I have recently had the chance of reasonable test rides on Bosch and Panasonic drive bikes so I thought it might be helpful to offer a few personal observations about how these drive systems compare with the Impulse system I am most familiar with. I must stress these are personal opinions and other people could well ride the same bikes and come to different conclusions - it is always best to try out a variety of bikes for yourself, although this can often be difficult to arrange with limited availability of many premium brands. For reference, the bikes used for this comparison were step-thru models of a Swiss Flyer (Panasonic 25.2v system), Gepida (Bosch 2013 console / software) and Kalkhoff Agattu (Impulse 2013 software). The bikes all had similar specs (apart from the motor / battery) and had the same Nexus 8 hub gear. They are similarly priced at a little under £2000. All the bikes are available with larger capacity batteries at additional cost (Panasonic 403Wh, Bosch 400Wh and Impulse 612Wh)
The most striking thing, perhaps not that surprisingly (given the 25.2v battery - 302Wh) was the lack of power from the Panasonic motor. I would liken it to driving a minibus up a hill. It would climb steep hills slowly in a low gear but even gentle inclines seemed to require quite a bit of effort in higher gears. The 3 levels of assist seemed to only marginally change the feel of the assistance provided. With gentle pedalling, the torque sensor sometimes made for a jerky ride but overall it was generally quite smooth. On the plus side, this was the quietest of the 3 motors. It may be that the latest 36v system has more power but i'm told this is not noticeably the case by someone who has tried both.
The Bosch system (36v battery - 300Wh) was much more powerful but noticeably noisier that the other two. The four levels of assist gave clearly differentiated levels of assist. The assist was delivered smoothly across the range. The bike also felt better with the assist turned off although this might be nothing to do with the motors, just a comparison between the Gepida and the Swiss Flyer. Having said that, the bikes have the same gears and weigh about the same so they ought to be similar to ride unpowered. The Bosch console (the only bike with a display console of the three I tested) was well located, easy to read and informative.
The Impulse system (36v battery - 540Wh) on the Kalkhoff feels similar to the Bosch with plenty of power and clearly differentiated assist delivered through the 3 settings. Delivery is smooth and it's quieter than the Bosch, but not as quiet as the Panasonic. This year's Agattu models don't have a display console but they are available on other Kalkhoff models.
So, motor wise I would say there is not a lot to choose between the Bosch and the Impulse with the Panasonic being disappointing in comparison. Taking into account the battery capacity provided in the standard spec the Kalkhoff offers the best value package and all round solution for those requiring extended cycling range. If range is not important, then it would be a question of personal preference.
The most striking thing, perhaps not that surprisingly (given the 25.2v battery - 302Wh) was the lack of power from the Panasonic motor. I would liken it to driving a minibus up a hill. It would climb steep hills slowly in a low gear but even gentle inclines seemed to require quite a bit of effort in higher gears. The 3 levels of assist seemed to only marginally change the feel of the assistance provided. With gentle pedalling, the torque sensor sometimes made for a jerky ride but overall it was generally quite smooth. On the plus side, this was the quietest of the 3 motors. It may be that the latest 36v system has more power but i'm told this is not noticeably the case by someone who has tried both.
The Bosch system (36v battery - 300Wh) was much more powerful but noticeably noisier that the other two. The four levels of assist gave clearly differentiated levels of assist. The assist was delivered smoothly across the range. The bike also felt better with the assist turned off although this might be nothing to do with the motors, just a comparison between the Gepida and the Swiss Flyer. Having said that, the bikes have the same gears and weigh about the same so they ought to be similar to ride unpowered. The Bosch console (the only bike with a display console of the three I tested) was well located, easy to read and informative.
The Impulse system (36v battery - 540Wh) on the Kalkhoff feels similar to the Bosch with plenty of power and clearly differentiated assist delivered through the 3 settings. Delivery is smooth and it's quieter than the Bosch, but not as quiet as the Panasonic. This year's Agattu models don't have a display console but they are available on other Kalkhoff models.
So, motor wise I would say there is not a lot to choose between the Bosch and the Impulse with the Panasonic being disappointing in comparison. Taking into account the battery capacity provided in the standard spec the Kalkhoff offers the best value package and all round solution for those requiring extended cycling range. If range is not important, then it would be a question of personal preference.