Which is best Crank or hub drive

[Iainj837]

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

 

[Drago]

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

 

[ebikeerwidnes]

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.

 

[Iainj837]

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

 

[Drago]

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.

 

[the snail]

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.

 

[ebikeerwidnes]

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!!

 

[Mike_P]

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

 

[Drago]

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.

 

[ebikeerwidnes]

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

 

[Mike_P]

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.

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.

 

[gzoom]

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

 

[Tenkaykev]

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

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.

 

[Drago]

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.

 

[ebikeerwidnes]

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