Mid-drive vs hub motor: Experiences

[FlatSix911]

One of the things that I think everyone misses on this thread is that this is very early days. I suspect there is the potential for enormous improvements, both in efficiency and the riding experience, still to be discovered for e-bikes. Just three thoughts on things nobody is doing that should be "well duh" items:

1. When you are pedaling, the power you put into the bike continuously varies, from near zero when the pedals are at 12 o'clock/6 o'clock to the maximum somewhere around 9 o'clock/3 o'clock. Why doesn't someone make a pedal-assist system that "modulates" the power output so that peak motor power is produced when pedal input is the smallest and vice versa?
2. It seems very natural as well that you would produce higher levels of assist at lower speeds, as that is most likely when you need more assist (to accelerate or get up a hill).
3. While we are on the subject of hills, it might be wise to have a clinometer as input to the assist system to give an even bigger boost when you are starting up a hill.

Interesting discussion. As previously noted, Yamaha has recently added a clinometer to assist on hill climbing when needed.

Regarding pedal efficiency, decades ago Shimano started experimenting with Oval chainrings... Biopace, etc. to optimize power output.

I would imagine, current software could easily be tuned to modulate the power output at various points on the chainring pedal stroke.

Biopace - Wikipedia

en.wikipedia.org

 

[AHicks]

So much of this thread still seems to be more about controller differences and how different software used cadence and/or torque sensors together or separately to control the power applied to the motor. I only have two hub motors, one is Cadence only, the other is cadence and torque supposed to be so much better, but I find it only better at some things like smith starts if you're not use to an e-bike/cadence sensor and have no throttle. The problem with my Cadence/Torque hub motor (Juiced), is that I cannot get the power level I want for the cadence I want, not by adjusting gears or assist level. With my cadence only hub I can get it right as long as I have the right gear (so not very good at top speed due to limited/unsuitable gear ratio). On the Hub/torque bike often at many cadences, it does not matter what assist level I'm in for a given gear and cadence I get the same speed, to me, if I increase the assist I want faster speed without changing anything else. Now I don't have a mid-drive yet (probably buying one next, but more for the IGH than the motor. A lot of what I read in this thread I've experienced between my different implementations of Cadence and Cadence/torque implementations, so I still don't really understand what might be really different with a mid-drive. The saving grace on both my bikes is the throttle, as that is the only way I can control the assist properly for the given terrain, available gear ratio, cadence, and my desired energy output. I might be more affected by this as I have a relatively low cadence, and cannot do a high cadence for any length of time, but I can keep a low cadence very well even with a fair bit of power behind it. To me most bikes are not properly geared for this.

Maybe, if you were so inclined, you could consider a bike where you are able to change/modify PAS levels? Or, possibly better yet, modify your own bike with the installation of an aftermarket controller? Speaking from my own experience with an aftermarket controller, I think the ability to set up the controller using settings I like, vs. those the OEM's think (guess?) I should like, makes a night and day difference in the riding experience. That's me though...

 

[AHicks]

Funny you'd share this. You're more diplomatic then I am

I was just Speaking to a Friend of Mine who has a few Hub Drives: We were discussing what type of Ebike I should consider. He tells me he uses Hub verses Mid Drive for exactly what you said. He told me he's ok with being Fat and likes the feel of Help moving the pedals . He also loves the Throttle : Told me he uses it as much as possible. Said he was more into exploration and stops for a Beer along the way.

He added that For older people that have lost health a Hub Drive is definitely more practical.

He commented that Mid Drives are geared more for people like me who are into Bicycle Riding for exercise and just want to go faster for the same effort :

So your post makes good sense. And also explains that the Average American is Lazy LOL .

Just Like Going to the gym. Every Year January is loaded with New People with New Years Resolutions to Get in Shape. By Mid February less then 2% are still at it

I agree on the lazy, and I think many others might as well. The problem is, when it comes to bikes, there are varying degrees of lazy..... We SHOULD be able to select the level of lazy we're feeling at the moment. We CAN select the level of lazy with decent controller programming.....

 

[tomjasz]

A MAC motor allows me to use, 36V, 48V, 52V, and 60V batteries. Coupled with a controller that will recognize and work with a range of voltages, and fits in my frame mount Hailong cases is a win for me!

 

[harryS]

Yikes. As a retired engineer, I never tried to understand that Grin stuff. There needs to be a Turbotax version. Just plug in the motor name, your weight, and see when the motor will melt.

 

[Explorer-1]

I want to know why the GMAC 8T has 10 revolutions per volt, and the 10T has 8 revolutions/volt? What does the 8T and 10T actually stand for?

 

[Explorer-1]

Maybe, if you were so inclined, you could consider a bike where you are able to change/modify PAS levels? Or, possibly better yet, modify your own bike with the installation of an aftermarket controller? Speaking from my own experience with an aftermarket controller, I think the ability to set up the controller using settings I like, vs. those the OEM's think (guess?) I should like, makes a night and day difference in the riding experience. That's me though...

It is very possible I will do that for my next bike since I'm going to try to ensure a pretty open system. I don't like getting ripped of for batteries or having a expiry date on my bike.

 

[Ravi Kempaiah]

What does the 8T and 10T actually stand for?

Copper winding in the motor.

Stromer ST2 - Technical review

I have learnt quite a bit from reading other people's experiences on this forum. As a researcher, I enjoy learning new technologies and keeping up with the pace. Close to 18 months ago, I put together this presentation for my own understanding but being lazy, I never published it anywhere...

electricbikereview.com

Check out the images in this post to see the visuals.

 

[Explorer-1]

Copper winding in the motor.

Stromer ST2 - Technical review

I have learnt quite a bit from reading other people's experiences on this forum. As a researcher, I enjoy learning new technologies and keeping up with the pace. Close to 18 months ago, I put together this presentation for my own understanding but being lazy, I never published it anywhere...

electricbikereview.com

Check out the images in this post to see the visuals.

Aah! So 8-Turns vs 10-Turns for the coil.

 

[tomjasz]

Yikes. As a retired engineer, I never tried to understand that Grin stuff. There needs to be a Turbotax version. Just plug in the motor name, your weight, and see when the motor will melt.

It's really quite easy. You're the best builder resource here, that really surprises me. Maybe it's just that you have what you need and the rest is minutia? What I find most useful is plugging in a grade and checking overheating chances.

 

[AHicks]

It is very possible I will do that for my next bike since I'm going to try to ensure a pretty open system. I don't like getting ripped of for batteries or having a expiry date on my bike.

I want to know why the GMAC 8T has 10 revolutions per volt, and the 10T has 8 revolutions/volt? What does the 8T and 10T actually stand for?

To take that 10t vs. 8t just a little further, the ability to order differently wound motors gives you the ability to order one custom wound to best meet your needs. Available in 8t, 10t and 12, with 8 being the fastest with the least amount of torque, and the 12t slowest w/the most torque. The 12t has various top speed specs depending on where you are reading (20-24mph), but even the slowest speed is 5 mph faster than I've ridden (under power) in recent memory. So that's the way I went. It's just loafing along consuming less than 100 watts in PAS 1 for the most part, powering right over little rises and stuff with no additional effort or throttle needed. BUT, there's all the torque I want when pointed at a hill and tickled with a little poke of throttle....

And speaking of hills, if you are spending much time in them, or looking to supplement battery life, there are MAC's with regen, LOT'S of regen, so much it's variable as you don't want all of it that's available all at once (possibly causing the rear tire to loose traction). It's the GMAC, a pretty new concept. Won't expand further here, but a very interesting option worth checking out.

Last, I'm right there with you on the open system - with no or a very minimum of proprietary parts. Keeps the bike very serviceable (and "up-dateable") for as long as you want to maintain it!

-Al

 

[Explorer-1]

To take that 10t vs. 8t just a little further, the ability to order differently wound motors gives you the ability to order one custom wound to best meet your needs. Available in 8t, 10t and 12, with 8 being the fastest with the least amount of torque, and the 12t slowest w/the most torque. The 12t has various top speed specs depending on where you are reading (20-24mph), but even the slowest speed is 5 mph faster than I've ridden (under power) in recent memory. So that's the way I went. It's just loafing along consuming less than 100 watts in PAS 1 for the most part, powering right over little rises and stuff with no additional effort or throttle needed. BUT, there's all the torque I want when pointed at a hill and tickled with a little poke of throttle....

And speaking of hills, if you are spending much time in them, or looking to supplement battery life, there are MAC's with regen, LOT'S of regen, so much it's variable as you don't want all of it that's available all at once (possibly causing the rear tire to loose traction). It's the GMAC, a pretty new concept. Won't expand further here, but a very interesting option worth checking out.

Last, I'm right there with you on the open system - with no or a very minimum of proprietary parts. Keeps the bike very serviceable (and "up-dateable") for as long as you want to maintain it!

-Al

Ya, I saw that that a 12T was available in those visuals. Although I feel 24mph is just a little slow, I like the Class 3 rated speed of 28mph for when I'm on some busier road sections, or I have a long straight away as I often do here. I try to be off roads as much as possible, but they are unavoidable here. Do you know if the 12T 24mph was with a 48V or 52V battery? I would think about adjusting though possibly, I do like torque for a more all-terrain bike, more than going for speed.

 

[Rick53]

every bike is different, i actually get a better workout with my Hub/torque sensor bike over my Mid drive/cadence bike, that said i do enjoy a powerful hub drive over a mid drive as long as im not riding off road, off road ill take a mid drive.

I didn't say you didn't get any Exercise : The person I mentioned is really into Hub Motors : He specifically said a Hub Motor assists your pedal Stroke : A mid Drive doesn't assist you pedaling : It responds to it > Which is just what Lenny said only differently

 

[tomjasz]

Exercise. It has nothing to do with mid or hub. Either system can provide the same functions. Simple PAS, or torque sensing.

 

[Rick53]

I didn't say you didn't get any Exercise : The person I mentioned is really into Hub Motors : He specifically said a Hub Motor assists your pedal Stroke : A mid Drive doesn't assist you pedaling : It responds to it >

Exercise. It has nothing to do with mid or hub. Either system can provide the same functions. Simple PAS, or torque sensing.

Exercise. It has nothing to do with mid or hub. Either system can provide the same functions. Simple PAS, or torque sensing.

IYO?

 

[tomjasz]

IYO?

IME

 

[Trail Cruiser]

I have owned mid drive, direct hub drive, and geared hub drive. Hub drives are easier to ride, easier to shift, effortless stop and go maneuvers. The mid needs finesse on shifting. I like the manual motor cut off over a gear sensor for shifting. I forced myself to want the Bosch ebike but was disppointed since shifting is not always smooth. And I hated it when the shifting is clunky.

My summarized observation and recommendation are the following.:

As a high speed commuter ebike, get a direct hub drive.
For mountain biking over steep hills, get a mid drive.
If you want inexpensive and easy riding experience, get a geared hub drive.

 

[fooferdoggie]

Yes a direct drive may be great once it reaches speed but on a commute there are a lot of starts and stops sometimes. Do you think you could get 25 miles going 20 to 22 on flat surfaces using a 36v 500 watt battery? Like I use on my Bosch in full assist?

 

[tomjasz]

Yes a direct drive may be great once it reaches speed but on a commute there are a lot of starts and stops sometimes. Do you think you could get 25 miles going 20 to 22 on flat surfaces using a 36v 500 watt battery? Like I use on my Bosch in full assist?

This is a silly thread and comparison. It's about where and how you ride. But after testing the Bosch and Yamaha drives, well keep them. No throttle and simply anemic after riding a Bafang mid-drive. Nearly every version is quicker than Bosch and it's competition. Repairable for DIY. In the end, I've transitioned to MAC hubs 42T X 20T single speed. I could dial it up to do wheelies, instead, it's just quick to get up to speed. Cruise control is sweet! It can also be a battery miser.

 

[Trail Cruiser]

Yes a direct drive may be great once it reaches speed but on a commute there are a lot of starts and stops sometimes. Do you think you could get 25 miles going 20 to 22 on flat surfaces using a 36v 500 watt battery? Like I use on my Bosch in full assist?

Going 20-22 mph on my direct drive, I could barely reach 20 miles on my 417.6 wh battery. I used to do 25 mile round trip and carry a spare battery to switch halfway along the trip.