Video: Flecc was right with: "through gears vs. hubmotor"

[kraeuterbutter]

when I first came here to the forum, I thought i need a bike, were the motor can use the gears..

Point 1:

everywhere you heard, that Hubmotors do not run efficient at hills, and are not at all suitable for going up hills

well.. part of that is right,
but as flecc wrote in his article:

we are not driving E-Bikes, we are driving "Hyprids"...
there is the motor, and there is the human
and the human can still use the gears !

i have an Bafang 24V 180Watt Motor in my bike,
powering it from 36Volt-Batteries with an 14A controller
tires are 26"x2,35" BigApple

this little beast is a fast motor as this video may show:



Video YouTube - Bafang Speedtest 50km/h

on this video, a "booster"-pack was used (2s Lipos with 7,4Volt)
the voltage on load was about 41Volt

so: its a little fast motor, not realy a torque-monster with that setup

i tested the torque: hills with 9% without pedaling are NOT possible
(20kg bike, 78kg driver -> so ~100kg)

nevertheless:
here are some videos of doing hills from 30% - 40% as an hyprid mashine (motor + human)

some datas:
temperature in the shadow was -8°C rising to -5°C during filming

the tires are Big Apples, roadtires, not realy suitable for heavy offroad-use

Video1: YouTube - Bafang Bergfahrt
the slope at the end of the hill is 38%, with motor doable, without motor (second try) not
the slope in the video-center-position: 34%

###############

Video2: YouTube - Bafang Bergfahrt Part 2
there are slippery leaves/foliage
first with motor -> its easily doable
then two tries without motor and not so good results

###############

Video3: YouTube - Bafang Bergfahrt Part 3
first with motor
second without motor
i use noose/straps/loop on the pedals, so a little accident on that video happend

###############

video4: YouTube - Bafang Bergfahrt Part 4
doing a hill with only one hand on the handle-bar, the other one in the air
first with motor -> no problem
then without motor.. you see, very soon i have to use both arms

the slope when driving behind the dog and on the right side i have measured with 21% and 23%
on the left side the slop goes up, up to 38%


###############
video5:
30% rising to 38% slope


i have measured, were i actually was driving, not somewere else on the slope

Point 2:
another thing i have often read: you can´t go offroad with an front-hub, you need a reardrive (rearhub, or drive through gears) for that,
because the front-hub will spin and spin and spin, of absolut no use because front wheel is lifted

i think the videos should show, that also with a fronthub, which results in a all-wheel-drive, going up hills is doable
(as said, the motor is no torque-monster)

the bike is geard 18:18 in first gear, which is too fast for my leg-power and the hill-grades
the motor is not able to do 9% for its own, but is nevertheless a great help at even steep hills

i think with this road-tires on the video and a REAR-motor i would not have the same good results climbing hills,

because all the torque would go to the rear-wheel, resulting in

• lifting up the front more easily
• loosing traktion on the rear more easily
• weight-distributation would be worse with an rear-hub (see also point 1)

so..
maybe this was interesting or funny to watch for some..
greets,
Reini

 

[stokepa31_mk2]

when I first came here to the forum, I thought i need a bike, were the motor can use the gears..

Point 1:

everywhere you heard, that Hubmotors do not run efficient at hills, and are not at all suitable for going up hills

well.. part of that is right,
but as flecc wrote in his article:

we are not driving E-Bikes, we are driving "Hyprids"...
there is the motor, and there is the human
and the human can still use the gears !

i have an Bafang 24V 180Watt Motor in my bike,
powering it from 36Volt-Batteries with an 14A controller
tires are 26"x2,35" BigApple

this little beast is a fast motor as this video may show:



Video YouTube - Bafang Speedtest 50km/h

on this video, a "booster"-pack was used (2s Lipos with 7,4Volt)
the voltage on load was about 41Volt

so: its a little fast motor, not realy a torque-monster with that setup

i tested the torque: hills with 9% without pedaling are NOT possible
(20kg bike, 78kg driver -> so ~100kg)

nevertheless:
here are some videos of doing hills from 30% - 40% as an hyprid mashine (motor + human)

some datas:
temperature in the shadow was -8°C rising to -5°C during filming

the tires are Big Apples, roadtires, not realy suitable for heavy offroad-use

Video1: YouTube - Bafang Bergfahrt
the slope at the end of the hill is 38%, with motor doable, without motor (second try) not
the slope in the video-center-position: 34%

###############

Video2: YouTube - Bafang Bergfahrt Part 2
there are slippery leaves/foliage
first with motor -> its easily doable
then two tries without motor and not so good results

###############

Video3: YouTube - Bafang Bergfahrt Part 3
first with motor
second without motor
i use noose/straps/loop on the pedals, so a little accident on that video happend

###############

video4: YouTube - Bafang Bergfahrt Part 4
doing a hill with only one hand on the handle-bar, the other one in the air
first with motor -> no problem
then without motor.. you see, very soon i have to use both arms

the slope when driving behind the dog and on the right side i have measured with 21% and 23%
on the left side the slop goes up, up to 38%


###############
video5:
30% rising to 38% slope


i have measured, were i actually was driving, not somewere else on the slope

Point 2:
another thing i have often read: you can´t go offroad with an front-hub, you need a reardrive (rearhub, or drive through gears) for that,
because the front-hub will spin and spin and spin, of absolut no use because front wheel is lifted

i think the videos should show, that also with a fronthub, which results in a all-wheel-drive, going up hills is doable
(as said, the motor is no torque-monster)

the bike is geard 18:18 in first gear, which is too fast for my leg-power and the hill-grades
the motor is not able to do 9% for its own, but is nevertheless a great help at even steep hills

i think with this road-tires on the video and a REAR-motor i would not have the same good results climbing hills,

because all the torque would go to the rear-wheel, resulting in

• lifting up the front more easily
• loosing traktion on the rear more easily
• weight-distributation would be worse with an rear-hub (see also point 1)

so..
maybe this was interesting or funny to watch for some..
greets,
Reini

Great work kraeuterbutter. Man and machine in perfect harmony! Just goes to show how much of a help our motors are and a very clear demonstration of the joint effort required in a hybrid machine .

 

[The Maestro]

Excellent videos! Looks better than mine which is 36V motor powered by 36V. By the way, have you any idea whats the top speed of a 24V bafang running at 36V ?

 

[flecc]

Great videos, and a perfect demonstration of the benefits of two wheel traction on poor surfaces Reini. Although single wheel traction if used is best on the rear wheel, as you say, that would cause big problems in those conditions, and most of those climbs would not be doable.

It does help being your age though!

I get the impression that your dog has given up trying to understand you.
.

 

[wurly]

Very interesting. It's about weight transfer. Too much power from the rear wheels makes the weight shift to the rear making the bike (and you) light on the front. (edit :and two wheel traction is better..i agree Flecc)
It seems front hub motors are the way to go. It makes me rethink my ideas on building a rear hub for my next bike.
I'm also surprised at how fast the overpowered 24V hub motor performs. What make controller are you using?

 

[The Maestro]

I guess the 24V motor is wound to give 20mph no load speed at 24V so 36V may give about 27 mph no load and maybe meaningful assistance up to 22-23 on the road ??

 

[flecc]

It seems front hub motors are the way to go. It makes me rethink my ideas on building a rear hub for my next bike.

I prefer a rear hub motor for on road use with normal road tyres, less weight in the front wheel improves the handling and steering since the front motor is effectively unsprung weight at the front in relation to the body. For that reason I converted my Torq to rear motor and both my bikes are rear motor now since I don't have to worry about traction for my riding circumstances.

Unless the motor is very heavy (Crystalyte etc), the differences aren't large though, and the Schwalbe Big Apples that Reini uses do improve e-bike reaction to front weight.
.

 

[kraeuterbutter]

for the dog

I get the impression that your dog has given up trying to understand you.

he is maybe wondering, why the trailer is missing..

because thats the way he normaly travels on our up to 50km trips through our hilly region

------------

for the speeds:
for all values you have to concern, that i use a BigApple-tire, which is more like 26,5" than 26" in diameter, so a little speed-plus (and little torque-minus)

at least with booster-pack i have measured last time:

49V charger-shut-off-voltage
44V no-load-voltage
voltage under 14A load: ~ 41Volt

without pedaling this results in ~40km/h in flat area
with pedaling i can reach 50km/h (but its hard pedaling so not for long time)

up to 41km/h (so slightly pedaling nesseccary) the currents stay high at 14A (thats were the controller limits)
only above 41km/h the currents go down

at 50km/h the current is down at 7A

(+/- 1A (was using a clamp-on ammeter, and reading the ampermeter and the tacho and pedaling at same time is not that easy )


my conclusio:
more than 36V is not usefull with that motor..
when not pedalling a lot, the motor is not able to "spin out" on flat, the airdrag is to big, controller has to limit currents all time until you help a lot or it goes downhill

exception: 20" wheels... then i think higher voltages than 36V would be great


oh.. for the speeds with 36V-battery (34V under load):
at speed of 33km/h the amps start to go down from the 14A level
at 36-37km/h the current goes under the 9A mark
(when i was testing this, there was no absolut flat street, so it was very slightly uphill and i was also pedaling a little to help)


for the hill climbing
on the hill-climbing video i was using during all scenes a 10s2p BOSCH-drill-battery, mounted close to the braket
so 36V nominal with 2,2Ah, 1,2kg heavy..
34V under load

the other batteries you see mounted top of the frame are not used, even not charged... mounted them half year ago provisorily, but as it is often:
provisorily mounted things do last longer than planed (1200km now for me )
i use them only, when going more than 10-15km, so when i need more capacity
on the videos they are only dead weight

@The Maestro:
i guess, the 36V Bafang has more torque, than my 24V Bafang..
because: they both have the same gearing, the same gearbox, same housing
so the difference can only be windings..
for that he must have more torque than mine (?)

at least i see absolut NO reason to overvolt my motor so extremely like the Amis do (72V, 80V and using 30A controllers),
and then wondering that the teeth of the gears are like butter (when they peak with far over 1000Watt)

as long as you pedal, the result is very good, also on hills and also with lower voltage and currentlimit

-----------------------

for the "front or rear" thing
i have not tested a rear motor so far..

i didn´t want to say, a front is better, just that a front is not as bad as often said
("with a front you can´t go up hills because you loose traction immediatly")

the bafang is a relativly light motor
i guess on cruising at higher speeds, the centrifugal forces of the heavy Big-Apple-tires have maybe more effect than the motor itself (where the weight is very close to the axel concentrated)

at least: iam always wondering anew, after i have driven my electric-BigApple-bike (with only 2-2,5bar), how hard my normal front-suspension-montainbike feels in comparison (feeling every little stone and gouge where the BigApple roles smooth over without giving it to the handlebar)

for the frontmotorweight: amazingly i am used to it after 1200km... its no problem..
even wheelis are possible without a problem (iam not good at wheely-driving, but 30m are (sometimes) possible)
on the other side, i hate to drive with my normal bike with 1kg heavy U-lock on the handlebar, i place it always when possible in my backpack just to save weight on the front..
strange

(so.. that posting is a little confuse now, written as like as the infos were dripping out of my brain into the fingers)

 

[flecc]

No problem Reini, your post is very clear. Now I can understand why your dog was looking a bit lost!

On my rear motors, I have two bikes:

The Q bike is used for a wide range of on road purposes including towing very heavy loads. For best traction
when towing uphill with large load, rear wheel drive is far better. In addition, for maximum stability especially
when braking downhill with heavy trailer load, the maximum rear end weight is best to anchor the unbraked
trailer firmly.

My T bike is a fast pleasure bike which is only used on road in dry conditions, so two wheel traction isn't
needed but best handling is desirable.

So you can see my preference for rear drive is mainly due to my personal circumstances.
.

 

[kraeuterbutter]

well, my desition for the front-hub was not inspired by any deeper thoughts..

there is only one shop in Austria selling cheap hub-motors...
and one year ago he had only front-hub-motors..

i also thought, that it would be easier to mount a front than a rear hub

now - at the end - iam happy, that it works that good for me

for hauling big heavy trailers like you do, a strong torquy rear-hub is for sure better..
my "fast" 24V Bafang has not that much torque, that i see the risk that it will wheelspin on asphalt.. before that happens it stalls..

on hills it is like - a little comparison - like bench-pressing:

when you are lying on your back, and try to bench-press 60kg and notice, you wont make it -> than two fingers of a partner helping are enough and you will make it..
so on hills, the bafang gives this 2 fingers (and a little more), and suddenly steep hills are doable which weren´t before without motor..
not because you get 500Watt (you by far don´t get anything close from the motor at such low speeds)
its "a little help from my friend" not more, not less

 

[wotwozere]

Hi

I wonder if it can work up the hills with someone over weight.
Nice video

Thx

Bob

 

[flecc]

so on hills, the bafang gives this 2 fingers (and a little more), and suddenly steep hills are doable which weren´t before without motor..
not because you get 500Watt (you by far don´t get anything close from the motor at such low speeds)
its "a little help from my friend" not more, not less

That's so true about small power increases Reini. My Torq was a very poor hill climber on power only, unable to manage 7% and struggling on 6%. A slight increase in battery voltage to give 50 watts extra from the motor meant it was able to climb 10% on power only, a big gain for so little extra power.
.

 

[kraeuterbutter]

you have to differ between
"help from the motor"
and
"a hill-climbing motor"

if you expect to drive up hills without pedaling -> forget it
(at least with the motor i have on the videos)

its not able to climb a 9% slope with me without pedaling (~75kg (a average value between for and after christmas))

i guess that it also will not make 8% slope

so: you have to pedal most of the weight for your own up the steep hills as i do
when you are heavier, you have to input also more power
the motor gives you than a little help which can make the difference..

for the motor its unimportant, if you have 70kg or 120kg
YOU have to manage for example 8km/h speed minimum
the motor will add some extra-watts to that, at 8km/h he will ad the same amount of watts, unimportant if you have 70kg or 120kg

of course: result of - let say - 70Watt added gives better benefit when you are 70kg "light" as the same 70Watt will do when you have 120kg

---> even when you are a 40kg light child, the motor will not be able to bring you up such steep hills at his own..

 

[daniel.weck]

big hill !

So, tell us how you did climb this 39% slope in your video !! ??

YouTube - Kanal von Kraeuterbutter

 

[flecc]

I think some of the secret with all the hill climbing with a rider/hub motor combination is the carry over effect of
the continuous motor power. Riders are probably capable of much more than they realise on down pedal strokes,
but it's the top and bottom dead centres that fail them. Having some carry-over power plus the power added to
the pedal strokes can make a very big difference.

And kraeuterbutter is strong too of course!
.

 

[Artstu]

He doesn't need a motor by the look of it

 

[daniel.weck]

He doesn't need a motor by the look of it

LOL, good point !!

 

[kraeuterbutter]

i think its like Flecc discribed in his last posting

and i think, its because i LIKE bicycling !

somebody who does not REALY like bicycling expects, that the motors does do 80%

somebody like me, who feels the difference in the rollresistance of a marathon or a Kojak,
or the rollreistiance of a 4bar tire compared to 6bar tire
or the air drag difference if cycling high or very low on the front bar,

somebody who feels this 20-30watt differences,
such a person feels VERY much the difference when there are maybe 60Watt (?) on such a steep hill or even more are added

maybe you should not fokus on this video on the ramp..
look on my other videos where i compared with motor and without motor climbs on the same hills..

its - i think i have said it here somewhere already - like the phenomen on body builders..
lifting a heavy weight of let say 100kg with your arms..
the first 6 times it works fine, the 8th time it works not so fine, and the 10th time its not possible anymore to lift the weight when lying on the bank..
BUT: it needs somtetimes only 2 fingers of two helping hands and the weight can be lifted

a hubmotor is very much more, than only 2 helping fingers

for me a electric bike is still a sport machine, not a "haha, i have a motor, now i never have to sweet anymore"

greets from my 8 weeks-holiday in Thailand/Laos/Cambodia/vietnam
reini

 

[flecc]

That sounds like great oriental holiday Reini, quite a change from home in Austria.
.

 

[kraeuterbutter]

yeah..
my girlfriend is already here for 16 week
my money was not enough, so only 8 weeks..

sound much, but hey: in the moment for example we live in a bugalow which costs 1,5 US$ each day/person (around 1 Euro per person)

i have driven many 100km with motorbikes and bicycles here,
changed my mind in many aspects..

when you first see for example traffic in hanoi (or saigon, 5million motorcycles only in his city !) you think about chaos and that you dont wona drive here

but when you try you will notice after some time, that its even nicer to drive here than in europe with the bike/motorcycle..
the speeds are much slower, you (nearly) never have to stop on a crossing because everybody just drives into the crossing
but it does work, and that not bad...

when i go with the bike in vienna, i have to stop every second crossing for a red light
here driving i slower, but you dont have to stop, so at the end its a much more flowently style of driving

catastrophal are the bikes here.. only one gear, breaks which are fare under the level of the old candilever-breaks wie used, every bike i was driving with has destroyed ballbearing at the pedals (not only making little noice but sometimes as much destroyed you realy believe the pedals will fall of the bike),...

oh man, i could wright a whole thread only about driving here and the bikes..
but driving with motorcycle was much fun here..
and much safer as you may believe when seeing youtubevideos..
there is not such a speeddifference between motorcycle (around 50km/H) and cars (nearly non existing) than in europe, where cars are double as fast as motorcycles or bicycles...

make the speedlimit for all the same in the cities (around 30km/h) and you dont need such silly things like bikepaths...

nevertheless i realy look forward sitting on one of my bikes again..
hey, even each 300 US$ wallmart-bike in europe has MUCH better quality than the bikes here
(going from 0 to 15km/h here with the bikes: it feels like it takes for ever with only one gear and the saddle down as like as you are only 120cm high - so not at all comparable with the onegear-"fixxies" in europe which you bring in few seconds up to 30km/h and more)

greets,
Reini