Highest Torque Low Speed Geard Hub Rear Motor?

[BigBird]

I'm thinking of adding a rear geared hub motor to our ECDM Ventana full suspension MTB Tandem. (Using a front hub motor is complicated by the upside down Maverick DUC32 Air Forks) So I'm looking for ideas on what rear hub motor will work the best at the very LOW speeds and steep hills that one encounters on a MTB tandem. It also needs to have a sturdy freewheel mount as we run VERY low gears so, even though we are OLD (70+) we can put a lot of torque through the freewheel. (We currently have a 20T graney with a 12/36 free hub). We will still be pedaling but the steep hills are getting tougher each year!

Thanks for any ideas!

 

[amberwolf]

Well, I don't know it's torque level, but the Fusin 1000W that I reviewed here:
http://www.endless-sphere.com/forums/viewtopic.php?f=4&t=39877
has a cassette mount built in, and so I presume that would be a lot stronger than the typical freewheel-mount threads cut into the cast alloy sidecovers (whcih have been known to break off for some people on some motors).

I knwo there are other cassette type motors out there, too. Regardless of their torque, if you are putting a lot of pedal torque into it, I'd recommend getting a cassette type hub instead of one with a threadon freewheel.


Alternatively, NielP has a thread he's working in now (sorry I don't have a link) to get a needle/roller-bearing inside a regular freewheel, to get better support of it on the axle. Since his axle is a lot larger than normal I don't think you'll need to go thru the same hoops he does to get it to work, and coudl probably find a roller bearing and sleeve that would just plain fit over the axle on the hubmotor, and fit inside the freewheel's inside diameter, too.



As for which motor, you might look at the http://ebikes.ca simulator, and see if any fo the motors you are considering are in the list. If so, try them out under the conditions you expect, and see which performs the best for you.

 

[Chalo]

This sounds like a job for Stokemonkey!

Although Stokemonkey was conceived as an add-on for cargo bikes, tandems also offer room to accommodate it, somewhere in the stoker's portion of the frame. By using a double chainring on the rear timing crank, the motor can feed its power in the same way as the captain.

 

[Cephalotus]

The BionX d-Series is compatible with 9x and 10x cassettes, offers 50Nm peak torque and 25Nm continous torque and only weights around 4kg (incl. controller).

If you use the BionX controller it's a proprietary system with an expensive battery.

You also need to check if the axle and the spokes / rim will be able to withstand the extra weight and forces on a tandem bike!

PS: I missed the "geared motor" in your thread title. The d-series Bionx is a direct drive motor.

 

[sulee154151]

I'm thinking of adding a rear geared hub motor to our ECDM Ventana full suspension MTB Tandem. (Using a front hub motor is complicated by the upside down Maverick DUC32 Air Forks) So I'm looking for ideas on what rear hub motor will work the best at the very LOW speeds and steep hills that one encounters on a MTB tandem. It also needs to have a sturdy freewheel mount as we run VERY low gears so, even though we are OLD (70+) we can put a lot of torque through the freewheel. (We currently have a 20T graney with a 12/36 free hub). We will still be pedaling but the steep hills are getting tougher each year!

Thanks for any ideas!

 

[SlowCo]

maybe a Bafang middrive system on the front bottom bracket would be a better idea with gearing of the rear cassette adjusted to the larger front sprocket (44T standard or 42T bling ring). From 250W assist for the 36V BBS01 kit to the 48V 1000W BBSHD. Good reviews from em3ev on here:

https://endless-sphere.com/forums/viewtopic.php?f=31&t=75503&p=1141284

250W kit with battery: http://em3ev.com/store/index.php?route=product/product&path=50_45&product_id=183

 

[Drunkskunk]

The MAC 12T is the slowest, highest torque geared hub motor available. That would be good for 200RPM. There are faster options with the same torque.

If torque is your goal, you might be better served by a BBS02 750w or BBSHD 10000w mid drive attached to the front crank. you would get higher torque output

 

[999zip999]

What does your front crank setup look like ? Pic as the the middrive might not work. If not a mac will.

 

[amberwolf]

Sorry guys, you got skunked by a copypasta spammer, who stole BigBird's post from here:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=64698

:/

Spammer is nuked now, though.

I'll be merging this thread with that one so the answers will be useful to someone in a search, later.