Help deciding between three motors.

[Bobby]

Hello,
This is my second ebike build. I’m converting a 26” Elcony fat tire bike. My previous build had a 52v battery/1000w direct drive. The motor was fast, but not enough torque. I mostly do light trail riding, commute on flat ground and ride with a passenger who is 130lbs, I’m 170lbs. My previous motor had no problem with that load on flat ground, but couldn’t do hills. Bafang sells a geared hub motor (link attached) it has 85Nm of torque. I’ve read geared hubs aren’t great at top speed, I like to hit 30mph, I’m concerned the geared hub with fat tires will be slow. Middrives would be an option, but they don’t have throttle only. Thoughts and opinions are appreciated.

Thank you.

BAFANG 48V 1000W Rear Hub Motor : 26 Inch Fat Tire Electric Bike Conversion Kit with Battery (Optional) for Rear Cassette Wheel with LCD Display & PAS https://www.amazon.com/dp/B09BTD4FR6/ref=cm_sw_r_cp_api_i_Z18FEKG3DJZ90BFZVR0A?_encoding=UTF8&psc=1

 

[Grumpy old man]

I just built a middrive fat bike. It has both peddle assist and throttle, you can use throttle only. My Bafang 1000w will hit 30 mph on throttle only, gearing will dictate top speed or hill climbing ability. Middrive allows you to use lower gears for hills.

 

[DCErik]

A geared hub will climb better than a direct drive, but is still a poor choice for riding off-road because a) it adds unsprung weight and b) it will struggle to shed heat when pushed hard. As Grumpy notes above, all DIY mid-drive kits include both a throttle and some kind of pedal assist sensor, and you can install either or both.

Also, 'pedal'.

 

[Bobby]

I just built a middrive fat bike. It has both peddle assist and throttle, you can use throttle only. My Bafang 1000w will hit 30 mph on throttle only, gearing will dictate top speed or hill climbing ability. Middrive allows you to use lower gears for hills.

Looks awesome

 

[Hoggdoc]

Looks awesome

Based on your stated uses I would go with a mid drive motor such as a Bafang BBSHD stay away from their newer motor the M620 as they have taken away the user's ability to program the motor. Caution be sure to carefully measure your bottom bracket width so you buy the correct model. Also be sure to purchase a shift sensor as well.

 

[Bobby]

I just built a middrive fat bike. It has both peddle assist and throttle, you can use throttle only. My Bafang 1000w will hit 30 mph on throttle only, gearing will dictate top speed or hill climbing ability. Middrive allows you to use lower gears for hill

Is the middrive installation process difficult? I called my local bike shop and they don’t work on electric bikes. I see that I need a bottom bracket tool and a chain removal tool.

 

[DCErik]

An untrained bonobo can install a rear hub motor kit in around 2 hours using only household tools and a crank puller. For a mid-drive conversion the bonobo will require 2-3 additional hours, a bottom bracket removal tool, and the wrench that tightens the lockring on the mid-drive.

 

[Grumpy old man]

Is the middrive installation process difficult? I called my local bike shop and they don’t work on electric bikes. I see that I need a bottom bracket tool and a chain removal tool.

Not difficult at all....lots of YouTube videos for guidance. Be sure to measure the bottom bracket and order the correct size. BB tool was included in the kit, chain removal is not required.

 

[Hoggdoc]

Is the middrive installation process difficult? I called my local bike shop and they don’t work on electric bikes. I see that I need a bottom bracket tool and a chain removal tool.

It really there are several videos on YouTube showing the step by step.

 

[Bobby]

Not difficult at all....lots of YouTube videos for guidance. Be sure to measure the bottom bracket and order the correct size. BB tool was included in the kit, chain removal is not required.

The bike is a 26” Elecony fat tire bike, it hasn’t arrived yet. I can’t find any info online about the bottom bracket size. Is there any general Fat tire bottom bracket size? I read that the 750w midrive does not fit on fattire bikes.

 

[Hoggdoc]

I would say the best thing to do would be to wait until the bike actually gets there so you can take some accurate measurements of the bottom bracket both the ID internal diameter as well as the width.

As far as the 750 W motor not fitting fat bikes I have not heard that it really depends on what the width of the bottom bracket is and what’s available in that motor size.