Xtracycle conversion

[lawson415]

HI All

We are thinking of adding electric power to our daughter's Xtracycle . She lives on a big hill in Seattle and she and/or her husband carry a lot- 2 year old kid, 5 bags of groceries, etc.

I see there are several members with Xtracycles on this forum. I like the all wheel drive aspect of front hub motors but am do not know how they would be for a long heavy Xtracycle What are your thoughts on motor, controllers,battery etc for xtracyle?

Regards

Robert

 

[slacker]

i have a surly big dummy with a rear 9c motor and 36volt lead acid battery.it rides and handles like a dream.you will not be sorry putting a hub motor on it.

 

[deardancer3]

the long length would easily be supportive of a chain drive, which youre loads would appreciate. consider a cyclone, but their are others too.

d

 

[Rifle]

I think
front hub + big uphilll + rain + lots of cargo = traction issues

 

[joe tomten]

Definitely do a rear wheel drive. Much safer and more forgiving in the event of rear wheel slippage (merely scary) than front (devastating).

If the hills are really steep and prolonged then a stoke-monkey might be the only (easy) way to go. Or possibly a geared MAC rear hub or similar.

Our build:
Bike: electra townie (crank forward, low C/G, allows battery just behind the seat, low, but within wheel base for a very stable riding platform.)
Motor: 9C 2807 DD hub, does great where I am, which has moderate hills, and plenty of headwinds. Crusing speed is ~21-25mph on the flat with vigorous pedeling.
on 48Vnom. lifepo4. (Keling 48v15ahr)
Lyen mini-monster controller


Longtails were born to be electrified.

 

[amberwolf]

I'm partial to thru the chain drives vs hills, because you can shift the gears to get better speed on the flats but shift down again to get better torque on the hills, to put less load on the motor than with a hub.

The StokeMonkey system was *designed* for the xtracycle setup, and does this, albeit in a way I don't like (forces pedalling with the motor; I found that to be a problem for me many times on CrazyBike2 when I had my powerchair motor setup that way).

But you can add a thru-the-chain drive via jackshaft, too, that combines pedals plus motor before going back to the rear wheel.

For very simple instalation and maintenance, a rear hub is probably the best choice. But for more efficient operation, and keeping the motor and battery requirements down (assuming big long hills frequently on a trip), thru-the-chain drive is probably better.

If you want to poke around the forum, you'll see a number of builds that do this in various ways, sometimes called BB or bottom bracket drive, Cyclone, Elation, StokeMonkey (SM), etc.

 

[snowranger]

I too was thinking about the stokemonkey but the high expense and increased drivetrain wear put me off. A good geared hub motor like a bmc would be a good compromise between a big direct drive hub and a thru the bike chain drive system.

Pluses:
Light weight (10 lbs)
Good torque.
Reasonably quiet.
Reasonably low amp requirements around 25 amps.

Minuses:
Less ability to overvolt and overamp.
More expensive.

A good way to mount a battery would be to use the old brake bosses as an attachment point behind the saddle. I've got over 8,300 miles doing San Francisco hills on my xtracycle with bmc V1 motor, having to change the white gears out. The new V2 torque motors should be very durable at 36-48 volts.

 

[dogman dan]

Normaly I'd say a front hub would be fine, but like said above, in a wet place rear motor would be best.

My recomendation for a simple hub motor install would be the 9 continent 2806 winding. The low speed motor will do better on hills than the normal kit motors. Run it on a 48v controller, for a max speed of 20 mph.

Get it here only, at the moment. http://endless-sphere.com/forums/viewtopic.php?f=31&t=26603

Right now I have a 2807 on my longtail cargo bike, running 36v. Next time I have a tire or tube issue, I'm putting my 2810 on it for sure. It's too sluggish on the hills now, and going 48v will have me going too fast for city use.


The BEST motor for an extracycle remains the stokemonkey for sure, but it lacks the simplicity of the hubmotor. Choosing the slower wind hubmotor will take some of the disadvantage of a hubmotor away. The 2810 motor is a pretty good compromise, giving you better than normal hill climb, but keeping the simplicity of hubbies.

 

[grindz145]

For a utility bike, you can't go wrong with a dead-reliable hub motor.

Check out cycle9.com, They're all about electric cargo bikes.

You're other off-the-shelf option is a stoke-monkey kit, which uses a hub motor by itself, and gears it. It's a nice setup that only works with the xtracycle, and it is kind of expensive, but for really crazy hills a geared setup does have a leg up.