Toshi
10 kW
build an elegant one, ride it around in the seattle rain, and then we will become believers.
I don't like hub motors - (crappy ones)
- Thread starter swbluto
- Start date
You're right about the "experts" blowing controllers. 
Sure, they might have specialized knowledge in respectable fields, but it seems like the one major issue has already been solved(add extra caps - This was recumpence's problem, but he's solved it and no other member following this advice has had this problem including I.) and the other issue(LivingForPhysics, I believe) was clearly not being cautious and he clearly didn't do any heating calculations or heat sinking or incremental testing, so I'd hardly call him an "expert". The basic idea at this point is, add caps and the appropriate heat sinking and you're fine. If more testing by members are done, we can better knowledge of what the limits are and what add-ons are needed and so a better picture can be attained for comparing one option to another.
I agree that each option has its relative advantages and disadvantages, and how much each relative advantage and disadvantage matters will vary from one person's set of preferences to the next. It's clear weight doesn't matter much to you whereas it does to me.
However, I do like me some safety, and I think heaviness in the bike is pretty much a necessary consequence at higher sustained speeds(As opposed to simply being able to sustain 30 mph up a hill), so the extra weight of a 30 pound hub motor may be insignificant with a DOT approved road-safe bi/motor-cycle(Consisting of DOT approved components) of some sort. At that point, though, you're probably starting to look at true motorcycle motors in which case hub/R/C quibbling becomes inconsequential(Although, there are motorcycle hub motors but doesn't the cost difference start to matter much more for the larger hub motor than and so the geared motor is clearly more economical?).
Sure, they might have specialized knowledge in respectable fields, but it seems like the one major issue has already been solved(add extra caps - This was recumpence's problem, but he's solved it and no other member following this advice has had this problem including I.) and the other issue(LivingForPhysics, I believe) was clearly not being cautious and he clearly didn't do any heating calculations or heat sinking or incremental testing, so I'd hardly call him an "expert". The basic idea at this point is, add caps and the appropriate heat sinking and you're fine. If more testing by members are done, we can better knowledge of what the limits are and what add-ons are needed and so a better picture can be attained for comparing one option to another.
I agree that each option has its relative advantages and disadvantages, and how much each relative advantage and disadvantage matters will vary from one person's set of preferences to the next. It's clear weight doesn't matter much to you whereas it does to me.
However, I do like me some safety, and I think heaviness in the bike is pretty much a necessary consequence at higher sustained speeds(As opposed to simply being able to sustain 30 mph up a hill), so the extra weight of a 30 pound hub motor may be insignificant with a DOT approved road-safe bi/motor-cycle(Consisting of DOT approved components) of some sort. At that point, though, you're probably starting to look at true motorcycle motors in which case hub/R/C quibbling becomes inconsequential(Although, there are motorcycle hub motors but doesn't the cost difference start to matter much more for the larger hub motor than and so the geared motor is clearly more economical?).
Toshi said:
Elegance? Hah. You know that requires some capital expenditure in designing something that would be essentially new(Though, that may be a better platform for the awesomeness and power of larger outrunners, overall). But, dealing with the rain is not a problem. All you really need is metal that won't rust(For the motor's main construction) and bearings that'll work well in the rain(Clearly, that already exists). The electricals don't matter because the magnet wire is insulated and the RC controller uses a pretty dang sophisticated "pedal first" mechanism that allows you to start from 0 mph, much like a hall-sensored controller, except you don't have to deal with hall sensors! That was the enemy you were suggesting, right?
But, yeah, clearly time and money needs to be involved with researching and developing solutions that are elegant. But is it possible? I say heck yes! I do wonder if it'd ever be nearly as simple as mounting a hub motor, though, if you want it on any bike. A better solution might be "designed for" bikes, but the current market size may not justify that pursuit.
And, for the record, I've already ridden my electric scooter in the rain and it still operates like new. My motor is even particularly more vulnerable as it's essentially right in front of the wheel. However, time will tell if this lasts.
dogman dan
1 PW
Still trying to wear out my stone wheel. :lol: I used to have the same type of argument on ski lifts, DH skiers vs snowboarders, vs telemark skiers. All the arguments were stupid. MY argument was not. It went like this, today I'm on the telemarks because the powder is perfect and it's more fun to telemark turn in easy snow, AND, I'll beat you to the first tracks since I can climb faster on these skis. Tomorrow the snow will melt some, and be as heavy as cement, and I'll be on the snowboard then since snowboards turn easy in that kind of snow. Later, after a cold night makes it all into ice, I'll be on downhill skis since I'll fall less and that freakin hurts when the mountain is all ice.
The point of the story is that I never shut my mind to any of the tools avaliable, and was therefore free to use the one that best suited what I wanted to do and the conditions present at that time. It's called freethinking. It gets harder to do the older you get.
The point of the story is that I never shut my mind to any of the tools avaliable, and was therefore free to use the one that best suited what I wanted to do and the conditions present at that time. It's called freethinking. It gets harder to do the older you get.
StevenR
100 W
It seems the same effort needs to be applied to the hub motor as have been to the hobby motors - serious weight reduction. I saw in some thread that the mass of copper in an X5 was less than a pound. How much for magnets? Five pounds? Why does the darn thing weigh more than 20 pounds? I agree with both sides of the argument to some extent although I lean towards the hub motor for the reasons expressed and the inherent elegance of the hub motor concept. Where are these super cool MIT designs we keep seeing? Do we have to get some Chinese firm to steal one and start cranking them out or what?
I sort of agree that the hubmotor has flaws example heat and it is a heavy design. I believe we need to add transmissions to ebikes. If we had a cvt or 2 speed gearbox for hills than the motor could be run at the most efficient rpm and hubmotor or not that bike would be a very nice ride. The cvt would be ideal for a nonhub drive. The hubmotor could have a planetary gear on the inside with a clutch to disengage it and run direct when you don't require low gearing. If I had the time I would design a bike with a cvt from a pocketbike use a nice jackshaft mounted behind the motor between two bearings at either end and run a chaindrive to the rear wheel. If you had a two speed hub motor it would also be a good setup. Hub motors can and will be improved and Im sure your designs will also improve.
dogman dan
1 PW
Oh yeah, there's room to improve for sure. Bear in mind the original market for theses things is NOT rich americans. To me the real limitation on hub motors is not weight, but cooling. What we want to do is far beyond what the typical hubmotor is designed for. Select the proper tool for what it is that you want to do. Higher performance is not likely to come from hubmotors beyond a certain point. But if you just want to get from a to b cheap, and the distance is somewhat short, a hubmotor is fine.
icecube57
10 MW
Im sure dogman can agree to this. Atleast designers arent pushing brushed hub motor technologies. Cursed Heat! No heat issues on my brushless. woopie! But seriously if i had a cnc machine i would be all over brushless. But the closest thing you are going to get to a bolt on kit is modify a currie USPD and i dont have the time or patience. We as american want instant gratification... rc motors just dont tickle my fancy.... Work is a turn off.... thats my 11-7 job. When i come home i often hop on the bike to clear my mind. Not to tinker with it for months and i finally get it right to realize its far from perfect. But RC does pay off with speed and torque.... consumption is another story... yeah you can dump a load of current on them and they will be as fast as greased lightning but it kinda brings of the myth of if i drive fast to get to the gas station i will get there quicker and use the same amount of gas as if i drive slower and take more time. But if you buy quality items like the X-5 there a less than a hand full of people that have taken the motor to its death running it at 3-4 times its rating and its one of the motors that the more you give it the more it gives back. But you paid the price fore the indestructable flexibility. On rc motors you can pick up for a 10th of the cost of the x5 and run the damn thing into the ground and still have plent of money in the budget to buy 9 more. I brought up several points but i think its a balanced topic. They have their pros and cons but they both achieve the desired goal.
SamSpeed
1 W
A couple weeks ago John in CR said -- "... silent operation will be hard to give up." I second that motion.
My non-geared hubmotor makes the only the slightest of sounds under power. I've only tried one non-hub setup -- a BMC motor -- and the noise was intolerable. At least to my sensibilities. Think most of the noise was from the chain drive.
Until someone comes up with a truly silent drive, it's hubmotors for me.
My non-geared hubmotor makes the only the slightest of sounds under power. I've only tried one non-hub setup -- a BMC motor -- and the noise was intolerable. At least to my sensibilities. Think most of the noise was from the chain drive.
Until someone comes up with a truly silent drive, it's hubmotors for me.
I've had a chain-drive and I currently use a belt drive. From what I can tell, a belt is much quieter than a chain but the motor+drive-system is still noticeable to the rider, but it doesn't seem to be "buggy" or "loud" to me like a chain system is. It sounds like a dull whir of some sort, rather than an obnoxious rapid-fire clink-clink-clink-clink and it's distracting. Some passerbys have said that it's silent(We were next to a slightly busy road) whereas a group of teenagers about 20 feet away noticed me buzz by behind them in the relative dead of the night as they rapidly turned to see "What's that?".
So, yeah, it depends on your drive system. It's possible to get it to be pretty quiet, but it'll still create more noise than a hub.
So, yeah, it depends on your drive system. It's possible to get it to be pretty quiet, but it'll still create more noise than a hub.
Almasi
100 W
SamSpeed said:
I agree totally with you... I preffer a silent hub motor that make 2KW of power, more than a noisy 10KW Ebike!
In french there is an expression, 'La parole est d'argent mais le silence est d'or' (word is silver..but silence is gold) and that explain why 95% of people will preffer a hub motor.
Robin
recumpence
1 GW
I would not say 95% of people love hub motors. I would say 95% of people like ease of installation.
That is what most of this boils down to.
Matt
That is what most of this boils down to.
Matt
Well, you might have something there. Why do people like electrics to begin with? Is it because it's much more silent than gassers? But why do people like gassers? Is it because it's more powerful and has significantly greater range? So, I guess, if the majority of people prefer more power as opposed to silence, they'll take the gasser, and the majority of people who prefer silence will take the electric so the electric crowd will largely be pre-polarized to silence as opposed to power. Eh, well, I guess I'm not among the majority which isn't a tragedy in any sense. I consider it essential for those that push the boundaries and advance humanity and the available choices.
Almasi
100 W
recumpence said:
You're right Matt, but there is also the clean look, reliability, price...... for me, it's the stealth look / zero noise that was the most important.
My 2 first Ebike use Crystalyte hubmotor....I plan the third one to use one of your drive Matt...and make it more between the Ebike and a MotoCross... at that point, I will only care about speed
Robin
recumpence
1 GW
When driving a finishing nail, grab a finishing hammer. When driving a 16 penny framing nail, use a sinker. When removing a really tight bolt, use a breaker bar. When unclogging a toilet, grab a plunger.
Everything has an application. I absolutely LOVE the project part of this. I am a glutton for punishment, I guess.
However, I want to add an E-drive to my wife's Giant Revive. That drive will be simple. I may go with a freewheeling small hubbie, or add my production drive in the simplest way possible. I do not want to put 200 hours of labor into a bike that will only need 400 watts to get up hills at 10 to 12mph once in a while. But, for huge power wheelies at 35 to 40mph, I am thinking some more time and money will be required.
Each drive used will be chosen for the intended application.
Matt
Everything has an application. I absolutely LOVE the project part of this. I am a glutton for punishment, I guess.
However, I want to add an E-drive to my wife's Giant Revive. That drive will be simple. I may go with a freewheeling small hubbie, or add my production drive in the simplest way possible. I do not want to put 200 hours of labor into a bike that will only need 400 watts to get up hills at 10 to 12mph once in a while. But, for huge power wheelies at 35 to 40mph, I am thinking some more time and money will be required.
Each drive used will be chosen for the intended application.
Matt
JinbaIttai
100 W
swbluto said:
I guess. Mounting a motor that makes it so pedaling is no longer needed seems like the wrong tool for the job to me, however fine that tool may be. We are talking about e-bikes, not electric motorcycles, right?
It seems like anything that expands your options sounds like the right tool to me! :lol: You, of course, have the option of going slower and pedaling if you want, when you want but you also have the option of going faster if you want, when you want. Am I the only one that dreads climbing hills at 5 mph only to have the hub motor over-heat half way up?(Or am I among the few with that problem?) I just have this great preference to not be significantly slowed by hills and having that option available is greatly valuable.
Lucky_Hoodlum
10 W
- Joined
- Apr 11, 2009
- Messages
- 66
I have not an electric bicycle yet i am still in the gathering information stage. I have however discounted using a hub
motor, i think these are good for only flat ground and require much power to be able to make up steep hill, the more
powerful hub motor also is heavy and hard to pedal this isn't good i think. The best hub motor has to offer is easiness of fitting to
bicycle, i see no other advantage. I much like the recumppence drive he make and sell, i think i make similar setup to this. I
I believ this is the best type of setup and much work should be put ino this area not hub motor.
I do however worry only about speed controller i have read that people have burnt them i can see this a problem i hope might
be solved before i commence a build. I wish to not offend people here with hub motor though I make appolgy now
if I offend any one.
motor, i think these are good for only flat ground and require much power to be able to make up steep hill, the more
powerful hub motor also is heavy and hard to pedal this isn't good i think. The best hub motor has to offer is easiness of fitting to
bicycle, i see no other advantage. I much like the recumppence drive he make and sell, i think i make similar setup to this. I
I believ this is the best type of setup and much work should be put ino this area not hub motor.
I do however worry only about speed controller i have read that people have burnt them i can see this a problem i hope might
be solved before i commence a build. I wish to not offend people here with hub motor though I make appolgy now
if I offend any one.
recumpence
1 GW
I am in a different catagory than many others here. I like an overpowered E-bike, but I also like to pedal. What I like is pedalling as much as I can and when I need help, the motor is just a thumb twist away.
I like being able to go for a ride trying for the best efficiency I can achieve, then going for another ride doing almost all pedalling, then going for another ride using the motor 90% of the time going 40mph on back roads.
It is the versatility of E-biking I like most. I ride (pedal) at least 3 to 4 times more now than before I had the motor and I am in far better physical condition. That is because I can ride no matter what hills stand in my way or how fresh I feel for riding that long distance. I used to have to stay home if my legs did not seem up to the task. Now, I never think about that. I just go riding and use the motor as much as my legs require.
Matt
I like being able to go for a ride trying for the best efficiency I can achieve, then going for another ride doing almost all pedalling, then going for another ride using the motor 90% of the time going 40mph on back roads.
It is the versatility of E-biking I like most. I ride (pedal) at least 3 to 4 times more now than before I had the motor and I am in far better physical condition. That is because I can ride no matter what hills stand in my way or how fresh I feel for riding that long distance. I used to have to stay home if my legs did not seem up to the task. Now, I never think about that. I just go riding and use the motor as much as my legs require.
Matt
recumpence said:
It seems counter intuitive but that seems to be the prevailing trend. I've also noticed I wouldn't go bicycling before due to whatever inclines that made bicycling more difficult than I thought it should've been, but the motor solved that problem, and as a result I end up bicycling much more, not less. As a result, I've lost a whole lot more weight than I did otherwise(Not that I was a fatso, but I was following that path of the average car driver. :lol: ).
dogman dan
1 PW
I agree, a motor, whatever kind, makes the bike a lot more appealing in wind, heat, or up hills. I got into this looking for a way to avoid the car for short trips to the grocery store for a few items. Instead I got a lifestyle change, a better body weight, better breathing, and I use the bike for trips far longer than I ever felt were bike distance. Even when in colledge and I had only a bike for transport I never rode this far. 8) I just reached my goal of 3000 miles this year on the ride home today.
RC's are more efficient right? Is this only because of the weight? Or are the motors also more efficient regardless? I'm going to have a hub for my first bike, but if RC can offer a significant increase in efficiency I might have to consider it in the future (definitely a belt based system though, noise is inconsistent with biking).
I think this was analyzed in the progenitor topic(it's a sticky now) in the non-hub motor section, but it seems that the motor efficiency of RC motors can be in the 86-89% range and hub motor are typically in the 73-83% range at best but you also have to take into account that RC motors also have drive system losses that hub motors don't have, so I suspect they're probably comparable in terms of overall efficiency. As far as how much heat RC motors generate per given amount of power, however, RC motors generally win and that's partially what allows them to be more powerful for a sustained amount of time. The other part is the open air design which is like a built in cooling system, for outrunners.
Why are they more efficient? Probably has something to do with the compact design of R/C motors given how valuable compactness is in the R/C market, and the corresponding "air gap" is less which helps maximize efficiency(That is, the part of the electromagnetic field that interacts with the magnets is near 100% intensity, so the electromagnetic potential is more fully utilized).
Why are they more efficient? Probably has something to do with the compact design of R/C motors given how valuable compactness is in the R/C market, and the corresponding "air gap" is less which helps maximize efficiency(That is, the part of the electromagnetic field that interacts with the magnets is near 100% intensity, so the electromagnetic potential is more fully utilized).
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