it needed more power going up hills you could possibly change the controller to a KT one with a max current of 18 amps. (KT controller + display £80ish) and / or change the battery to 48v (batteries are relatively cheap at the minute £200 ish)

The thing to be careful with second hand e-bikes is the battery, I have had one with a knackered battery and had to replace it, so factor that into the price

So post some pictures on here and someone here will check it is generic technology and that the motor can cope with 48v

Negotiate a price and buy it. Alternatively £550 or slightly more would be enough for you to buy a good condition, highly specced second hand donor bike and convert it to your exact preferred specification

If you want more power upgrade to a dual 36/48 v controller with max current 18 amps

If you still want more power (or the battery is knackered) upgrade to 48v battery

(My prediction is you will be amazed how good it is without any modifications and it will suit your needs)

 

[Nealh]

If one want's hill climbing ability with a hub motor one would be better off with a 48v motor rated for the correct RPM winding rather then overvolting a 36v motor of the same rpm. For flat terrian it doesn't matter.

 

[Peter.Bridge]

If one want's hill climbing ability with a hub motor one would be better off with a 48v motor rated for the correct RPM winding rather then overvolting a 36v motor of the same rpm. For flat terrian it doesn't matter.

Can probably get cheaper from Chinese sellers but if you want to buy all from one place with the Woosh support

Woosh Bikes - Online Shop

Online shopping for electric bikes and conversion kits. All models are in stock unless otherwise indicated on the web page and can be despatched on the same day or next business day. We will email you the tracking link as soon as the item has been despatched.

wooshbikes.co.uk

 

[Mr. B Ikeman]

Thanks for all the replies so far.
I ended up getting that used bike for £550. Not an amazing bike and frame, though the plan was to just get something to test out ebiking on quickly and if I liked it, work on getting it into shape. I do like it and it should be good enough for my needs at the moment, though it'll be a bit of a project bike too.

Doesn't have a PAS fitted, thumb throttle only. Took it out last night, was pretty heavy on the throttle until I noticed the rear brake calliper (Hydraulic front and rear brakes, nothing special, Tektro. I could swap over my old Avid Juicy 5s, but one has half the lever snapped off and the other has the lever bent at an angle and to replace them you need to disassemble the entire cylinder, so maybe something I'll do later) was rubbing the disc pretty badly, so got that corrected. Had figured the hub motor was causing lots of friction on tiny inclines/the flat.
Took it out again tonight, 4 and a half mile cycle, lots of hill climbs, took some of the steeper hills (not the steepest, but fair inclines) and it has no problem getting up them with minimal pedalling. I could probably fit combined cleat/standard pedals and if my leg gives out, get up using one leg and cleats.

Regarding the battery, I measured a voltage drop of 1.7ish (could be .1-.2 off) from 41.8 (maybe 41.9) to 40.1 (maybe 40.2) on a 4.2 mile cycle. Using a slight bit of throttle on any minor incline and full throttle on the steeper hills. I'll probably have to take it out on a longer cycle (probably a day out) to see what condition the battery is in, but that doesn't seem terrible given that it held a charge of just under 42V after being charged up last night.

If you've any suggestions on maintenance, what to budget for to get it into better nick and so on, they'd be appreciated. I'll probably look into fitting a PAS, though maybe it's me but a bad PAS feels like it would potentially be more dangerous than a bad throttle, at lights when crossing roads I'll usually have one foot on the pedal, one on the ground and usually get the pedal moved up so I can take off quickly. I could see that trying to move the bike forward depending on the PAS system and controller, or am I way off on that and PAS requires a significant amount of pedal turn before kicking in?

 

[Peter.Bridge]

Thanks for all the replies so far.
I ended up getting that used bike for £550. Not an amazing bike and frame, though the plan was to just get something to test out ebiking on quickly and if I liked it, work on getting it into shape. I do like it and it should be good enough for my needs at the moment, though it'll be a bit of a project bike too.

Doesn't have a PAS fitted, thumb throttle only. Took it out last night, was pretty heavy on the throttle until I noticed the rear brake calliper (Hydraulic front and rear brakes, nothing special, Tektro. I could swap over my old Avid Juicy 5s, but one has half the lever snapped off and the other has the lever bent at an angle and to replace them you need to disassemble the entire cylinder, so maybe something I'll do later) was rubbing the disc pretty badly, so got that corrected. Had figured the hub motor was causing lots of friction on tiny inclines/the flat.
Took it out again tonight, 4 and a half mile cycle, lots of hill climbs, took some of the steeper hills (not the steepest, but fair inclines) and it has no problem getting up them with minimal pedalling. I could probably fit combined cleat/standard pedals and if my leg gives out, get up using one leg and cleats.

Regarding the battery, I measured a voltage drop of 1.7ish (could be .1-.2 off) from 41.8 (maybe 41.9) to 40.1 (maybe 40.2) on a 4.2 mile cycle. Using a slight bit of throttle on any minor incline and full throttle on the steeper hills. I'll probably have to take it out on a longer cycle (probably a day out) to see what condition the battery is in, but that doesn't seem terrible given that it held a charge of just under 42V after being charged up last night.

If you've any suggestions on maintenance, what to budget for to get it into better nick and so on, they'd be appreciated. I'll probably look into fitting a PAS, though maybe it's me but a bad PAS feels like it would potentially be more dangerous than a bad throttle, at lights when crossing roads I'll usually have one foot on the pedal, one on the ground and usually get the pedal moved up so I can take off quickly. I could see that trying to move the bike forward depending on the PAS system and controller, or am I way off on that and PAS requires a significant amount of pedal turn before kicking in?

Sounds like the battery is good, that's always a worry on second hand purchases. What you need is a dual 36/48 v sine wave KT controller/display/throttle/pas kit, at least 15 amp max, maybe 18 amp max. This will have the cadence sensor and you can set the throttle to behave in a UK legal way, ie twist and go up to 6 km/h and then you can use the throttle above that but need to be pedalling.

Something like https://topbikekit.com/t06ss-36v48v-kt-dual-motor-driving-brushless-sine-wave-controller-p-904.html

 

[Nealh]

Enjoy your moped , hope you have insurance for it . Let alone an SVA.

 

[saneagle]

The hub-motor shouldn't have any friction unless something is wrong. Do the wheels spin freely? What motor is it? What diameter is it?

 

[Mr. B Ikeman]

The hub-motor shouldn't have any friction unless something is wrong. Do the wheels spin freely? What motor is it? What diameter is it?

Wasn't the hub motor, back brake disc was rubbing up against the caliper as it wasn't aligned. Easy fix, loosen the bolts off, push the brake down and tighten it up again.
There's still some friction, though it seems to be entirely in the brakes and bearings. Wheels spin roughly as freely as on my old bike, back when it was in okay (but not perfect) working order. Will need to get some penetrating oil and lubricate things.

Enjoy your moped , hope you have insurance for it . Let alone an SVA.

A throttle feels much more natural to me. Maybe it's because I grew up riding motorcycles, but the first thing I do when things go wrong is stop operating

the throttle. This immediately stops power.
Maybe I'm mistaken, but do pedal assist systems not keep providing power for a short time after you stop pedalling? Only a half a second or so and if you're still working the pedals trying to get a bike under control, you're still applying power.
I suppose you could add a kill switch, but that's a positive action you have to take, thumb off throttle is simply stopping doing something, which is easier to drill into your head/muscle memory, which I would need to re-learn entirely with a PAS system. Though I'm still intent on fitting one.
But that's just my 0.02

Sounds like the battery is good, that's always a worry on second hand purchases. What you need is a dual 36/48 v sine wave KT controller/display/throttle/pas kit, at least 15 amp max, maybe 18 amp max. This will have the cadence sensor and you can set the throttle to behave in a UK legal way, ie twist and go up to 6 km/h and then you can use the throttle above that but need to be pedalling.

Something like https://topbikekit.com/t06ss-36v48v-kt-dual-motor-driving-brushless-sine-wave-controller-p-904.html

Good to hear the battery is good, will get looking into that ESC and PAS system. Good to hear the battery (probably) isn't wrecked too. Voltage was being read by the BMS and sent to the LCD so it's not a multimeter reading, but I'd hope the BMS can accurately read battery voltage.

 

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my bike cuts power soon as you stop pedaling tho bosch did make a motor called race that did have a over run when you stopped peddling, cant see why lol.£££££££

 

[Nealh]

PAS overide does/can occur with cheaper/crappy sp;eed control systems, never had over ride with any of my better KT systems or need for brake sensors.
.One reason why most crappy systems utilise brake kill switch's as std.

Twist and go aren't natural for pedal cycles as they have never needed them, for powered push bike use they are a carry over from two wheeled motor cycles which is what any powered two wheel pushbike without PAS is classed as .

Any E - push bike not operable by PAS is no longer a push bike under EAPC legislation and are classed as motor cycles and a whole lot of headaches should you injure or kill some one .

 

[chris_n]

You should buy electric scooter for UK in just 230 Pounds, here is the detailed comparison of Electric scooter vs E bikes

Totally illegal and SPAM!

 

[Mr. B Ikeman]

Pedal assist sensor arrived today, I'm glad I tested it out in the house rather than outdoors as it gives power to the motor when pedalling backwards as well as forwards. Better to find that out indoors than when getting the pedals rotated back so I can put my weight on them for taking off at lights.
PAS a cheap split disk ebay one, though I assume a dual hall sensor will register when the bike is being pedalled forwards?

However a throttle just feels safer, I don't want a motor kicking in when I've got assist set high but need to navigate between a parked car and a wall for example, which, with a throttle, I can easily and instantly change the amount of assist by just letting off the throttle.

Which has me thinking, is there any commercial product (I've done a bit of looking) that allows you to plug both a PAS and throttle in but will not allow the throttle to work unless the sensor registers pedalling. Basically a logical AND that converts the throttle into an analogue assistance selector switch as I rarely use the throttle alone, maybe 5% of the time and always when crossing roads so I can stand up on the pedals and keep good situational awareness. Other than that, I'll be pedalling and have managed hilly rides of 8-9 miles without any big issues, so throttle only may not be something I need, though a 'pseudothrottle' would work better for me than having a digital selection of 5 settings that I need to faff around with an LCD display to change.

So, does such a product exist? I imagine it would be legal as you can't add power unless you're pedalling.

If not, are there any standards on the voltages and digital protocols used for the throttle and assist sensor? If it's 5v or 3v3 I could maybe make a system (easily, not requiring logic level converters) myself using an arduino or pi pico.

 

[Nealh]

Generic speed control devices are on/ off with nil speed control between, one get max power all the time. Signal wire has about 1v on it and is simply activated by a magnet.
PAS setting has no effect on how the speed control device works.

 

[saneagle]

Pedal assist sensor arrived today, I'm glad I tested it out in the house rather than outdoors as it gives power to the motor when pedalling backwards as well as forwards. Better to find that out indoors than when getting the pedals rotated back so I can put my weight on them for taking off at lights.
PAS a cheap split disk ebay one, though I assume a dual hall sensor will register when the bike is being pedalled forwards?

Which has me thinking, is there any commercial product (I've done a bit of looking) that allows you to plug both a PAS and throttle in but will not allow the throttle to work unless the sensor registers pedalling. Basically a logical AND that converts the throttle into an analogue assistance selector switch as I rarely use the throttle alone, maybe 5% of the time and always when crossing roads so I can stand up on the pedals and keep good situational awareness. Other than that, I'll be pedalling and have managed hilly rides of 8-9 miles without any big issues, so throttle only may not be something I need, though a 'pseudothrottle' would work better for me than having a digital selection of 5 settings that I need to faff around with an LCD display to change.

So, does such a product exist? I imagine it would be legal as you can't add power unless you're pedalling.

You're describing how a KT controller works.

 

[Mr. B Ikeman]

Generic speed control devices are on/ off with nil speed control between, one get max power all the time. Signal wire has about 1v on it and is simply activated by a magnet.
PAS setting has no effect on how the speed control device works.

Thanks. I assume no commercial product exists where you can just plug in a throttle and PAS sensor in then feed the output to the throttle wire on the bike and have it so the throttle only works when the PAS sensor is registering pedalling? That would allow me to choose the amount of motor power very finely with the throttle, though should still be EAPC legal as I would just be setting the assistance amount and the throttle couldn't work (unless it was set up to work only as a walk assist) unless the pedals are being used. Seems like it would be a really useful piece of kit, the throttle on the bike allows for fairly fine adjustment and isn't as stop/go as simple pedal assist is.


If not I guess I'll have to test it with a multimeter and logic analyzer, maybe bring the bike round to a mate's place and use his oscilloacope if it's an alalogue signal. If I can get that worked out I can probably use a microcontroller to lock the throttle out until the PAS is activated. Expensive cadance (and especially torque) sensors are probably on par, maybe better than a throttle, though the cheap £15 one I got is an absolute widowmaker.

Feels like the EAPC regs were drafted by someone who has never used either a motorcycle, or ebike and have just come to the assumptive conclusion that throttles are bad because they seem too much like a motor vehicle, changing PAS settings (the LCD on the bike goes from 0 to 5) would require me to take my hand off the bar partially. Whereas a thumb or twist throttle still allows me to have full control and easy reach to the brakes, so having a system that meets the requirements, but is still safe and doesn't require purchasing a torque sensor and the tools to pull out the spindle on my bike is something I'd appreciate, even if I need to make it myself.

PS: Thanks for convincing me to not go for a 1kw+ motor, this geared hub motor definitely helps out and I'm probably getting better exercise too because I don't have a massive weight on the back wheel.