2812 9 continent motor in 26" wheel

Just a teaser today. more info will follow when I get some miles on it.

The motor is the 2812 rear 9 continent from Methods in the for sale section. It came in 20" wheel. I swapped rotors with another motor to get 26" wheel for my off road sand worm bike. Currently running a Lyens 72v 20 amp 9 fet controller on it. It puts out around 1300 peak watts with this motor.

Not a huge amount of power to play with, but keeping it low keeps motors cool. I've been ridng 2810 motors on this bike for a year and loving it. But the 2812 should grind through the deep sand with less overheating. On a first short ride it seemed to ride deep sand well, but still bogs down in that same spot where the sand completely covers the rim and 2.5 inch tire. Buried in wont change without running a huge wattage I guess. Rides wonderfully through soft sand as long as the rim is not buried.

On 72v 20 amps, I am getting 25 mph top speed, and nearly wheelie grade torque. I'll stack it against a 48v gearmotor any day.

On 72v 40 amps, I get 26 mph top speed, and it will climb 7% grade at 20 mph. Pulls about 1500 watts doing it, so that doesn't heat a motor too fast.

Put this motor on a bmx bike with 20" wheel, and I bet it really has nice torque.

Pic of the bike, with a different motor on it.

Cool, I am loving my 6x10 in a 20 inch wheel. It seems to be around 18 mph. @ 60 v = 15s . You should put that 20 inch on the 6x10 and do a comparo.. Mine wants to wheelie a lot I got the Turnigy hooked up and with my modded 9 fet it is pulling 50 amps max. and peaks at 3000 w . Most of the time it is more like 40a and 1500 w unless I really lug it. A 5x12 in a 26" would be great for a bolt up offroad setup as long as you have the volts. And hi volts/low amps should be a watt miser too.

Yeah, tempting to put the old fried and repaired 2810 winding into that 20" laced rotor and let er rip with 3000 watts. I just may have to scare up a bmx frame one day.

I'm hoping I can have a longer ride before overheat with the 2812. My closest riding is a trail I built specificly for pedaling with the dogs. Even 7 mph on it is really tricky. I'm hoping I can just cruise it at 5 mph on the 2812 with less heat. That slow riding is really hard on it though. Hopefully a slower winding will help.

When it comes to the steep hills or deep powdered sugar sand, I won't get miracles from 1300 watts. At some point, x steep requires more watts, and then you risk meltdown if you keep on riding after the hill. Can't wait though, to ride a few short rides with the 40 amp controller. It might be just perfect though, to get a 12 fet lyens programmed to 30 amps. Get a good kick with just a bit less overwatting. The 9 fet 20 amp controller is definitely wimpy, but should keep the motor from getting too much watts all day.

My problem is I always want about 15 miles of riding. Problem solved if I have two dirtbikes. Ride each about 8 miles. 8)

Myth confirmed. The 2812 motor definitely runs cooler on the trails I have near the house. I'm staying cool a bit longer, and using a bit less watthours on this twisty trail that is ridden between 5 and 10 mph. I use smaller blips of throttle and spend more time coasting. The 2810 bogged longer and made some heat. The 2812 gets going a tad faster, and spends less time in the heat making slow speeds. The result is a more responsive, more enjoyable ride. Top speed is still there on the straight roads, with 25 mph possible.

Runs into the laws of physics on a really steep hill though. In 26" rim gearing, you just only get so much grunt per watt. I could add amps, and will at least try it later on, but it still doesn't ride like a trial motorcycle. Can't roll straight up boulders or anything, doesn't really want to wheelie. But it does ride nicer on a slow trail, which is what I primarily want. More importantly, I can ride longer. 8) 8) 8)

Again, this is the 2812 rear motor, 26" rim , 9 fet 20 amp lyens controller, 20s 72v lipo. Great bike for riding on dirt trails.

If I remember right, 480 amp-turns is saturation for the 9C (measured by Justin), so you need 40A of phase current to get to that point on a 12 turn wind. Beyond that makes heat quicker than adds torque.

Dogman, sounds like your 2812 at 40 amps would work really well on pikes peak?

Now put that back in a 20" with Delta/Wye switch. Climb like a billy goat - flip the switch and fly I know my 6x10 in a 20" makes way less growling noise at low speed now. I just put the speedo on that was matched to my 20" front- which I am using and it shows 25 mph. @ 15s It feels fast but not sure if it is right. I need to check calibration.

I have to wonder if any hubmotor could take 40 amps on pikes peak. You really looked at that event? 7700 feet of elevation gain! I suspect you'd smoke the motor before the end of the 24.5 miles. Even if the heat is minimal, that's a loooong ass climb.

But a hubmotor like a 2812 would have an advantage I think, if it was running about 15 mph, over a faster winding. I wish I could afford that trip this year. I'd like to just see if a stock 2807 on stock 36v could even get up it. Theoretically, set the throttle to 800 watts and you'd never overheat. I've proved it works for 10 miles, but for 25? who knows. Who has 25 miles of continuous 7% uphill road to do the test on? Most of the roads In my state are only 10-15 miles long of that kind of grade continuous.

I'll try my 40 amp controller later, but not till I get a thermometer on it.

Some vid from yesterdays ride. I tried to show some footage of a near stop on a sharp turn then throttling up to fast as I could go on the narrow trail.
http://www.youtube.com/watch?v=5eSS2R9Ljvk

dogman said:

You really looked at that event? 7700 feet of elevation gain!

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Looking at the peak this morning............

Dogman, you have experience with low humidity cooling issues. The higher altitude at Pike's peak may produce similar cooling issues. These high altitudes are not good for heat transfer.

Is the data for what happened to the other competitors available somewhere? Was the 9C experiment already run? Or an Xlyte??

This may be an application for a water cooled hubmotor.

All I heard was that only optibikes finished. I am assuming that trying to climb pikes peak with a normal hubmotor would run out of power if they used stock 10 ah batteries. One thing about that 10 ah battery, few hubmotors will melt down before 10 ah is done. If a hubbie pulled 1000 watts, then it would use up 1000 wh in one hour. Lots more than a 36v 10 ah battery has.

And btw. send that snow down here. We got a half inch of rain last winter, on Oct 5th.

My point is that cooling in the thinner and dryer air will be significantly reduced. So they may melt even at 500 watts. Need more data.

Yeah it might be dry up there. August is a good month though, for it to be humid. Thunderstorm season.

I think 500 watts would be ok. In all my desert torture testing of motors, I've never melted one down on 500 watts. Even in 10% humidity and 110 F ambient, they seem to hit a temperature equilibrium below the danger zone of above 200F. At 500 watts, I've mostly seen temps max out around 170F.

But 500 watts is going to be pretty puny on 7-8% grades, so the motor could bog down and then melt. At 800 watts and above, then you see a higher equilibrium temp, but I bet a 9c motor could take 250 F for a long time.

When I melted a motor in the death race the other day, we read about 400F inside there. Since the string inside tying the windings caught fire, I'll assume at some point it was at 451F.

After some more riding, I continue to be really pleased with this 2812 winding when run at 72v. Still haven't gotten around to playing with more amps, or less volts.

It sure grinds through the deep sand nice! I'm really enjoying riding in some places I used to avoid due to the deep sugar sand.

I just got back from a 5 mile ride with a 40 amp 72v controller. Gives me about 2500 peak watts, but mostly you see about 2000-2200 on the CA when starting out in deep sand. VERY quickly drops back to what I normally saw on the CA when using the 20 amp controller, 1000 watts or less.

Interesting the difference in how it rides. Not that much noticeably better at a hard start. Once buried in sand, or on a steep hill, 0-5 mph doesn't seem to respond much better than the 20 amp controller. Basicly, as long as you are stalling it, you are stalling it. The difference is the big controller is just making more heat in the motor. Yes, the motor got hot quicker, may have gotten hotter by the end of the ride. Just judging it by hand, and keeping the ride short so I don't melt this thing. But it makes sense, pulling the bike out of the deep sand at 2300 watts is going to make about 1000 more watts into heat than the 1300 watts I'd get with the 20 amp controller. I found it suprising that it didn't pop out of the sand better. The light bulb is finally starting to light up in my dog brain, why folks are liking hubmotors in 20" wheels. For the terrain I ride though, I'll stick to 26" for now. Big wheels roll over big holes nice.

But once moving,,,, now there you can really feel some improvement. The response between 5 mph and 15 mph is quite a bit snappier, and riding around on sugar sand trails is a breeze. Once hydroplaning on the sand, it rides dreamy. But it doesn't ride the deep sand much better than the 20 amp controller did once up to speed. Basicly, both controllers would push the bike along fine though the deep sand, using about 800 watts, and going about 10-15 mph. Faster is possible, but not dodging the cactus. On a straight road, even in the deep sand, both controllers will take the bike to 25 mph easily.

The 40 amp controller climbs a steep hill much better than the 20 amp. But at a price. You just can't pull 2000 watts on these 9 continent motors indefinitely. Others will brag how much watts thiers are taking, but they aren't doing it continuously in most cases. On a big long steep hill, you will pull that kind of watts continous, so be carefull on big hills with big controllers.

Top speeds are about identical. No suprise, top speed of 25-26 mph only pulls about 700 watts. So either controller can do that easily. That's an interesting result, since with a 2807 motor, there is a definite top speed difference with these two controllers. I suppose the reason has to do with aerodynamic drag on the faster motors. Going 40 mph simply takes more watts than the 20 amp controller provides, so it goes slower on the fast wind motors. With the slow wind, both controllers have plenty to go the same 25 mph.

Great results, dogman. Fire up the simulator and see if you can predict what you are getting, and then predict what would happen with that setup on Pike's Peak. I'm going to do it for my 72V 6x10. Just to see what speed it would go, and what power it would dissipate. Then we can speculate on whether it would overheat or not.

Have you put a thermocouple into the windings yet? It would be really nice to get some real winding temperature data.

Nothing on the windings, It's fairly hard to cram two more wires into those hubs so I haven't bothered. I'm sure I'll screw up and melt another motor without it though.

Right now I'm pretty much relying on keeping rides to less than 5 ah, which should be stopping in time. I'm pretty sure 2000 watts continuous up pikes peak would melt any 9c motor. But two of them, each pulling about 700 watts would be pretty likely to make it. Question is, would that be faster than the 12 mph opti? This is a pretty slow motor. I need to go ride it up my test hill and see what it's top speed is compared to the other windings of 9c. But right now, riding up that hill with a 50 mph tailwind doesn't get you any info.

No, but you can put out your sail and have some fun. Hypermiling uphill.

With two motors the torque winds are not needed. Using two motors doubles the torque and thrust which is quite an increase, much more than the torque wind typically does. And it does it without requiring increase in system voltage.

I just so happen to have a 2wd 9c 2807 26" wheels with 9fet ebike.ca controllers....battery is 12S4P times 4.Ya, 4 packs in paralell. cells are emoli 26700. About 50 pounds of battery on the top tube, total the bike weighs about 130, its a tidal force with mazocchi 888 iirc front.I weigh 225lbs.I went up a big hill we have here for 1 mile. Both motors were just barely warm at bottom of hill before climbing, say 80 deg.f . at the top temp was about 100. It was 4mi to bottom of hill, 1mile up, 4mi home. elevation gain was 526 ft. in that mile. slowest that it went was 13 mph for 200 yards during the steepest part of the hill...took approx. 3 min.total time max watt was 2100. ca said 100w/per mile, motors were barely warm at the top, low voltage on cells was 44v when drawing 2100 watts. Voltage was 47.9 resting at bottom, 47.3 on top resting. the controllers are set for 25 amp . On level ground bike does 28 mph. I hope this gives you guys some insight for this lively disscussion!

cassschr1 said:

I just so happen to have a 2wd 9c 2807 26" wheels with 9fet ebike.ca controllers....battery is 12S4P times 4.Ya, 4 packs in paralell. cells are emoli 26700. About 50 pounds of battery on the top tube, total the bike weighs about 130, its a tidal force with mazocchi 888 iirc front.I weigh 225lbs.I went up a big hill we have here for 1 mile. Both motors were just barely warm at bottom of hill before climbing, say 80 deg.f . at the top temp was about 100. It was 4mi to bottom of hill, 1mile up, 4mi home. elevation gain was 526 ft. in that mile. slowest that it went was 13 mph for 200 yards during the steepest part of the hill...took approx. 3 min.total time max watt was 2100. ca said 100w/per mile, motors were barely warm at the top, low voltage on cells was 44v when drawing 2100 watts. Voltage was 47.9 resting at bottom, 47.3 on top resting. the controllers are set for 25 amp . On level ground bike does 28 mph. I hope this gives you guys some insight for this lively disscussion!

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Sounds like a winner!

Are you anywhere near Pike's Peak? We have a test run for you.

It would be really cool to run some bikes like that up a hill like that. One stock 2807, one dual 2807, one 2810, one dual 2810. I just don't think I can budget the money to go to the pikes peak ride in august. Dual 2810's should beat those opi guys easily if run at about 800 watts per motor.

Anyone have any 2810 in a 20" beside me? Mine is still showing 24 mph. on 15s. I wish I had a gps to make sure. It should be really close to a Crystalyte 409 for speed, maybe a tick slower. We need data

Today I tried my other bike up the same hill ( see a couple posts above) it to is a tidal force with 26" wheels. a 5305 rear, methods 100v,100a controller, battery is 28s5p A123. This time speed at the slowest was 28 mph, mostly in mid thirtys. Time to top of hill was 2 min 10 sec. On the flats bike will do 42 mph, Max draw was 125a. Voltage resting was 93, LV was 84 on the trip up. My impression was this is much faster. Some curves in the road are pretty tight and I wasn't at full throttle either. Maybe the motor would overheat doing pikes peak...I don't know. This hill is steep enough that I wont ride down the whole way, there would be too much speed and not enough brake. Both bikes have front gator hydrolic and rear avid bb7s

Good example of how good it works to heave power at a good motor for a short duration. The deal on Pikes peak is that it's 24 miles of steep hill. That's a looong time to be trying to shed heat from a hubbie. But mo watts is mo bettah for a short hill for sure.


Back to my 2812 in 26" wheel. I've been riding the snot out of it, and though the weather is not hot yet somehow, the results are in. Compared to 1000 watts of power continuos seen on the CA on a 2810 with 48v 20 amp controller, the 2812 on 72v 20 amps is superior in many ways.

More power than the 1000 watt 2810. The 2812 sees 1300 watts continuous on steep hills since the controller has more volts.

More efficient than the 2810. Really? more watts and higher voltage is more efficient? How can this be? But the CA is not lying. I often saw wh/mi in the low 50's with the 2810 setup. Now I think low 40's is high.

Runs noticeably cooler than the 2810. Again, how can this be? I'm pushing at least 200 watts more on the steep hills! Obviously I'm lugging the motor less when crawling up something steep at 10 mph. Keeping the motor in the happy place rpm a bit more is making less heat, hence increasing the efficiency. I was getting honest to god convinced my CA was wonky for a week or so there. Anyway back to heat, Riding in at most 90 F ambient temps, I've yet to see more than 105 F measured at the axle. And that is while climbing hills I never even considered trying to climb on the 2810.

Hill climbing. Climbs steeper hills than the 2810, or if nothing else goes further up before the get off and push part starts. 20 degrees is possible. Degrees baby,,,, not percent. In other words, climbs a blue square ski slope!

Top speed. The 48v 2810 went 20 mph. Perfect for keeping it legal if you are riding a blm, No MOTOR vehicles posted trail.
The 2812 on 72v is going about 24 mph top speed. Close enough to fudge it, and slow up a bit if the lycras are eyballing you. Nicer of course to have 5 mph more speed when you ride the paved road to get to the dirt riding. 72v on a 20' wheel should be just about legal. 8)

Overall rideability. In the dirt, you want to get a smooth response to the throttle with little time lag. You have to slow down for some turns, or gigantic holes, rocky parts, etc. It's nice to get back going asap. This motor does this better than the 2810. 300 more peak watts certainly helps, as does the fact that the stalling speed of the motor is slower. So you go from 5 mph to 15 mph better on the 2812. It seems like I have better low speed throttle controll too, and don't need to use full throttle as much as i used to on the 2810.

Just got back from a nice ride to a picknic spot on the Organ mts. Nice paved road, a favorite of the motorcycles. Most of the climb to the picnick grounds is at least 10% and the steep bits that are at least 1/4 mile long are 13% About a 3 mile ride.

For the majority of it, 10% grades the motor was climbing at 15-17 mph, and pulling about 1200 watts. The steep spots drew 1300 watts, and slowed to 10-12 mph. Heating was pretty minimal, about 60 degrees above ambient. So the motor temp inside was estimated to be at about 120F. AFTER climbing miles of 10% and steeper grade!

Other motors I've run on this route have not only been barely able to go 8 mph with pedaling, but they were smoking hot at the top. This one climbed it at 10 mph on the 13% steep bits, and mostly cruised it at 15 mph. All while staying cool and efficient. 43 wh/mi at the top. Used just under 4 ah of 72v.

For a hub motor folks, that is awesome performance on a hill that steep. You want to go crosscountry over mountains, this motor at 72v 20 amps will do it.