How much torque is enough?

[skritikos]

View attachment 72371
Cube ebikes seem to be very popular in Greece lately. Saw this one today when I was purchasing some muc-off products and it’s the 8th cube ebike my lbs sold this month. Greece has been on lockdown since 7th November. Thankfully bike shops are classified as essential and are allowed to remain open like pharmacies, supermarkets and bakeries. Impressive sales of one brand in an island of only 75k residents. The lbs owner told me that compared to last year he sold zero cube ebikes in the month of November and only five for the entire year of 2019.

this whole handlebar rising structure (that is an aftermarket installation) seems totally wrong and probably a bit dangerous to me

 

[Akrotiri]

this whole handlebar rising structure (that is an aftermarket installation) seems totally wrong and probably a bit dangerous to me

I actually asked the lbs owner specifically about the handlebars and why set up like that. He told me one couple in their mid 50s ordered two cubes , one diamond frame for the guy that was delivered 2 weeks ago to them and the other step thru for the customers wife which got delivered to the store the day I was there early this week. It came with regular riser bars but she requested and prefers the extra high riser bars. Lbs owner said she’s very short so she needed them and doubts she will ever ride above even 15kph so he’s not worried about her getting impaled by the riser bars at high speed in the event of a crash.

 

[Alaskan]

Check Bosch's site and see the Gen 3 motors. The first one was the Active Line Plus and the next year (2020) the new Performance Line. I know, as I'm riding this every day

Following your advice I went to the Bosch-ebike.com site, searched and found just what I expected...no reference to motor generations, only year of introduction. If you can find a chart showing motor "generations" on the Bosch site, please share it. I think the generation designation is something the public refers to with little uniformity in understanding.

From others more knowledgeable than I, I have been led to understand that the Performance Line motors, including the CS and Speed versions, skipped a generation from gen 2 to gen 4 and that gen 3 designation only applied to Active Line motors which were the first to have the larger 1:1 drive sprocket. I am curious and certainly willing to update my understanding if you can point to something from Bosch to the contrary.

 

[skritikos]

Thanks again Stefan!
Those of you that already have the bikes you want are so lucky. It’s nearly impossible to buy anything now - one dealer told me yesterday that everything was back ordered and delivery would be in May / June next year.
I’ll keep looking.

I was on the hunt on September waiting for the 2021 models.
I got the one and only XL of my model and colour that appeared in Germany on a very big dealer.
In 5 days it was with me in Greece (and just 19 euro shipping).

I hope you will receive yours asap. I'm sure you will enjoy it a lot.

 

[skritikos]

I actually asked the lbs owner specifically about the handlebars and why set up like that. He told me one couple in their mid 50s ordered two cubes , one diamond frame for the guy that was delivered 2 weeks ago to them and the other step thru for the customers wife which got delivered to the store the day I was there early this week. It came with regular riser bars but she requested and prefers the extra high riser bars. Lbs owner said she’s very short so she needed them and doubts she will ever ride above even 15kph so he’s not worried about her getting impaled by the riser bars at high speed in the event of a crash.

I can understand the reason, but the steerer and the headtube are not designed to accept such huge torque values created by the handlebars so far away from the end of the headtube.
I know that Cube overbuilds their frames in that area but still. It seems wrong and an accident waiting to happen.

 

[skritikos]

Following your advice I went to the Bosch-ebike.com site, searched and found just what I expected...no reference to motor generations, only year of introduction. If you can find a chart showing motor "generations" on the Bosch site, please share it. I think the generation designation is something the public refers to with little uniformity in understanding.

From others more knowledgeable than I, I have been led to understand that the Performance Line motors, including the CS and Speed versions, skipped a generation from gen 2 to gen 4 and that gen 3 designation only applied to Active Line motors which were the first to have the larger 1:1 drive sprocket. I am curious and certainly willing to update my understanding if you can point to something from Bosch to the contrary.

All Bosch documentation has the information for the different motors.

e.g. pages 32, 33 and 89

https://www.bosch-ebike.com/fileadmin/EBC/Service/Downloads/Bedienungsanleitungen/MY2021/Produktkatalog/Bosch-eBike-Product-Catalogue-MY2021-EN.pdf?_=1599566539

and their user manual of all three Gen 3 motors:

https://www.bosch-ebike.com/fileadmin/EBC/Service/Downloads/Bedienungsanleitungen/MY2021/AL_ALPlus_PL/Bosch-eBike-Manual-DriveUnit-Active-Line-Active-Line-Plus-Performance-Line-BDU3xx-MY21-WEU.pdf?_=1598969753

 

[Akrotiri]

I can understand the reason, but the steerer and the headtube are not designed to accept such huge torque values created by the handlebars so far away from the end of the headtube.
I know that Cube overbuilds their frames in that area but still. It seems wrong and an accident waiting to happen.

It’s definitely not the speed motor and I think it’s the base active line motor with 40nm of torque. Not sure though.

 

[skritikos]

It’s definitely not the speed motor and I think it’s the base active line motor with 40nm of torque. Not sure though.

with my 26 kg tank of a bike and without any motor support (as I go much faster than 25.5 downhill) I have exceeded speeds of 70km/h very easily.
I dont want to calculate the forces applied on the headtube and steerer when braking from speeds like this

Hopefully the owner of that modded bike will stick to much slower speeds )

 

[Akrotiri]

with my 26 kg tank of a bike and without any motor support (as I go much faster than 25.5 downhill) I have exceeded speeds of 70km/h very easily.
I dont want to calculate the forces applied on the headtube and steerer when braking from speeds like this

Hopefully the owner of that modded bike will stick to much slower speeds )

As the owner of the lbs described her to me she’s the type thats scared of her own shadow. She’s not traveling above 15kph under any circumstances.