Hub drive or mid drive.

john peck

Well-Known Member
Having changed from a hub to a mid drive the climbing ability of the mid is dramatically better than the hub. Also a major unexpected bonus of the mid drive is the ability to use the power a lower speeds than a hub. Low gearing and a mid drive allow low speeds without risk of stalling/overloading the motor and this is surprisingly useful in some situations such as maneuvering around obstacles or pedestrian traffic.
What hub drive were you using? What gearing? Mine climbs about anything without getting close to my lowest
gear. I´ve never yet used it, even on the steepest hill around here, & that´s mighty steep.
 

fooferdoggie

Well-Known Member
what is mighty steep? to me thats over 20% where I am putting out at least 350 watts plus on turbo on my bosch powered bike.
 

john peck

Well-Known Member
what is mighty steep? to me thats over 20% where I am putting out at least 350 watts plus on turbo on my bosch powered bike.
My bike will do that. It´s nothing fancy really, just an ´80s type mtn bike with a 500w German motor. I have a
standard old 48/38/28 triple crank & basic 28/14, 7 spd. freewheel. Bet yur bike cost ´at least´ twice as much.
Don´t know about degrees, but I´ve no trouble with a hill that gains 180 feet* in a 1/4 mile & I´ve done steeper on dirt.
*according to google maps terrain anyway?
 
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fooferdoggie

Well-Known Member
so this hill is no problem?
IMG_1242.jpeg
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I have a hub drive that would handle that hill - with my 300lb butt aboard. Hell yes, we'd be grunting for sure, but so will a mid drive. Especially a small one....

I will admit, getting the bike moving from that stop sign might be a challenge. Not that hard though. Just make the right turn and stop after a bit, turn around, and do a "rolling stop" to make a right to continue to the top. Nothing to it... ;)
 

Headdamage

Member
Region
Canada
What hub drive were you using? What gearing? Mine climbs about anything without getting close to my lowest
gear. I´ve never yet used it, even on the steepest hill around here, & that´s mighty steep.
Old bike was an Ultra Motors A2B Metro (500-750ish watt direct drive hub motor I believe, I don't recall what gearing it had), new bike is my old Kona Hoss with a BBSHD 11-46t cassette and 42t bling ring.
 

tomjasz

Well-Known Member
AWD Mid+hub is the best of the AWD concept. Its an absolute mountain goat. There is a learning curve associated with a powered wheel on serious singletrack but the article gets into that.
Got me thinking. I blew the idea off but I’m thinking a 350-500W dual drive version might be fun. I have the parts...
 

m@Robertson

Active Member
Region
USA
Got me thinking. I blew the idea off but I’m thinking a 350-500W dual drive version might be fun. I have the parts...
treat it as a project that is non-essential and you can take your time with is the best way to go about it... its not easier to do and cable management is a pain in the butt. You do not need high power to enjoy the benefits of 2wd. I mean... more power is more good right? But if you have the parts and the time on your hands its definitely worth a shot to see what happens. I will say a dual hub is best suited as a flatland/street cruiser or commuter. The mid+hub I did was created when I found hills the hub bike - even with 4kw peak going to the ground - struggled against in my home town. Regardless... never up, never in. Gopher it!
 

m@Robertson

Active Member
Region
USA
so this hill is no problem?
I have a hub drive that would handle that hill - with my 300lb butt aboard. Hell yes, we'd be grunting for sure, but so will a mid drive. Especially a small one....
Maybe thats the takeaway here. Small mid drives... I have no problem believing there are limits to what a production ebike mid with 50 or 80 Nm can do.

On a BBSHD with a bike geared right I can take that hill no problem. How can I say that? I have ridden a basic rescued Motobecane Lurch build with a 52v/30a BBSHD up a steep downhill chute kind of trail at a park, so steep I was leaning way over the handlebars, eventually unable to pedal, on throttle at 2 mph and still the front wheel was in the air, until I jumped off as the bike flipped. So, it was a hill that could not be ridden (up) by a bicycle at all. It wasn't the motor or the gearing that stopped me, it was the inability to keep the front wheel on the ground thanks to gravity and a ridiculous grade. So if its a public road, a respectable mid with big gears (even with that big 42T up front) should be able to ride it day in/out.

This is a Google Maps link about in the middle of a hill where that 'basic' bike lives, and you can spin around and look up and down that hill... its not the small steep hills that made me have to give up my hubs. Its lonnnng ones like this, day in and day out (the ride down is a kick in the ass though). I weigh 250 lbs so that doesn't help.

 

FlatSix911

Well-Known Member
Region
USA
City
Silicon Valley
Hah thats my article and my bike. The pic that you showed was it being all cleaned up. Its all dirty again as of yesterday. Not as bad as it is here, but dirty is its native state.
View attachment 84255
As I said in that article and the companions to it - from experience actually building bikes that are all more powerful than anything that can be bought retail:
  • Single (rear) geared hub drive is out of its league overland. Period. I am talking 80Nm bigfoot Bafang 750's with a 35a controller and a 52v battery. Reason being it is singlespeed and powers the bike thru the axle. You try riding with no gears up a hill and see how you like it. Motor may be powerful enough to get you by but it is by no means in its element. Want to upgrade that hub to 60v so it is running 2kw continuous (it can take it)? It will be good (40 mph) on the street but overland meeting resistance from muck and reeds etc... you'll peanut-butter the nylon gears.
  • Dual geared hub has all the wonderfulness of awd but is still saddled with the axle-powered singlespeed thing. I could get my 4kw+ 2wd geared hub bike to climb anything, but my ears told me the hub motors would not live forever and I want forever.
  • Mid drive alone is good enough for all overland conditions. There is a reason all quality eMTBs that are not the budget version are mid drives. It will not set the world afire with speed, and a conversion bike has to be built with more care, planning and experience than a hub bike, where all you have to do is mount the motor and run some wiring (kind of).
  • AWD Mid+hub is the best of the AWD concept. Its an absolute mountain goat. There is a learning curve associated with a powered wheel on serious singletrack but the article gets into that.
I think there is a misperception with regard to the motor delivering speed. If you need a mid drive in the first place, speed is a non issue. Chances are you are pedaling, and going 5-10 mph or less and thats plenty fast for conditions. At 5 mph, wending your way thru rocks, mud and crap... you don't want speed you want predictable torque at low speed.
A hub motor is not at its best doing that. But if you are riding on dirt roads (doubletrack) or wider trails, and you can open it up... the big, powerful direct drive hub will do that job better than a mid. The question then is are you stressing the internal gears too much on that hub motor, or if its a direct drive, have you loaded the bike up with so much weight in the rear wheel and the battery that its no longer a bike you would ever want to pedal and you are having fun hauling ass on a low cost motorcycle.

Both mid drive motors and hub motors are great. but determining which one is better for your job - depends on that job. There's no one right answer.
Matt,

Welcome to EBR and thank you for sharing your wealth of knowledge on this forum.

I have been staying up late recently reading your blog... great stuff, long may you ride! ;)


Tales On Two Wheels
Life is like a wheel… and it will run your ass over if you don't watch out
Tales On Two Wheels

Table of Contents​

Not quite a Site Map, this page lays out all of the site’s posts in outline form, on one screen, separated by the main category of each and ordered depending on how I think it will be best represented.
  1. Battery Stuff
  2. The BBSHD (and BBS02!)
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  5. Cargo Bike Stuff
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ElevenAD

Well-Known Member
so this hill is no problem?
View attachment 84259
the Ariel Rider Grizzly i road would eat that hill alive throttle only even if i had someone riding tandem but the Grizzly Hub motors also have gears with steel teeth so they dont turn to mush under the power! if it was dirt and loose rock that would be another story. i think this is why the bike is so powerful,maybe other companies should look into lining their gears with metal?
this guy's XClass in the vid below has a single AR motor on a 48v system and the last hill he climbs at 21mph is decent, The AR grizzly has 2 motors,runs on a 52v system and has 2 battery packs!
 
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Catalyzt

Active Member
Region
USA
Maybe thats the takeaway here. Small mid drives... I have no problem believing there are limits to what a production ebike mid with 50 or 80 Nm can do.

On a BBSHD with a bike geared right I can take that hill no problem. How can I say that? I have ridden a basic rescued Motobecane Lurch build with a 52v/30a BBSHD up a steep downhill chute kind of trail at a park, so steep I was leaning way over the handlebars, eventually unable to pedal, on throttle at 2 mph and still the front wheel was in the air, until I jumped off as the bike flipped. So, it was a hill that could not be ridden (up) by a bicycle at all. It wasn't the motor or the gearing that stopped me, it was the inability to keep the front wheel on the ground thanks to gravity and a ridiculous grade. So if its a public road, a respectable mid with big gears (even with that big 42T up front) should be able to ride it day in/out.

This is a Google Maps link about in the middle of a hill where that 'basic' bike lives, and you can spin around and look up and down that hill... its not the small steep hills that made me have to give up my hubs. Its lonnnng ones like this, day in and day out (the ride down is a kick in the ass though). I weigh 250 lbs so that doesn't help.

I'm still scratching my head r.e. low-power mid drives. I know that, for example, the Charge XC uses the same motor my bike does, it's a full 6 pounds heavier, and I only weight 150 pounds. But I'm finding my bike very tricky to ride-- as I mentioned, there are some moderate grades where it's both slow and a lot of work.

I think it's worth doing a good weight-weenie and trying to get my Moto down to 46 pounds from 49-- I think it will make a difference. Locking out, wearing a lighter jacket, carrying less, all of that already helps.

But I wonder how the hell a 175 or pound rider can stand a 55 pound bike where there are a lot of hills. I'm not that weak, my shifting technique is improving, but it's not terrible. Did I get that spoiled on a 40 pound 250 Watt hub drive?
 

m@Robertson

Active Member
Region
USA
Matt,

Welcome to EBR and thank you for sharing your wealth of knowledge on this forum.

I have been staying up late recently reading your blog... great stuff, long may you ride! ;)
Thx @FlatSix911 much appreciated. I've been all over FB for years and I am trying to branch out and learn things myself, in the process.

The whole reason I created the blog is because I am involved in a number of ebike/bike groups. I created the blog for no other reason than to be able to post a link to a commonly raised topic rather than typing it up over and over in a paragraph-plus. Its grown with the build threads .. and a few rants :D

Hey have we crossed paths before? I seem to recall we've chatted, on a bike you had something to do with that I was writing up. Does that ring a bell?
 
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m@Robertson

Active Member
Region
USA
I rode my Surly BFD into work and took the trails instead of the pavement. In addition to being able to outrun a Belgian Shepherd in a lonnnng sprint, whose owner annoyingly didn't keep him under control, I took that 'chute' this morning to see about backing up what I said before.

And I kind of did. Sort of. The bike is set up for street and mild groomed trails, so a 48T front chainring on a 130 BCD adapter... no offset on purpose so it can get to the bottom 6 or so cogs on the SRAM NX drivetrain with good alignment. So I climbed up to a 24T cog. Well, so that ain't happening. I got halfway up and decided to bail as while I was still making progress, I was full assist and mashing the pedals hard verrry slowly. Doing all the right things to break a chain. So street config even though big fat knobbies... 48x24 is not going to cut it.

Thats about a 63-inch gear. What if I go to my parts pile and pull out my Luna chainring and put the 42T ring on (I am doing the ring swap after work) and mount THAT sucker, which will give me something ridiculous like 20mm offset? The bike will be in full 'trail' mode and I'll be restricted to the biggest 6 or 7 cogs. So I can do a 42x46 rear. Thats about a 29 inch gear. Insanely low. I gotta try it, no matter how impractical it is.

Being able to reconfig a bike from being a flatland special to take on the Fresno Alps is a nice spiff.

Also, I hope that dog got lost on his way back.
 

Handlebars

Well-Known Member
Region
Canada
Matt,

Welcome to EBR and thank you for sharing your wealth of knowledge on this forum.

I have been staying up late recently reading your blog... great stuff, long may you ride! ;)

Matt said:
I am riding a rolling worst-case scenario.
😄
 

PedalUma

Well-Known Member
Region
USA
Remember that all traffic must be obeyed! No running the stop sign 1/2 way up that hill!

My attempts at humor often backfire.
Yesterday I used a 350W on a fast and hilly group ride of 35 miles. The Vado 4 and Ultra were drafting. I used one 10.5Ah battery. It was a blast.
 

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theemartymac

Well-Known Member
Remember that all traffic must be obeyed! No running the stop sign 1/2 way up that hill!

My attempts at humor often backfire.
Yesterday I used a 350W on a fast and hilly group ride of 35 miles. The Vado 4 and Ultra were drafting. I used one 10.5Ah battery. It was a blast.
Well now we know where the username comes from! lol
 

fooferdoggie

Well-Known Member
Looks like the one on Egg & I Road; reminds me of an olympic ski jump comin down. Why? Have you
climbed it? Looks to gain 120 ft in 200 yds or less. Egg & I isn´t ´that´ steep but it´s 3 times as long.
Thereś one like that leaving Virginia City on the way to Carson City.
yep its at least 20% grade or a bit more. my garmin wont get the cal;umation in time before you run out of hill. its a bear one of the steepest I have found.