Shifting Technique with Internal Hub

[Riversurf]

I'm playing around with downshifting technique on uphills with a internal hub (Shimano Nexus Inter 7 powered by a Bosch Performance Line mid-drive motor). Wondering what approaches others have found the most efficient/effective. For instance: Sometimes I stop pedaling completely for a split second and then downshift, even in the midst of pretty steep grades. It works well enough, but obviously I lose some speed in that instant. Other times I just let up pressure a bit as I shift, just as I would with a derailleur, but the responsiveness is lower and it seems to require split second timing. The former technique seems to be most effective, but perhaps there's some middle ground, some combination of approaches, or something I'm not even aware of, that would work best. (One thing that the internal drive allows you to do is downshift over the entire range of ratios when pedaling stops.)

 

[AlanDB]

I have a Nexus 8 on my Gazelle e-bike. I use your first method ... stop pedaling briefly when shifting. The tech at my LBS told me that damage to the internal geared hub could occur if it is shifted under any kind of torque, so I try to play it safe and stop pedaling. I trusted that the information given by my LBS is accurate, but would be interested in hearing other opinions.

 

[Riversurf]

I have a Nexus 8 on my Gazelle e-bike. I use your first method ... stop pedaling briefly when shifting. The tech at my LBS told me that damage to the internal geared hub could occur if it is shifted under any kind of torque, so I try to play it safe and stop pedaling. I trusted that the information given by my LBS is accurate, but would be interested in hearing other opinions.

Interesting, and kind of gratifying, to know that the "stop pedaling" technique was recommended to you.

 

[Mr. Coffee]

When your pedals are at the 12 o'clock and 6 o'clock position you are exerting exactly zero torque on the drivetrain. With a little practice you can coordinate your shifting with that pedal position. This is analogous to power-shifting an old Volkswagen.

In practice you still have to pause your pedaling, but the pause is typically much briefer if you use this technique.

 

[tompat]

When your pedals are at the 12 o'clock and 6 o'clock position you are exerting exactly zero torque on the drivetrain

Is this really true for mid-drive electric bikes?

 

[6zfshdb]

My ebike does not have a mid drive motor so I can't offer any advice here. I do have a question though. On every bike I've owned, the derailleur won't shift if the pedals aren't moving. I've been told that doing so can cause damage to the derailleur. I'm curious how this would work for ebikes with combo mid drive motor / derailleur drive trains.

 

[Mr. Coffee]

Is this really true for mid-drive electric bikes?

Well, it works for my Bosch Performance CX and Rohloff hub.

 

[Nova Haibike]

I do have a question though. On every bike I've owned, the derailleur won't shift if the pedals aren't moving. I've been told that doing so can cause damage to the derailleur. I'm curious how this would work for ebikes with combo mid drive motor / derailleur drive trains.

More specifically the chain needs to be moving for a derailleur equipped bike to shift. If the chain is not moving and the shifter is actuated, it jams the chain against the cogs(s) until the chain is moving again. It will not damage the derailleur per se; it is just harder on the chain. With a mid-drive, the extra torque it provides, it can make the shifting a little rougher under load, so unless the system has shift detection, it is a good practice to ease off on the pedal pressure when shifting,but it is not 100% necessary any more than it is when pedaling hard with a regular bicycle.

 

[Trail Cruiser]

When your pedals are at the 12 o'clock and 6 o'clock position you are exerting exactly zero torque on the drivetrain. With a little practice you can coordinate your shifting with that pedal position. This is analogous to power-shifting an old Volkswagen.

In practice you still have to pause your pedaling, but the pause is typically much briefer if you use this technique.

I made a thread about timed shifting. The Bosch mid drive has a built in shift detection system that decreases the power (apparently, not completely shut down) during shifting to reduce the load.

https://electricbikereview.com/foru...load-and-the-art-of-precision-shifting.24395/

It helps a lot if you have a cadence meter, since you will know exactly when to downshift. In most cases, you downshift when your cadence drops below 60 rpm.