Are mid drives just naturally less zippy than hub motors?

[SC00CHB00CH]

Mid drives can multiple their torque (nM or ft/lbs)
BUT there is no free lunch. When they multiply torque (let’s say 10X) their speed/ angular velocity is 1/10.
Power stays the same ….you just geared way down for more torque.
A 500 watt motor only has 500 watts, period.

My experience with a Stromer direct hub drive is that I often encounter mid drives bikes on a hill and they are doing 12 ? Mph as I pass them doing 18-20 mph in 8th gear/ of 11.

Can 500 W mid drives blast up hills?
Maybe I just haven’t seen the right mid drives??

I am very intrigued by the new Trek TQ 250 W motor!! That mid drive looks like next gen goodness….

Here's a quote from Stromers website "The power is transmitted directly to the hub on the rear-wheel motor and accelerates without detours over crank, sprockets and chain."
Pretty much what I've been saying over and over in this thread concerning the functionality of rear hub motors.

A 750 watt bafang mid-drive can do 1400 watts peak. Mine would do 1280 watts up steep hills and hit 20mph using the 28tooth front and 32 rear all week long and twice on Sundays.

My mid-drive climbs hills without pedaling at all, pedaling is an option but not needed to climb hills.

120nm torque , 1280 watts , with a total weight of 40lbs -18kg

 

[tomjasz]

Can 500 W mid drives blast up hills?

Mine can climb like a billy goat but I don’t “blast” anywhere.

 

[MinnBobber]

@SC00CHB00CH ,
I wanted to compare 500 watt systems, can mid drive 500 W climb at 20 mph?
Your 1280 watts better be able to blast up hills.

My point was to counter the hub drive stereotype
that they cannot climb…..

 

[tomjasz]

@SC00CHB00CH ,
I wanted to compare 500 watt systems, can mid drive 500 W climb at 20 mph?
Your 1280 watts better be able to blast up hills.

My point was to counter the hub drive stereotype
that they cannot climb…..

Why Hub Motors - Learn

Learn why we chose to keep our focus primarily on hub motor drive systems over mid-drive conversions.

ebikes.ca

 

[Jason Knight]

Yes even though you have 9 speeds , almost all hub motors only allow a single gear ratio. The single largest advantage that mid-motors have over hub motors is their gear ratio.

You say that as if it matters. Given the ridiculously high RPM and consistent torque across the entire RPM range typical of electric motors in general, that very notion that having the drive train in there helps is 100% bullcookies.

This is why most successful EV's and hybrids use hub motors in fixed gearing, not a single motor with transmission. If a Tesla Model 3 is fine with a fixed 9:1 gear ratio, there's no reason to think a bicycle hub motor is at a disadvantage to mid-drive in that regard.

To think that having variable gearing between motor and output on an EV provides benefit is to fail to understand the power and capability of the electric motor in general. All you're doing is adding complexity, energy loss, and probably -- like my friend who has mid-drive -- breaking chains left and right.

The energy loss introduced in the drivetrain having far more negative impact on performance than the different gear ratios provide. Anyone well versed in EV's would/should be laughing in your face over claims of that particular "advantage". You're talking engineering gibberish.

Something that seems to be all too common amongst biking enthusiasts and the sucker-bait propaganda they swallow hook, line, sinker, and a bit o' the rod.

 

[Jeremy McCreary]

@tomjasz: Finally, a well-informed, realistic, and completely rational discussion of hub motor vs. mid-drive pros and cons! Thank you very much for sharing that Grin link.

A choice like this should be an engineering decision based on the bike's primary mission and a realistic cost/benefit analysis -- not on emotion, zealotry, current fashion, "ha, my bike's more expensive than yours", marketing hype, or what the cool kids happen to be doing at the moment.

Though I knew little of this at the time of purchase, feeling much better about my hub motor now. Clearly, they're not for everyone. But a hub motor's clearly the best choice for me.

 

[AHicks]

@tomjasz: Finally, a well-informed, realistic, and completely rational discussion of hub motor vs. mid-drive pros and cons! Thank you very much for sharing that Grin link.

A choice like this should be an engineering decision based on the bike's primary mission and a realistic cost/benefit analysis -- not on emotion, zealotry, current fashion, "ha, my bike's more expensive than yours", marketing hype, or what the cool kids happen to be doing at the moment.

Though I knew little of this at the time of purchase, feeling much better about my hub motor now. Clearly, they're not for everyone. But a hub motor's clearly the best choice for me.

Thank you. Nicely put. Nice also to read also your recent input on other subjects here at EBR as well. Starting to look forward to your input. -Al

 

[tomjasz]

My Grin 9c FH212 with cooling fins attached with thermal tape and statoraide is a climbing beast. Not good for an offroad mtb but for a commuter with hills a fantastic performer. Doubt it!? Use the Grin motor simulator.

 

[Djangodog]

You say that as if it matters. Given the ridiculously high RPM and consistent torque across the entire RPM range typical of electric motors in general, that very notion that having the drive train in there helps is 100% bullcookies.

This is why most successful EV's and hybrids use hub motors in fixed gearing, not a single motor with transmission. If a Tesla Model 3 is fine with a fixed 9:1 gear ratio, there's no reason to think a bicycle hub motor is at a disadvantage to mid-drive in that regard.

To think that having variable gearing between motor and output on an EV provides benefit is to fail to understand the power and capability of the electric motor in general. All you're doing is adding complexity, energy loss, and probably -- like my friend who has mid-drive -- breaking chains left and right.

The energy loss introduced in the drivetrain having far more negative impact on performance than the different gear ratios provide. Anyone well versed in EV's would/should be laughing in your face over claims of that particular "advantage". You're talking engineering gibberish.

Something that seems to be all too common amongst biking enthusiasts and the sucker-bait propaganda they swallow hook, line, sinker, and a bit o' the rod.

Your data is missing a key component. Unlike a Tesla, or other EV, this is an “e-bike”. It’s supposed to have two motors, (one electric and the other more or less human). The human benefits from the gears. If it is missing the human component all together, then it is an e-motorbike.

 

[SC00CHB00CH]

You say that as if it matters. Given the ridiculously high RPM and consistent torque across the entire RPM range typical of electric motors in general, that very notion that having the drive train in there helps is 100% bullcookies.

This is why most successful EV's and hybrids use hub motors in fixed gearing, not a single motor with transmission. If a Tesla Model 3 is fine with a fixed 9:1 gear ratio, there's no reason to think a bicycle hub motor is at a disadvantage to mid-drive in that regard.

To think that having variable gearing between motor and output on an EV provides benefit is to fail to understand the power and capability of the electric motor in general. All you're doing is adding complexity, energy loss, and probably -- like my friend who has mid-drive -- breaking chains left and right.

The energy loss introduced in the drivetrain having far more negative impact on performance than the different gear ratios provide. Anyone well versed in EV's would/should be laughing in your face over claims of that particular "advantage". You're talking engineering gibberish.

Something that seems to be all too common amongst biking enthusiasts and the sucker-bait propaganda they swallow hook, line, sinker, and a bit o' the rod.

On a mid-drive bike , gears absolutely matter. Whether it's one gear or 12 gears , the way a mid-drive works is propelling the bike through the gears. Without a chain and gears a mid-drive simply does not work to propel the bike forward. We're not talking about cars. I'm simply telling you how the mechanics of a mid-drive works versus a rear hub drive and why this one advantage a mid-drives has over hub drives. A rear hub drive DOES not require gears (specifically rear cassette bicycle gears) to propel the bike forward. Certainly hub drives have advantages over mid-drives as well.

This isn't propaganda but the explanation of the mechanics of how mid-drives work on a bike. Cars are another animal all together. If anything certainly rear hub motors are more like electric cars than mid-drives are more like actual bicycles. Is that a bad thing? No it's just mechanically how they work.

Here's an article talking about mid-drives versus rear hub motors.
"The topic of what is better, hub drives or mid-drives, stirs strong opinions. But it's an apples-to-oranges comparison, says Ed Benjamin, chairman of the Light Electric Vehicle Association.

"When someone asks which is better, well that entirely depends on what you're doing with it," Benjamin said. "Mid-drives provide a higher-performance experience in every respect."

"Hub motors are roughly 30% efficient, while a mid-motor from Bosch is designed to run at about 70% to 80% efficiency," said e-bike drive system engineer Zach Krapfl, co-founder of VPL, which distributes Bosch motors in North America to small- and medium-sized brands.

"In the IBD world, mid-drives are still dominating because you get that better efficiency and better torque," Krapfl said.

E-bike motor trends: mid-drives vs. hub drives

(BRAIN) — When Specialized announced the re-launch of its Globe brand in May as an affordable electric bike purveyor focused on car-replacing transportation, the company released only one spy photo showing an e-bike obscured by cargo baskets and cactuses. While the e-bike's frame was largely...

www.bicycleretailer.com

Going back to the original comment "are hub drives generally more zippy?" I'd say yes but no as well.

Yes in that rear hub motors sort of give you that feeling of being pushed forward like an electric car while a mid-drive motors sort of pulls you , so yes I would agree hub motors feel more zippy .

Are they more zippy? Depends on the build.

 

[MinnBobber]

Here's an article talking about mid-drives versus rear hub motors.

"Hub motors are roughly 30% efficient, while a mid-motor from Bosch is designed to run at about 70% to 80% efficiency," said e-bike drive system engineer Zach Krapfl, co-founder of VPL, which distributes Bosch motors in North America to small- and medium-sized brands.

———————————

B.S. alert on this article.
“Bosch mid drives 70-80% efficiency and hub drives 30%. “
Where did that come from?

A direct drive hub motor with no loses getting to the drive wheel vs mid drive with gears or belt and then sprocket chain transfer…..

Gee, does he happen to sell mid drives??
Why yes he does.

Mid drives rule for E mtn biking but to say “ mid drives provide a higher performance experience in every respect “…..your bias is showing.

 

[tomjasz]

Your data is missing a key component.

Typical for him.

 

[tomjasz]

"Mid-drives provide a higher-performance experience in every respect."

Total BS

 

[SC00CHB00CH]

Why Hub Motors - Learn

Learn why we chose to keep our focus primarily on hub motor drive systems over mid-drive conversions.

ebikes.ca

B.S. alert on this article.
“Bosch mid drives 70-80% efficiency and hub drives 30%. “
Where did that come from?

A direct drive hub motor with no loses getting to the drive wheel vs mid drive with gears or belt and then sprocket chain transfer…..

Gee, does he happen to sell mid drives??
Why yes he does.

Mid drives rule for E mtn biking but to say “ mid drives provide a higher performance experience in every respect “…..your bias is showing.

B.S. alert on this article.
“Bosch mid drives 70-80% efficiency and hub drives 30%. “
Where did that come from?

A direct drive hub motor with no loses getting to the drive wheel vs mid drive with gears or belt and then sprocket chain transfer…..

Gee, does he happen to sell mid drives??
Why yes he does.

Mid drives rule for E mtn biking but to say “ mid drives provide a higher performance experience in every respect “…..your bias is showing.

Bosch have some of the best designed motors in the industry they absolutely some of the most efficient motors in the industry. I'd take an engineers statement over a internet forum commenter whom is emotionally attached to his rear hub drive. That article you commented on that I posted has many good things to say about rear hub motors as well, they talked about "Specialized" coming out with a rear hub bike. Irregardless of efficiency stats from actual ebike motor engineers. Facts don't care about your emotions. What "facts" am I referring to?

A hub drive directly applies torque to the wheel, operating independently of your bike’s gears.<--why is this fact a conspiracy in this thread??

A mid-drive motor is instead installed between your pedals. This type of motor directly drives your bike’s front chainring (a sprocket that’s part of the crankset), so it is influenced by your gearing. <--- fact or yet another conspiracy??

These two facts in this thread seem to be considered "mid-drive" bias. It's not bias it's simply the mechanics of how the motors work.

 

[tomjasz]

I'd take an engineers statement over a internet forum commenter whom is emotionally attached to his rear hub drive.

So you think Grin, ebikes.ca Justin Elmore isn't an engineer? FFS he's been an industry leader for more than a decade. Don't be blindsided by some corporate behemoth. Spoken like a blindsided n00b. Smacks of the days when idjets dissed front wheel drives,
Kidz...

 

[tomjasz]

Something that seems to be all too common amongst biking enthusiasts and the sucker-bait propaganda they swallow hook, line, sinker, and a bit o' the rod.

as is evident by your choice...just sayin...

 

[fooferdoggie]

So you think Grin, ebikes.ca Justin Elmore isn't an engineer? FFS he's been an industry leader for more than a decade. Don't be blindsided by some corporate behemoth. Spoken like a blindsided n00b. Smacks of the days when idjets dissed front wheel drives,
Kidz...

mid drives are more efficient because they operate closer to the optimal speed for the motor. its as simple as that. as long as yousay peddle at 80 rpms them motor will be at the same efficiency despite the speed. a hub drive is only efficient at the sweet spot and thats usually pretty fast the hub motor will only be the most efficient at a set speed the bit drive is the most efficient at normal cadence over the whole range of speed.

 

[SC00CHB00CH]

Total BS

So you think Grin, ebikes.ca Justin Elmore isn't an engineer? FFS he's been an industry leader for more than a decade. Don't be blindsided by some corporate behemoth. Spoken like a blindsided n00b. Smacks of the days when idjets dissed front wheel drives,
Kidz.

I was responding to 'your' comment. Are you Justin Elmore? Or are you speaking in 3rd person?
I could argue that Justin is biased towards because that's all he sells are hub motors based on the link "you" provided. His hub motors are MASSIVE and they need to be compete with mid-drives. I've currently ordered a hub motor folding bike from Luna. So I am not biased. My mother owns a pedego hub bike as well.

The one gripe I have in this thread is the lack of people to simply understand the mechanics of a mid-drive and how they use the rear cassette and front chain ring to propel the bicycle while rear hub drives do not. It's like there is the mental block that some people can't except simple mechanics of the two motor types. It seems to be the common theme here.


Here is the bike I built , starting with a SAVA carbon folding bike.
36mph top speed , throttle only on a flat road , climbs any hill with throttle only , total weight 40lbs. 120nm of torque and a peak wattage of 1280watts.
I took this bike to an EBIKE shop here in Asheville for a IGH possible install , all they sell are hub motor bikes and the Bosch mid drives among regular bicycles . All of the mechanics fell in love with the bike and the one consistent comment was "man this thing is fast."

I could've made her a little lighter by swapping out the heavy spring brooks seat and the super heavy suspension stem and possible get a carbon fiber handle bar. I'd imagine I might squeeze it down to 35lbs perhaps? But it's not even needed , at 40lbs with a rider weighing 220lbs the thing is crazy fast , ZIPS up hills , ZIPS around corners , ZIPS right along side cars. I think I'll rename her "Zippy."
It cost me around around $3000 to build.

 

[Jeremy McCreary]

Bosch have some of the best designed motors in the industry they absolutely some of the most efficient motors in the industry. I'd take an engineers statement over a internet forum commenter whom is emotionally attached to his rear hub drive. That article you commented on that I posted has many good things to say about rear hub motors as well, they talked about "Specialized" coming out with a rear hub bike. Irregardless of efficiency stats from actual ebike motor engineers. Facts don't care about your emotions. What "facts" am I referring to?

A hub drive directly applies torque to the wheel, operating independently of your bike’s gears.<--why is this fact a conspiracy in this thread??

A mid-drive motor is instead installed between your pedals. This type of motor directly drives your bike’s front chainring (a sprocket that’s part of the crankset), so it is influenced by your gearing. <--- fact or yet another conspiracy??

These two facts in this thread seem to be considered "mid-drive" bias. It's not bias it's simply the mechanics of how the motors work.

Totally agree, those are mechanical facts, not biases. But by themselves, they don't make mid-drives vastly superior for all purposes. Ebiking seems to be a pretty big tent outside this forum.

 

[MinnBobber]

I totally understand how mid drives use the gear reduction to get more torque BUT a quality hub electric motor doesn’t really need a transmission/ gears.
Look at diesel electro locomotives. They pull 150 tons from a dead stop, via electric motors, and no 12 speed trannies required.

That’s the low end beauty of electric power.
It’s not like a gas engine that needs to build rpm’s to get power.