Touring - Dual Motor vs Single Motor

[Gloop]

I am having trouble deciding what would be better on a tour. For terms of reliability...

A two motor e-bike with independent everything..each 40 amps. This might be helpful over the mountains but not so helpful on long flats..
A single motor e-bike with a spare motor/wheel/controller on the trailer. 40 amps.

I would prefer to have a single e-bike when i get back from tour cause I sometimes ride buses and most of my riding is suitable for single motor, but I guess I could always deconvert after tour.

 

[d8veh]

A 40 amp motor in your front wheel can be tricky to install and will mess up your suspension. If it's a DD, you'll have extra drag too. We need to some more details to give sensible comments.

 

[spinningmagnets]

There are benefits and drawbacks to every configuration. kingfish, Ben Chiu's "Duty Cycle", Zlatko's "Mental manno", teklektiks Yuba Mundo, and several others have run a dual motor set-up. All but one ran matched geared hubmotors, and I do recommend a geared motor for the front.

There was one E-bike that had geared in the front, and a direct drive in the rear, so that he could use regen as a braking option. Since a bike slows down a little when climbing on the hills, the geared hub was one-turn slower than the rear hub. On flat land he only used the rear hub, when accelerating from a stop or climbing hills he used both.

You might consider a sensorless controller as an option for one of the controllers, so a hall-sensor burnout wouldn't leave you stranded.

 

[dogman dan]

One 40 amps powered motor will suffice for touring, even over the big mountains. 48v 40 amps, about 2000w. It's plenty. The motor needs to be big, not a 28 mm 9c type or something, Big motor. My touring bike runs a 5305 crystalyte. Gets over the rocky mountains just fine, loaded down with camping gear.

But an emergency motor is not a bad idea. That could be a front hub, fairly small geared motor. If you die in the mountains, you turn down hill to return to civilization. On the flat, a 250w setup would get you limp in assist.

To me the ideal though, would be a larger geared motor up front, so you could run 3000w up the big hill if you wanted to. Geared so it just freewheels when it's off. Two throttles, or a switch to control throttle signal to either or both controllers. Possibly just a pushbutton throttle on the geared. Jab the button for a quick blast on that short 13% grade.

But seriously, one big reliable motor will do er. If you aren't flogging the thing, if it always is running cool, there is just no reason to have a motor fail. Spare controller not a bad idea, or one set up to mail to you fast. But you won't kill a big enough motor even in the mountains.

Mostly you will be running well below 400w, any more, and you will have to stop to charge too often. So touring is actually kind of easy on the motor.

 

[Drunkskunk]

A 2nd motor capable of 40A with all the needed equipment is going to run close to 20 pounds of additional bike weight. And you don't want that kind of power on a front wheel.
A small geared motor for the front makes more sense, but a well tested and setup single motor makes even more sense.

I mean really, you don't mount a second motor onto a car to go on a long trip, do you? Build the bike to be reliable, test it for trouble, and then don't worry about it.

 

[Gloop]

Ok here is some more information.

I currently own a direct front drive Crystalyte H35 hub motor on a steel-frame suspensionless bicycle. Running 48V at 25 amps.

I plan to buy 2500wh of batteries to be mounted in a massive 4x2 trailer, as well as a second motor system either as a backup or to install in the rear. I never realized it, but you guys are saying geared hub motors have less rolling drag than direct drive?
I heard the drag on a H35 was equivalent to a knobbly tire. Is this correct. So a second DD H35 in the rear would mean two knobbly tires on tour?
Anyway, for now, I am stuck with a DD front motor.

I buy from ebikes.ca and on their site they say the controller is for both sensored and sensorless...im not sure what my motor is?

If i am buying a spare motor for the trailer I do not want a 250 watt motor to save 10 lbs and limp home. I want a same H35 or something like it so I can continue my tour. And if my motor ever breaks down at home, I would have a spare.

The reason I want a spare everything is that ebikes to me dont seem that reliable. I will have two motors, two controllers, and 4 batteries. I hope nothing can go wrong on tour. I can't just call my dad up and ask him to drive 1500 km+ to pick me up and drive me home if something goes seriously wrong with the equipment. I need peace of mind. My bike is only worth 110 so if that fails i can buy a new one enroute. My trailer is heavy duty and cost $1000.

I have before lugged my trailer with 2 dogs, a huge kennel, and 1000 A4 flyers on climate change across the Rocky Mountains, on a 25 amp controller and Nine Continent 500Watt DD. I burnt out the motor but it still carried me to Calgary where my parents lived near at the time so they could pick me up. Worst case, if a cycle analyst fails, the only thing i wont have a spare of, i can get a part mailed.

 

[amberwolf]

There are benefits and drawbacks to every configuration. kingfish, Ben Chiu's "Duty Cycle", Zlatko's "Mental manno", teklektiks Yuba Mundo, and several others have run a dual motor set-up. All but one ran matched geared hubmotors, and I do recommend a geared motor for the front.

There is also my CrazyBike2, which uses dual DD hubs (different types and wheel sizes), one each front and rear, 40A 12FET controllers on each, "48V" 14s EIG NMC 20Ah pack, independent throttles, linked ebrake for regen.

Acceleration from a stop using both motors is MUCH better than with just one, especially when pulling a loaded trailer.


Not sure why it would be bad to run a 40A controller on a front wheel...unless perhaps without torque arms/plates, or something like that.

 

[amberwolf]

I currently own a direct front drive Crystalyte H35 hub motor on a steel-frame suspensionless bicycle. Running 48V at 25 amps.

Is that similar to my HSR3548 (20" rear on CB2)? If so, the motor will do pretty well at 40A for at least shorter bursts, like accleration from a stop, especially if it is in a smaller wheel like mine is. I don't have much in the way of hills around here, so I don't know how this motor would perform on them at those currents.

I plan to buy 2500wh of batteries to be mounted in a massive 4x2 trailer,

Sounds like my flatbed kennel trailer MkIII, used to haul the St Bernards around (one at a time), or various other large/heavy cargo.

I never realized it, but you guys are saying geared hub motors have less rolling drag than direct drive?

Essentially, yes, because unpowered any motor acts as a generator, pulling power from the spinning wheel (some of which is wasted as heat in the motor). Since geared motors generally have a freewheeling clutch specifically to prevent this, they will have less drag than a DD motor--but still more than a non-motor wheel.

I buy from ebikes.ca and on their site they say the controller is for both sensored and sensorless...im not sure what my motor is?

If you have only 3 wires from the motor, it's sensorless. If there are eight (3 fat and 5 thin) wires, it's sensored.

My trailer is heavy duty and cost $1000.

Wow...I could probably build a few dozen trailers for that much! (I have trouble imagining spending that much money on any one single thing).

 

[Rodney64]

Ok here is some more information.

I currently own a direct front drive Crystalyte H35 hub motor on a steel-frame suspensionless bicycle. Running 48V at 25 amps.

I plan to buy 2500wh of batteries to be mounted in a massive 4x2 trailer, as well as a second motor system either as a backup or to install in the rear. I never realized it, but you guys are saying geared hub motors have less rolling drag than direct drive?
I heard the drag on a H35 was equivalent to a knobbly tire. Is this correct. So a second DD H35 in the rear would mean two knobbly tires on tour?
Anyway, for now, I am stuck with a DD front motor.

I buy from ebikes.ca and on their site they say the controller is for both sensored and sensorless...im not sure what my motor is?

If i am buying a spare motor for the trailer I do not want a 250 watt motor to save 10 lbs and limp home. I want a same H35 or something like it so I can continue my tour. And if my motor ever breaks down at home, I would have a spare.

The reason I want a spare everything is that ebikes to me dont seem that reliable. I will have two motors, two controllers, and 4 batteries. I hope nothing can go wrong on tour. I can't just call my dad up and ask him to drive 1500 km+ to pick me up and drive me home if something goes seriously wrong with the equipment. I need peace of mind. My bike is only worth 110 so if that fails i can buy a new one enroute. My trailer is heavy duty and cost $1000.

I have before lugged my trailer with 2 dogs, a huge kennel, and 1000 A4 flyers on climate change across the Rocky Mountains, on a 25 amp controller and Nine Continent 500Watt DD. I burnt out the motor but it still carried me to Calgary where my parents lived near at the time so they could pick me up. Worst case, if a cycle analyst fails, the only thing i wont have a spare of, i can get a part mailed.

Having the controller run sensorless is a good idea. The 5 small wires are hall sensor wires. If either of these fail or one of the hall sensors in the motor fail then you can still run sensorless. The motors rougher on take off but at least you can still run. Just a matter of disconnecting the hall wires from the controller so you do not blow anything.

 

[macribs]

If you are to do a dual motor setup for tough climbing and as a backup motor I would recommend using a direct drive hub motor, a powerful one like qs 205 H50 or H35 or mxus 3000 + a mid drive setup. For mid drive and you situation I would think that the Tangent Drive kit would be perfect. It uses an Astro 3210 and has a 80:1 reduction meaning you will climb vertical if your traction let you. The tangent drive is light weight and highly efficient. https://endless-sphere.com/forums/viewtopic.php?f=31&t=70098

If there is any noticeable drag from the Tangent drive even if it has freewheel, you could even unhook the chain for the tangent drive and put chain back on if you have hub failure or you know you will have days with steep heavy climbing and a big ass trailer behind you.

 

[dogman dan]

That's another thing worth trying. Mid drive + a large direct drive.

I see it as pointless to carry a second H series motor as a spare. But if you do need the better power all the time, hell yeah two big motors. But Amberwolfs use is not a tour, he rides an urban commute, range is not an issue. But getting out of the way of pissed off cagers is!

Again, touring, you only will need to use 200-400w for lots of the ride, and 2000w should get you up large mountain passes unless you are just needlessly over heavy. My touring bike fully loaded with 2000wh and camping gear weighs in at about 400 pounds. That includes two gallons of water too!

You aren't that likely to fry an H series motor's windings. Certainly cannot fry it unless you stupidly keep riding when it's overheating, so a thermometer is 25 pounds lighter than a spare huge motor. If you do lightly cook it, you just need new halls eventually. Your controller will keep going sensorless, so you could just finish an entire tour with cooked off halls.

But adding a second, much smaller and lighter gear motor, or mid drive that freewheels, is not a bad plan. This will give you additional wattage when you most need it, some damn switchback someplace that has 200 feet of 15% grade.

But if you don't care about carrying that second H series motor's weight, then you want to run both motors all the time. Don't run one, while the other is dragging down the bike. Nothing really wrong with that plan aside from the weight and cost. Each motor would then rarely pull more than 500w, and they would both end up pulling less than 1500w each climbing the steepest of highway roads. State highways in the US really rarely exceeds 8% for very far. Scout your trip using a mapper like map my ride, so you don't plan on ascending one of those rare 15% grade roads.

If you really are going dual motors, two cheap 28 mm type motors would give you all you could ever need in power and reliability. But nothing wrong with overkilling it with two H models.

 

[Brentis]

Not to piss on Tanget Daves mid drive, I quite like it!
But the OP is looking for reliable to redundancy. Two stones reliable.
Most mid drive builds I've seen have required more maintenance and have more reliability issues, than a properly set up DD hub drive.

I think you are getting some sound advice.
There are a couple of threads about members long treks across North America, on phone so can't post links easy, but search it out. Kingfish, grindz?(Troy), of course Justin's across Canada, there are quite a few long journeys done.
Great reads and you'll learn tons, and relieve some worries maybe.

Good luck and safe journey!

 

[macribs]

Not to piss on Tanget Daves mid drive, I quite like it!
But the OP is looking for reliable to redundancy. Two stones reliable.
Most mid drive builds I've seen have required more maintenance and have more reliability issues, than a properly set up DD hub drive.


Good luck and safe journey!

Well redundancy it is with DD hub and a Tangent drive. 1 battery. 2 controllers, 2 throttles and 2 motors. Now that could be even taken even further by adding a battery solely for the Tangent Drive. There is your redundancy. Double up on everything. No single point of failure. The redundancy of a dual motor, but without a heavy hub motor in the front wheel.

If hub stop working or the hubs controller is fried, there would still be enough power in the tangent drive to complete the tour. Heck he could even trow in a spare light rear wheel on his trailer and swap if the hub or hub controller dies. And run efficient on the astro/tangent drive. Still be able to climb anything and pull a truck if needed.

The TAngent drive has freewheel so there should be no problems to rely solely on the hub motor for most of the journey.

 

[dogman dan]

Reliability should be there with almost anything that's used only on the steepest hills to aid the DD motor. But,,,, hard to break much on a front hub motor, especially if it will run sensor less.

My touring lame compared to Grindz, Kingfish, or Justin. Only two nights away trips so far for me, 200-250 mile rides. But I have done years of riding 60 mile day trips. That reminds me of the time the dd motor failed me, uhhh, wait a min, it never happened. Lots of those day trips up huge mountains, like 10 miles of non stop 8%. What I have had issues with are wires, connectors, CA shunts, Controllers and of course tires. And finding places to charge, out here towns are very far apart. You must have 70 mile range.

He's worrying about something that won't happen, as long as his H motor will get him up 10% grades at 15 mph. If it won't, then maybe he does carry enough weight to need 4000w by having a second motor.

Bottom line is, his current motor is utterly reliable, unless he goes out and kills it with an overloaded bike. Up to 400 pounds, he's got no problems in sight with just one motor that can pull 2000w.

Google Marissa Muller, she just rode across the continent towing a solar charging trailer with a 750w bike.

 

[Brentis]

Not to piss on Tanget Daves mid drive, I quite like it!
But the OP is looking for reliable to redundancy. Two stones reliable.
Most mid drive builds I've seen have required more maintenance and have more reliability issues, than a properly set up DD hub drive.


Good luck and safe journey!

Well redundancy it is with DD hub and a Tangent drive. 1 battery. 2 controllers, 2 throttles and 2 motors. Now that could be even taken even further by adding a battery solely for the Tangent Drive. There is your redundancy. Double up on everything. No single point of failure. The redundancy of a dual motor, but without a heavy hub motor in the front wheel.

If hub stop working or the hubs controller is fried, there would still be enough power in the tangent drive to complete the tour. Heck he could even trow in a spare light rear wheel on his trailer and swap if the hub or hub controller dies. And run efficient on the astro/tangent drive. Still be able to climb anything and pull a truck if needed.

The TAngent drive has freewheel so there should be no problems to rely solely on the hub motor for most of the journey.

Maybe I shouldn't say anything as it may sound stand off'ish.
Maybe the OP has a trust fund for such a situation.
But to spend $1400 on a back up system that is unproven(anyone run one of these for any amount of time) seems foolhardy to me.You could buy 3 maybe 4 hub kits for the price of that.
Just seems way more complicated and expensive than it need be.
Mid drives can be sexy as all get out. Or they can turn a commute/tour into a nightmare of frustration.
DD hub, one moving part for the reliable win.

A 2nd motor capable of 40A with all the needed equipment is going to run close to 20 pounds of additional bike weight. And you don't want that kind of power on a front wheel.
A small geared motor for the front makes more sense, but a well tested and setup single motor makes even more sense.

I mean really, you don't mount a second motor onto a car to go on a long trip, do you? Build the bike to be reliable, test it for trouble, and then don't worry about it.

+1 and touché

On second thought....
Maybe one of those 6' long jet motors strapped aside in case something happens.

 

[Gloop]

I have checked ebikes.ca and the only options they have for a rear hub is the Ezee which is 4kg and the H35 which is 7.5 kg. The H35 is 500-600 bucks the Ezee is 700 bucks.

Maybe i should just stay as a single motor and if a motor does break on me have it shipped. A spare H35 in wheel is about 22 lbs.

I guess what will determine if i can go dual motor or not, is whether i have enough money for 3 or 4 batteries.

The smallest motor is an outrider that weighs 2.4 kg. I guess i could pack that as a spare on the trailer. (its not available in rear models)

 

[Grizzl-E]

2 small geared 350w mxus motors. Individual 17 amp sine wave controllers. Pas is only hooked up to rear motor and the geared front motor causes no drag. Throttle to both. Carry an extra throttle in your bag and an extra tiny controller.

Cheap, reliable, climb anything, lightest weight, best efficiency without going mid drive.

Oh ya and it's nearly invisible if your battery is in a bag so not such a theft target.

 

[dogman dan]

Though nice, that would be a bit underpowered for climbing huge mountains when the bike could load out to 400 pounds easy.

He's already talked about 4000w of power in the first post. Two larger geared motors though, that could run reliably at 3000w. Like two ezees. I like the idea of one HS and one front Ezee, if you are going with grin for everything.