Looking for rear Hub motor for hitting 40mph on flats

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Aug 28, 2016
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Since I currently ride a cheap ebay hub motor, I am currently shopping for a bigger hub motor that can get me to 40mph.

I currently weigh 150 pounds and my bike usually comes in at 50 pounds. My riding style is mostly flat road with occasional small hills between 0-1% grade.

I currently run a 9C 28mm stator 6 turn hub motor clone after cracking open my motor and seeing what's inside. My goal was to try to get this thing to go 40mph but it seems I will need a bigger hub motor to go that fast without frying anything. This is why I come back to endless sphere to ask, what is the best price/performance ratio hub motor that can get me 40mph?

Here's the problem, I am a broke-ass 19 year old college student who can't afford to dump $300-400 on a crystalyte or MXUS hub motor, but could live with spending $150 on a hub motor as that was more reasonable. If I can't get a hub motor (preferably already laced to a 26" rim) I will probably not even bother buying and just live with moving at 30mph.

Are there hub motors out there that can get you to 40mph for under $300 laced to a rim? If it was just a bare motor, then I would also have to buy a truing stand which would be even more cost. Or does something like that not exist?

After doing some poking around on the interwebs, it seems hub motors that will get me to 40mph for under $300 don't exist, unless I didn't look enough. Maybe someone knows of a hub motor that I don't but it seems all hub motors that will get you to 40mph quickly get very expensive.
 
If you're too broke to pay $400 for a motor, you're too broke to repair and upgrade your bike after running it at 40 mph. That's not bicycle territory, and going that fast routinely will destroy a lot of normal bike parts. Your low weight gives you an advantage, but kinetic energy (and thus the beating your bike takes) scales as the square of velocity.

Tell us more about your bike, and we'll let you know whether even 30 mph is within its capabilities.
 
A 9c motor can do 40mph and survive it pretty long, on the flat. Up the voltage, this is not hard on a motor. You will need power too, and learn to dose it because that, can be hard on a motor. Fit a temp sensor inside, add ferrofluid to better disperse heat. 40 mph is not that hard, but you will have hard acceleration and need to keep yourself from abusing it.

You will need better brakes, tires and ideally, suspension. Otherwise you will be safe riding that speed only on perfect surface, in perfect conditions.
 
First, let me add why I wanted to do this:

I am currently trying to beat a guy in my area on a moped, who a few weeks ago absolutely smoked me. If I DO go to 3000w, it will only be for a few miles to beat him in the race, and this will probably occur on mostly flat ground.

Most of the time, I run my system at 52v 30A 1500w and I have been fine with this speed. The acceleration is great at 30A and a 52v battery can get me up to a cruising speed of 30mph all day in my environment. I have been riding 16 miles a day to and from my university at 30mph all day with no torque arm for about 1000 miles, so that has been working just fine so far.

My bike is a gary fisher mountain bike with a cromoly frame with Avid BB5 disc brakes installed. The rear drop-outs have done totally fine with no torque arm so far at 1500w.

Riding style is flat road between 0-1% grade.

I currently have two batteries. I have a 52v 20AH battery built from old power tool cells and a 72v 10AH battey also build from old power tool batteries. I haven't used the 72v battery yet.

Other comments:

Here's what I've noticed with ebikes. If you want to go 20mph, you can buy a cheap $150 ebay kit + some SLA batteries and build something for $300. If you want to go faster, you have to go to lithium ion and higher voltage, and this can add a few hundred dollars

however, if you want to go up to 40mph, prices for parts that will do so absolutely skyrocket in price, and things start to become unaffordable. You need to buy a $500 hub motor + a really thick steel frame + very high discharge cells that can add an additional $500.

Since I don't have money, I always try to maximize my price/performance. These cheap $150 hub motors (although many people don't like them) seem to hit a great price/performance. You can get up to 30mph on these things with a 52v 25A controller and they don't cost a ton unlike the other brands out there.

Not everyone is rich people, so maybe don't be so condescending. Some of us come here because we are looking for information and want to maximize our dollars we have available. We all have dreams to go faster, but not all of us can afford it. Maybe it's time to come back down to earth and manage your expectations for a given price point :) .
 
You can feed a 9c 10kw in acceleration bursts. That is enough to beat many motorcycles on a start. So, to beat a moped, you don’t need another motor. You only need to know how, and to learn the limits of your motor. Pushing a 9c close to its limits, is scary already for most.

Buy a big motor with lots of copper and 50mm magnets, chances are that feeding all it can take will be beyond the ability to deal with it, for you and your bike. And yes, if you do that, you will need lots of money to upgrade everything.
 
If your controller can handle the 72V battery then use that. More volts = more speed. Just be careful not to overheat the motor. There is a lot of info on cooling hub motors here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=48753&p=1379082

And look at Statorade:
http://www.ebikes.ca/product-info/statorade.html

http://www.ebikes.ca/shop/experimental/statorade.html

And read Wes Newell's advice for cheap and fast with a 9C type motor:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302
 
FWIW if you do end up getting a bigger motor un-laced then you can just use your bike frame for the truing stand to lace the wheel .. so you would not need to buy a truing stand for that .. good luck, hope you beat the gasser one way or another..

CUDAcores89 said:
Since I currently ride a cheap ebay hub motor, I am currently shopping for a bigger hub motor that can get me to 40mph.

I currently weigh 150 pounds and my bike usually comes in at 50 pounds. My riding style is mostly flat road with occasional small hills between 0-1% grade.

I currently run a 9C 28mm stator 6 turn hub motor clone after cracking open my motor and seeing what's inside. My goal was to try to get this thing to go 40mph but it seems I will need a bigger hub motor to go that fast without frying anything. This is why I come back to endless sphere to ask, what is the best price/performance ratio hub motor that can get me 40mph?

Here's the problem, I am a broke-ass 19 year old college student who can't afford to dump $300-400 on a crystalyte or MXUS hub motor, but could live with spending $150 on a hub motor as that was more reasonable. If I can't get a hub motor (preferably already laced to a 26" rim) I will probably not even bother buying and just live with moving at 30mph.

Are there hub motors out there that can get you to 40mph for under $300 laced to a rim? If it was just a bare motor, then I would also have to buy a truing stand which would be even more cost. Or does something like that not exist?

After doing some poking around on the interwebs, it seems hub motors that will get me to 40mph for under $300 don't exist, unless I didn't look enough. Maybe someone knows of a hub motor that I don't but it seems all hub motors that will get you to 40mph quickly get very expensive.
 
My advice would be to not worry about who's d*ck is bigger, and let the gasser go. Take the money you save trying to get another 10mph out of your bike and treat yourself to something that will make you happy for more than the 10 seconds you get passing the moped that one time. You can feel good about the fact that you built your bike and got it to just the way you want it, where that gasser jerk just went out and bought a moped. There will always be somebody faster. Life is too short to worry about who has the fastest bike in the neighborhood. Just my 2¢.
 
zro-1 said:
My advice would be to not worry about who's d*ck is bigger, and let the gasser go...

You can feel good about the fact that you built your bike and got it to just the way you want it...

Well, I was 19, a long time ago, but I remember that nothing and no one could have stopped me from trying to build better. Even today, I don’t let myself being too proud of what I have built, always looking for some things I could have missed, that could be improved.

Money is only a mean of building better quality, or taking shortcuts to better performance. Learning is the way to improve, using what we have already. To achieve the best possible performance with the components that we have in hand to build with, is the fundamental essence of competitive building.
 
MadRhino said:
Learning is the way to improve, using what we have already. To achieve the best possible performance with the components that we have in hand to build with, is the fundamental essence of competitive building.

Decades of selective hoarding surely helps. It's seemingly the only way I can afford new bike projects anymore.
 
Okay so about the moped dude, leave him to himself. Makes sense, don't get involved with jerks.

BUT, there actually IS a very practical reason for me to go 40mph at least for 2-3 miles every day on my commute.

I rode this bike 32 miles a day round trip to and from my university. That's why I've done about 1000 miles on this bike so far. My ride runs along a bike trail that runs next to a road, but the bike trail ends abruptly. The speed limit on this road is 40mph.

For a 3 mile stretch of road, the bike trail I ride on abruptly runs out. This section is still on the ground, but there are guard rails on the road + there are absolutely no shoulders to ride on. The reason the trail runs out is for those 3 miles, the trail turns away into a forest, except years ago the trail was flooded with a 3-4ft deep river and it has never been restored. What does this mean?

It means in order for me to connect back to the bike trail, I have to get right on the road and take up a lane.

Since my bike can only go up to 30mph, multiple times I have had drivers angrily passing inches from me because my 30mph was apparently too slow for them. In this scenario, I would have to bet that going faster like closer to 40mph at least briefly would allow me to what I would describe as "blend in" with traffic just for those 3 miles. Drivers wouldn't feel a need to pass me anymore meaning in this scenario, moving faster would in theory be safer. Then after I was out of it, I can hop back on the bike trail and resume riding at 25-30mph.

This stretch of road takes me about 6-8 minutes to cross at 30mph, so that's how long we would be running at probably 2-3kw or whatever speed is required.

I have a hunch that adding FF + heatsinks will allow the motor to take a 10 minute burst like this. This section or road is also totally flat and slight downhill near the end so there are no hills to climb.

But the biggest reason to just finish this project is I already have all the parts on order. You don't just spend $200 on ebike parts and not use them. The FF is coming on monday from lunacycle, some arctic silver epoxy is coming from newegg and I already have heat sinks i've cut up with a miter saw to fit the hub motor.

we'll see where this goes but the verdict from you guys seems to be that:

1. 25-30mph is fast enough practically speaking on your bike and current configuration.

2. If you want to go at or faster than 40 mph, expect to pay big bucks for a gigantic hub motor, high discharge batteries and a rigid frame. Basically your bike is no longer a bike, it's a motorcycle.
 
The way you deal with drivers who don't let you share the lane peacefully is... don't share the lane. Take it. Ride right down the middle if they won't be cool.

They do it for construction equipment, oversized loads, horse drawn whatever-- so they can do it for you. It's your right to take the whole lane if it's impracticable to stick to the right edge. So if that's what they choose, so be it. If the cops give you any static, tell them what's up. The best thing is to know the law where you are and be able to quote the relevant section. There isn't anywhere in the country a cyclist can't take the lane of a surface street if it's necessary for safe passage.

Note that if you're riding an illegal unlicensed electric motorcycle-- y'know, like something that can go 40 mph but doesn't have plates or insurance-- you don't have the right to the lane anymore. No matter how you behave. Just sayin'.
 
Chalo said:
The way you deal with drivers who don't let you share the lane peacefully is... don't share the lane. Take it. Ride right down the middle if they won't be cool.

They do it for construction equipment, oversized loads, horse drawn whatever-- so they can do it for you. It's your right to take the whole lane if it's impracticable to stick to the right edge. So if that's what they choose, so be it. If the cops give you any static, tell them what's up. The best thing is to know the law where you are and be able to quote the relevant section. There isn't anywhere in the country a cyclist can't take the lane of a surface street if it's necessary for safe passage.

Note that if you're riding an illegal unlicensed electric motorcycle-- y'know, like something that can go 40 mph but doesn't have plates or insurance-- you don't have the right to the lane anymore. No matter how you behave. Just sayin'.

Yeah that's exactley what I do, I take the entire lane when i'm riding. Yet they just make their way into the left lane and wizz right past me.

Would love to know how to solve asshole drivers.

What should I do with all my parts then like the 72v controller coming in and the FF? Install it or just sell the stuff or something?
 
What it the make and model of your motor? What is the make and model of your controller? What kind of batteries are you running?

If you want help, we need to know what you are running on now. Be very specific.

:D
 
Try it. If it's not to your liking, or if heat is a problem, the ferrofluid won't hurt anything and you can revert to a lower voltage battery and controller. And if it meets your expectations, there you go. Just keep an eye on your bike's condition and don't let maintenance slide.

I don't know whether I'd get unwelcome attention riding the street at 40 mph on my bike here, because I've never tried it. I ride the street at about 18 mph average, on a bike that could just make it to 30 if I wanted to burn my battery up that quickly. I let cars squeeze by when I can safely make room for them. Then I squeeze by them when they stack up in traffic. My chosen speed guides my choice of routes, since I usually have a range of options.
 
e-beach said:
What it the make and model of your motor? What is the make and model of your controller? What kind of batteries are you running?

If you want help, we need to know what you are running on now. Be very specific.

:D

Motor is a 9C clone 9x6, 6 turn hub motor with 28mm stator and 0.5mm lams. Been running the motor at 52v 30A all day no problems as measured by my turnigy watt meter.

I have two battery packs ready go to. One is a 52v 16AH 14S8P battery made from Samsung 20R 18650 cells and the second one is a 72v 10AH (20S8P) battery made from samsung 13Q 18650 cells pulled from old power tool batteries and individually tested. Both packs can do 50A continuously all day with minimal self-heating as measured by my custom load tester made from heating elements.

Both packs are BMSless and are simply bare packs with the balance wires exposed. Last time packs were balance charged was 2 months ago and all cells are 20-30mv within each-other.

I bought a greentime 48-84v 45A "1500w" controller from aliexpress to deliver the power:

https://www.aliexpress.com/item/GREENTIME-15-Mosfets-48-84V-1500W-45Amax-Dual-mode-Sensor-Sensorless-Brushless-DC-Motor-Controller/32218294528.html?spm=a2g0s.9042311.0.0.07P0cQ

Road condition: Riding is 16 miles with very few stops on mostly flat road that is between 0-1% grade. hub motor has handled 1500w just fine all at stock so far.

Running a 2007 gary fisher wahoo mountain bike with cromoly frame. Dropouts have held up nicely so far with no torque arms installed thus far. I have kool-stop ebrakes on both the front and the rear as well as Avid BB5 brakes on the front. Yes, I have both rim and disc brakes on the front at the same time and they are both pulled by a dual pull brake lever. The new controller I bought also has regenerative breaking but i'm concerned it won't activate with a 72v battery.

Was hitting 30mph easily at 1500w with my current riding configuration.

Goal is to hit 40mph for a brief 3 mile strip of road, otherwise I really like cruising at 25-30mph for safety and more efficiency.

Modifications planned:

1. Plan to add Ferrofluid to the motor to help the heat conduct away.

2. Plan to add custom cut 20x20x40mm heatsinks to the hub motor with thermal glue. Heatsinks are already cut and glue is on order.

3. If that won't do it, i'll add a 12v server fan to the outside of the hub motor mounted to the rear swingarm to blow air over the hub motor but for a 10 minute ride I think that would be overkill.

To ensure I actually ride at 25-30mph after that 3 mile strip the rest of the ride, I plan to use a 72v battery and switch the "3 speed switch" on the new greentime controller to 50% thus (theoretically) limiting my power to 72v at 20 something amps to give me 1500w of power, just at 72v instead.

All parts are ordered and arriving in the mail as early as tomorrow as we speak. Just wanted to know if it's possible to run 40mph for say, 10 minutes while I cross about 3 miles of road before I can hop back onto the bike trail on my ride.

For now, that's the plan. Only concern now is cooking something. The 9C clones apparently really don't like running over 2000w, especially for long periods of time, so I will either have to live with a lower speed and figure out what the hell i'm going to do with my extra parts I ordered or i'm going to be able to run the desired wattage to get me up to speed, just not for long.

I'm trying to avoid spending big bucks on a more specialized motor from the likes of MXUS or clyte since ebay is flooded with 9C hub motors and can be obtained very cheaply. But if you can't reach the speed on my 9C then you just can't do it :D .

Not all of us on the forum have tons of money to buy high power parts, so we go here to see if we can squeeze every last dollar of what we currently have without burning anything up. I'm just asking for some real expertise from someone who likely has more ebike experience than me about whether this is doable.
 
Chalo said:
Try it. If it's not to your liking, or if heat is a problem, the ferrofluid won't hurt anything and you can revert to a lower voltage battery and controller. And if it meets your expectations, there you go. Just keep an eye on your bike's condition and don't let maintenance slide.

I don't know whether I'd get unwelcome attention riding the street at 40 mph on my bike here, because I've never tried it. I ride the street at about 18 mph average, on a bike that could just make it to 30 if I wanted to burn my battery up that quickly. I let cars squeeze by when I can safely make room for them. Then I squeeze by them when they stack up in traffic. My chosen speed guides my choice of routes, since I usually have a range of options.

You probably live in an area where you can choose to do that. I live in Michigan, where everything here is cars, cars, cars and more cars (which is why my riding is nearly flat roads). As such there are few to no bike lanes here, so I have to at least make an attempt to keep up with traffic because otherwise drivers give me the finger and zoom inches past me if i'm not going at least 25mph at all times. Michigan is a hostile environment for biking, but I do it anyway because I love to ride my bike. My other choice would be getting back into a car and joining everyone else on the road, but doing that doesn't really encourage people to get on bikes and ride everywhere like we would want people to do.

That's why I was seeking more speed in the first place. I don't have the money to go out and buy a motorcycle or a high-wattage hub motor, so I wanted to see what I can do with what I've got. Obviously I would love to ride slower but in my situation where basically everyone drives, I have to at least make an attempt to keep up with traffic. Otherwise I will just be passed and glazed by a car that will knock me to the side of the road.

The only routes to my university is either a highway (not happening) or taking a bike trail that runs 16 miles to my university with a 3 mile break in the middle. Unlike you I don't have choices when it comes to safer routes because bicycle infrastructure doesn't exist here.

WE both have different riding styles and objectives. I need to go fast to keep up with traffic, but it sounds like you can go slower because you have better routes available to you. I wish I could be in your shoes and move at a more leisurely pace, but I need to keep up with two-ton hunks of metal full of drivers on their cell phones, so I've gotta move fast or get knocked over. On top of this, I am a 19 year old without the money for a motorcycle or car, so an ebike was a good option for me since i'm electrically inclined. This is where we are now and I am trying to do the best with what I have, but not all of us have bike lanes or even road shoulders to rely on.
 
I don’t let cars pass me, I don’t let them even come close to my tail. I pass them when I feel safe to, then fly ahead quickly. I know they are not to be trusted, that is why I build bikes that are able to outperform them anywhere in the city.

Yet, even with all the performance and experience required, I hurt myself sometimes. Riding in city trafic does require constant focus. One second of distraction, one move that is not the best choice for the situation, can be punished with pain. I survived more than half a century riding horses, motorcycles and bikes. I know pain, as well as I know that performance is not the enemy. A rider is his own enemy, when he is accepting to ride a bike that is not in perfect condition, when he is letting himself being distracted, when his overconfidence does lead him taking unnecessary risks.

So, build and maintain your bike at its best. Ride consciously. Never trust other users of the street. Never thrust that your skills can save you from being stupid or distracted. I have a broken finger today, just painful enough to remind me all this. :wink:
 
It sounds to me like a 16 miles one way commute is the choice you've made that drives other subsequent difficult choices. I'm reminded of the time when I was in college when I moved back to my folks' house and rode 10 miles each way through suburbia and downtown on my pedal bike. (At my fastest, I could make the trip in just under 30 minutes door to door. That was much faster than I go on my e-bike today.)

But for most of my college years, I did what I do now-- I lived within a couple of miles of where I needed to get to. Then and now, it meant reducing expenses by living with roommates, making do with scruffy housing, and of course going without a car. I know that sometimes things don't work out that way, and you have to improvise. But don't be like the dumb jackasses clogging the roads and spewing fumes every day; remember that a long daily commute is only improvising. It's not the right way. It isn't OK.
 
CUDAcores89 said:
....All parts are ordered and arriving in the mail as early as tomorrow as we speak. Just wanted to know if it's possible to run 40mph for say, 10 minutes while I cross about 3 miles of road before I can hop back onto the bike trail on my ride.

Check my math, but 40mph for 4.5 minutes is 3 miles. So to do what you want will only take about 5 minutes. The only way to know is to try it for short bursts and check the motor for heat. If you are not hot after say 30 seconds at 40ish, go for 1 minute etc.

At 72v 45a that is a dangerous bike. Make sure your tires can handle it. Handling a front blow out at that speed would be bad. As for attaching something that might come flying off the motor at speed, I would avoid that. Glue only works until it doesn't. People say fluid in the motor works, but they also complain about leaks. It might be better to put holes in the side covers for cooling. That may require opening the motor and using something like EL™601 Red Insulating Varnish to protect the magnets and stater from rust. Research "Waterproofing an e-bike motor".

If you haven't done so, be sure to check out Wes Newell info as posted above,
(or here: https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302)
also, look at his signature for more clues because he goes over 40mph with an inexpensive yescomusa hub motor. I run a yescomusa hub motor my self but between the stop lights and stop signs around here I can really only average around 12mph no matter how fast I drive. I don't need the speed.

Also, don't forget to set it up to pedal fast, and, becoming aerodynamic helps a lot. A small front fairing and a tucked position might be what you need.

:D
 
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