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The eBike thread

13468938

Comments

  • Registered Users, Registered Users 2 Posts: 837 ✭✭✭BarryM


    I meant to reply to this post but I forgot all about it.

    What kind of upgrade are you looking for? more power ?

    Chances are if you want more power you will have to upgrade the battery and the controller and motor so you would probably be looking at purchasing a whole new kit.

    Yes, power upgrade. Suspected what you said might be the case. Bummer.

    Thanks for the info.


  • Registered Users, Registered Users 2 Posts: 1,153 ✭✭✭Joe1919


    unkel wrote: »
    Yes they have a BMS:

    Linky

    Hi. Some of the cheaper batteries have a BMS with no balance function. I suspect that this may be in your case as there is no mention of a balance function in the e bay link. I had similar experience. The battery will not charge fully as when battery becomes unbalanced, some cells will have high voltage and will shut off BMS before charging is complete.
    If you have good technical experience and the time, these batteries can be manually balanced (say every 3 to 6 months or so) by bleeding down the high cells and/or individually charging up the low cells (e.g.with modified 5 volt mobile phone charger). However, this involves opening the battery wrapping and is usually not recommended due to safety reasons.


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    I reckon that must be it Joe. Probably my own fault in hooking the single packs up and discharging them too quickly (leading to some cells voltages going below others)

    Still with 40.3V and the packs now in parallel (8Ah) it is more than plenty for my range needs. And unlike an EV, should the batteries be completely depleted I can still peddle home :D


  • Registered Users, Registered Users 2 Posts: 1,153 ✭✭✭Joe1919


    unkel wrote: »
    I reckon that must be it Joe. Probably my own fault in hooking the single packs up and discharging them too quickly (leading to some cells voltages going below others)

    Still with 40.3V and the packs now in parallel (8Ah) it is more than plenty for my range needs. And unlike an EV, should the batteries be completely depleted I can still peddle home :D

    It may not be your fault. Sometime batteries that are on offer (cheap) have been in storage for a while and may already be out of balance when sold. Batteries are best fresh.

    A battery that is cutting off at 40.3 will have a substantial loss of capacity. Under normal circumstances, the 36v battery is charged at constant current (e.g 2amps) until it reaches 42 v. The battery continues to be charged at 42v until the charging current drops to a fraction of an amp. This is often called the constant voltage or saturation phase. A battery which terminates its charge at 40.3V due to BMS shut off will not reach the constant voltage/saturation stage and will lose a lot of capacity.


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    I wouldn't call it a substantial loss of capacity though. Roughly still at 80%

    Not too bad for a 36V 8Ah pack that I bought for €90 including shipping :)

    You're right that the batteries more than likely have been sitting in storage for some time. These are the packs that went into the hoverboards / electric scooters that were the big Christmas present hit last year and the year before. It's (just) more profitable to sell these overstock packs as is than to dismantle them and sell individual cells I guess.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Time to move to LiPo !

    You'd make a 20 Ah 36 v pack quite cheap, you'd have to buy a RC style balance charger and balance leads and PSU though + cell voltage monitors, or just buy proper battery from em3ev, he builds his own and not your cheap junk.


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    or just buy proper battery from em3ev, he builds his own and not your cheap junk.

    I had a look at the prices on his website. He knows how to charge.

    My packs are fine for my needs. Cheap and cheerful!


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    unkel wrote: »
    I had a look at the prices on his website. He knows how to charge.

    My packs are fine for my needs. Cheap and cheerful!

    They all know how to charge and you get what you pay for and his reputation on endless sphere is excellent.

    You pay for good quality or a bit less for not so good quality.

    Besides, once you get your head around using LiPo, you'll never look back.

    https://hobbyking.com/en_us/turnigy-5000mah-6s-20c-lipo-pack-w-xt-90.html

    4 of these for 44v and 10 ah would cost 173 euro's ex shipping.

    20 C discharge 2 C charge, charge it at 20 amps in 30 mins lol :D

    Bunch of 30 amp anderson connectors for dead easy connecting.


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    Update: for the craic I put a power meter between battery and controller. Turns out my 500W motor actually produces nearly 1kW :eek: :D:p

    No wonder that tiny battery pack could only hack that for 15-20s, that was discharging at 23A or nearly 6C :eek: :eek: :eek:

    Bike is great for taking the dog out for some serious exercise. She's lost some weight and she is well fit now (I'm not) :p


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    unkel wrote: »
    Update: for the craic I put a power meter between battery and controller. Turns out my 500W motor actually produces nearly 1kW :eek: :D:p

    No wonder that tiny battery pack could only hack that for 15-20s, that was discharging at 23A or nearly 6C :eek: :eek: :eek:

    Bike is great for taking the dog out for some serious exercise. She's lost some weight and she is well fit now (I'm not) :p

    No way you don't take the dog for a walk with you on the bike ? :eek:

    The motor isn't producing 1 Kw , that's what's being pulled from the battery. The motor simulator is the place to go to find out what maybe going to the motor.

    Now imagine 5 Kw ? :eek: :D


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  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    No way you don't take the dog for a walk with you on the bike ? :eek:

    Dog off the lead by the canal or in the park.
    The motor isn't producing 1 Kw , that's what's being pulled from the battery.

    So where is that 1kW going then if not to the motor? ;):p


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    unkel wrote: »
    Dog off the lead by the canal or in the park.



    So where is that 1kW going then if not to the motor? ;):p

    You're probably loosing about 30% due to inefficiency. But go to the ebikes.ca motor simulator, it's pretty cool to mess around with.

    Actually I'll play around with it, so your setup is what 20 amp controller and 36 Volts ?


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Crap, I can't remember what wind that motor is, so many motors these days but I remember the Chaps on endless-sphere knew the motor specs and compared it to a nine-continent and I can't remember which one.

    But that's actually about 828 watts, 36V x 23 amps :D


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    You're probably loosing about 30% due to inefficiency. But go to the ebikes.ca motor simulator, it's pretty cool to mess around with.

    Actually I'll play around with it, so your setup is what 20 amp controller and 36 Volts ?

    I very much doubt there is 30% loss to inefficiency. But let's say 20% loss (I put a few figures into that site you mention and all combos I tried had 80% or higher efficiency). I saw 930W, so that effectively means 750W which is less than 20A controller * 40V battery, so well in spec.

    Interestingly that is enough to give me a Vmax on the flat of 30-35km/h but it would not propel me up a long steep hill. I guess you would need 2-3kW for that :D


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    unkel wrote: »
    I very much doubt there is 30% loss to inefficiency. But let's say 20% loss (I put a few figures into that site you mention and all combos I tried had 80% or higher efficiency). I saw 930W, so that effectively means 750W which is less than 20A controller * 40V battery, so well in spec.

    Interestingly that is enough to give me a Vmax on the flat of 30-35km/h but it would not propel me up a long steep hill. I guess you would need 2-3kW for that :D

    Well it's not going to be accurate because we need to know the actual motor specs, lots of the Chinese motors are clones but we need to know the windings etc but yes you could loose 30 % depending on terrain too , geared hubs are more efficient but on hills you could loose much more than 30%.


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    Mostly flat here in Lucan! Apart from the climb from the village up to the N4. Must try that sometime. I'd say the motor won't be able to pull me up. Me + bike >125kg

    Anyway, I'm glad I didn't go for the 250W motor kit. That would not have been adequate for me even on the flat. With the current setup it also effortlessly drove at speed (>20km/h) through a field of long wet grass.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    unkel wrote: »
    Mostly flat here in Lucan! Apart from the climb from the village up to the N4. Must try that sometime. I'd say the motor won't be able to pull me up. Me + bike >125kg

    Anyway, I'm glad I didn't go for the 250W motor kit. That would not have been adequate for me even on the flat. With the current setup it also effortlessly drove at speed (>20km/h) through a field of long wet grass.

    Yes, you see now why the "legal" ebikes are pulling over 700 watts ?

    Chain drives are more efficient though for hills.

    Hubs with power are great though , geared hub at 2 Kw is brilliant, just have to watch the really slow steep trails.


  • Registered Users, Registered Users 2 Posts: 453 ✭✭nokiatom


    @nokiatom , Tell me, what was the outcome of the tests I asked you to do, I forget now.

    Still can't remember if it sounds more like your battery or not.
    it appears to be the battery. when i took the battery off the bike it showed a date of 2013. the battery is fully charged and getting a reading of 31.5v. I didnt realise they are expensive to buy...approx 200 euro from China including DHL delivery. Found a crowd here in Ireland that refurbishes them....they are charging 300 euro for my size of battery!!


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    nokiatom wrote: »
    it appears to be the battery. when i took the battery off the bike it showed a date of 2013. the battery is fully charged and getting a reading of 31.5v. I didnt realise they are expensive to buy...approx 200 euro from China including DHL delivery. Found a crowd here in Ireland that refurbishes them....they are charging 300 euro for my size of battery!!

    The batteries are expensive but compared to running a car it's nothing if you have to spend 500 Euro's every 5 years.

    Electric bike also encourage people to go out and put some effort into cycling, this has tremendous health benefits.

    Your battery is 6 years old, you got your moneys worth.

    My advice now is get a good one from em3ev, take pics and email them and tell them this is what you want/need in order to fit your existing bike or you might have to do some simple rewiring.

    You might find good quality batteries elsewhere but I do not know where that has this level of good reputation, you could go to the endless-sphere website and ask People there. But I do know there are a lot of dodgy sellers in Europe bringing in Dirt Chinese made batteries and selling for well above their price instead of selling the good quality Chinese batteries and selling them at a decent price. Be warned and shop where recommended or you could find yourself with a crap battery.

    Do not use LiFeP04 for an Ebike, it has good life cycle but it's too large and heavy for ebike use.

    Can you post a pic of your bike and battery ?


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  • Registered Users Posts: 928 ✭✭✭Utter Consternation


    I've been looking at getting an ebike and saw this. I'm looking at this or trying to get something similar because i want a bike that is step through and has a forked kick stand which would hold it upright as i'm loading a child into a child seat. I've dodgy knees and poor balance so i'm thinking of supplementing my daily commute with an electric some days to take the pressure off. It seems very reasonably proced.

    I've a question about the power of this. It has a 250W brushless Bafang geared hub motor with 80 Nm of torque and 5:1 planetary gear reduction. Is it adequate to give you enough power to assist you going up a hill?

    The weight of the bike itself is 29.5kg and i weigh just under 12 stone.

    If you're going 25kmph do you have to be pedaling that quick also? There's only the one gear on this bike.

    I don't want to be stuck with a pig of a bike.


  • Registered Users, Registered Users 2 Posts: 31,138 ✭✭✭✭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.


  • Registered Users, Registered Users 2 Posts: 12,566 ✭✭✭✭Calahonda52


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

    “I can’t pay my staff or mortgage with instagram likes”.



  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Registered Users, Registered Users 2 Posts: 837 ✭✭✭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......


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


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  • Registered Users, Registered Users 2 Posts: 31,138 ✭✭✭✭Lumen


    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.


  • Registered Users, Registered Users 2 Posts: 12,566 ✭✭✭✭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/

    “I can’t pay my staff or mortgage with instagram likes”.



  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Registered Users, Registered Users 2 Posts: 837 ✭✭✭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.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


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  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    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


  • Registered Users, Registered Users 2 Posts: 837 ✭✭✭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?


  • Registered Users, Registered Users 2 Posts: 837 ✭✭✭BarryM


    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.


  • Registered Users Posts: 928 ✭✭✭Utter Consternation


    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.


  • Registered Users, Registered Users 2 Posts: 298 ✭✭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.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    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 :D


  • Registered Users Posts: 928 ✭✭✭Utter Consternation


    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??


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  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Registered Users, Registered Users 2 Posts: 1,153 ✭✭✭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

    Bike-Europe-New-EN-15194_NEW-558x420.jpg

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


  • Registered Users, Registered Users 2 Posts: 3,397 ✭✭✭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/


  • Registered Users, Registered Users 2 Posts: 1,153 ✭✭✭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.


  • Registered Users, Registered Users 2 Posts: 298 ✭✭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.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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.


  • Registered Users, Registered Users 2 Posts: 23,656 ✭✭✭✭ted1



    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


  • Registered Users, Registered Users 2 Posts: 65,717 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    xckjoo wrote: »
    Yea, “250 watts” my tuchus!

    Nice to see Micah is throwing some Yiddisch at it :D


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    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 .......


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  • Registered Users, Registered Users 2 Posts: 23,656 ✭✭✭✭ted1


    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.


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