Dual motor

I'm thinking about building an e-bike with two motors, both on the rear & front wheels, or front motor and & chain drive motor together.

I'm still gathering information. Does anyone have heard about someone doing such a project? Do you have links?

The easiest way would be with two controllers, two pedal sensors (one on each side of the BB) and one throttle. You can use one battery, but it needs to be able to provide a lot of amps, which normally means lipos. Probably best to use two separate batteries. I'm assuming that you don't want to run both motors all the time, in which case, if you get one of those throttles with a built in on/off switch, you can use it to switch off one controller and then you need another switch to switch off the other one. You can use one throttle and one pedal sensor to work both controllers, but you can't connected them directly. You need some additional electronics.
If you gave us some idea about what you are hoping to achieve and what motors you'd be using, it would be easier to advise.

There were some weird issues with stuttering IIRC some people were having. Should have a deep dig through the archives before you start building a dual DD hub bike.

For a DD hub/chain combo, make sure the hub tops out faster than the chain.. and a freewheel on the chain drive motor should keep things simple. I think Mark's motorcycle was setup like this.

ronipozn said:

I'm thinking about building an e-bike with two motors, both on the rear & front wheels, or front motor and & chain drive motor together.

I'm still gathering information. Does anyone have heard about someone doing such a project? Do you have links?

Click to expand...

Here is a video of dual motors
http://www.youtube.com/watch?v=U40w4Y9OO3s

Jack, almost did a triple motors, with push trailer.

Here is picture of dual motors with Surly Pugsley
View attachment 1

This is what Jack wanted to do with his dual motors to run it as snow bike.

Whats your budget, and why do you want two motors?

One possible scenario is to have adequate power when occasionally hauling heavy loads, but then you can have good battery range when you're not loaded and just commuting. Do you want to be able to cruise ultra-quiet occasionally? Is you commute hilly in one part (two motors) and yet flat for the long distance majority (one motor)? What top speed? Do you want to run in the snow or on a beach?

You might also be better served by developing a plan around having two bikes, each with its characteristic strength.

If you could provide more details about what you want to accomplish, there are a variety of benefits to a two-motor system (and yes, its been done before several times). You have many choices, each selection with its own peculiar benefit and drawback...

Hopefully I will have the funds one day to build a dual motor recumbent. I am wanting to put a Bionx 500 rear wheel hub motor. Along with that a cyclone 500. I figure I can put the Bionx on whatever level of peddle assist and use the cyclone throttle. It would be a bike that would cruse at 25 fairly easy. Depending on range I need for that ride I can use the Bionx on assist level 1 then when I use the cyclone up switch to a stronger level of assist with the Bionx. For shorter rides use level assit 4 on the Bionx for high speeds.

I have plans on two different projects, one a trike and one a bike, to use a hubmotor in one wheel (front on bike and right rear on trike) and a chaindrive thru the regular drivetrain.

The hub is meant as additional power, if ever needed, but mostly it is intended as a backup system to get me home if the primary chaindrive fails. I've had enough problems with my CrazyBike2's original powerchair-motor chaindrive system, destroying things due to misalignment of chains/sprockets and/or frame twisting from the torque, that I really need some option for getting home besides just the pedals (because I can't really pedal hard enough to be useful for very long anymore).

In both cases, it would be a small geared hub that would simply freewheel when not in use, to present as little drag on the system as possible.

You can take a look thru my Delta Tripper and Bolt-together Semi-recumbent threads for more info on those ideas.

My dualie ~
9c's (the bargain ones from ebikes.ca)
dual 40a infineon controllers
48v 15Ah lifepo
38mph on flat
can carry me (200 lbs) UP Gatensbury in Coquitlam

Ive been thinking about a Dyual motor bike too...was thinking 2 9c 2806 from, 2 infinion 40 amp controllers, and a 60v 20amp ping.

valsislav ...how did you hook up the throttle/batteries and the controllers for your bike?

Two 40 amp controllers on a single 20 amp hour ping is a going to kill the battery.
That battery is maybe good for one 40 amp controller but not two.

Stephen

I'm having no problems with 15Ah lifepo 48v and the 2 40A controllers, though my rides never use more than 1/3 of the capacity.
As for the throttle, just splice it to both controllers, but use only one of the 5v power wires - unless you want to be popping wheelies.

Edit!

I am having problems with battery - so do not do what I did re. no BMS!

Thanks valsislav,

Anyone know of a build thread for a dually?

Moo

Methods did a dual setup that could do a double burnout.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=12356

farewellhcl0808 said:

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Click to expand...

Spammers should be executed on the spot.

moostrodamus said:

Thanks valsislav,

Anyone know of a build thread for a dually?

Moo

Click to expand...

I built a 2WD bike and drove it from WA-State to CA and back: Back in the Saddle: Going to California: 2011. One Throttle, two controllers (master-slave created from two Lyen 12-Fetters), and two E-BikeKit wheels. Dialed in the programming for economy, though it had great climbing ability and never became hot.

Cheers, KF

Kingfish said:

moostrodamus said:

Thanks valsislav,

Anyone know of a build thread for a dually?

Moo

Click to expand...

I built a 2WD bike and drove it from WA-State to CA and back: Back in the Saddle: Going to California: 2011. One Throttle, two controllers (master-slave created from two Lyen 12-Fetters), and two E-BikeKit wheels. Dialed in the programming for economy, though it had great climbing ability and never became hot.

Cheers, KF

Click to expand...

Ive meant to ask you Kingfish,,, how is your Duel motor with amp consumption? do the motors half each others power consumption? or pull more or less amps,,, does it help your range? ,,,im really trying to wrap my head around this technical electrical duel setup,,, im enjoying mine but have no CA yet to know whats going on,,, my 30-50a bms was cutting off and im going to upgrade it now

CF, a good thread-read is the 2WD (Two-Wheel Drive) FAQ.

You can do this with One battery pack, One throttle, One 3-Way & Cruise & EBrake using Two controllers paralleled, Two motors individually tied to each controller, and Two CAs - one for each.

The overall power is divided somewhat arbitrarily between the two controllers depending on load.

• Going uphill, both will pull evenly.
• On somewhat of a flat whilst in Cruise Control, one will take the lead and the other will go into "slip mode"; pull enough current so that it essentially freewheels... however on the slightest increase in load - it will pick up the slack until Cruise cannot be held.
• Rarely do they go into contention. I beat that by setting the power a little stronger on the RWD, and by having a smaller tire on the rear - so even on a flat, both wheels turn at different rates and that seems enough to fool the controllers.

I don't measure Amps; I measure pack Voltage because the shunts have been modified by trace-beefing and I do not have equipment capable of measuring scant ohms accurately, so I just measure voltage. I know the battery capacity, I know from experience how to set the amount of theoretical current to the wheels, and thus am able to calculate roughly the overall power consumption. The CAs validate this by using Miles per charge; I know how many miles I should have covered by x-amount of voltage drop - which is not exactly linear, but then I understand that too.

During the winter I get less production cos of the studded tires + cold weather; seems like 20% less capacity. I'm about to test a new theory though with the impending tire swap: Use new tubes w/o Slime.

FWIW, my DD 2WD is operating less than 4 hp. Specifically -
The Base configuration for my RWD is 24.2A Batt/60.8A Phase
And the FWD is 20A Batt/51.2A Phase.

Total Amps are 44.2 Battery & 75.4A Phase; 44.2A x 63.3V (when Batts are hot) about 2800 W or 3.75 hp.
I don't run at 100% though: The 3-Way is set to 52%, 86%, & 120% for Street-Legal Speed (used maybe twice), normal cross-country & commuting, and Speed-Testing. So at 86% the maximum power is about 3.2 hp; with the FWD pulling at 45% - that's about 1.45 horses up front, and 1.77 in the rear.

It doesn't have any problem climbing or getting warm after a good long hard ride.

Considering that I don't know the shunt values - this is all hypothetical. The other way to calculate consumption is to measure the battery pack against miles using voltage:

I have 5S1P 5Ah Zippy FlightMax Qty-18, arranged in 15S6P -> 63.3V @ 30Ah -> 1899 potential Watt-Hours. This pack can take me 50 Seattle/hilly miles on a single charge & I've done it multiple times. On a flat - it might take me 70-80 miles; I just don't know. However we can extrapolate that I am getting about 1.67 miles per Ah... up to a point to where battery mass affects performance. Case in point: I went 167 miles on a single charge carrying 100 lbs. of LiPo cross-country in a 15S26P configuration; 167 miles/130Ah = 1.28 miles/Ah. Not that good - but then I was facing head winds between San Rafael & Fort Bragg.

Your performance is relative by your choice of motors, bike frame, riding style, commitment to pedal, terrain, weather, caloric uptake, health, and especially the size of wire between batteries-controllers-motors + and the quality of the connectors.

Anyway - that's longwinded :lol:
Good hunting & safe travels, KF

Depending on you ultimate power level in the rear wheel your money would probably be better spent on a single controller and a single motor that can do what you want. The rear motor is trying to lift the front end of the bike when you apply power, and at high power levels of 5kw and up, wheelies become a serious problem, they are easy to accidentally perform with a speed throttle. If it can't lift the front wheel it pushes the bike forward. So when you have two motors and you use both the rear one is basically just reducing the traction of the front one, which severely limits the power the front one can provide. In a commuter bike, TWD becomes useful when you want to split the thermal load of your demands between two controllers or two motors (ie if neither controller/motor could do it alone), but with infineon controllers and crystalyte hub motors being throuroughly tested now, thermal load has ceased to be as large a concern; the new Cycle Analyst even includes a temp sensor. If you aren't looking to exceed 5kw then just set up an 18 fet infineon with one of the newer HS motors in a 20-26 inch rim. That will get you between 60-90km/h and you shouldn't overheat unless you flog the hell out of it with accel and decel.
Tell us WHY you want a TWD system. Also WHAT you want to do with it. Finally, HOW MUCH can you spend. That will give us much better parameters to help you.

thanks for the valuable info Kingfish,,,

I have a Bionx wheel and I would like to connect it to another throttle and controller (and to 2 12volt in series acid batteries (24v) batteries). Is this possible? If anyone can help me I would be grateful

Off topic from what u had in mind OP i am sure, but my 2wd ebike fantasy is combining the strengths and weaknesses of petrol and electric for unlimited range, among other things.

On a adventure bike trip, charge points are a drag.

The hub motor, which assists getting up to comfortable rolling speed for the; torque challenged, ungeared, unclutched petrol motor, ALSO allows regen recharging of the battery when easy cruising on petrol.

where i am from (oz), petrol bikes are illegal - IF they catch u actually powering the bike using petrol

so i figure, a, very simple and light, easily deactivated petrol motor (like a 25cc 2 stroke brushcutter friction drive), and ebike only when around towns, and use petrol on the open road backroads.

it would add plausibility if the petrol and hub motors drive the same wheel, as in, "i charge my bike at night by running it up on a stand when i camp officer" (which would make it a one wheel drive with 2 motors ).

I have ridden such a friction drive, and combined with a small light geared hub motor as above, it would be a pretty versatile vehicle for some needs.

I could see that working in rural usa, where u cant beat petrol for the long run from the farm to town, but electric is way better for hills and round town for peacefully running errands.

Kept simple, the ICE motor should be under 3kg extra on the bike (even the 4 stroke honda gx25 is only 2.5kg), yet produce ~750w, all day if needed.

just one hr of 750w in lifepo4, is ~6kg in cells.

u dont need pull start. just get rolling on electric and pop start it.