Hub motor industry dying?

[wturber]

People still make fun of electric vehicles.
Think about how much money dragsters drop to make that mile in 1 second.
Electric can do it, and faster, much simpler, and cheaper yet they are made fun of by ignorant people.

Instant torque from zero rpm!

Best electric Dragster is 1/4 mile in 7.274 seconds @ 185 mph. That's way worse than the best Top Fuel or even the best Top Alcohol.

Electric is nifty, but it is hardly an obviously better technology for cars.

 

[markz]

If they spent the same kind of money, I'd bet they get a sub 5s electric drag.
1-MegaWatt of Power https://www.youtube.com/watch?v=Kl55IpJxqq0

 

[wturber]

If they spent the same kind of money, I'd bet they get a sub 5s electric drag.
1-MegaWatt of Power https://www.youtube.com/watch?v=Kl55IpJxqq0

Maybe. But until someone actually does it you can't say it is so. Right now what we have is a HUGE gap in a sport where small fractions of a second are big.

 

[furcifer]

to add in my experience, using the grin hub motor hasn't caused any problems with the local police, and I more or less see them every single day, multiple times a day. For context though, my system is entirely pedal assist so I more or less fly under the radar this way

The problem here is the police do "crackdowns" where they target certain violations. I would put it out there nobody is flying under the radar, they just haven't turned it on yet.

It's tough to say what will happen, but I know I'd rather be riding a mid-drive when they do. Hub motors over about 8" in diameter are way too obvious. But there's little difference between something like a BBS01 doing 500W and a BBSHD pulling 2500W.

So you may as well paint a bullseye on a hub motor until the laws are changed in most areas. The same goes for riding anything that looks like a MX.

 

[MadRhino]

Here anything that looks like a scooter or motorcycle are severely kept off the bike paths with 170$ tickets. Other than that, ebikers are never bothered as long as they wear a helmet and don’t run trafic lights.

 

[wturber]

Here anything that looks like a scooter or motorcycle are severely kept off the bike paths with 170$ tickets. Other than that, ebikers are never bothered as long as they wear a helmet and don’t run trafic lights.

Yep. That's what I saw in the reports in the Phoenix area. If your ebike looks like a moped and you are riding on the sidewalk or a bike path, you draw attention and reveal Police ignorance. But if you look like a weird conventional bicycle, they pretty much ignore your existence unless you do something additional to make yourself stand out ... like maybe zipping along at 40 mph on a flat road.

 

[amberwolf]

That's what I saw in the reports in the Phoenix area. If your ebike looks like a moped and you are riding on the sidewalk or a bike path, you draw attention and reveal Police ignorance. But if you look like a weird conventional bicycle, they pretty much ignore your existence unless you do something additional to make yourself stand out ... like maybe zipping along at 40 mph on a flat road.

Even *really* wierd stuff like my trike is generally ignored (though I'm on the streets 99% of the time, because its' safer than the sidewalks), because I'm riding "normally" and as safely as it's possible to do under the conditions at the time.

 

[qwerkus]

How do you guys cope with motor overheating in such hot places like Phoenix ? Maybe it's not even competition of mid drives that will kill the hub motor industry as OP suggested, but climate change... Morning temps should not be an issue, but coming home from work at 6p.m when it's 50°C outside - ouch; that must hurt.

 

[Ford Prefect]

That never stopped us (humans) of using inefficient technology. I think there was a G5 PowerMac with liquid cooling, because the processor were highly inefficient.
Heatsinks, Active Cooling, … there will be a way. Ever heard of heatpipes? Should be doable for geared hubs. DDs are said to have less thermal problems.

 

[parajared]

How do you guys cope with motor overheating in such hot places like Phoenix ? Maybe it's not even competition of mid drives that will kill the hub motor industry as OP suggested, but climate change... Morning temps should not be an issue, but coming home from work at 6p.m when it's 50°C outside - ouch; that must hurt.

Phoenix goer here.
Ambient temperature is nothing compared to motor temps. I consider the cut-off motor temperature to be about 250 degrees Fahrenheit. Hot day, cold day it doesn't matter all that much, your motor will cool right down even if it's 110 degrees out.

I measure temps using a rc on-board sensor (https://www.amainhobbies.com/traxxas-onboard-temp-gauge-tra4091/p17707). I did the thicker phase wire mod and put the sensor into the hub while I had the motor open.

 

[wturber]

That's what I saw in the reports in the Phoenix area. If your ebike looks like a moped and you are riding on the sidewalk or a bike path, you draw attention and reveal Police ignorance. But if you look like a weird conventional bicycle, they pretty much ignore your existence unless you do something additional to make yourself stand out ... like maybe zipping along at 40 mph on a flat road.

Even *really* wierd stuff like my trike is generally ignored (though I'm on the streets 99% of the time, because its' safer than the sidewalks), because I'm riding "normally" and as safely as it's possible to do under the conditions at the time.

The stuff I ran across when I looked was ebikes that looked like mopeds. Weird is probably better than looking like something that they think they know about.

 

[wturber]

How do you guys cope with motor overheating in such hot places like Phoenix ? Maybe it's not even competition of mid drives that will kill the hub motor industry as OP suggested, but climate change... Morning temps should not be an issue, but coming home from work at 6p.m when it's 50°C outside - ouch; that must hurt.

Not problems really. I have a DD motor. I don't send it much more than 1000 watts. I put Statorade in it, but not because it seemed to need it. I just did it for insurance. I don't have a core temp sensor, but the shell never gets all that hot. I also like to crank hard on the uphill climbs. That's more fun when you know you have motor assist in case you over do it.

 

[wturber]

How do you guys cope with motor overheating in such hot places like Phoenix ? Maybe it's not even competition of mid drives that will kill the hub motor industry as OP suggested, but climate change...

Climate change? Really? Get serious. Let's say that the dire predictions come true. That's 2-3 centigrade maybe 75 years from now. Do you think a motor cares about 2-3 degrees centigrade?

 

[qwerkus]

Climate change? Really? Get serious. Let's say that the dire predictions come true. That's 2-3 centigrade maybe 75 years from now. Do you think a motor cares about 2-3 degrees centigrade?

I don't know where you are living, but here in Europe climate change is definitely real and relevant for ebikes. It's not the increased 1.5°C (2.5°C in 2050) that matter, but the shift in weather patterns. As a result hot spells (when hot and dry sahara air flies over europe) in summer are now 10 times more likely to hit us than in the 80s, and I can tell you from experience that I'm not going out with bbs02s anymore when it happens. For an instance, this year, they hit the 43°C mark in Paris for the first time in History, which means more like 55°C in full sun. It doesn't mean it's hot every day, but when it does, I've seen tires exploding and bike handles / saddles starting to melt.
Same goes for rain in Fall/Winter: increased frequency of extreme rainfall = better waterproofing required. On the plus side ice covered streets are mostly a thing of the past, which means more days out riding
Anyway, I'm not saying climate change kills ebike motors now; I'm just saying it might be relevant for people pushing their motors to the limit, as I did with the bbs02.

 

[MadRhino]

Here it always been too cold in the winter, and too hot in the summer. Climate change hadn’t changed much where I live, except up north where the permafrost does start to melt, so polar bears might migrate south to our countryside backyards. We are not going to have parrots and monkeys anytime soon. We’ve had some -30 a dozen times last winter.

Summer is hard on batteries, because I feed serious power. Easy to puff rc lipos if they are not well vented. My dirt bike hub is OK climbing 20 grade at 50mph for a few miles, controller too.

 

[wturber]

Climate change? Really? Get serious. Let's say that the dire predictions come true. That's 2-3 centigrade maybe 75 years from now. Do you think a motor cares about 2-3 degrees centigrade?

I don't know where you are living, but here in Europe climate change is definitely real and relevant for ebikes. It's not the increased 1.5°C (2.5°C in 2050) that matter, but the shift in weather patterns.

I live in Fountain Hlls, AZ which is a suburb of Phoenix, AZ. I've lived in the Phoenix area all of my 60 years. This is a place where I keep a towel in my car in the summer time so I can hold the steering wheel. I've never heard of a bike tire exploding "due to the heat" - and I've ridden 100 psi tires in 120 degree F (49 C) (actual temperature - not some inflated made-up temperature) on hot asphalt.

Yes, heat waves do happen from time to time. But these days it is popular to attribute any unusual weather to climate change - be it a deeper than usual freeze, a hotter than usual summer, more rain, or less rain - its all climate change. Paris' previous record high temperature was recorded 70 years ago. And, BTW, Parisians feel the effect more than those outside of the city due to its pronounced heat island effect.

https://www.thelocal.fr/20190725/heatwave-heat-sink-effect-raises-temperature-in-paris-by-up-to-10c

Anyway, heat will affect the rider and batteries long before most motors care. I'm far more concerned about my batteries in mid-day summer heat than the motor.

 

[Hummina Shadeeba]

especially in america its popular to disregard global warming based on first hand experience, foxnews, or trump tweets despite evidence from real scientific research and evidence

 

[donn]

Ambient temperature is nothing compared to motor temps. I consider the cut-off motor temperature to be about 250 degrees Fahrenheit. Hot day, cold day it doesn't matter all that much, your motor will cool right down even if it's 110 degrees out.

Right - 110°F air will "feel" just about as cold to a 250°F object, as 100°F air. (or 43°C as 38°C, you prefer.) It isn't a question of what you think about climate change, it's just about whether a hot day can set your motor on fire.

At any rate, given that they do get hot - can you ventilate an off-hub motor, in a way that isn't really feasible in a hub? I've never looked close to see whether those are just cooling fins, or if there's air flow to the core.

 

[amberwolf]

How do you guys cope with motor overheating in such hot places like Phoenix ?

Doesnt' affect it significantly.

On the SB Cruiser, my MXUS 4504 on the left side, used as the only motor with the generic 15FET at around 1000-1500w cruise, 20MPH, will reach about 60-65C peaks at the windings, when it's 45C ambient. That drops in seconds to the mid 50s once acceleration or braking is over, and in minutes during cruise or at stop drops to low 50s.

I never measured the old 9C 2807 I used ages back on it and CB2, but it had to work harder to do the same job, with less mass to absorb spikes of heat, and it probably didn't get that much hotter.


A very small geared hubmotor that can't shed the heat it makes easily, that starts at a higher base core temperature (let's say, sitting in the direct sun on a 45C day so it starts out at >45C), might have a harder time of it. I used a little 350w Fusin front geared hub (but probably saw twice that power or more at full load) on DayGlo Avenger, and pulling a trailer full of St Bernard a couple of miles got it pretty toasty; I don't recall the ambient temperatures, but one time it got hot enough to cause the halls to temporarily malfunction. Wrapping it with a rag and pouring water onto that cooled it enough in a few minutes to keep going, but it kept heating up and stopping. If it had been kept to the design limit, in normal use, it would not have had a problem.

A small DD hubmotor would probably not have had that problem (the 9C, for instance, never did that, even when run at more than twice it's "rated" power level). I worried that they would, but it never happened.

Dogman smoked one of those 9Cs in the DeathRace, becuase the tire on that wheel was basically flat, but he kept racing anyway. The extra load on it plus already pushing it way harder than it was designed for was too much for it. That wouldn't happen in normal use.

 

[amberwolf]

Also, there's plenty of people using hubmotors, at slow speeds on big things, on the hot playa at Burning Man every year.

It isn't a question of what you think about climate change, it's just about whether a hot day can set your motor on fire.

No. Not under normal usage at designed power levels.

If you're outside the normal usage points for it, or above the power levels it's meant for, you could do it even in a blizzard.

If the controller is properly designed for the motor, it wouldn't *let* you exceed the motor's capabilities, including temperature, but that's not very common, even on "OEM" ebikes.

At any rate, given that they do get hot - can you ventilate an off-hub motor, in a way that isn't really feasible in a hub?

Sure. If it's an inrunner instead of outrunner (like a hub is), there's some cooling methods (both active and passive) that can be used that can't easily be done (or at all) on a hubmotor / outrunner, because the coils (which generate the heat) are on the outside, and the magnets on the inside. There's a bunch of threads around the forum on these.

 

[qwerkus]

Anyway, heat will affect the rider and batteries long before most motors care. I'm far more concerned about my batteries in mid-day summer heat than the motor.

I totally agree with that, though it's an ongoing challenge to find a shady place to park on hot days. Now I'm basically carrying an umbrella with me...

 

[Ianhill]

Anyway, heat will affect the rider and batteries long before most motors care. I'm far more concerned about my batteries in mid-day summer heat than the motor.

I totally agree with that, though it's an ongoing challenge to find a shady place to park on hot days. Now I'm basically carrying an umbrella with me...

I got a kuberg freerider and if I give it the death it's always the motor to warm first, it's running 12kw and kicks like a mule does 35mph top end but properly pull a small caravan.

It's hard to judge the motor temp by touch the case is usually aluminium that gives good heat transfer to skin so a 80c motor will feel hot to touch while a 80c bit of plastic won't feel as hot even though they are at the simular states.

I was concerned with battery temps the bike uses 130 cells in a black case but it doesn't get warm even with the heatwave we had it's always the motor that's hot but it takes a full discharge and a adult rider pushing hard to get it there and it's still fine in reality there's another 20c or so left boundary but you can't hold your hand on it for too long.

Liquid cooling be nice, a small compact dirt bike with the heart of a monster beating inside it.

 

[Ianhill]

And to add there's no reason a hub motor can't be liquid cooled it's just not needed at current power levels,

If the axle had openings on both sides it's feesable that liquid cooling could enter one side with a phase and halls and exit the opposite side with the 2 remaining phases, a fair bit of brain storming and forward thinking on design would be needed to get a decent water tight reliable motor but the power level would be well beyond an ebikes needs only the most hard-core need to even apply for such a ride and the cost would limit the numbers so much the venture becomes more enthusiastic than venture capital be a good brand building exercise though for a company with cash on hip and a ladder to climb.

 

[Grantmac]

Adding even more weight to the rear wheel in the form of liquid cooling would have very limited application as opposed to simply building a better architecture where the motor in in the middle of the vehicle.

 

[Ianhill]

Adding even more weight to the rear wheel in the form of liquid cooling would have very limited application as opposed to simply building a better architecture where the motor in in the middle of the vehicle.

Can't agree more I got a mxus 3k in a2b metro and it's a lovely ride but it's rear end is slow to react to suspension travel the damping of the shock has to be set up slow and obviously any heavy off roading suffers but on the road though i find the hub a decent enough ride, I got a scooter hub and build that has stalled I got the parts just need time and a kick up arse with some inspiration and cash.