Well that turned out to be interesting.
Spooling back: I had written previously about the pedalling cadence that flows from the Bafang two-speed automatic gearbox in the rear hub drive e28.X. While my research suggested that a faster cadence was healthy, my sense was that, for me, it would feel better if it were a little slower – and I am not the only one thinking that.
I posted a link to the article on the Estarli Riders Club group on Facebook. Estarli (administrator of the group) commented:
Just so you know, the e28x actually comes with two ratio options — you can choose a larger front crank to reduce your cadence.
I followed this up with an e-mail to them asking for more information. Back came this intriguing response on the issue:
The larger front crank is the standard that we fit onto this bike, it is referring to the teeth of the crankset which is 48t. There is a smaller crankset option which is 42t.
The next time I got out my e28.X I tried counting the number of teeth. I was somewhat surprised to find that the crankset on my Blike subscription bike had … 42 teeth: it was the smaller one.
I posted on Facebook about it and at the time of writing this, three other people had chimed in to say that the ones in their households – all bought a few months ago – also had cranksets with 42 teeth.
Estarli clarified that it would depend on when they had been built:
But the current standard is the 42T which we think gives you the best balance of pedalling cadence and climb ability. However there is a choice of a 48T that can be fitted from new or upgraded later through an Estarli service centre.
I have suggested they might want to mention that as being an option on their website, because it does not seem to be widely known. It would be useful to include some actual performance data of some sort on the effect of the 14% increase in the number of teeth from 42 to 48. The swap would also involve a longer belt, I presume. I do not know whether there has been any similar consideration of the rear drive cog sizing, by the way.
Meanwhile – breaking news – I have also gathered that, in a spirit of constant research and development, Estarli are actively working on a three speed automatic gearbox e-bike, which is something I suggested in my previous discussion about cadence.
Apparently they have been testing a few such motor technologies. They are fine tuning the feel and function and have encountered some teething issues. But they say it is something they definitely plan to offer once it meets their demanding standards: there is no likely date yet.
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