Apologies for disappearing after I dropped the three letter bomb. I’m currently at a remote location with limited connectivity. The current space weather has affected both our internet access and offered a pretty unique opportunity for our flight test campaign, so I’ve been flat out.
I will be the first to admit that I may be exceedingly picky in my assessment of the ebikes I’ve ridden, but both the ep8 and specialised systems felt distinctly unrefined and awkward. Not so much in the individual modes they were using but in the way that they are applied. Specifically it’s the i value that I believe needs tweaking. Both systems felt like they suffer from integral windup. Alternatively it could be a form of set point hunting.
Not knowing much about the members of the control loops, I couldn’t tell you where it’s coming from or which of the issues it’s likely to be. Maybe it’s the suggested stock firmware issue? Or maybe the model specific tuning didn’t do the systems justice? Regardless, control loops that contain significant human input, and are broad in their applications can be very difficult to tune.
The commander of this facility has a trek rail and I had a quick ride of it over the weekend. I will say that the Bosch system felt more consistent in its behaviour than the other two I have ridden this year. This doesn’t surprise me as I have previously worked with teams from Bosch and have been very impressed by their electric powertrain engineers. It’s probably the closest to a system that I would hand over money for. When I get back home next month, I will borrow a different friends Shimano equipped bike to see if I am being unreasonably critical or if my negative impressions are justified.
Btw this is a very short and easy to understand video that shows what each of the letter does.
[https://youtu.be/qKy98Cbcltw](https://youtu.be/qKy98Cbcltw)
Oct. 31, 2021, 8:32 a.m. - Sean Chee
Apologies for disappearing after I dropped the three letter bomb. I’m currently at a remote location with limited connectivity. The current space weather has affected both our internet access and offered a pretty unique opportunity for our flight test campaign, so I’ve been flat out. I will be the first to admit that I may be exceedingly picky in my assessment of the ebikes I’ve ridden, but both the ep8 and specialised systems felt distinctly unrefined and awkward. Not so much in the individual modes they were using but in the way that they are applied. Specifically it’s the i value that I believe needs tweaking. Both systems felt like they suffer from integral windup. Alternatively it could be a form of set point hunting. Not knowing much about the members of the control loops, I couldn’t tell you where it’s coming from or which of the issues it’s likely to be. Maybe it’s the suggested stock firmware issue? Or maybe the model specific tuning didn’t do the systems justice? Regardless, control loops that contain significant human input, and are broad in their applications can be very difficult to tune. The commander of this facility has a trek rail and I had a quick ride of it over the weekend. I will say that the Bosch system felt more consistent in its behaviour than the other two I have ridden this year. This doesn’t surprise me as I have previously worked with teams from Bosch and have been very impressed by their electric powertrain engineers. It’s probably the closest to a system that I would hand over money for. When I get back home next month, I will borrow a different friends Shimano equipped bike to see if I am being unreasonably critical or if my negative impressions are justified. Btw this is a very short and easy to understand video that shows what each of the letter does. [https://youtu.be/qKy98Cbcltw](https://youtu.be/qKy98Cbcltw)