A-DamW
10 kW
This is super cool to hear 'Nep,
Good things take time.
'lightest.bike' 1.7kg 1000w mid drive
- Thread starter Grantmac
- Start date
Good things take time.
Not enough phase amps to deliver full power... i've also cut off the bottom of the torque curve.
It's 95F out and i gave it 42 phase amps / 30 battery amps and went up the short test hill w/o pedaling and in the wrong gear.
Saw 1350w briefly and 27.4A max amp draw.
Highest temperature i could read off the case was 60C.
This motor is the gift that keeps giving more watts.
Next step is to bump it to 45 phase amps. and take it up the 6 mile climb at full power with pedaling.
I think think beyond that point, i might be pushing it with the gears. I think i'll keep the power to ~1400w, because this is enough for 30mph duty.
Saw 1350w briefly and 27.4A max amp draw.
Highest temperature i could read off the case was 60C.
This motor is the gift that keeps giving more watts.
Next step is to bump it to 45 phase amps. and take it up the 6 mile climb at full power with pedaling.
I think think beyond that point, i might be pushing it with the gears. I think i'll keep the power to ~1400w, because this is enough for 30mph duty.
Make sure you use some good tape on that so the rest doesn't all fall out.
TPEHAK
10 kW
MakerX GO-FOC M100 75V 120A controller is significantly smaller than the one on the picture
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Yeah i'm definitely abusing the fact that my startup torque is at least 25% lower than yours. I'd probably destroy the big plastic gear before the clutch but we'll see. I'm willing to toast at least one in the name of science.
One important thing i'm minding is maintaining thermals so that we don't have any degree of plastic gear melting. That means i get nervous around 85C so i'm tuning my power so that in no condition, do i exceed that by much.
The case is a great place to monitor thermals due to it being an inrunner, but there's likely some hot spots i'm not monitoring. Since i'm just entering the territory where i'm thermally pushing the unit, i think inserting a 10K NTC sensor, plugging that into the VESC, and adding a power rollback starting at 85C would be smart.
re: controller
Looked it up:
Go-FOC M100
Very nice packaging and it'd fit between the 68mm bottom bracket area and there'd be room to run wires out the side without kinking them up.
Only problem is 40A cont ( i could easily exceed that ), and the packaging seems to work against you if you want to add a heatsink ( i'm not going to assume it sheds heat directly to the case )
This might be an ideal pick if you wanted to go with higher voltage, which is a real possibility on the dual chainring drive since you can change chainring sizes to compensate. But i don't know if i wanna do that yet.
Other units offered by makerX are a bit too wide. Shame, because they look nice.
This Spintend looks like the ticket.. if the continuous amp handling is 1/3 of the listed amp spec.. that gives me 50A phase cont without an added heatsink. And that's the max i'd be willing to run. I like this parallel motor cable version too.
Nice to know there's some options.
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This one's for you, ES:
Sorry, i did not have my usual camera rig setup so i had to hold the action cam. You can't see the watts readout until one short part of the video. Typical draw is from 1000-1150 when doing 30-35mph; start seeing the watts rapidly climb as the motor starts struggling on a hill or during acceleration ( close to mid RPM ), hitting a peak of 1550w.
Max temp was 65C during this motor abuse run.
I'll fix my video rig and do a longer test up the 6 mile hill climb at 80F while pedaling later. I think the heat will be the same though, let's see!
Sorry, i did not have my usual camera rig setup so i had to hold the action cam. You can't see the watts readout until one short part of the video. Typical draw is from 1000-1150 when doing 30-35mph; start seeing the watts rapidly climb as the motor starts struggling on a hill or during acceleration ( close to mid RPM ), hitting a peak of 1550w.
Max temp was 65C during this motor abuse run.
I'll fix my video rig and do a longer test up the 6 mile hill climb at 80F while pedaling later. I think the heat will be the same though, let's see!
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"This video is age-restricted and only available on YouTube. "
My unit has been modded. Freewheel one way inner needle bearing is now a beefy csk20pp srag clutch, it probably won't break anymore.
Only one problem: not having the motor for a while, i went on another path.
Now i have the motor and all ots components, and actually no suitable bike to mount it. The banshee that was hosting it, now is on a 18hp conversion.
If someone, maybe you @neptronix, is interested to look at what has been done on my unit, i can ship it if someone want to pay shipment from italy.
I also have a badass molicel p50b battery that i have to get rid of, being 72v the new setup on the bike.
And all the other stuff.
Nep, any interest?
Only one problem: not having the motor for a while, i went on another path.
Now i have the motor and all ots components, and actually no suitable bike to mount it. The banshee that was hosting it, now is on a 18hp conversion.
If someone, maybe you @neptronix, is interested to look at what has been done on my unit, i can ship it if someone want to pay shipment from italy.
I also have a badass molicel p50b battery that i have to get rid of, being 72v the new setup on the bike.
And all the other stuff.
Nep, any interest?
I'm very interested but don't have much free cash until fall or winter.
I'd be happy to buy the unit or just the modified clutch.
PM me a price and we'll take it from there privately.
It's very difficult to ship batteries via air to another country, so i gotta pass on that
I'd put it up in our for sale section.
I'd be happy to buy the unit or just the modified clutch.
PM me a price and we'll take it from there privately.
It's very difficult to ship batteries via air to another country, so i gotta pass on that
I'd put it up in our for sale section.
Seems like my legs could tolerate a little more cadence at full charge. And i'm concerned about having good cadence at middle to low charge.
So i'm going with a 42T -> 41T/40T on the motor drive sprocket at 44T on the bike drive sprocket.
This way i can get a slightly higher top speed and utilize the extra power more on the flat.
This is also good for chain wear. The drive sprocket on the lightest is 10T, so it'd be smart to pair it with an odd tooth gear anyway. Hopefully the 41T works out as it'd also mostly eliminate the need for the tensioner, which may be responsible for some of the warbling noises during certain RPM ranges while accelerating.
See ya next week when i have parts in.
So i'm going with a 42T -> 41T/40T on the motor drive sprocket at 44T on the bike drive sprocket.
This way i can get a slightly higher top speed and utilize the extra power more on the flat.
This is also good for chain wear. The drive sprocket on the lightest is 10T, so it'd be smart to pair it with an odd tooth gear anyway. Hopefully the 41T works out as it'd also mostly eliminate the need for the tensioner, which may be responsible for some of the warbling noises during certain RPM ranges while accelerating.
See ya next week when i have parts in.
On the next episode of discovering the ultimate VESC tune..
Switched from the hybrid mount to medium mount since i'm committed to dual chainring mode.
Unfortunately a 41T will not work, i need a wider than 123mm bb to make it happen, which i'm not willing to do.
I was able to use a 40T inner sprocket and some spacers to get the chainline within 1mm of perfect.
This means i could run up to a 50T chainring on the outer... which means 35mph speed is very possible now
It also means i probably gained 1mph or so and should be able to solidly sustain 30mph.
I probably have 100rpm cadence now when the battery is fully charged, which is starting to get uncomfortably high. I can limit the max eRPM with the VESC to make this 100RPM into 90RPM and have a nice equal cadence until it starts dropping around 25-33% SOC. So, this high cadence is actually ideal.
Next, it goes up my 6 mile climb in 80F weather with me pedaling.
@limiky wants to give me his experimental unit. I'll pick that up next month. It may go on the recumbent or it may be a spare parts unit.
Switched from the hybrid mount to medium mount since i'm committed to dual chainring mode.
Unfortunately a 41T will not work, i need a wider than 123mm bb to make it happen, which i'm not willing to do.
I was able to use a 40T inner sprocket and some spacers to get the chainline within 1mm of perfect.
This means i could run up to a 50T chainring on the outer... which means 35mph speed is very possible now
It also means i probably gained 1mph or so and should be able to solidly sustain 30mph.
I probably have 100rpm cadence now when the battery is fully charged, which is starting to get uncomfortably high. I can limit the max eRPM with the VESC to make this 100RPM into 90RPM and have a nice equal cadence until it starts dropping around 25-33% SOC. So, this high cadence is actually ideal.
Next, it goes up my 6 mile climb in 80F weather with me pedaling.
@limiky wants to give me his experimental unit. I'll pick that up next month. It may go on the recumbent or it may be a spare parts unit.
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hillslayer@
10 kW
I really think you should dual motor this, lightest 750 watt hub made, will take worry about over working on climbs plus increase climb speed and save wear on the mid -drive and chains, when not needing it for just cruising on the flats. Just giving you something to think about.
I've kinda thought about that. 4lbs 250w hub motors exist and could easily burst up to 500W and have torque where the drive doesn't have it. it's a nice path to 2000w peak which would be ideal for actually getting up to 35mph and holding it.
But it's so cool to have a bike that only has 15lbs extra over a pedal bike. So easy to handle and just chuck in a car.
If 1500w-1600w works out long term with the torque reduction, any additional weight i'd like to add on is extra battery, if i can get away with it
But it's so cool to have a bike that only has 15lbs extra over a pedal bike. So easy to handle and just chuck in a car.
If 1500w-1600w works out long term with the torque reduction, any additional weight i'd like to add on is extra battery, if i can get away with it
Which 4lb motor are you referring to?I've kinda thought about that. 4lbs 250w hub motors exist and could easily burst up to 500W and have torque where the drive doesn't have it. it's a nice path to 2000w peak which would be ideal for actually getting up to 35mph and holding it.
But it's so cool to have a bike that only has 15lbs extra over a pedal bike. So easy to handle and just chuck in a car.
If 1500w-1600w works out long term with the torque reduction, any additional weight i'd like to add on is extra battery, if i can get away with it
Okay. Ended up going out in 85F weather instead up the 6 mile moderate hill climb.
Conditions:
- slight tailwind
- no downshifting to improve efficiency
- pedaling at mid effort
My power peak was north of 1600w. The motor can also sustain 28mph on top gear with me pedaling up about 1% grade. This is a pretty impressive feat considering i am 250lbs.
I measured a peak temp at the top of the hill of 70.5C and the unit rapidly started to cool down as soon as i unlocked my phone to take this picture.
The mid drive provided an admirable performance and even achieved a top speed of 33mph on flat ground. The pedaling cadence still isn't too high.
While climbing, i could see wattages from 1050w to 1300w. About 1.2kw continuous average.
I think i am right on the edge of pushing it too far at this point. This would have melted offroad or in truly hilly conditions under moderate operator neglect + high ambient heat.
I could feel the power just beginning to falter at the end of the ride, so that stator is 80C or higher inside.
I think the required modifications needed to keep this tune are:
- add heatsink(s) to the stator side for hopefully 15% better heat shedding ( i have 12.5mm of height )
- add NTC 10k sensor and wire to the VESC + program in some mild thermal rollback
Otherwise, the correct thing to do would be to shave off 100 watts, or downgear by 2T on the bike side chainring.
Regardless of this, the efficiency was exceptional. I came home with a much higher charge on the way home than expected.
If I could find a watercooling block with the correct inlet/outlet orientation and height ( shouldn't be impossible), i think i could add a few more hundred watts, since the case is thermally linked to the stator so well.
I am seeing if i can get another internal clutch so that i can test the mechanical limits, since i've got a good idea what the thermal limits are now.
Conditions:
- slight tailwind
- no downshifting to improve efficiency
- pedaling at mid effort
My power peak was north of 1600w. The motor can also sustain 28mph on top gear with me pedaling up about 1% grade. This is a pretty impressive feat considering i am 250lbs.
I measured a peak temp at the top of the hill of 70.5C and the unit rapidly started to cool down as soon as i unlocked my phone to take this picture.
The mid drive provided an admirable performance and even achieved a top speed of 33mph on flat ground. The pedaling cadence still isn't too high.
While climbing, i could see wattages from 1050w to 1300w. About 1.2kw continuous average.
I think i am right on the edge of pushing it too far at this point. This would have melted offroad or in truly hilly conditions under moderate operator neglect + high ambient heat.
I could feel the power just beginning to falter at the end of the ride, so that stator is 80C or higher inside.
I think the required modifications needed to keep this tune are:
- add heatsink(s) to the stator side for hopefully 15% better heat shedding ( i have 12.5mm of height )
- add NTC 10k sensor and wire to the VESC + program in some mild thermal rollback
Otherwise, the correct thing to do would be to shave off 100 watts, or downgear by 2T on the bike side chainring.
Regardless of this, the efficiency was exceptional. I came home with a much higher charge on the way home than expected.
If I could find a watercooling block with the correct inlet/outlet orientation and height ( shouldn't be impossible), i think i could add a few more hundred watts, since the case is thermally linked to the stator so well.
I am seeing if i can get another internal clutch so that i can test the mechanical limits, since i've got a good idea what the thermal limits are now.
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Checking in.
I finally got a response from matteo. Looks like i can order some spare drivetrain parts.
Matteo tells me the motor was tested at 120c continuous, so my max of 100c is pretty conservative.
I think i got the motor in the 100C range on my last high heat hill climb. I could tell it was struggling on the last part. So i don't want the motor to hit that temp because the efficiency gets low when the copper is hot.
A plan on this thread is cooking to improve the thermal characteristics so that i can get away with beyond 1600w peak:
thermal glue - does it work well for adding heatsinks?
It is super hot out here, if i don't hit the road at 7am i'm screwed because it's 78f already. I am hoping it cools down soon!
I finally got a response from matteo. Looks like i can order some spare drivetrain parts.
Matteo tells me the motor was tested at 120c continuous, so my max of 100c is pretty conservative.
I think i got the motor in the 100C range on my last high heat hill climb. I could tell it was struggling on the last part. So i don't want the motor to hit that temp because the efficiency gets low when the copper is hot.
A plan on this thread is cooking to improve the thermal characteristics so that i can get away with beyond 1600w peak:
thermal glue - does it work well for adding heatsinks?
It is super hot out here, if i don't hit the road at 7am i'm screwed because it's 78f already. I am hoping it cools down soon!
This just in:
- i can get spare clutches
- they have some boards laying around which would make the external controller conversion easier
- 140c sounds like a suggested stopping point but i wonder about those magnets, i still want <100c
But
- it's sweltering outside
- it's not payday yet
So, see you in a few weeks!
- i can get spare clutches
- they have some boards laying around which would make the external controller conversion easier
- 140c sounds like a suggested stopping point but i wonder about those magnets, i still want <100c
But
- it's sweltering outside
- it's not payday yet
So, see you in a few weeks!
78F. bwahahaha.... it doesn't even get that cool here right now in the deepest darkest part of the night / morning.
I think today it was almost 90F before the sun came up, and I don't know what hte high was but it was still 111F at my house when I got home.
The new lighting-battery-system SoC meter I stuck on the trike this past weekend has a temperature sensor on it that just hangs out in the air at the handlebars, and on my ride home today it said it was 46C, which is about 115f; it reads about two degrees C higher (almost 4F) just sittting there in the same ambient stable conditions as the CA's sensor in the righthand motor; I'd take the average of them as probably good. So probably about 113F for real during the ride.
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raylo32
100 kW
Yesterday morning we woke up to 78 degrees F... maybe doesn't seem as "hot" as PHX until you consider the 77 degree dew point. Just awful. But the good news for us is that we finally got a front come through with cooler less humid air, first time this summer. Too bad the roads and trails are soaked today from all the rain in that front. But we are in for a fantastic weekend.... no motors overheating here, although I'll probably be on the pedal bike.
78F. bwahahaha.... it doesn't even get that cool here right now in the deepest darkest part of the night / morning.
I think today it was almost 90F before the sun came up, and I don't know what hte high was but it was still 111F at my house when I got home.
The new lighting-battery-system SoC meter I stuck on the trike this past weekend has a temperature sensor on it that just hangs out in the air at the handlebars, and on my ride home today it said it was 46C, which is about 115f; it reads about two degrees C higher (almost 4F) just sittting there in the same ambient stable conditions as the CA's sensor in the righthand motor; I'd take the average of them as probably good. So probably about 113F for real during the ride.
bedesign
10 mW
I asked an AI about max temp for bike magnets -
References:
Typical neodymium magnets start to lose magnetism at around 80 °C; e-bike magnets commonly keep below 95 °C for longevity.
Neodymium magnet grades have max working temps approximately from 80 °C to 200 °C depending on grade; typical e-bike grades are in the 80-120 °C range.
Magnet coercivity and demagnetization risks increase with temperature, recommending minimum coercivity for e-bike motors at elevated temps (up to 100-120 °C) for high-performance motors.
Common user experience and e-bike community consensus maintain around 80-95 °C as max safe temperature.
References:
Typical neodymium magnets start to lose magnetism at around 80 °C; e-bike magnets commonly keep below 95 °C for longevity.
Neodymium magnet grades have max working temps approximately from 80 °C to 200 °C depending on grade; typical e-bike grades are in the 80-120 °C range.
Magnet coercivity and demagnetization risks increase with temperature, recommending minimum coercivity for e-bike motors at elevated temps (up to 100-120 °C) for high-performance motors.
Common user experience and e-bike community consensus maintain around 80-95 °C as max safe temperature.