Overload protection/high torque motors

[gentle jim]

First time posting. I have been reading extensively for some time. I really hope that I'm not repeating an existing topic. But, I am older and there's a "lot" out on this site. Some great information, a lot of which is over my head.
I have used ebike.ca's simulator and really like it. However, it shows that almost all of the motors will burn up if used for a 200 pound person, like me, climbing a 3,000 foot elevation over 10 miles, even with my pedaling at a 6mph pace. What are the strongest motors available? What do you think about brush motors over geared motors? Which ones are the least likely to overheat? I have read that more coil mass will take longer to heat-up. I can drill holes in the motor casing, but I live in a damp place and I don't want my motor to rust. I also read that there's a ratio between the number of copper coils to the amount of torque. Do any of them have fail-safes where they shut-down before they allow the motor to burn up? Basically, I'm looking for a motor that will endure. I plan on using 48V 20ah batteries with it, and not in succession. But, I'm open to suggestions. I have a dream of using my bike, with trailer, to get to and from town. Then when my car dies, I'll drop car payments, car maintenance, insurance... and be living that much more simply.

 

[dogman dan]

200 pounds is not over the line, I'm 180-190, and ride up very steep stuff.

3000 vertical feet is a serious climb, but I've done similar on standard kits, with some energetic pedaling. But not pedaling my guts out.

Here's what matters. What grade is the road? Up to 10%, most hubmotor kits that are capable of 1000w can do it, even for many miles. The climb I was refering to was 20 miles long. The first ten miles easy, at 5% or less. The next 8 miles, at about 7-8%. The last two, 10%.

Winding of the motor matters. Slow windings tend to climb hills cooler. But not always faster. So you trade speed for a cooler motor in general with slow motors. I'm the slow motor fanboy here. Check out some of my threads in pics or reviews on slow windings. Search 2812, or 2810 9continent.

Another guy I recall rode up to a ski area daily. He climbed mostly 8-10%, but lots of it. You do heat up a motor, but depending on the grade, and what motor you are using, you reach an equilibrium temperature at some point. If you can reach equilibrium temperature at less than 200F, you have no real problems.

Where are you? ( just country and state) Legal issues are you main impediment. John in CR is unlimited, and builds bikes that haul ass up hills. I am nearly as lucky, I have only a legal speed limit to comply with. I can watt up too all I want. In the USA, you may be able to just keep it near 20 mph max speed, yet ride with nobody realizing that your bike has 2000w, rather than the legal limit of 750 common in many states.

 

[wesnewell]

By my calculations that's only a 5.7% grade. Any 48v 1000w motor will handle that easily.

 

[dogman dan]

Yep, no particular problem if the grade is fairly constant. If it's a US state highway, above 10% grades are quite rare. They really try to keep it down to 8% max to avoid having to have it be too dangerous for trucks.

The key thing is keeping the motor at a speed above that motors mimimum for climbing a hill. For typical hub kits, it's 15 mph. at 6%, that should be easy. Slow winding motors I like so much can climb as slow as 10 mph, making keeping to the minumum even easier.

Gotta be willing to pedal, but not to the point where you are unable to talk normaly.

Just went and looked at the biggest climb I ever did. Turns out a bit shorter, the steep 10 miles was 2000 ft gain not 3000ft. But the bottom line is my motor did not keep getting hotter and hotter. It got hot in the first few miles, then reached equilibrium at a safe temp. So it would not matter much if the ride was longer. Steeper would matter, but not longer.

 

[gentle jim]

Thank you Dogman and Wes, my commute is the last half of the Tour of the Unknown Coast in Northern California.
Here is a link to the hardest section: www.youtube.com/watch?v=CDbfYnPZyWQ. The notes say that it is an 18-20% grade. I have climbed it, grinding on the pedals in my lowest gear, after a break at the bottom of the hill. It is only about 1/4- 1/2 mile I think. I am hoping to get exercise with my electric bike. I'm plan to use the crank arm tension throttle control, so that when I gear down and spin it will reduce the strain on the motor or gear up, reducing my cadence, to get more of a power assist. I thought of using a Turnigy Watt Analyzer to manage the strain on the motor.

 

[dogman dan]

Ordinary hubmotors don't gear down. Bottom bracket drives allow you to downshift, they drive the chain. close to 20% is serious climbing. How long is this 20% grade section? 10% is where stock motor kits just about max out, even when pushed to 48v.

 

[wesnewell]

Since you can pedal up it without a motor, why would you worry about doing it with a motor. It will just make it easier and a lot faster.

 

[gentle jim]

Wes, you sound like my older brother... My problem is that it takes me 7 hours to get to town, by bike, without any assistance. I was hoping to make it in 3 hours. My brothers answer is to start training harder. I was actually hoping to haul my Burley trailer for my weekly trip to town for groceries and supplies. The climbs aren't as severe on the return trip, when the trailer would have groceries, etc.

Dogman, thank you for the references. My eyes are bleary. The "off road mode legal", the Oakland ladies "someone needing e-bike.." and "where to buy a 9C 2812..." lots of great information.
I am not hoping to go over 30 mph, but to average 20mph. Our roads are filled with nasty pot-holes. I'm 53 and my bones don't mend that well. I don't worry about police. I have only seen the sheriff out here twice in the last 4 years.

A lot of postings mentioned the speed requirement in order to not burn out the motors. That made me realize that what I'm really looking for is a non-hub motor, like the "stokemonkey". This quote from one of your postings hit home "As you shift gears to maintain normal pedal speeds, you keep the motor operating between its most powerful and efficient speeds, for several times the torque, higher top speeds, and much better range than typical electric bike products lacking variable motor gearing."
I really like the idea of pedaling, for the workout, but would appreciate the visualization of riding a tandem with a stronger cyclist as my partner. What are my alternatives?
I thought the gear-driven motor would answer my burnout issues. I could gear down to where I was pedaling at 90rpm and moving like a snail, the motor would be tied into that gear ratio and wouldn't encounter the stress of a 1:1 gearing on the 20% grade climb.

If that isn't feasible, then I would be back to looking at a crank-arm tension driven throttle that I could disengage if I sensed that the strain on the motor was too much. I'm afraid that the climb with a trailer, much heavier bike (with motor and battery), etc. will make an unassisted climb much harder for me...

Any other suggestions on configurations would be helpful.

There were a couple of comments I couldn't understand. The 2810 motor on 18s. What's the 18s? and CA settings? or dp CA?
Thanks!

 

[ZOMGVTEK]

....Hubzilla and 3kWh of LiPo on the frame? You can cut that commute down to an hour or two.

You can just set the cruse to 30 and sit back. Should be able to manage 30 up hills too.

If you have 2-3K burning a hole in your pocket, it wouldn't be that terrible of a way to spend it. But yeah, this approach is a whole lot closer to buying a motorcycle than pedaling a bike.

 

[dogman dan]

18s lipo, translates as 18cells in series, lipo is 4.2v per cell. A few volts less than 72v nominal.

CA is an ebike computer called a cycleanyalyst. The DP model plugs straight into your controller, if it has a CA plug, allowing the CA to limit speed, limit watts, and other functions. The stand alone kind works with any controller, and still gives you a lot of great information in a fuel guage type manner. It's a very sophisticated watt and volt meter.

 

[gentle jim]

Thanks for clarifying those terms for me. I am going to continue reading posts in an effort to understand enough to feel confident that what I buy won't be too far away from what I need. I have a friend of a friend that builds e-bikes that I'm hoping will be my trainer. I wish that there was a good book or place to learn the basics of building e-bikes.

 

[wesnewell]

Hubzilla would easily do the job for you at 48V.
http://greyborgusa.com/products/motors/hubzilla/

 

[dogman dan]

Is California a good state to build and ride an illegal homemade unlicenced motorcycle? Might be better to do some kind of looks at least moped legal approach. A slower winding hubzilla would be perfect though, not crazy slow like the 9c's I ride. But wound to go 25 mph on 48v would be good. The same as a 2808 or 2809?

Too bad the stokemonkey is now unobtanium. That's been the perfect thing for quite awhile. Gone bye bye though. You can get an optibike, but $$$$.

Dual hub 2810 9 continent motors would likey do it. Still only 20 mph at 48v, but a solid 2000w of power. You'll have a lotta money in batteries. Maybe two 48v cellman packs? Two 48v 15 ah pings?

 

[pwbset]

Another guy I recall rode up to a ski area daily. He climbed mostly 8-10%, but lots of it.

Hi gentle jim.. I'm the guy dogman is referring to here. I was out of the ebike game last summer, but am putting together my 4th build for this summer and trying to source a motor now also. I can tell you my past experiences though in case they help.

I used a rear Crystalyte 4011 motor in a 26" wheel at 2-2.2kw of sustained power during about 20 minutes of sustained climbing on 8-10% mountain roads at about 18mph, but the motor would be extremely hot by the time I got to the top. I always put a fan on it in my office right away and it never seemed to lose power or fry the halls or windings or anything, but I also pedaled quite a bit and arrived to work sweaty (good for getting in shape though haha). I weigh 200lbs.

I then switched to an older style rear Crystalyte 504 (symmetrical) in a 24" wheel. 25lbs compared to the 15lb 4011. At the same 2-2.2kw power levels I'd still go about 18mph due to the smaller tire size, but I didn't have to pedal at all if I didn't want to, which was nice. Had I a better controller/battery setup I could have easily gone up the mountain at 30mph or more. That motor barely ever got warm. That setup weighed in over 80lbs though. Heavy bike.

For this summer I'm trying to keep weight down to a minimum. I've decided on a cheapo hard tail Costco bike and a cellman 52v11.5ah "A123" triangle battery system... still not sure about controller, but will probably go with a infineon one... and am looking into either a 10t or 12t MAC motor or maybe a 2810 or 2812 9C motor. Not sure, but I want a sustained 2.5kw this summer for just a bit more speed. I wanted a hubzilla or HT3525 Clyte, but I think it's overkill for my commute... though they could handle the heat better that's for sure. It's easy to read about all these high power builds and how cool they are, but in reality if a motor can handle it 2-2.5kw sustained is a lot of power on a mtn bike. Anything over 30mph and I feel like things get dangerous, but then again I've wrecked badly before so have some respect now for ebiking.

Dogman knows a ton about trail riding and hill climbing so listen to him and others here and read, read, read and post a build thread of your own. ES members are incredibly helpful.

I can't wait to start riding again this summer!! Haven't had an EV grin in way too long! 8)

 

[999zip999]

You need a great battery to power it an a123 from cellman is plug and play. Or lipo after reading it's pro's and con's, not plug and play. You have to unplug and seperate to charge in a protected garage ect. That hill is a wall. Maybe a 2812 ? It's slow. A 2810 kit from methods called a wife's bike kit, maybe but that a mountain. 48v or more.

 

[parabellum]

I can drill holes in the motor casing, but I live in a damp place and I don't want my motor to rust.

You also can use "Oil cooling" approach on hub motors. Even Cellmans Mxus DD kit can take a lot of abuse and serious climbs if heat is dissipated.
http://endless-sphere.com/forums/viewtopic.php?f=30&t=34369

 

[gentle jim]

Thanks for the help. I will definitely post progress once I get started.
Dogman, I can't speak for California in general, I live in a very remote area of Humboldt county where police are busy with other pursuits. I plan to have saddle bags in back and to always be pedaling and rarely go over 30 mph. This is a big tourist destination and lots of long distance cyclists travel through. I'm hoping to go under the radar, by appearing to be a cyclist in "great" shape...
Pwbset, have you looked at the Clyte HS5340? Several postings have referred to it as a reliable heavy duty motor. Especially if you drill holes in it for cooling.
Based on all my reading, I was considering going with two 48V 20ah Ping batteries (one to swap in when the other dies), a 25A Infineon controller, CycleAnalyst and the HS3540 motor. Then use this with the ebike.ca pedelec torque sensor and throttle potentiometer (4 level cruise control). I may also install a throttle, that can bypass the pedelec set-up, in case the torque sensor fails.
I'm hoping to put the cruise at the lowest setting and grind my way through the 20% grade section. I'm afraid that I will be going the pace I would without an ebike given the increased weight of the bike.
I'm open to advice. Has anyone had the 9C 2810 or 2812 and a Clyte HS3540 to make a comparison? I like the idea of the a123 batteries that can fit in the triangle. I'm considering converting my Marin Nail Trail and I'd have to put the batteries off a rack on the seat post stem. That'd be a lot of weight...

 

[999zip999]

Get a controller that has a plug for a cycle analyst and get one. Then you can get a higher amp controller and turn it down to your needs. But can't turn a 20amp' higher. If you don't give a strong battery it will burn up going up a long hill. Balance.

 

[parabellum]

Has anyone had the 9C 2810 or 2812 and a Clyte HS3540 to make a comparison?

9C 2810 or 2812, Clyte HS3540, MXUS and GM 1000/48 are same design of motors with slightly different stator and magnet wide.
HS or HT will have more torque because of widest stator of 35mm (sometimes 32mm) but same heat dissipation area as other 3 participants which reduces the extended possibility without cooling modifications.
My personal opinion is HS or HT of crystalyte was my worst investment considering worst mashining and assembly quality and triple+ cost of maxus (26mm stator) or GM 1000/48(30mm stator).
Never got my fingers on 9C.

 

[999zip999]

My 9c works fine as I have lot's of hills and tops out at 23mph on 60v. 35amps. off the charger. I'm going up to 72v for more speed. It does have a whine at 14-15mph. It sounds bad be works

 

[dogman dan]

HT motor. You need some advantage from the lower speed winding. HS is for max speed on flatter terrain. Boot it with power if you want, but by 30 mph you ARE conspicuous. So hit the brakes a bit and faux pedal when you do see a cop. But if you build a super Ebike, you will stand out, doing 45 mph and all.

Two 48v 20 ah pingbatteries is going to weigh 40 pounds. Screw that. At most, carry 30 ah. Even that is going to make your frame flex like rubber.

Put a rear motor on a bike, and 30 pounds of batteries on it in panniers, and it's going to handle like dogshit unless it's good longtail cargo bike.

How much range are you needing? At 20 mph, a 48v 15 ah ping is good for at least 25 miles. Or more, slowing to just 18 mph gets you close to 30 miles. With a 5 amp charger, a 48v 15 ah ping recharges in 3 hours even if fully discharged.

 

[mikebikerad]

Hi Jim,

Good to see ya on here

Mike