Building my first ebike, would appreciate some advice
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The more amps you give it, the faster it goes up the hills. Simples! If you're not to heavy, 20 amps will be enough. If you've eaten too many pies 30 should do it.
Hi Thamosy,
To be honest I've always pedalled with the motor up hills so I couldn't give you a definitive answer until this morning.. when I didn't pedal!
The steepest hill I cycle up is so steep it would have me zig zagging across the road and lifting my front wheel with every stroke of the pedals before I had the motor, even in the car I eventually have to change down into first, if I take a run up (dangerous) I can get just up there in second without stalling but I have to time it just right..
Before I had the motor I'd have to stop at the top of the hill to catch my breath, my legs would be burning and I'd be wondering what the hell I was doing this for.. on my trip there's another two hills just ahead, not quite as severe as this though but they're still hard going.
Now I have the motor if I pedal with it I'm still a bit out of breath BUT according to my speedo I'm climbing the hill at around 15-17kph! While this does seem a little slow it's much better than the 4kph I was getting before the motor.. however thats with pedalling..
If I really go for it up any other steep hill where I'm standing on the pedals giving about 80% effort I can easily climb around 20-25kph - about as fast as most ebikes would go on the flat.
As an experiment this morning I tried the steep hill without pedalling and kept a close eye on the motor temperature.
d8veh is right, it's basically about how many amps you can put into the motor without frying it. Frying it WAS what I was most concerned about. All up weight with me on the bike is probably just under 135kgs, the controller is a 30Amp and the BMS is set for 30A continuous, 60A peak.
I approached the hill at full throttle.. with a short run up it I was probably doing about 35kph, the speed soon scrubs off though and the speed settled around 6-7kph. The motor was coping okay but I didn't really like the idea of the motor labouring so I pedalled gently for a couple of revolutions and the speed soon went to about 10-12kph, then stopped pedalling and my speed settled again to about 6kph. All the time the CA is reporting Watt/Hr consumption of just under 1500!
The motor heated up by about 20-25 deg C to about 45-50 (ambient temp at 8am this morning was 22 deg C according to the Cycle Analyst) This is what I was most worried about and the reason I went with the 10Turn motor despite Pauls recommendation of the 8T. When I get home which is uphill all the way, the motor temp is around 100degC, ambient temps of around 33-39degC depending.
It was an interesting experiment today, I normally pedal with the motor and it's amazing what a difference it makes I find the motor mainly needs help just to start moving, once it's about 5-10kph there is a surge of torque and it accelerates briskly up to 40kph eventually topping out around 45kph. On the flat I can do around 38-42Kph consuming 500-600 Watt/Hrs.
Shortly I will write up my experiences so far, but in short the kit has exceeded my expectations. However I also overspeced my setup, I should have gone with the 12Ah batteries (that bit smaller and lighter and most importantly.. easier to package!) It's also probably too fast, certainly on the dirt, my tyres are too skinny, there is no suspension and it's very tiring on the arms. On the road however it's an absolute dream, but again.. illegally fast and for that reason I couldn't recommend it.
I haven't tried programming the controller yet as the Cycle Analyst which sits on the handlebars is a much more refined solution and it's easier to setup parameters in that than it is to program the controller itself. I've had to speak to Paul from EM3EV and the guys at Eclipse Bikes to sort out a few niggles (I wired the BMS up incorrectly and thought I'd blown it but managed to disconnect it as soon as I smelt the burning circuit smell!) It all seems to be working okay now.
If you're still waiting for the motor kit to arrive I'd get on with building your battery pack, it took me quite a few tries to package it in the frame bag you see in the pictures, it was a very very tight fit and even now I'm not too happy with it. I've had to lay some thin plywood sheet to stop the cells from resting on each other. I though this would be most important off road as the cells may rub inside the bag and I don't want them getting damaged. Also I ended up building the pack for the bag, getting it wrong, almost frying the BMS and then building it the normal way (Eclipse kindly sent me lots of pictures of their build for reference), then breaking it down to fit into my frame bag. All in all I have spent about 9 hours building and rebuilding the battery..
Oh I also had problems with soldered connections, I had some bullet connectors on the battery - controller connection.. well needless to say I didn't do my side very well and ended up cutting them off and using a decent crimped connection.. I can do that properly!
I'll report back after my first full month.. but I can say that I have bought a better bike to put the kit on.. it's arriving next week ;-)
To be honest I've always pedalled with the motor up hills so I couldn't give you a definitive answer until this morning.. when I didn't pedal!
The steepest hill I cycle up is so steep it would have me zig zagging across the road and lifting my front wheel with every stroke of the pedals before I had the motor, even in the car I eventually have to change down into first, if I take a run up (dangerous) I can get just up there in second without stalling but I have to time it just right..
Before I had the motor I'd have to stop at the top of the hill to catch my breath, my legs would be burning and I'd be wondering what the hell I was doing this for.. on my trip there's another two hills just ahead, not quite as severe as this though but they're still hard going.
Now I have the motor if I pedal with it I'm still a bit out of breath BUT according to my speedo I'm climbing the hill at around 15-17kph! While this does seem a little slow it's much better than the 4kph I was getting before the motor.. however thats with pedalling..
If I really go for it up any other steep hill where I'm standing on the pedals giving about 80% effort I can easily climb around 20-25kph - about as fast as most ebikes would go on the flat.
As an experiment this morning I tried the steep hill without pedalling and kept a close eye on the motor temperature.
d8veh is right, it's basically about how many amps you can put into the motor without frying it. Frying it WAS what I was most concerned about. All up weight with me on the bike is probably just under 135kgs, the controller is a 30Amp and the BMS is set for 30A continuous, 60A peak.
I approached the hill at full throttle.. with a short run up it I was probably doing about 35kph, the speed soon scrubs off though and the speed settled around 6-7kph. The motor was coping okay but I didn't really like the idea of the motor labouring so I pedalled gently for a couple of revolutions and the speed soon went to about 10-12kph, then stopped pedalling and my speed settled again to about 6kph. All the time the CA is reporting Watt/Hr consumption of just under 1500!
The motor heated up by about 20-25 deg C to about 45-50 (ambient temp at 8am this morning was 22 deg C according to the Cycle Analyst) This is what I was most worried about and the reason I went with the 10Turn motor despite Pauls recommendation of the 8T. When I get home which is uphill all the way, the motor temp is around 100degC, ambient temps of around 33-39degC depending.
It was an interesting experiment today, I normally pedal with the motor and it's amazing what a difference it makes I find the motor mainly needs help just to start moving, once it's about 5-10kph there is a surge of torque and it accelerates briskly up to 40kph eventually topping out around 45kph. On the flat I can do around 38-42Kph consuming 500-600 Watt/Hrs.
Shortly I will write up my experiences so far, but in short the kit has exceeded my expectations. However I also overspeced my setup, I should have gone with the 12Ah batteries (that bit smaller and lighter and most importantly.. easier to package!) It's also probably too fast, certainly on the dirt, my tyres are too skinny, there is no suspension and it's very tiring on the arms. On the road however it's an absolute dream, but again.. illegally fast and for that reason I couldn't recommend it.
I haven't tried programming the controller yet as the Cycle Analyst which sits on the handlebars is a much more refined solution and it's easier to setup parameters in that than it is to program the controller itself. I've had to speak to Paul from EM3EV and the guys at Eclipse Bikes to sort out a few niggles (I wired the BMS up incorrectly and thought I'd blown it but managed to disconnect it as soon as I smelt the burning circuit smell!) It all seems to be working okay now.
If you're still waiting for the motor kit to arrive I'd get on with building your battery pack, it took me quite a few tries to package it in the frame bag you see in the pictures, it was a very very tight fit and even now I'm not too happy with it. I've had to lay some thin plywood sheet to stop the cells from resting on each other. I though this would be most important off road as the cells may rub inside the bag and I don't want them getting damaged. Also I ended up building the pack for the bag, getting it wrong, almost frying the BMS and then building it the normal way (Eclipse kindly sent me lots of pictures of their build for reference), then breaking it down to fit into my frame bag. All in all I have spent about 9 hours building and rebuilding the battery..
Oh I also had problems with soldered connections, I had some bullet connectors on the battery - controller connection.. well needless to say I didn't do my side very well and ended up cutting them off and using a decent crimped connection.. I can do that properly!
I'll report back after my first full month.. but I can say that I have bought a better bike to put the kit on.. it's arriving next week ;-)
For reference my commute stats according to the Cycle Analyst:
Distance ~30km
Watt/Hrs ~ 500
Watt/Hrs per km 17
Average speed 35km/h
Max speed 51km/h
Round trip time: 50mins
Amps used ~10A
Those stats cover going home yesterday, pedalling with little effort, and today I didn't pedal at all (well a handful of revolutions) so absolute worst case scenario.
Distance ~30km
Watt/Hrs ~ 500
Watt/Hrs per km 17
Average speed 35km/h
Max speed 51km/h
Round trip time: 50mins
Amps used ~10A
Those stats cover going home yesterday, pedalling with little effort, and today I didn't pedal at all (well a handful of revolutions) so absolute worst case scenario.
Thanks so much for writing that up. It’s VERY encouraging, especially your stats. I’ll be really interested to read your final report.
Because of those stats I’m going to delay my battery building until the winter since my present (old 36V) ones may well be okay for the present. I don’t think I’ve any hill that compares with the description of yours (although you didn’t say how long it was?). I’ll upgrade to 48V only if I need to. Also, it’s good to know that you think 12Ah would’ve been adequate, although because I’d like to opt for a pannier-style configuration I’m thinking more in terms of in terms of two 10Ah that I’d connect in parallel. After your experience though, maybe that would be well OTT.
To a future on top of the world ..... and still breathing!
Because of those stats I’m going to delay my battery building until the winter since my present (old 36V) ones may well be okay for the present. I don’t think I’ve any hill that compares with the description of yours (although you didn’t say how long it was?). I’ll upgrade to 48V only if I need to. Also, it’s good to know that you think 12Ah would’ve been adequate, although because I’d like to opt for a pannier-style configuration I’m thinking more in terms of in terms of two 10Ah that I’d connect in parallel. After your experience though, maybe that would be well OTT.
To a future on top of the world ..... and still breathing!
No problem, Thamosy, I'm happy to offer my thoughts.
The steepest hill is quite short, only 300-400m, but it's soooo steep if I wasn't feeling really up for it in the morning it would put me off cycling.. sad I know.. but some days I just didn't feel like it.
Once I get through town it's mainly downhill to the coast, however coming back I have to go up this hill, it's not a steep gradient but it's about 3km long and can get me to the lowest big cog on the front in places and one route in particular has heavy traffic (for here anyway).
Now I have the motor if I go full throttle my speed uphill is about 35km/h which is not much slower than the cars, it's a 50kph limit.
On fairly shallow gradients there doesn't seem to be much difference whether you pedal or not, obviously if you pedal the battery will go that bit further but when you're putting 1000 watts into the motor your 100-200 watt effort doesn't make that much difference.
Cruising on the flat around 38-42kph I'm drawing about 500/600 watts at 25-30% throttle. I tend to use the pulse and glide method, full throttle starts then freewheel for as long as I can, pedal on the flats to keep the speed up or if it's a bit hilly then I use the motor.
If I were you I would stick with your 36V battery, if it can supply a decent amount of amps (30 odd) then you will not notice a difference in hill climbing power, the 48V battery will just give you a higher top speed, but in my opinion my bike is too fast at 48V. Also I wish I'd bought the 12Ah batteries, as they are lighter (marginally) and I could package them in the frame bag that bit better, I use 10Ah per day and thats worst case scenario.
I'm seriously considering downgrading to 36V (means new BMS and charger) or going the whole hog buying more batteries say 72V and converting a registered and legal motorbike. I'm also looking to add rear panniers to make the bike that bit more practical as I'm using it a lot more often.
As a motorcycle rider, I'd recommend you put the batteries inside the frame rather than over the back wheel, especially if you have steep hills. Though if you can mount them low at the back you'll probably not notice too much. I have no experience with rear mounted batteries.
On one of my first runs one of the connections came loose on the battery (my dodgy wiring effort) and I had to cycle home, uphill all the way. With 8Kg of battery and 4kg of motor the bike felt like a total dog. Once you've added your ebike kit you do not want to run out of juice, it's doable but no longer a pleasant ride.
If you are an experienced rider and comfortable in traffic then I'd recommend a top speed of 30-35km/h any more is asking for trouble from the authorities.
Anyway thats my rambling over.. I just want to make one more point.. and it's very important.. when I first set out building the bike my concern was simply to get from A to B as fast and easily as possible. Now I can do that I find I take more scenic routes to work and absolute top speed is not that important, of course it's nice, but I simply enjoy taking routes I'd have previously thought were too difficult or slow and seeing new places. So my commuter machine is going to transform into a touring machine, I'll buy some panniers and a lock and make it that bit more practical.
The steepest hill is quite short, only 300-400m, but it's soooo steep if I wasn't feeling really up for it in the morning it would put me off cycling.. sad I know.. but some days I just didn't feel like it.
Once I get through town it's mainly downhill to the coast, however coming back I have to go up this hill, it's not a steep gradient but it's about 3km long and can get me to the lowest big cog on the front in places and one route in particular has heavy traffic (for here anyway).
Now I have the motor if I go full throttle my speed uphill is about 35km/h which is not much slower than the cars, it's a 50kph limit.
On fairly shallow gradients there doesn't seem to be much difference whether you pedal or not, obviously if you pedal the battery will go that bit further but when you're putting 1000 watts into the motor your 100-200 watt effort doesn't make that much difference.
Cruising on the flat around 38-42kph I'm drawing about 500/600 watts at 25-30% throttle. I tend to use the pulse and glide method, full throttle starts then freewheel for as long as I can, pedal on the flats to keep the speed up or if it's a bit hilly then I use the motor.
If I were you I would stick with your 36V battery, if it can supply a decent amount of amps (30 odd) then you will not notice a difference in hill climbing power, the 48V battery will just give you a higher top speed, but in my opinion my bike is too fast at 48V. Also I wish I'd bought the 12Ah batteries, as they are lighter (marginally) and I could package them in the frame bag that bit better, I use 10Ah per day and thats worst case scenario.
I'm seriously considering downgrading to 36V (means new BMS and charger) or going the whole hog buying more batteries say 72V and converting a registered and legal motorbike. I'm also looking to add rear panniers to make the bike that bit more practical as I'm using it a lot more often.
As a motorcycle rider, I'd recommend you put the batteries inside the frame rather than over the back wheel, especially if you have steep hills. Though if you can mount them low at the back you'll probably not notice too much. I have no experience with rear mounted batteries.
On one of my first runs one of the connections came loose on the battery (my dodgy wiring effort) and I had to cycle home, uphill all the way. With 8Kg of battery and 4kg of motor the bike felt like a total dog. Once you've added your ebike kit you do not want to run out of juice, it's doable but no longer a pleasant ride.
If you are an experienced rider and comfortable in traffic then I'd recommend a top speed of 30-35km/h any more is asking for trouble from the authorities.
Anyway thats my rambling over.. I just want to make one more point.. and it's very important.. when I first set out building the bike my concern was simply to get from A to B as fast and easily as possible. Now I can do that I find I take more scenic routes to work and absolute top speed is not that important, of course it's nice, but I simply enjoy taking routes I'd have previously thought were too difficult or slow and seeing new places. So my commuter machine is going to transform into a touring machine, I'll buy some panniers and a lock and make it that bit more practical.
Just to let you guys know that my own MAC motor upgrade is now complete and I'm well pleased. The motor (500W 36V) has better torque than I'd ever hoped and I soon anticipate tackling one of the top British "test hills". Our local one is third on the 1920s list compiled for motorists at that time.
But before that I'd like to tell folk that it IS possible to run the MAC geared hub in reverse. It's done with a modified clutch and it's a great plus since I'm disabled and although I can manually wind my trike backwards it's so much easier with a bit of power. Paul at EM3ev arranged for this clutch to be made for me. Don't ask me how it works, to me it looks much the same as a standard clutch, but it adds that "Rolls Royce" to my upgrade.
I'll drop back to let you know how I glide up our local mountain - - as I fully expect to. If not I'll be switching to 48V ....
But before that I'd like to tell folk that it IS possible to run the MAC geared hub in reverse. It's done with a modified clutch and it's a great plus since I'm disabled and although I can manually wind my trike backwards it's so much easier with a bit of power. Paul at EM3ev arranged for this clutch to be made for me. Don't ask me how it works, to me it looks much the same as a standard clutch, but it adds that "Rolls Royce" to my upgrade.
I'll drop back to let you know how I glide up our local mountain - - as I fully expect to. If not I'll be switching to 48V ....
You've done very good, and feel free to be proud of yourself.I didn't have much time over the weekend to work on fitting everything to the frame, but managed to test fit the components and it all looks like it should fit okay.
The battery bag is pretty tight but I'll be able to get all the cells in there and the BMS too, the controller will be in a separate bag behind the seatpost. I'm going to run a small tube under the top tube to contain the wires from the handlebars going to the controller. I could run them through the bag but this bike will have to do double duty until it's paid for a dedicated leisure bike.
The only thing missing from this pic is the seatpost bag with the controller in it, hopefully it'll be a very neat installation...
MS.
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