Pedaling with motor off (Bosch Active Line Plus)

[tympos]

Today I took my bike to return home from work. At some point I realised I forgot to turn on the ebike... So naturally, I have the following questions:
1. Is it ok for the specific motor to be used when off? Could that create any problems?
2. The same question, but with the ebike "on" and pedal assist to "off"
3. Is there any drag when off, either entiry off or off from the pedal assisting options? (I can not understand, it's harder that way but I can not tell if it is from the motor or from the weight of the bike).
4. Can I use the ebike without the battery? The bike is a Cube nature hybrid one with a fully integrated downtube battery. Is the structural integrity of the bike compromised with the absence of the battery? i.e. does the battery contributes to the overall stiffness and structural capacity of the downtube? I undestand that it is an almost impossible scenario but imagine if I miscaclulated the battery capacity when riding with a friend, I could put the battery to my frined's backpack and come home much easier (tha battery is about 3kg).
Thanks for your answers

 

[indianajo]

Court hasn't reviewed that particular model that I see, but other cube models seem to have mid level Bosch mid drives. Active line or performance line. Those you are dragging the motor with your feet with the power off. The top of the line bosch motor has a one-way clutch in it to allow you to pedal power free without dragging the motor, but the bikes with that motor tend to cost ~$4500 up.
Mid drives that don't drag the motor when pedaled unpowered come from yamaha, brose, and shimano steps. Geared hub drives except for the GMAC have a one way clutch and don't drag the motor with your feet unpowered. I have one of those, since I ride unpowered unless the wind is >12 mph in my face. I carry 12 lb of motor & battery + 20 lb of tools, bags & water, quite easily unpowered. With full repair kit & water but no groceries or supplies, my bike weighs 94 lb. As compared to a headwind, which affects us vertical spine riders a lot.
Riding the bike for all errands since I quit working in 2008 has taken 50 lb of lard off my middle, which is the best place to lose the weight. Before I bought the electric cargo bike, my steel MTB with baskets & tools weighed 74 lb.

 

[Stefan Mikes]

Answering the OP questions:

1. You can safely ride your e-bike with power off
2. You can absolutely safely ride your e-bike with the motor on but with assistance OFF
3. The Gen 3 motor is believed to create some pedal drag. However, that is not that dramatic as described by many users. The true fact is the biggest drag is created by the heavy e-bike, especially when starting from stand-still and accelerating. Tympos, do several experiments:
   a. Start your ride with the motor on and be in middle gear. Accelerate to say 20 km/h and then switch the assistance to OFF. Downshift with derailleur and continue pedalling. You will notice that riding at constant speed without assistance is not that hard!
   b. When you happen to replace the chain sometime in the future, spin the cranks with your hand (motor switched off and no chain on the e-bike). Can you feel any resistance? I doubt.
4. You can safely ride your Cube without the battery (only cover the battery cavity against rain or dust). e-bikes are heavy because of the structural reasons. The integrated battery is not the structural component of the e-bike! (On contrary: the battery is a delicate component that has to be protected against any damage by the frame). So feel free to ride the e-bike with no battery.

There are a lot of myths around e-bikes. One of them is the "significant motor/pedalling drag". It is because the perceived drag comes from the fact mid-drive motors are strong and assisting the rider very much. The drag is especially nasty on accelerating (e-bike is heavy). Yet, the actual motor drag is not as significant as it is believed.

P.S. The best proof to bust the "motor drag" myth is to ride a hub-drive e-bike. When the assistance is on, e-bike rides easily. Switch the hub-motor off and you suffer terrible drag. But there is no motor in the bottom bracket there... Why riding a hub-drive motor e-bike with no assistance is so hard then? (Answer: Because the e-bike is so heavy).

 

[Dallant]

If you were riding without even realizing your bike was off, that’s a good thing!
I agree with Stefan. That said, the battery in place MAY help support the bike frame when under stress but the weight difference will definitely be noticeable. I’d be interested in what the Cube folks would say about this.

 

[indianajo]

P.S. The best proof to bust the "motor drag" myth is to ride a hub-drive e-bike. When the assistance is on, e-bike rides easily. Switch the hub-motor off and you suffer terrible drag. But there is no motor in the bottom bracket there... Why riding a hub-drive motor e-bike with no assistance is so hard then? (Answer: Because the e-bike is so heavy).

This is a complete fantasy about geared hub motor bikes. It is true about direct drive hub motor bikes. Most posters on this forum can't tell the difference. And as I said, weight doesn't matter much, frontal drag in the wind is 20 times worse.

 

[Stefan Mikes]

This is a complete fantasy about geared hub motor bikes. It is true about direct drive hub motor bikes. Most posters on this forum can't tell the difference. And as I said, weight doesn't matter much, frontal drag in the wind is 20 times worse.

What type of mid-drive e-bike do you own, Jo?

 

[fooferdoggie]

Court hasn't reviewed that particular model that I see, but other cube models seem to have mid level Bosch mid drives. Active line or performance line. Those you are dragging the motor with your feet with the power off. The top of the line bosch motor has a one-way clutch

this is a myth. this the amount of resistance

 

[retiredNH]

Indianajo, you don't need to spend $4500 or more to get a top of line Bosch. I have a Trek Allant 8s, paid $4300. Top of line motor.

My normal riding style is to always start out with the motor off. I get better control that way. I tend to activate the motor only when going uphill, so I ride most of the time with the motor off. And, as others have clarified, most mid drives have NO motor drag. Not sure where the myths come from.

 

[fooferdoggie]

Indianajo, you don't need to spend $4500 or more to get a top of line Bosch. I have a Trek Allant 8s, paid $4300. Top of line motor.

My normal riding style is to always start out with the motor off. I get better control that way. I tend to activate the motor only when going uphill, so I ride most of the time with the motor off. And, as others have clarified, most mid drives have NO motor drag. Not sure where the myths come from.

it is pretty persistent. I think it is a argument that people love hub drives use to justify their purchase.

 

[Stefan Mikes]

That said, the battery in place MAY help support the bike frame when under stress but the weight difference will definitely be noticeable.

Dallant, let me convince you the battery plays no structural role:
Typically, an integrated battery is a collection of delicate cells smartly welded together and stored in a plastic casing (that is of course reinforced with some metal to not fall apart). The last thing the designer would like to were applying any significant stress to the battery (which might end up with a cell damage and fire).

Notice how thick the bottom "tube" of a mid-drive e-bike is: it has to not only withstand the bike + rider weight but also support the heavy battery safely.

I'm not a Bosch bike user but could read about "transportation covers" to protect the battery cavity against rain or dust when the battery has been removed. No battery ride = yes; soiling the battery compartment (and especially electrical contacts) = no.

 

[retiredNH]

Dallant, let me convince you the battery plays no structural role:
Typically, an integrated battery is a collection of delicate cells smartly welded together and stored in a plastic casing (that is of course reinforced with some metal to not fall apart). The last thing the designer would like to were applying any significant stress to the battery (which might end up with a cell damage and fire).

Notice how thick the bottom "tube" of a mid-drive e-bike is: it has to not only withstand the bike + rider weight but also support the heavy battery safely.

I'm not a Bosch bike user but could read about "transportation covers" to protect the battery cavity against rain or dust when the battery has been removed. No battery ride = yes; soiling the battery compartment (and especially electrical contacts) = no.

But the flaw in your argument is that the rider is at least an order of magnitude heavier than a battery, which weighs in at 10 pounds or so for the biggest. Yes, the designers don't want stress on the cells. That's easy enough to avoid with a protective case. But at least on my Trek Allant, the battery mounts, top or bottom, are nowhere near robust enough to add significant structural support. In fact, the top of the battery is held in by a thin piece of sheet metal (1/8 inch?), part of the lock, that is maybe 2 inches wide, extending less than 1/2 inch. Not much structural support there! The fact is that the housing for the battery is a very good structural shape. It doesn't need to be massive to do its job.