The eBike thread

Lumen

So 75+30+25 (for child+seat?)=130kg.

If the motor really outputs 250W at the speed you want to go at, and you produce a modest 100W through pedalling, that gives you a power to weight ratio of 2.7 W/kg.

This is about half the power to weight of a WorldTour racing cyclist, a freak of nature in perfect physical condition. In other words, plenty.

The question is whether that power output is realistic.

Calahonda52

Don't know why the OP says only one gear: the back looks like having a derailleur

https://cleantechnica.com/2019/08/22/the-1299-radrunner-by-rad-power-bikes-redefines-the-electric-utility-bike/


Complementing the 750 watt Bafang motor, a single-speed drivetrain makes riding the RadRunner a breeze. Just get on and pedal. When a lower gear would normally be needed, the electric motor steps in to fill the gap with four levels of pedal assist and a throttle to really get things moving.

So if it is really pumping out 750 watts or at least sucking it from the battery then it will have decent power if the 80 nm torque is to be believed, however if it has been reduced to 250 watts for Europe then I would run a mile. 250 watts is not enough not for a hub motor , chain drive might be just about do-a-ble but remember, the big ebike motor manufacturers such as Bosch, Panasonic etc are running at least 700+ watts the limitation is the acceleration and speed and this is the most important limits for "safety" as this is the test that gives them their certification, if the test included real power calculations the ebike market will die very quickly if People have to have real 250 watt motors.

So I would say without testing the bike, especially with no form of gearing then get an ebike kit yourself and put it on an existing bike.

The Bafang BBSHD or even the BBS02 motor would give good performance.

Definitely test out the bike, preferably with some hills. Or try get some kind of review from a ebike forum from People that have real experience with the bike.

BarryM

Is it 250 or 750?

I think, but maybe I'm misinformed, that 750 is not street legal in the EU?

I note that the NL version is 250, the US version is 750.

Is it a US originating product?

Surely a kit is a bit OTT? Unless you have a) a suitable bike and b) the skills c) the time......

BarryM

BarryM wrote: »

Is it 250 or 750?

I think, but maybe I'm misinformed, that 750 is not street legal in the EU?

I note that the NL version is 250, the US version is 750.

Is it a US originating product?

Surely a kit is a bit OTT? Unless you have a) a suitable bike and b) the skills c) the time......

I could not tell you if it's been turned down to 250 watts and if it has I would not touch it, 250 watts is not much power for heavy bike + rider + Child.

There's no way to tell unless you actually take it for a spin, if you have flat terrain then 250 watts might, just might help, if you got hills forget it but it would seem to be a 750 watt motor and could just, if you're lucky have a 250 watt sticker on it, that's the way the likes of Bosch and Panasonic do it etc.

If it's the full 750 watts then this is a different story, could even pull more power but I would not worry about power, the only thing that gets the EN certification for electric bikes is the limited acceleration and top speed if power were measured then most ebikes would not exist in Europe.

A kit is not excessive, usually you can build a far higher power bike for trails , hills off road through woods etc where you need this power. However you don't have to go nuts and can build one that meets your needs. A kit can be installed on an existing bike and can be plug and play, anyone with basic bicycle mechanical knowledge and someone with basic electrical knowledge can install it no problem.

Lumen

Calahonda52 wrote: »

Don't know why the OP says only one gear: the back looks like having a derailleur

I think it's just a chain tensioner.

Calahonda52

Lumen wrote: »

I think it's just a chain tensioner.

Correct
.
the single-speed drivetrain is reliable and quiet with a chain tensioner and alloy chainring guide to protect your pants or skirt clean while reducing drops

https://electricbikereview.com/rad-power-bikes/radrunner-eu-version/

It's just hard to know because it still stated 80 Nm torque, now that might sound a lot but as speed increases torque reduces and in a fixed gear hub motor on hills that could be an issue especially considering the bike itself has no gearing.

I would estimate that the bike is the same as the non e.u version but just with a 2500 watt sticker, could be wrong, if it really is 250 watts walk away.

The wheels are in my opinion too thick.

One advantage though of the smaller wheel diameter is that you get more torque than from a 26 inch wheel and larger.

The bike really needs to be tested before buying and remember hills are a whole different ball game.

BarryM

I have a 250W trike. I live in deepest rural Ireland. I can manage most of the hills by judicious riding/pedalling/planning. It has 5 speed gear, and three power options. The main problem is keeping up the speed when making a turn on a slope.

I bought this model for the reasons mentioned by the OP, low cross bar, my brother in law has a 'fat wheel' version of the same trike, it has a 'double' cross bar but his arthritic knees make getting on and off tricky. I was informed by the producer (Jorvik) that >250W is not street legal (in the UK I presume), that is why I asked the question(s) following the OP's question. In fact I am not sure that my brother in law's model is street legal, it is marketed .as 'off road'

This thread is very useful, even if it bit 'techie' - typically the suggestion of a kit for an existing bike is probably more than (most?) people on here could either manage or want to do.

I am not a luddite, but if we are to increase the use of ecological modes of transport we might need to make suggestions that most readers can appreciate.

Keep up the good work everybody.

Just remember that 250 watts of " legal" power is not what gets ebikes their EN certification it's restricted speed and acceleration and the likes of Bosch, Panasonic are 750 watts and above in reality.

A 250 watt bike might be more like 500 watts + with just a 250 watt sticker.

Geared hub motors are great but they like power, Chain drives are better for lower power setups because when the motor starts to struggle you an get full torque again by dropping a gear or two, when a hub motor slows down under load it becomes inefficient.

Ebike kits are not that difficult to install certainly nothing like when I first started building them, I had the soldering iron out etc, you don't have to do this mostly today.

The bafang BBSHD should be all the power anyone needs.

I like my Bosch 2013 ebike but I wish it had more power and allowed a higher speed, sometimes you are fighting the point where the motor cuts in and out and it can be annoying, it would be nice it there was 5 more Kph allowed. The limits in Europe are too ridiculous !

Some will say the power of 50 Nm is plenty and it is for a lot of situations but for longer larger hills it can be very tough when your legs get tired because a throttle is not allowed and so you have to remain peddling. Not everyone wants to kill themselves peddling.

The current gen Bosch is up to 75 Nm but the best motors are made by Brose in Berlin and they are up to 120 Nm, they would be amazing.

The Brose ebikes are available in Haibike bikes but they will cost a penny.

unkel

BarryM wrote: »

This thread is very useful, even if it bit 'techie' - typically the suggestion of a kit for an existing bike is probably more than (most?) people on here could either manage

I'm by no means handy, but I found converting my bike pretty easy. I did the easiest conversion, a full kit which included a front wheel with built in motor. Replace the brakes and connect everything to the controller (plug and play) and that's it

BarryM

unkel wrote: »

I'm by no means handy, but I found converting my bike pretty easy. I did the easiest conversion, a full kit which included a front wheel with built in motor. Replace the brakes and connect everything to the controller (plug and play) and that's it

Grand, what make and model of (non electric?) bike did you have? How much did you spend?

BarryM

Deleted User wrote: »

Just remember that 250 watts of " legal" power is not what gets ebikes their EN certification it's restricted speed and acceleration and the likes of Bosch, Panasonic are 750 watts and above in reality.

A 250 watt bike might be more like 500 watts + with just a 250 watt sticker.

Are you saying a 250W motor is really 500 or 750? Who does the EN assessment?

Some will say the power of 50 Nm is plenty and it is for a lot of situations but for longer larger hills it can be very tough when your legs get tired because a throttle is not allowed and so you have to remain peddling. Not everyone wants to kill themselves peddling.

What do you mean by 'not allowed'? I have several a long hills in the vicinity and can manage them by a lower gear / increased power combination.

Utter Consternation

Deleted User wrote: »

Just remember that 250 watts of " legal" power is not what gets ebikes their EN certification it's restricted speed and acceleration and the likes of Bosch, Panasonic are 750 watts and above in reality.

A 250 watt bike might be more like 500 watts + with just a 250 watt sticker.

Geared hub motors are great but they like power, Chain drives are better for lower power setups because when the motor starts to struggle you an get full torque again by dropping a gear or two, when a hub motor slows down under load it becomes inefficient.

Ebike kits are not that difficult to install certainly nothing like when I first started building them, I had the soldering iron out etc, you don't have to do this mostly today.

The bafang BBSHD should be all the power anyone needs.

I like my Bosch 2013 ebike but I wish it had more power and allowed a higher speed, sometimes you are fighting the point where the motor cuts in and out and it can be annoying, it would be nice it there was 5 more Kph allowed. The limits in Europe are too ridiculous !

Some will say the power of 50 Nm is plenty and it is for a lot of situations but for longer larger hills it can be very tough when your legs get tired because a throttle is not allowed and so you have to remain peddling. Not everyone wants to kill themselves peddling.

The current gen Bosch is up to 75 Nm but the best motors are made by Brose in Berlin and they are up to 120 Nm, they would be amazing.

The Brose ebikes are available in Haibike bikes but they will cost a penny.

I have read online that the 250watt is actually the 750watt dressed down, but cannot confirm that.

I won't be doing any serious hills with this bike as is is to be used in Dublin CC but it is heavy and i don't want to be dragging it around the place.

Low Energy Eng

I'll post up detailed feedback of my build later but at the moment I can say I'm very happy with my 500w geared rear hub motor.
Had an average of 30km/hr on a 20km round trip last week.
One very steep long hill and it blitzed it.

BarryM

BarryM wrote: »

Are you saying a 250W motor is really 500 or 750? Who does the EN assessment?

For the likes of the Bosch/Panasonic and many other electric bikes that's exactly what I'm saying yes and they're perfectly legal as they have their EN 15194 certification.

BarryM wrote: »

What do you mean by 'not allowed'? I have several a long hills in the vicinity and can manage them by a lower gear / increased power combination.

I meant a throttle is not allowed on ebikes in Europe.

Low Energy Eng

Low Energy Eng wrote: »

I'll post up detailed feedback of my build later but at the moment I can say I'm very happy with my 500w geared rear hub motor.
Had an average of 30km/hr on a 20km round trip last week.
One very steep long hill and it blitzed it.

500 watt but probably a lot more to be honest.

You should put a watt meter on it out of curiosity.

Seemingly there is legislation being considered that would increase ebike power to 500 watts, in the U.S it's 750 watts and throttle is allowed but not in nanny E.U.

It makes sense to increase the power in the legislation because ebikes are already well above 500 watts anyway never mind 250 watts.

unkel

Deleted User wrote: »

500 watt but probably a lot more to be honest.

You should put a watt meter on it out of curiosity.

That's what I did. My 500W hub motor turned out to be 930W

Utter Consternation

Utter Consternation wrote: »

I have read online that the 250watt is actually the 750watt dressed down, but cannot confirm that.

I won't be doing any serious hills with this bike as is is to be used in Dublin CC but it is heavy and i don't want to be dragging it around the place.

I emailed them to question the power of the motor and got this:

The RadRunner as a single geared bike with a 250W motor on only 1 speed, maxes out at around a 15% incline.
It can handle small slopes but will struggle with steep slopes and starts to become uncomfortable to go up hills steeper than 15%.
We tested riding up on bridges here without any problems.

I think this should be ok for my daily commute from Tallaght into Dublin CC??

Utter Consternation

Utter Consternation wrote: »

I emailed them to question the power of the motor and got this:



I think this should be ok for my daily commute from Tallaght into Dublin CC??

If it can handle a 15% grade then it's more than 250 watts being pumped into the motor, but don't take their word for it, test it. If they won't allow you test it tell them where to go.

I will advise you to take it for a test drive to get a feel for it and test out the single gear setup because you might find yourself hardly able to peddle without motor where as a normal Ebike without motor and proper gearing you can ride almost as normal without motor power, I don't think you'll do that on this bike.

I wouldn't buy without testing because you may find it hard to sell or be offered a lot less.

Joe1919

In the link below, there is photos of special test jigs that are used to test and verify that the maximum continuous power is less than 250 W, (if bike is to comply with en15194 standard ).

https://www.bike-eu.com/laws-regulations/nieuws/2017/11/revised-en-15194-e-bike-safety-standard-implemented-10132012



PS. Maximum continuous power is not the same as maximum (peak) power

xckjoo

Joe1919 wrote: »

PS. Maximum continuous power is not the same as maximum (peak) power

This concept has puzzled me for a while so I decided to do a (small) bit of research. Looks like Max Continuous Power is a self-reported metric related to the safe operating power of the motor (i.e. a motor with a rating of 250W indicates that it is safe to operate at 250W for prolonged periods of time but could also potentially be safe to operate at higher power levels too). It's an interesting one from a legality point-of-view. Not sure how they'd ever enforce it.



Source: http://www.ebikeschool.com/myth-ebike-wattage/

Joe1919

xckjoo wrote: »

This concept has puzzled me for a while so I decided to do a (small) bit of research. Looks like Max Continuous Power is a self-reported metric related to the safe operating power of the motor (i.e. a motor with a rating of 250W indicates that it is safe to operate at 250W for prolonged periods of time but could also potentially be safe to operate at higher power levels too). It's an interesting one from a legality point-of-view. Not sure how they'd ever enforce it.

Source: http://www.ebikeschool.com/myth-ebike-wattage/

If you look at the photo, the rear wheel is engaging with a drum ( a sort of rolling road setup). Certainly, it seems to me to be a mechanical test in that its the mechanical output of the drive wheel that is measured (dynamometer?) rather than the voltage and current of the motor. I think the motor operation temperature is also measured and because it is kept low for safety reasons and continuous use , the motor is often rated much lower than in actual fact it is. i.e a high safety margin.

Of course the mechanical power should be equal to the electrical power input multiplied by the overall efficiency (including tyre efficiency?), but with an electric motor, the power input is governed by the load or brake resistance set for the rolling load.

Low Energy Eng

xckjoo wrote: »

This concept has puzzled me for a while so I decided to do a (small) bit of research. Looks like Max Continuous Power is a self-reported metric related to the safe operating power of the motor (i.e. a motor with a rating of 250W indicates that it is safe to operate at 250W for prolonged periods of time but could also potentially be safe to operate at higher power levels too). It's an interesting one from a legality point-of-view. Not sure how they'd ever enforce it.

Source: http://www.ebikeschool.com/myth-ebike-wattage/

Thanks, looks as though my 22A controller & 48v battery = 1056watts.
Seems to tally with what Mad Lad suggested.
Delighted.

This 250watt law is effectively like saying the law restricts cars to 2.5litre engines, some companies just tune that 2.5litre engine more powerfully.

Nobody actually cares in reality about power because it's acceleration and power limit that really only matter. This is what bureaucrats can't get through their thick useless skulls when they're being chauffeured around in their tax payer funded cars.

The speed limit is ridiculously and it should be 5 Km/hr higher because you find yourself fighting at the point of where the motor cuts out and can be irritating.

Take the Bosch 2013 motor for instance, I can guarntee it was providing full 700 or more watts wen I was climbing mount leinster and it was very tough at that, if anyone hasn't being up there it has 20% + grades in some parts, not going to do that with 250 watts, I guarantee it.

ted1

[Deleted User] wrote: »

Take the Bosch 2013 motor for instance, I can guarntee it was providing full 700 or more watts wen I was climbing mount leinster and it was very tough at that, if anyone hasn't being up there it has 20% + grades in some parts, not going to do that with 250 watts, I guarantee it.

That’s just a daft argument, the law is not going to make limits based on people cycling up mount Leinster.

I cycle over 20,000km a year and rarely find a gradient over 10% unless I go out specifically looking for one.
A quantifiable unit like Watts is ideal limitation, it puts a theoretical and physical limit on the power being outputted. If you want higher then get a motorbike.
The speed is fine. If you want to go faster get a regular bicycle, the majority of people I see in electric bikes don’t demonstrate good bike handling skills , and also have poor Road positioning

unkel

xckjoo wrote: »

Source: http://www.ebikeschool.com/myth-ebike-wattage/

Yea, “250 watts” my tuchus!

Nice to see Micah is throwing some Yiddisch at it

ted1

ted1 wrote: »

That’s just a daft argument, the law is not going to make limits based on people cycling up mount Leinster.

I cycle over 20,000km a year and rarely find a gradient over 10% unless I go out specifically looking for one.
A quantifiable unit like Watts is ideal limitation, it puts a theoretical and physical limit on the power being outputted. If you want higher then get a motorbike.
The speed is fine. If you want to go faster get a regular bicycle, the majority of people I see in electric bikes don’t demonstrate good bike handling skills , and also have poor Road positioning

No I think the speed limit is about 5 Km/h too low, power limits, well Bosch ate up to 75 Nm of torque and probably over 1 Kw of power at this stage.

The best of the ebike motors of course being Brose, made in Berlin, output a respectable 120 Nm of torque , my 2013 Bosch just 50 so yes it's plenty for most but sometimes more power would be nice when you are not in the form for peddling like mad. Grand for those riders who do it all day every day and weigh 60 Kg.

It would be interesting to see the power consumption of the Brose motor.

Regarding ebikers handling skills, well , just like non ebike riders and car drivers there are idiots everywhere, nothing will change that. Imagine People texting while driving on the motorway or browsing .......

ted1

[Deleted User] wrote: »

No I think the speed limit is about 5 Km/h too low, power limits, well Bosch ate up to 75 Nm of torque and probably over 1 Kw of power at this stage.

The best of the ebike motors of course being Brose, made in Berlin, output a respectable 120 Nm of torque , my 2013 Bosch just 50 so yes it's plenty for most but sometimes more power would be nice when you are not in the form for peddling like mad. Grand for those riders who do it all day every day and weigh 60 Kg.

It would be interesting to see the power consumption of the Brose motor.

Regarding ebikers handling skills, well , just like non ebike riders and car drivers there are idiots everywhere, nothing will change that. Imagine People texting while driving on the motorway or browsing .......

If you don’t want to pedal , get a motorbike.
The m 102kg and manage it everyday without an engine.

Regarding handling skills. The majority of people I pass in ebikes are not like regular car or bike users. They generally have poor road awareness and skills. It may be the demographic of being either extremely unfit ( good to see them getting exercise, I’m not knocking them ) or elderly and mightn’t have cycled in a while , 25kmh is a good top end.