October 21, 20241 yr I have a rear drive motor e bike but it can't get me up some hills. I'm 100kg without much stamina. I have seen on youtube some of the electric mountain bikes in high gears going up pretty steep muddy hills. I'm not planning on going off road but I'd like to be able to get up steep ish hills without much effort, even if it is slowly. I've been thinking to get one of those ebikes with a bosch motor because the bosch motors and their torque are stated on that website, and these bikes say which motor is on them. So I'm wondering with my weight how many NM of torque I will need on one of these motors to get up hills easily? Or even on other motors.
October 21, 20241 yr I have a rear drive motor e bike but it can't get me up some hills. I'm 100kg without much stamina. I have seen on youtube some of the electric mountain bikes in high gears going up pretty steep muddy hills. I'm not planning on going off road but I'd like to be able to get up steep ish hills without much effort, even if it is slowly. I've been thinking to get one of those ebikes with a bosch motor because the bosch motors and their torque are stated on that website, and these bikes say which motor is on them. So I'm wondering with my weight how many NM of torque I will need on one of these motors to get up hills easily? Or even on other motors. Post details of what exactly you already have, motor, controller and battery, so that we can propose options. You need more power, which doesn't necessarily mean you need a new motor. It's not the motor that determines the power you get, it's the controller, and the battery needs to be able to provide the power. In some cases, you can get what you need with what you have for no additional cost.
October 21, 20241 yr Author Post details of what exactly you already have, motor, controller and battery, so that we can propose options. You need more power, which doesn't necessarily mean you need a new motor. It's not the motor that determines the power you get, it's the controller, and the battery needs to be able to provide the power. In some cases, you can get what you need with what you have for no additional cost. The bike is an ADO AIR 20.
October 22, 20241 yr Just so we get an idea of the gradient , could you say which hill you are struggling with at the minute ? We can check how steep it is and how much power you would need to get up
October 22, 20241 yr THIS? Which version?? Oh it's single gear ! Won't help with steep hills ! Some info here https://www.reddit.com/r/ebikes/s/ap9VdXiT70 It doesn't look an ideal choice for a 100kg rider with limited stamina in hilly areas tbh Maybe try a shunt mod to the controller ? Edited October 22, 20241 yr by Peter.Bridge
October 22, 20241 yr I suspect the fact that it has a torque sensor and you say you have little stamina that is the problem. A Bosch motor won't solve that problem. Also as [mention=39093]Peter.Bridge[/mention] said, single gear doesn't help either . Edited October 22, 20241 yr by chris_n
October 22, 20241 yr Author I suspect the fact that it has a torque sensor and you say you have little stamina that is the problem. A Bosch motor won't solve that problem. Also as [mention=39093]Peter.Bridge[/mention] said, single gear doesn't help either . I thought a mid drive motor with gears would solve the problem if it has high enough torque like 70+ NM. Or would that still be a struggle to get up hills?
October 22, 20241 yr Author Just so we get an idea of the gradient , could you say which hill you are struggling with at the minute ? We can check how steep it is and how much power you would need to get up I get to around this point on this hill before I stop usually. https://www.google.com/maps/@51.4806075,0.0035728,3a,75y,146.35h,69.53t/data=!3m7!1e1!3m5!1sgLr-aeVj_NHyyEp4QTzNYw!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DgLr-aeVj_NHyyEp4QTzNYw%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D321.1282%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656?coh=205409&entry=ttu&g_ep=EgoyMDI0MTAxNi4wIKXMDSoASAFQAw%3D%3D
October 22, 20241 yr Folders are designed to be small and foldable. They are not powerful machines. Single gear on hills is a disaster.
October 22, 20241 yr OK just over 10% gradient for a quarter of a mile. There's lots of ebikes that will get a 100kg rider with limited stamina up that. The problem with a torque sensor is that the power that a motor produces is proportional to your pedalling effort - so the less pedalling effort you put in, the less power the motor supplies. I think you would be better off with a cadence sensor, that supplies the power if you are pedalling, irrespective of how much effort you a re putting in. Also single speed will limit the pedalling effort that you are putting in. You could get a Bosch motored mountain bike, but they usually have torque sensors, and are quite expensive to buy and maintain- seems a bit over the top for your requirements and you still have the torque sensor to "overcome". Woosh and Wisper do a range of ebikes that I think would cope with that sort of hill e.g https://wooshbikes.co.uk/?santana3 or if you wanted something cheap and cheerful https://www.electricscooterslondon.com/collections/electric-bikes/products/eleglide-m2-electric-mountain-bike?variant=44804086038752 Or if you wanted a cheap, nearly new , second hand bargain with the super powerful, high torque Aikema motor https://www.facebook.com/marketplace/item/1192161748484187/ Edited October 22, 20241 yr by Peter.Bridge
October 22, 20241 yr I thought a mid drive motor with gears would solve the problem if it has high enough torque like 70+ NM. Or would that still be a struggle to get up hills? To get full power you need to be pushing fairly hard on the pedals. Having said that it would get you up that hill relatively easily because of the gears. It depends really why you want a bike, if you want to improve your stamina then a torque sensor could be the way to go. If when you first get the bike you need full power in say 3rd gear as your fitness improves maybe you go up in 4th or 5th, then you find you can get up in a lower power level etc.
October 22, 20241 yr I thought a mid drive motor with gears would solve the problem if it has high enough torque like 70+ NM. Or would that still be a struggle to get up hills? A mid-drive torque sensor bike still requires some input from the rider, but with the highest torque ones on their highest assistance level in the lowest gear you will not struggle. The rider input demanded is very low. 70Nm will be fine, even more gives you margin. The worst that can happen is that you buy a bike with say 9 gears, and you feel the need for an even lower gear. That is easily solved by swapping to 10 or 11 speed. I swapped my 11-36 9 speed for 11-51 11 speed and there is nothing I cannot climb. For reassurance, hire a bike and go ride a big hill. It might cost £50 or £70 , but you will know the answer! It is not surprising that a single speed, torque sensor hub motor bike does not do what you need. A chunky rear hub, cadence sensor and gears might be enough, but many off the shelf bikes might not be enough.
October 22, 20241 yr The way "power" impacts on hill climbing is the speed you get up them, the work in climbing is achieved by the "torque" developed at the rear wheel. It does typically follow that the more power available tends to also come with higher torque, but as said in respect to climbing it is torque that climbs, power that impacts how quickly you climb. Hub motors don't share the selectable gearing that bikes can have, here the use of a crank motor can. The crank drive motor's torque can be multiplied by the gearing the bike can feature, just as with a pedal cycle. In that respect the crank drive motor can have an advantage over the same powered hub drive.
October 22, 20241 yr So - for the AKM128 (which I think the Wisper 705 and 905 use) with a max 17 amp controller (which I think the Wispers are set to) would get up a 100kg rider up a 10% hill easily with only 50 watts of pedalling power
October 22, 20241 yr Oh it's single gear ! Won't help with steep hills ! Some info here https://www.reddit.com/r/ebikes/s/ap9VdXiT70 It doesn't look an ideal choice for a 100kg rider with limited stamina in hilly areas tbh Maybe try a shunt mod to the controller ? +1 try the shunt mod first.. link removed.. google for a better example of the shunt mod.. and its implications. Edited October 23, 20241 yr by thelarkbox
October 22, 20241 yr The bike is an ADO AIR 20. That's not enough. This is what I said: "Post details of what exactly you already have, motor, controller and battery, so that we can propose options." If you're not capable of finding out that stuff, you're not capable of changing any motor.
October 22, 20241 yr I have a rear drive motor e bike but it can't get me up some hills. I'm 100kg without much stamina... The bike is an ADO AIR 20. Even fit people have trouble trying to get that up hills - belt drive and no gears and a torque sensor. It's the worst possible combination IMO.
October 22, 20241 yr Behold the majestic perfection of my easy to pedal, legal 720W hill devouring 36V BBS01B cadence sensored mid-drive 20" wheeled folding bike conversion and despair... for it will never be yours.... (unless you assemble your own). Quite easy to assemblate - my battery is on the pannier rack: It hits the 25kph limit faster at my Level 9, which is set to 20A. Tested climbing steep hills dragging a combined weight of over 180kg (bike trailer + cargo + me + bike), and that was when the controller was limited to 15A. With 52T > 32T = 32.5 gear inches on my bike. Part of one of those hills: I often pass by and laugh at resting non-electrical cylists defeated by this hill. However, progress was slow and not easy with that weight. 55kg lighter was easy. I have increased the current limit of the controller to 20A since. p.s. If you decide to get a BBS01B, check that the controller is fully programmable before you buy. And buy a largebattery to better vanquish hills. Don't buy a BBS01B which isn't fully programmable - mine was rubbish prior to programming, and I almost sent it back. https://edrivenet.com/bafang-programming/ https://www.bafangers.com/en/bafang-central-motor-programming-guide/ Edited October 22, 20241 yr by guerney
October 22, 20241 yr That guys method looks very dubious to me. The shunt is a resistance device made of wire of a known resistance. The voltage drop across the shunt caused by the current flowing through the shunt is used by the controller to calculate and limit how much current is passed through the controller to the motor. First he joins all the three shunts in that controller together, and then he plasters the whole length of the shunt wires with a massive glob of solder. That shunt is now not a shunt at all. It is now a very low resistance. Other shunt mod videos show a small part of the shunt being coated with solder to lower the shunt resistance just a bit. I doubt that the mosfets would last long if there were not 15 of them in that device. I reckon the only thing limiting power in that bike is the battery overload protection - or the mosfets blowing. That video is totally misleading for anybody on this forum, and what he does is unsafe for the controllers we use. It would be better not to show it. Instead, you could describe how to do it properly and safely, or find a video that explains everything, or make your own one and post it.
October 22, 20241 yr That video is totally misleading for anybody on this forum, and what he does is unsafe for the controllers we use. It would be better not to show it. Instead, you could describe how to do it properly and safely, or find a video that explains everything, or make your own one and post it. Yes - I agree. It isn't my video. That is why I made my remarks. The video is misleading and seriously wrong. It needs taking down.
October 22, 20241 yr https://www.youtube.com/watch?v=t3qDZxxzU8k:1 they need a paki shop and a burger van
October 23, 20241 yr Yes - I agree. It isn't my video. That is why I made my remarks. The video is misleading and seriously wrong. It needs taking down. my bad for the vid, i had seen it linked elsewhere as an example and when it was prominent in the google search results i lifted the link.. I probably should have watched it through first.. whoops.. will remove now.
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.