hillzofvalp
100 kW
Busy. MAybe next week when I diagnose the tire and reprogram kellys
Dual sport bike using a Hubmonster motor Video pg3
- Thread starter Bluefang
- Start date
Bluefang
10 kW
Well the hub is now filled with oil 
The no load at 82V with a tire speed of just under 130km/h.
Empty = 500W
200ml = 800W
Completely full = 900W Total volume was ~1 liter.
My theory is to completely seal up the hub, the exit wires are dabbed in epoxy at their soldier joint so it should stop even the seepage through the wire itself. With the hub sealed and as little air in it as possible, ie oil fill completely i am using a rubber diaphragm to hopefully stop pressure build up. As the oil heats and expands slightly it should push out the rubber diaphragm so the seals should only experience <1psi. I used a priming button from a petrol mower as it was the easiest to get my hands on and also readily available and long lasting. This should also lower the amount the oil tries to escape from other areas.
Have not load tested the bike yet as i had the hub air cooled before and sealed all the gaps with epoxy, ironically the ones that i did the neatest seal on was the point at which it leaked. Instead of letting the epoxy over flow and form a sealing lip i kept it flush with the metal. Easily fixed, just means waiting a few days till i have time to properly load test and see what effect the oil has had on the cooling of the hub. Stupidly for pictures i pulled everything apart before i thought about taking pictures and posting up more information. Will have to wait till tomorrow night before i get them up.
After this test is complete and proven then i will be selling the bike. I hope i can get the price i am thinking of for it but atm i am open to offers, i want it gone now that its working well so i can make use of all that building the bike has taught me. I already have plans to put together a bike to give Jonescg and co a run for their money in the Aus races, try for the landspeed record and do it so that its a fully road legal bike on top. All for $20k plus a bucket load of my time.
The no load at 82V with a tire speed of just under 130km/h.
Empty = 500W
200ml = 800W
Completely full = 900W Total volume was ~1 liter.
My theory is to completely seal up the hub, the exit wires are dabbed in epoxy at their soldier joint so it should stop even the seepage through the wire itself. With the hub sealed and as little air in it as possible, ie oil fill completely i am using a rubber diaphragm to hopefully stop pressure build up. As the oil heats and expands slightly it should push out the rubber diaphragm so the seals should only experience <1psi. I used a priming button from a petrol mower as it was the easiest to get my hands on and also readily available and long lasting. This should also lower the amount the oil tries to escape from other areas.
Have not load tested the bike yet as i had the hub air cooled before and sealed all the gaps with epoxy, ironically the ones that i did the neatest seal on was the point at which it leaked. Instead of letting the epoxy over flow and form a sealing lip i kept it flush with the metal. Easily fixed, just means waiting a few days till i have time to properly load test and see what effect the oil has had on the cooling of the hub. Stupidly for pictures i pulled everything apart before i thought about taking pictures and posting up more information. Will have to wait till tomorrow night before i get them up.
After this test is complete and proven then i will be selling the bike. I hope i can get the price i am thinking of for it but atm i am open to offers, i want it gone now that its working well so i can make use of all that building the bike has taught me. I already have plans to put together a bike to give Jonescg and co a run for their money in the Aus races, try for the landspeed record and do it so that its a fully road legal bike on top. All for $20k plus a bucket load of my time.
hillzofvalp
100 kW
I would only fill it part way. OTher tests done showed little improvement filling above about 300ml-400ml. oil won't seep through wires if it's low
grindz145
1 MW
hillzofvalp said:
Agreed, you'll make your live a lot easier if you keep the oil below the axle too.
Bluefang
10 kW
Well the idea is to have no leaking at all. Good oil seals can take up to 5psi. Air expands a bucket load more then oil. The oil volume will increase heat transfer, the small difference over 400ml I am pretty sure is related to no load power draw.
Either way it's a test that I have not seen done
Either way it's a test that I have not seen done
John in CR
100 TW
Did you increase the exterior surface area of the motor shell?
Bluefang
10 kW
Don't really need to, the shell is always significantly cooler thn the coils, 122 degree windings vs 60degree Celsius shell. I will hopefully find out tonight or tomorrow morning if it works
So far the bike is on its side and no oil is leaking at all. Once the epoxy over the parts that did leak yesterday it should be fine.
So far the bike is on its side and no oil is leaking at all. Once the epoxy over the parts that did leak yesterday it should be fine.
hillzofvalp
100 kW
I think he's getting at the fact that the shell is extremely poor thermal path.. and in order to get heat out of the oil you need the shell to have a good thermal path. Putting oil in without improving this path will have a positive effect, but it will only be a band aid
Bluefang
10 kW
Air has a thermal conductivity of 0.024
Oil is 0.1
Aluminum is 200 one side cover
Steel is 50, the whole motor shell and wheel spokes
Water is 0.564
According to wiki, so it should be able to compete with good air cooling.
Oil is 0.1
Aluminum is 200 one side cover
Steel is 50, the whole motor shell and wheel spokes
Water is 0.564
According to wiki, so it should be able to compete with good air cooling.
Bluefang
10 kW
The complete sealing of my hub seems to be working well atm. Been for a 15min ride around the streets along with holding it on full unloaded speed for a few min and its holding with no leaks. The hub temp stayed cooler then before but i will post up actual figures once i have made my normal run into work etc and have something to actually compare it too. I completely covered the outside of the areas that were leaking before, it does not look pretty atm but i will be sanding it all down smooth and building a better expansion bubble shortly. But atm its perfect for me to go out and really test the oil cooling tomorrow.
Tonight is all about simplifying the wiring on the bike and mounting one of the chargers on it to allow it to be charged anywhere.
Tonight is all about simplifying the wiring on the bike and mounting one of the chargers on it to allow it to be charged anywhere.
John in CR
100 TW
Bluefang said:
This is incorrect. Without some kind of piping, radiator, and pumping, all of the heat is transferred to the environment from the outer surface of the hubmotor, so you still have that transfer to air limitation. For continuous operation putting oil inside has a big fat zero effect on cooling, because the magnets' temp limits are lower than the insulation on the copper. There's some benefit in smoothing out the short term temperature spikes, since the oil will help heat up the shell more quickly, and in that way allow the motor to dissipate more heat to the environment early. GCinDC best documented the results of oil with the graphs he posted, which showed temps increasing and heading toward the same point with and without oil. The question bottom line is, without adding surface area (that's what radiators do) how much hotter do you think the motor can handle at the shell, and I would submit that the answer is not much. If the exterior surface isn't hotter, then it won't dissipate a single watt more heat.
Sure oil can help guys who need to dissipate an extra few hundred watts of heat by getting heat to the exterior more quickly and making the shell somewhat hotter, but even then it's not worth the mess and risks IMHO. Holes do about the same thing. Holes with interior blades to help internal turbulence where it's needed helps even more, and stimulates some flow through the motor. Large motor diameter helps tremendously, but HubMonster is compact.
It wasn't until I added exterior blades that I got meaningful flow through a motor that wasn't large diameter. The exterior blades create a large centrifugal fan that sucks air through the motor, and also creates more flow over the outside surface of the motor. In addition the air scoops on my swingarm force more air to flow at the motor.
Bluefang
10 kW
Yes i know air cooling works. Yes i have already built motors with vanes inside them to assist in air movement. With some more work and perfecting air cooling then maybe it will be better then oil cooling. My problem is i wanted a fully sealed motor.
But. The oil cooling that has been done already on this forum is not FULL oil cooling. And it is not on a well designed motor that can be setup for oil cooling properly. GCinDC does a great job of providing data, but the motors he is using do not lend themselves to oil cooling and due to having no actual oil seals(rubber sealed bearings ARE NOT oil seals). Also due to leaks the lower amount of oil does not help much, as i am pretty sure it was noted that almost no oil came out from his motor when he pulled it apart. 100ml is very different to almost 1l.
With the hub-monster you have a well machined shaft with proper bearings AND oil seals all that is left is to have a expansion baffle/diaphragm etc and seal the motor up properly in the wire slot. Difficult to get a good seal as i am finding out with my rushed jobs along with rewiring my bike and having a relay and contactor fail its been a shiet effort. Having started with a air cooled motor was not ideal and that is currently where my leaks are coming from.
To answer the question as to if the full oil cooling works the answer is a resounding HELL YES. To the sealing of the motor with the expansion setup HELL YES. To my sealing of the vents i had cut for air cooling.....well it worked great for one long run, started leaking on the recent test so i am halting everything till i can seal it up better, so HELL NO.
On a run into work and back, normal temp arriving to work with out oil was ~90. With oil it was 63. On the run home with out oil and zero traffic so i could go nutz its normally 122. With oil its 75. On todays test doing accelleration, brake/regen, accellerate, regen, accellerate for 15min. With previous air cooling it was hitting over 100, with oil it crept up to 80. The motor shell temp was within a few degrees of the coil temp from CA. Its for a long term commuter vehicle. I do not want to have to worry about getting something inside the motor and atm Oil cooling is working for me, just gota cover the slots i cut better.
But. The oil cooling that has been done already on this forum is not FULL oil cooling. And it is not on a well designed motor that can be setup for oil cooling properly. GCinDC does a great job of providing data, but the motors he is using do not lend themselves to oil cooling and due to having no actual oil seals(rubber sealed bearings ARE NOT oil seals). Also due to leaks the lower amount of oil does not help much, as i am pretty sure it was noted that almost no oil came out from his motor when he pulled it apart. 100ml is very different to almost 1l.
With the hub-monster you have a well machined shaft with proper bearings AND oil seals all that is left is to have a expansion baffle/diaphragm etc and seal the motor up properly in the wire slot. Difficult to get a good seal as i am finding out with my rushed jobs along with rewiring my bike and having a relay and contactor fail its been a shiet effort. Having started with a air cooled motor was not ideal and that is currently where my leaks are coming from.
To answer the question as to if the full oil cooling works the answer is a resounding HELL YES. To the sealing of the motor with the expansion setup HELL YES. To my sealing of the vents i had cut for air cooling.....well it worked great for one long run, started leaking on the recent test so i am halting everything till i can seal it up better, so HELL NO.
On a run into work and back, normal temp arriving to work with out oil was ~90. With oil it was 63. On the run home with out oil and zero traffic so i could go nutz its normally 122. With oil its 75. On todays test doing accelleration, brake/regen, accellerate, regen, accellerate for 15min. With previous air cooling it was hitting over 100, with oil it crept up to 80. The motor shell temp was within a few degrees of the coil temp from CA. Its for a long term commuter vehicle. I do not want to have to worry about getting something inside the motor and atm Oil cooling is working for me, just gota cover the slots i cut better
.Attachments
![DSC_0354[1].jpg](/sphere/data/attachments/72/72365-813837e2666a7b922badafdfbfbec543.jpg)
Sounds like you've got the cooling well under control, and you'll keep all of the salt out too. Temperature improvements seem better than I would've guessed, nice. Glad to see this thing running.
Bluefang said:Yes i know air cooling works. Yes i have already built motors with vanes inside them to assist in air movement. With some more work and perfecting air cooling then maybe it will be better then oil cooling. My problem is i wanted a fully sealed motor.
But. The oil cooling that has been done already on this forum is not FULL oil cooling. And it is not on a well designed motor that can be setup for oil cooling properly. GCinDC does a great job of providing data, but the motors he is using do not lend themselves to oil cooling and due to having no actual oil seals(rubber sealed bearings ARE NOT oil seals). Also due to leaks the lower amount of oil does not help much, as i am pretty sure it was noted that almost no oil came out from his motor when he pulled it apart. 100ml is very different to almost 1l.
With the hub-monster you have a well machined shaft with proper bearings AND oil seals all that is left is to have a expansion baffle/diaphragm etc and seal the motor up properly in the wire slot. Difficult to get a good seal as i am finding out with my rushed jobs along with rewiring my bike and having a relay and contactor fail its been a shiet effort. Having started with a air cooled motor was not ideal and that is currently where my leaks are coming from.
To answer the question as to if the full oil cooling works the answer is a resounding HELL YES. To the sealing of the motor with the expansion setup HELL YES. To my sealing of the vents i had cut for air cooling.....well it worked great for one long run, started leaking on the recent test so i am halting everything till i can seal it up better, so HELL NO.
On a run into work and back, normal temp arriving to work with out oil was ~90. With oil it was 63. On the run home with out oil and zero traffic so i could go nutz its normally 122. With oil its 75. On todays test doing accelleration, brake/regen, accellerate, regen, accellerate for 15min. With previous air cooling it was hitting over 100, with oil it crept up to 80. The motor shell temp was within a few degrees of the coil temp from CA. Its for a long term commuter vehicle. I do not want to have to worry about getting something inside the motor and atm Oil cooling is working for me, just gota cover the slots i cut better
hillzofvalp
100 kW
All it is is thermal mass. Give it 2.5kWh in 20-25 minutes and tell me what happens.
John in CR
100 TW
It's a bit more than just thermal mass. It keeps the copper temps from spiking so much, so that will improve overall efficiency at bit and reduce heat by not making some of it. It also increases the temperature of the outer shell both more quickly and overall, so that increases the temperature differential for the final stage of the heat pathway to the environment, which increases heat transfer accordingly.
Besides the inevitable leaks and potential for damage inside the motor, my biggest question is how much can we safely increase the outer shell temperature. I don't have an answer for that, but I suspect we're limited to a maximum increase in that final temperature differential of 20-30%.
That's why I asked about an increase in the exterior surface area. Double the surface area and you double the heat transferred at the same temperatures. I believe getting close to doubling it is possible, since the shell is smooth. It's also quite easy to increase the air flow and turbulence at the outer shell, which will directly benefit heat transfer too. Add the oil's benefits to that, and 2.5-3.5 times the power vs sealed seems possible.
My position is that's possible with ventilated cooling. I know because I'm already doing it, and my motor runs cooler than it did sealed at half the power, and I know of definite improvements I can still make. The risk is damage from the motor ingesting something it shouldn't, but I'm not aware of a single failure of that type unless you count Zappy's fan failure running his magpie through muddy streams. I avoid even light rains, so I'll take the risk of debris over certain oil drips, potential damage from erosion from 2krpm or breakdowns of the plastics from temperature or chemical reaction, or the oil causing a failure at the magnets from either the more direct thermal connection of the copper to the magnets or the fast moving oil getting under the epoxy and having magnets come loose.
Here's what I mean by exterior blades (interior blades/vanes produce a small fraction of the flow these puppies produce).
My next iteration will be 8 or 10 blades, and forget the exhaust slots. Instead I will put one large exhaust hole behind each blade to increase flow area right where the lowest pressure exists. I also plan a reverse curve on the blades to better protect the motor from debris, which will sacrifice some flow potential while increasing pressure. With our flow restrictions pulling a higher pressure will mean greater flow anyway. On the intake side I'll do some kind of air dam similar to what Hillsofvalp has. That's because my highest temps have been when pushing it really hard at high speed, and I think at high speed my slotted intakes are harder to get air into than at low speed, so the increase in pressure while at the same time decreasing the air velocity outside the intake slots should help flow a lot.
I'll save oil for use with a HubMonster when I use one or more to drive a boat, but the oil still won't be in the motor(s). It will be in the stuffing box for the shaft to prevent water from getting in.
Besides the inevitable leaks and potential for damage inside the motor, my biggest question is how much can we safely increase the outer shell temperature. I don't have an answer for that, but I suspect we're limited to a maximum increase in that final temperature differential of 20-30%.
That's why I asked about an increase in the exterior surface area. Double the surface area and you double the heat transferred at the same temperatures. I believe getting close to doubling it is possible, since the shell is smooth. It's also quite easy to increase the air flow and turbulence at the outer shell, which will directly benefit heat transfer too. Add the oil's benefits to that, and 2.5-3.5 times the power vs sealed seems possible.
My position is that's possible with ventilated cooling. I know because I'm already doing it, and my motor runs cooler than it did sealed at half the power, and I know of definite improvements I can still make. The risk is damage from the motor ingesting something it shouldn't, but I'm not aware of a single failure of that type unless you count Zappy's fan failure running his magpie through muddy streams. I avoid even light rains, so I'll take the risk of debris over certain oil drips, potential damage from erosion from 2krpm or breakdowns of the plastics from temperature or chemical reaction, or the oil causing a failure at the magnets from either the more direct thermal connection of the copper to the magnets or the fast moving oil getting under the epoxy and having magnets come loose.
Here's what I mean by exterior blades (interior blades/vanes produce a small fraction of the flow these puppies produce).
My next iteration will be 8 or 10 blades, and forget the exhaust slots. Instead I will put one large exhaust hole behind each blade to increase flow area right where the lowest pressure exists. I also plan a reverse curve on the blades to better protect the motor from debris, which will sacrifice some flow potential while increasing pressure. With our flow restrictions pulling a higher pressure will mean greater flow anyway. On the intake side I'll do some kind of air dam similar to what Hillsofvalp has. That's because my highest temps have been when pushing it really hard at high speed, and I think at high speed my slotted intakes are harder to get air into than at low speed, so the increase in pressure while at the same time decreasing the air velocity outside the intake slots should help flow a lot.
I'll save oil for use with a HubMonster when I use one or more to drive a boat, but the oil still won't be in the motor(s). It will be in the stuffing box for the shaft to prevent water from getting in.
Bluefang
10 kW
My next build will include a hubmonster or 2 and either 160volts and flowing oil cooling. Otherwise it will be 400volt + and water cooling.
With the leaks I currently have I have figured out my problem, using fiberglassing epoxy to seal holes is never going to work as well as a specific epoxy designed to seal holes and is impervious to oil. So I will order some tomorrow and sort it all out after I get back from holidays. I will also get more data specifically on a long high speed run.
Once it's proven to be reliable then I'll be selling it off at pretty much cost price to start on the next project
With the leaks I currently have I have figured out my problem, using fiberglassing epoxy to seal holes is never going to work as well as a specific epoxy designed to seal holes and is impervious to oil. So I will order some tomorrow and sort it all out after I get back from holidays. I will also get more data specifically on a long high speed run.
Once it's proven to be reliable then I'll be selling it off at pretty much cost price to start on the next project
Bluefang
10 kW
Its been sealed up fully again and its working well still with the oil cooling. Will be much easier if i start with a motor i have not hacked to pieces. Some photos of how it looks atm
View attachment 1
View attachment 1
John in CR
100 TW
FWIW the factory reported to me that the magnets and hall sensors have 150°C limits, and the magnet wire 180°C, so they recommend using a temperature limit of 120-125°C.
Bluefang
10 kW
Awesome to hear they are rated so well
I get back from Bali in afew days so I will set the CA to limit at 120. Will be interesting to see if I can get the motor to hit that temperature.
The motor rating should make It easier for the next few projects if I can get funding sorted now that I have the controllers sorted
I get back from Bali in afew days so I will set the CA to limit at 120. Will be interesting to see if I can get the motor to hit that temperature.
The motor rating should make It easier for the next few projects if I can get funding sorted now that I have the controllers sorted
parabellum
1 MW
O, that is no problemo. Magnets will stay in place until the whole ring is loose and finally magnet ring spins around the stator with no wheel on it. Very peaceful but noisy event. :lol:John in CR said:
Bluefang
10 kW
Still getting pin hole leaks thru the epoxy filling I did so I am going to strip it down again and weld up the side covers properly.
Oil cooling is working and the axle seals that I was the most worried about are holding perfectly.
[youtube]JvS2NVXZQ1Y[/youtube]
There is a increase in startup current using the balance mode so the bikes going great now
Oil cooling is working and the axle seals that I was the most worried about are holding perfectly.
[youtube]JvS2NVXZQ1Y[/youtube]
There is a increase in startup current using the balance mode so the bikes going great now
Bluefang
10 kW
Well sealing up my hub motor after i cut all the holes for air cooling was a complete failure Kept leaking no matter what i did with epoxy as the aluminum welder i asked to help out did not want to weld my side cover and trying to weld the main hub steel side was getting too hot so i had to go back to epoxy.
So back to air cooling and John from CR gets some extra points with the external blades on the motor. Previous air cooling with only internal blades was struggling to keep the hub under 100 degrees C even when running at a high speed, oil cooling was fairly similar, slightly larger vents with huge external blades and no internal blades its now holding below 80 degrees on a normal stop start commute and if doing a constant 80km+ its dropping temp down to ~65 and holding it steady.
Bikes running great and atm the BMS is stopping me going over 32kw so i am going to hack the bms connections and see how much power i can get out of the controllers before i go see what it gets on a Dyno.
[youtube]KoJiN_ccuFA[/youtube]
View attachment 4![DSC_0390[1].jpg](https://endless-sphere.com/sphere/data/attachments/73/73849-a8f4d9755cdb19630bbf776c48156ceb.jpg "DSC_0390[1].jpg")
Kept leaking no matter what i did with epoxy as the aluminum welder i asked to help out did not want to weld my side cover and trying to weld the main hub steel side was getting too hot so i had to go back to epoxy.So back to air cooling and John from CR gets some extra points with the external blades on the motor. Previous air cooling with only internal blades was struggling to keep the hub under 100 degrees C even when running at a high speed, oil cooling was fairly similar, slightly larger vents with huge external blades and no internal blades its now holding below 80 degrees on a normal stop start commute and if doing a constant 80km+ its dropping temp down to ~65 and holding it steady.
Bikes running great and atm the BMS is stopping me going over 32kw so i am going to hack the bms connections and see how much power i can get out of the controllers before i go see what it gets on a Dyno.
[youtube]KoJiN_ccuFA[/youtube]
View attachment 4
John in CR
100 TW
Sweet ! Nothing is a bigger relief than making heat problems go away without turning the controller down. Yeah, the blades are the single most effective cooling mod I'd done. I think I'll pick up a good benefit with an intake like HOV's also.
I've got my fingers crossed that you're right and I've been too conservative all along regarding the current handling. The copper is pretty thick, and not much thinner on each turn as the 3 phase motor that I fed 400A batter 550A phase. 200A battery 300A phase from each controller would certainly be something.
How happy are you with the throttle control? That remains my only real issue.
I've got my fingers crossed that you're right and I've been too conservative all along regarding the current handling. The copper is pretty thick, and not much thinner on each turn as the 3 phase motor that I fed 400A batter 550A phase. 200A battery 300A phase from each controller would certainly be something.
How happy are you with the throttle control? That remains my only real issue.
Bluefang
10 kW
Throttle control with a kelly is smooth as silk and fully adjustable in programming or with CA for the 72V or less controllers. You cannot use CA V3 with higher voltage controllers as it links the low voltage side and the high voltage side which kellys keep seperate for some reason.
The initial acceleration on the kelly still sucks, its good but nothing compared to a Lyen etc controller. But that should be solved when going to a much higher voltage and current then gearing it down to a proper top speed.
You have been way way way to conservative with the power handling of the motors since the start Hopefully soon i will be buying some more hubs from you to prove that beyond a doubt 
The initial acceleration on the kelly still sucks, its good but nothing compared to a Lyen etc controller. But that should be solved when going to a much higher voltage and current then gearing it down to a proper top speed.
You have been way way way to conservative with the power handling of the motors since the start
Hopefully soon i will be buying some more hubs from you to prove that beyond a doubt John in CR
100 TW
We'll see on the current limits, because you adopt what I view an erroneous approach used by most, which is trying to run electrics near their limits. Luke used to do that, even cutting motors open and pouring water in. 
He didn't get happy until he got a beast of a motor running nice and conservative.
Regarding your blades, after thinking about them I believe you're losing most of the flow they should draw through the motor. The blade throws air off the tips like any radial fan, and that creates the low pressure region behind the blade. With your flat blades open to the right the low pressure region will be filled by air rushing in from the open right side. Though not ideal, the angle iron blade I used seem to block that inrush of air from the right. The smoke test I did showed strong flow from the left, both into the intake holes in the cover and over the outside shell and through the holes in the rim, both of which are good for cooling. Air coming from the right and exhausted to the right does no cooling and reduces beneficial flow, because if it's blocked the air has to come from somewhere else. That's why a typical fan would have a flat plate running all the way to the blade tips to block flow coming in from the right.
WRT the Kelly throttle, if starts are too soft, then of course the throttle will be smooth on takeoff, just like low powered ebikes that don't have throttle issues. What holding speeds and changing speeds at cruise? Is the throttle smooth and natural feeling? I've yet to have a high powered bike that didn't need precision throttle control at cruise to avoid nasty surprise jerks.
John
He didn't get happy until he got a beast of a motor running nice and conservative.Regarding your blades, after thinking about them I believe you're losing most of the flow they should draw through the motor. The blade throws air off the tips like any radial fan, and that creates the low pressure region behind the blade. With your flat blades open to the right the low pressure region will be filled by air rushing in from the open right side. Though not ideal, the angle iron blade I used seem to block that inrush of air from the right. The smoke test I did showed strong flow from the left, both into the intake holes in the cover and over the outside shell and through the holes in the rim, both of which are good for cooling. Air coming from the right and exhausted to the right does no cooling and reduces beneficial flow, because if it's blocked the air has to come from somewhere else. That's why a typical fan would have a flat plate running all the way to the blade tips to block flow coming in from the right.
WRT the Kelly throttle, if starts are too soft, then of course the throttle will be smooth on takeoff, just like low powered ebikes that don't have throttle issues. What holding speeds and changing speeds at cruise? Is the throttle smooth and natural feeling? I've yet to have a high powered bike that didn't need precision throttle control at cruise to avoid nasty surprise jerks.
John
Similar threads
