# Which is best Crank or hub drive



## Iainj837 (26 Oct 2020)

I am thinking of getting an ebike as my new place of work is 36 mile round trip and a steep hill to climb I still want to cycle and still peddle but with some assistance.
Which is best Crank or hub


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## Drago (26 Oct 2020)

For tarmac duties it makes no difference whatsoever between rear hub and mid drive.


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## ebikeerwidnes (26 Oct 2020)

I have had both and they both work fine

Hub drives tend to be cheaper and simpler but can sometimes fell less like normal cycling
and cheap ones often seem to have sensors that just detect the pedals turning rather than proper torque sensors - so they can be fooled into powering the bike when you make little effort - which can drain the battery.


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## Iainj837 (26 Oct 2020)

ebikeerwidnes said:


> I have had both and they both work fine
> 
> Hub drives tend to be cheaper and simpler but can sometimes fell less like normal cycling
> and cheap ones often seem to have sensors that just detect the pedals turning rather than proper torque sensors - so they can be fooled into powering the bike when you make little effort - which can drain the battery.


I still want to use peddle power, just need that extra assistance there are 3 routes 1 route is 1 hour 45 1 hour 42 the other 1 hr 49


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## Drago (26 Oct 2020)

ebikeerwidnes said:


> I have had both and they both work fine
> 
> Hub drives tend to be cheaper and simpler but can sometimes fell less like normal cycling
> and cheap ones often seem to have sensors that just detect the pedals turning rather than proper torque sensors - so they can be fooled into powering the bike when you make little effort - which can drain the battery.


Indeed. Very cheap bikes and kits simply sense the roation of the chainset to provide the assistance, but this is real bottom end stuff. Anything even halfway decent uses torque sensing, which feels much more natural - the more power you pour on, the more the bike assists.

However, cheap mid drive systems - mainly conversion kits - can also have simple rotation sensors instead of torque sensing. Thats more a function of price point than an inherent difference between the 2 systems.


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## the snail (26 Oct 2020)

One drawback with crank drive is that there is more wear and tear on the transmission, so perhaps more expense, plus possibly less reliability. Probably more important to make sure the range/level of assist and ride suits you rather than whether it's hub or crank drive.


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## ebikeerwidnes (26 Oct 2020)

Iainj837 said:


> I still want to use peddle power, just need that extra assistance there are 3 routes 1 route is 1 hour 45 1 hour 42 the other 1 hr 49


Modern ones , as far as I know, all come with a controller mounted on the handlebars so you can change the assist level as you go along
The lowest setting is OFF - so you can pedal as much as you like!!


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## Mike_P (26 Oct 2020)

On a steep hill my crank drive ebike has left hub drive ones standing.


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## Drago (26 Oct 2020)

Mike_P said:


> On a steep hill my crank drive ebike has left hub drive ones standing.


Legal power is legal power, physics is physics.

A 250Wh mid drive bike with a typical 60NM will provide exactly the same level of assistance as a 250Wh hub drive bike with 60NM.

They all cut out at 15.5MPH, so the assertion that yours goes racing off from others with pretty much identical output does not, with respect, bear scrutiny.

Next you'll be telling us that you're one of these folk that goes around burning off roadies on your ebike. Feel free to meet with me at a convenient location and we'll see how it compares against all 19 stone of me on a hub drive machine.


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## ebikeerwidnes (26 Oct 2020)

I could be wrong here but
Firstly you mean 250W not 250Wh

but mainly - the 250W is not a constant - it varies and the specified number is an average not a peak - at times some of the motors will pump out a fair bit more than that - hence those motors will get you up a hill a lot easier

The bit about passing roadies is perfectly correct though - any good ride on a proper road bike will happily cruise past me when I am doing my 15.5 mph (or just over for a while) - so people who say they easily pass people on road bikes either mean your average Joe on the using a mountain bike with knobbly tyres and wearing tshirt and jeans - or they are saying their ebike is illegal


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## Mike_P (26 Oct 2020)

Drago said:


> Legal power is legal power, physics is physics.
> 
> A 250Wh mid drive bike with a typical 60NM will provide exactly the same level of assistance as a 250Wh hub drive bike with 60NM.
> 
> ...


I followed the hub ebike for some distance, as soon as the road steepened I flew pass which is borne out by the commentary at https://howtoebike.com/best-electric-bike-for-hills/ that hub motors are usually best for light hills and flat areas and if you’ve got a moderately steep street to climb, you’re going to need something beefier than a hub motor.


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## gzoom (27 Oct 2020)

Drago said:


> Legal power is legal power, physics is physics.........
> 
> .......... Feel free to meet with me at a convenient location and we'll see how it compares against all 19 stone of me on a hub drive machine.



But what about gearing? That will surely make a difference when you start getting into 10%+ hills which is quite common. Even in flat Leicestershire I've come across a few 20% ones!!

Woosh bikes seem to think this?

https://wooshbikes.co.uk/?motorcharts

If your any where near Leicestershire I would love to take you up on your offer. Be really interesting to see how a normal road bike, hybrid, mid drive, and hub motor bike manage a 20% incline with the same rider.

I could probably even wangle a Powermeter off a mate to make it into a proper geek feast


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## Tenkaykev (27 Oct 2020)

ebikeerwidnes said:


> I could be wrong here but
> Firstly you mean 250W not 250Wh
> 
> but mainly - the 250W is not a constant - it varies and the specified number is an average not a peak - at times some of the motors will pump out a fair bit more than that - hence those motors will get you up a hill a lot easier
> ...


Your remark about the 250 watts not being a constant is often misunderstood. I worked on repairing all types of Electric motors, they all have "Service ” or “duty cycle”ratings, S1, S2, etc alongside the power rating.
S1 was “continuous rating” and a 250 watt motor with an S1 duty Rating would happily put out that power all day long but could put out a great deal more on an intermittent basis. It could all get a bit esoteric with some duty cycles specifying the amount of time the stated power could be delivered for before a specified “off load” period to allow the motor to cool down.


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## Drago (27 Oct 2020)

Mike_P said:


> I followed the hub ebike for some distance, as soon as the road steepened I flew pass which is borne out by the commentary at https://howtoebike.com/best-electric-bike-for-hills/ that hub motors are usually best for light hills and flat areas and if you’ve got a moderately steep street to climb, you’re going to need something beefier than a hub motor.


Rubbish. There is nothing in the laws of physics or man that makes a hub motor inherently any less 'beefy' than a mid drive. Neither hub motor or mid drive has any difficulty assisting my 19 stones up a steep incline. The best of the legal examples all make in the region of 60-70NM of torque, regardless of where they are mounted - a 60NM motor neither knows nor cares if it is in the wheel, the frame, or even on a trailer pushing - it's still delivering 60NM.

If you were on one type of ebike and managed to get up a hill quicker than someone on a different type of ebike then that was down to your legs, and nothing else. That being the case, I would be grateful if you could explain the physics behind your assertion that mounting a motor in the middle suddenly makes it more powerful or efficient than mounting it within the rear wheel.


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## ebikeerwidnes (27 Oct 2020)

This is a question - not a comment 

Could the gears be part of the answer. Hub motors operate based on the speed of the bike - but crank mounted gears work based on the speed of the pedals - hence a crank mounted motor can be kept operating at an optimum number of rev at a slower speed by changing to a lower gear

I know the basics of how an electric motor works - but the details are something I have never had to look into. DO they have an optimum number of revs??
And if so can they be designed to operate better at e.g. 60-80 revs for a crank motor - but something else for a hub motor - and would this be require a different motor design for a folder with 20 inch wheels compared to a 'normal' sized road bike???

Thanks


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## Drago (27 Oct 2020)

But hub motors are geared too with their own gearing (aside from those cheap direct drive ones that originate from China).

Direct drive motors certainly have an optimum RPM, or at least do not perform well at very low revs. Again, most hub motors are geared anyway, which negates that problem.

As a very heavy rider I find neither system has any difficulty assisting me, and ride times on known routes are closely comparable. The only conclusion is that, on tarmac at least where mass centralisation is not a concern, that there is no noteworthy performance difference. The idea that one system will scamper away from another on a steep incline does not bear scrutiny when applied to reality. Advising a prospective buy to choose mid drive on that basis is deeply flawed.


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## Pale Rider (27 Oct 2020)

Iainj837 said:


> I still want to use peddle power, just need that extra assistance there are 3 routes 1 route is 1 hour 45 1 hour 42 the other 1 hr 49



Irrespective of motor choice, a problem you will have is a legal ebike will slow you down.

Looks like you are averaging close to 20mph, which you will not be able to manage on a bike restricted to 15.5mph.


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## Turdus philomelos (28 Oct 2020)

Iainj837 said:


> I still want to use peddle power


Then maybe you need to look at overall weight too then. My bike is well over 20kg laden with panniers. Good luck in search.


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## gzoom (28 Oct 2020)

@


Pale Rider said:


> Irrespective of motor choice, a problem you will have is a legal ebike will slow you down.
> 
> Looks like you are averaging close to 20mph, which you will not be able to manage on a bike restricted to 15.5mph.



It might not be slower but probably not much faster. It will make a difference to perceived effort though.

My average speeds on my roadbike and eBike is virtually identical. Though the eBike does offer the luxury of disc brakes, mudguards, lights.

It all depends on what you are after, my eBike is letting me commute to work all winter, as having the motor assistance really helps combat head wind/rain etc which isn't fun on any bike.

I do wish the eBike was lighter, you really feel the weight difference when riding. Hopefully one day we'll get sub 10kg eBikes with solid state batteries.

It should be possible as I see disc brake road bikes are now dipping under 6kg at top spec builds, though how much more a motor+battery would add to a £10k Specialized Aethos build I suspect would be very scary .


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## Pale Rider (28 Oct 2020)

gzoom said:


> Hopefully one day we'll get sub 10kg eBikes with solid state batteries.



I'm not holding my breath - advances in battery technology are glacially slow.

Lithium ion was a jump forward from lead acid about 15 years ago, but nothing has happened since.

The energy density of my 2010 Bosch battery is all but identical to a 2020 one.

I've lost count of the number of stories about promising laboratory batteries, but none ever reach the market.

No doubt the scientists are doing their best, and someone will crack it one day.

But you only have to look at electric cars to see that day is a long way off.

Despite the huge research and development budgets of the motor industry, the best they can come up with is still lithium cells, just lots and lots of them.


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## Zanelad (28 Oct 2020)

Pale Rider said:


> Irrespective of motor choice, a problem you will have is a legal ebike will slow you down.
> 
> Looks like you are averaging close to 20mph, which you will not be able to manage on a bike restricted to 15.5mph.



Not sure how. You can cycle faster than 15.5 mph, you'll just not get any assistance from the bike.

I notice a slight drag as the assistance on my ebike cuts out, but above 16-17mph it's no different from a "normal" bike. I can maintain an easy(ish) 21-22mph on mine I until my ageing body cries enough.


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## jowwy (28 Oct 2020)

i have 2 x crank drive E mtbs and they are both brilliant machines, probably because they are both Cube Acid's, one with a 500wh battery and one with a 400wh battery.......

ive not ridden a hub motor emtb, but i am intrigued by the ribble and orbea offerings, but i dont think the level of torque would be high enough for me


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## oldworld (28 Oct 2020)

Drago said:


> Indeed. Very cheap bikes and kits simply sense the roation of the chainset to provide the assistance, but this is real bottom end stuff. Anything even halfway decent uses torque sensing, which feels much more natural - the more power you pour on, the more the bike assists.
> 
> However, cheap mid drive systems - mainly conversion kits - can also have simple rotation sensors instead of torque sensing. Thats more a function of price point than an inherent difference between the 2 systems.


I'm a bit lost with torque sensing and rotation sensors on kits. I've not found an ebike that I like so I'm thinking of adapting my current bike. 
I've been looking at the Bafang middle drive kits but can't find information about torque or rotation sensors, maybe they don't have either?


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## CXRAndy (28 Oct 2020)

oldworld said:


> I'm a bit lost with torque sensing and rotation sensors on kits. I've not found an ebike that I like so I'm thinking of adapting my current bike.
> I've been looking at the Bafang middle drive kits but can't find information about torque or rotation sensors, maybe they don't have either?



Bafang are speed sensor motors. That means once the pedals are turning, you get a set amount of assistance- depending on what level you have selected. You don't even have to apply force on the pedals.

Torque sensing like the TSDZ2 multiply your input power. The amount of assistance is factored by assistance level and rider input


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## Pale Rider (29 Oct 2020)

Zanelad said:


> Not sure how. You can cycle faster than 15.5 mph, you'll just not get any assistance from the bike.



How likely is it the OP's quoted times are deliberately slower than he could easily manage?


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## rivers (29 Oct 2020)

Pale Rider said:


> How likely is it the OP's quoted times are deliberately slower than he could easily manage?


or even what he is getting as times from google maps for different routes


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## Notafettler (29 Oct 2020)

I have only had one, a kalkhoff crank drive. All the experts appear to be saying crank drive is better than hub drive. But the point the OP is making is making the journey easier and both will achieve that. With the length of journey I would only be interested in reliability and nothing else. I would suggest @Pale Rider is the best one to ask. As an aside hub gears are more reliable and will last considerably longer. Which means crank drive?


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## Notafettler (29 Oct 2020)

Pale Rider said:


> How likely is it the OP's quoted times are deliberately slower than he could easily manage?


How likely is it possible that they are faster! Google maps appear to think I can get there faster than I actually can....or to be more precise want to! 
Even using my electric bike i would at times struggle to get there in the time they say. Do the tosser even take into account the effect of Hills on cyclists compared to cars? Or the trailer I am pulling...forgot about the latter!


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## gbb (29 Oct 2020)

I err towards Dragos theory, torque is torque, power is power whether its hub or mid drive. Weight distribution, serviceability, reliability, cost, quality and even personal experience and preference are the options to consider imo.
Weight distribution, probably not even relevant on the road ?
Serviceability, no doubt the likes of Bosch have an excellent backup but my hub drive has been trouble free over 3000 miles plus and still working well.
Personal experience...we have both systems within the family and I prefer my hub drive, it feels like its giving you something, a kick, but my wife's Bosch mid drive feels benign, it gives you no sense of its input...which perhaps some people would like, but I don't personally.


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## Pale Rider (29 Oct 2020)

gbb said:


> I err towards Dragos theory, torque is torque, power is power whether its hub or mid drive. Weight distribution, serviceability, reliability, cost, quality and even personal experience and preference are the options to consider imo.
> Weight distribution, probably not even relevant on the road ?
> Serviceability, no doubt the likes of Bosch have an excellent backup but my hub drive has been trouble free over 3000 miles plus and still working well.
> Personal experience...we have both systems within the family and I prefer my hub drive, it feels like its giving you something, a kick, but my wife's Bosch mid drive feels benign, it gives you no sense of its input...which perhaps some people would like, but I don't personally.



I agree with your remarks about the ride of the Bosch system.

Most of the time I like its unobtrusive nature, although there are times when I wish it had more obvious in your face grunt.

Backup is a mixed picture because not all Bosch dealers have the relatively cheap diagnostic kit.

The term 'Bosch dealer' is something of a misnomer, 'reseller' would be more accurate.

Most bike shops become Bosch resellers by default when bike brands they already sell introduce Bosch bikes into their catalogue.


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## Dave7 (1 Nov 2020)

Zanelad said:


> Not sure how. You can cycle faster than 15.5 mph, you'll just not get any assistance from the bike.
> 
> I notice a slight drag as the assistance on my ebike cuts out, but above 16-17mph it's no different from a "normal" bike. I can maintain an easy(ish) 21-22mph on mine I until my ageing body cries enough.


Can I assume that if eg you are free wheeling (or pedaling) down a hill it will act as a normal none e bike ?


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## Pale Rider (1 Nov 2020)

Dave7 said:


> Can I assume that if eg you are free wheeling (or pedaling) down a hill it will act as a normal non e bike ?



You've asked this question a few times, and the answer is still 'yes'.

To delve into it a little deeper, the greater mass of the ebike means it tends to gather a little more speed than a push bike when freewheeling down hill.

Braking is more of a challenge, but nothing decent hydraulic discs can't handle.


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## ebikeerwidnes (1 Nov 2020)

Pale Rider said:


> You've asked this question a few times, and the answer is still 'yes'.
> 
> To delve into it a little deeper, the greater mass of the ebike means it tends to gather a little more speed than a push bike when freewheeling down hill.
> 
> Braking is more of a challenge, but nothing decent hydraulic discs can't handle.


My old ebike had normal bike rim brakes - nothing special
My wife's folder also has basic rim brakes
I have not had a problem stopping either of them compared to how I expect a normal bike to stop in spite of them being heavier
Of course, I am quite heavy myself so most of the excess weight on the bike is caused by my diet

OK - I need to say that I massively prefer the hydraulic disks on my own ebike - but that is more to do with feel and confidence - and, of course, the important point that they still work when the wheels get wet


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## Zanelad (1 Nov 2020)

Dave7 said:


> Can I assume that if eg you are free wheeling (or pedaling) down a hill it will act as a normal none e bike ?



The computer read out on my bike shows a maximum speed achieved of 40.2 mph. I gave up before the bike did. I don't bounce as well as I used to.


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## Stul (2 Nov 2020)

..just after I got my ebike I tried it out on a local long "downhill" bit and got over 40mph...but very scary and I will not be doing it again, (not sure that a polystyrene helmet would work very well if crashing at that speed!).


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## richtea (2 Nov 2020)

Stul said:


> ...and got over 40mph...but very scary and I will not be doing it again, (not sure that a polystyrene helmet would work very well if crashing at that speed!).


They're good for 15.5mph. A familiar speed?


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## Dave7 (3 Nov 2020)

Stul said:


> ..just after I got my ebike I tried it out on a local long "downhill" bit and got over 40mph...but very scary and I will not be doing it again, (not sure that a polystyrene helmet would work very well if crashing at that speed!).


I put a ceiling on my speed of 25 mph. As I have got older I seem more and more aware of what 'could' happen.


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## Stul (3 Nov 2020)

Dave7 said:


> I put a ceiling on my speed of 25 mph. As I have got older I seem more and more aware of what 'could' happen.



..me too!!


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## TyrannosaurusTreks (3 Nov 2020)

Pale Rider said:


> I agree with your remarks about the ride of the Bosch system.
> 
> Most of the time I like its unobtrusive nature, although there are times when I wish it had more obvious in your face grunt.
> 
> ...


I was chatting to our Bosch dealer today about diagnostic’s & he said after doing the training coarse they get a black dongle to diagnose motor’s but to be able to change perimeters etc the main uk Bosch manager has a silver dongle & only he can change these.😬😬🤔


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## ebikeerwidnes (3 Nov 2020)

Stul said:


> ..just after I got my ebike I tried it out on a local long "downhill" bit and got over 40mph...but very scary and I will not be doing it again, (not sure that a polystyrene helmet would work very well if crashing at that speed!).


Yeah - but at 40 m[h a crash is likely to involves a lot of skidding over tarmac but you head will mostly hit the ground at an acute angle and probably be OK (probably - do you really ant to go with probably won't be a vegetable!)
So a helmet is not as much use as you would think unless your head hits a stationary object - like a wall or car etc etc.

I still wear a helmet - but the only crash where it has helped was at about 2 mph going round a corner


TyrannosaurusTreks said:


> I was chatting to our Bosch dealer today about diagnostic’s & he said after doing the training coarse they get a black dongle to diagnose motor’s but to be able to change perimeters etc the main uk Bosch manager has a silver dongle & only he can change these.😬😬🤔


Sounds like increasing levels in wizardry
all bow down before the holder of the Octarine dongle

(maybe I read too many fantasy books)


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