this is kinda an odd question

P

potatonet

100 W
Joined
Sep 9, 2008
Messages
173
I am building another electric bike designed to tow people on mountain boards up a fire road.

What motor and controller should I buy, I want to be able to use this as my commuter bike as well. I just want to swap the motor out for trailering people up a hill.

here is what I have so far...

1- 50A CL controller
1 5303 motor (commuter motor)
1 406 motor (previous system, not a good idea).
1 bike - whatever I want to buy
1 - 48V 25AH battery lifepo4 ( I can make a bigger one if necessary

I need to tow at a maximum speed of 13 miles per hour, the entire road is uphill and is about 4-6 miles long. what kind of motor should I use here? should I custom wind an X5 motor?

total passenger weight would be 900 lbs including the bike. people are towing with a rope.

Thanks for any help you can give.

Spud
 
potatonet said:
I need to tow at a maximum speed of 13 miles per hour, the entire road is uphill and is about 4-6 miles long.
Click to expand...
What is the elevation change? (That will help to calculate the average slope)

Is the road gravel, dirt, grass, etc.?
 
correction, its about 8 miles and the elevation change is 1100 feet
http://maps.google.com/maps?f=d&source=s_d&saddr=willow+creek+rd+at+coast+hwy&daddr=38.419166,-123.030996+to:willow+creek+rd+at+coleman+valley+rd&hl=en&geocode=&mra=dpe&mrcr=0&mrsp=1&sz=14&via=1&sll=38.416476,-123.036318&sspn=0.047142,0.06197&ie=UTF8&ll=38.415468,-122.985506&spn=0.023571,0.030985&t=p&z=15
 
May I suggest adding a left-side-drive to your large hub? If you make it with a modular mount, you can easily remove the motor, controller, and battery for the second drive when you are not towing others. Just a thought...
 
potatonet said:
1- 50A CL controller
1 5303 motor (commuter motor)
1 406 motor (previous system, not a good idea).
1 - 48V 25AH battery lifepo4 ( I can make a bigger one if necessary
total passenger weight would be 900 lbs including the bike. people are towing with a rope.
Click to expand...

Hmm.. interesting situation you're in. Personally I don't think any of that will cut it. A 5303 is gonna suck way more than 50A and just bog. A 406 you could use as your commuter or sell 'cause that clearly ain't gonna work. That 25ah pack better be ready to deliver 5C+ sustained unless you get a better motor. My all up full rig weight is about 280lbs and my 504 dumping 3kw will climb a 9-10% grade @ 22mph... not really sure what it would take to do 900lbs @ 13mph at your grade.

A perfect system in my mind would be a 5305 (or if you can get your hands on the 5306 that they seem to be able to get in Europe) and a 20" wheel and at least a 72v battery & controller and a pack that is happy at 50A sustained. That might do it. :twisted:

Very cool scenario.. please keep us posted!
 
Maybe a 6KW Kelley hub motor running at 84V or even 96V (supposedly they can take it, I'll be getting one soon to play with), with an appropriate controller, that should do the job, but its going to suck a log of juice getting there and back so I'd suggest a bigger battery pack.
 
Im trying to avoid heating up the motor to excessive levels.

what about the EZee 26" motor, its got something like 85 lb ft of torque at 48V with my 50A controller.

I need a high turn motor, that is all.

the battery can juice it it just needs to be geared properly....

hey wait, could i just use a high powered strokemonkey kit and a rear dérailleur? as in put my 50A controller on the stroke monkey (make sure the stroke monkey is a 5305 or 5304)

optimal motor would be a 20 turn X5 sized motor at 48V

I dont mind paying a decent amount for what I need

imaging a constant 10% grade
 
can't you just re-lace the X503 into a 16" rim? or just put a 12"tire straight on to the hub :lol:
 
When you get it figured out let me know. Your are after what I want. The Puma I have will get to hot, so I assume the BMC's will get hot also.

You will need something that can disapate heat very well. I have fried 2 ESC's 1 set of wires and an aluminum case trying to ride up grades in the mountains.
 
Im gonna do a custom strokemonkey with a 5305 or if I can get a 5307 that would work.

the stroke monkey pulled someone up a 31.5% grade in SF with 495 lbs. Im looking at a 10% grade at 1000 lbs with a larger motor and controller.
 
I vote for the extracycle kit and stokemonkey the motor. Don't forget to put a thermometer on it, and make the battery bigger unless it is allready a high discharge rate cell. It would work just spoking it to a small wheel, but your need to commute on it makes the stokemonkey the way to go for the best can do it all bike IMO.
 
Im getting a surly big dummy and hooking up a stroke monkey to that with a 5306 or 5307 motor.

I will be watching bulk battery buys... or I will just buy another 48V 20Ah battery and use my other one as well.

would rather do it out of a123 cells but that would cost 1500 dollars
 
Dog beat me to it. I would defintely go stoke monkey an xtracycle. A DD hub motor alone is not going to be up to it. You would be dumping crazy amounts of power and generating alot of heat with no real mechanical motion to show for it.

A stoke monkey would have crazy torque. I would probably replace the motor and get a 408 4011 dual wound to try to get the best of both worlds... How about a stoke monkey with an X5305 lol that could haul a Mack Truck with a full load of asphalt lol.
 
Stokemonkey’s exceptional torque moves heavy loads off the line quickly, helps you walk your grocery-laden bike up stairs, and enables you to haul adult passengers up the very steepest streets. We've managed 480 pounds gross up the steepest block in San Francisco (31.5% grade).

This is at 500w so if you double or triple that with a controller at 50A or so you will be able to do what you want to do with this setup.
 
anyone know the gear reduction of a stroke monkey?

I know I can set it manually ( and I would set it as high as possible)

but what I calculated was 273 lb ft of torque.

14T on the motor
44T on the crank side with the motor
32T on the crank side with the derailleur
34T at the cassette.

4.2025:1 gear reduction at 65 lb ft of torque is 273...

would like to get this higher, hopefully the motor will stay cool...

so surly big dummy complete is 2400+500 for motor+ FREE for custom mounts from work+ another 500 dollar lithium battery + using everything I already have = 3400 dollars - wholesale discount for the surly = ???

expensive but worth it if I can get it to work well.
 
It sounds like it will be awesome. With the motor up out of the dirt, you could ventilate the cover too if heat is an issue, but running an x 5 though bike gears, you could break stuff, like chains and gear teeth. Oughta be able to tow several mountain bikers up a ski area road. But loaded down, I'd want to keep it on the big gear rings of the back cluster so all that force is not on just a couple teeth.
 
You could get one of Matt's dual drives with an Astro 3210-7 and gear it as low as you want. Gear it for 15mph and get HUGE torque!
 
Hmm, you basically need to recharge every trip. If this is any kind of commercial operation you need 2 packs - swapping packs between the charger and the bike at the base. And the pack should be able to provide adequate C-rating for the job. A123 pack is preferable as it will allow 15min charge time with appropriate charger.

For the motor as mentioned before the stokemonkey is probably your best bet. Or perhaps try an "all-wheel drive" system with two hubs on 20" or smaller rims - this will greatly help with traction.
 
If I had the choice of the rope tow or dragging myself up the hill w/something like this:
E-Skate-ES-01A-.jpg

...I think I know which I would pick
:)
tks
loK
 
what is this matt dual drive thing? and how do you ride that eskate?

this is for me on the weekends with my friends.

I know I would have to recharge every trip, I think a 48V 50Ah Li battery would do fine.

I think it will turn out to be a pretty sweet ride, I just have to build it.

should I just use my 406 motor and gear that down so I dont have to buy another motor? that thing has a lot of power as it is with my current setup. I also remember hearing something about a 5:1 gear reduction system in a 408 motor a while ago on a 700C wheel?

I worry about it heating up though as I have already begun to melt the wires (I will replace them with 10ga wires, right now they are the stock 16ga for the project motor).

I will definitely start a thread for that build when I get the parts.
 
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