Originally Posted by
rm -rf
I don't want to have to tell the bike when I swap cassettes. (Maybe that's next: an rfid chip in the cassette! I like that. But what happens if it reads both your chip and the next bike over?)
I suppose the cog sizes list could be calculated from a cadence sensor, a wheel speed sensor, and knowing where the shifters were on the front and back at the time. Actually, all it needs to know is the differences in cadence between cogs, to decide how many cogs to shift when the front is shifted. Assuming the front chainring sizes are known to the software.
True that would be slightly annoying, but in all honesty, how often does the average cyclist change cassettes on their bike? Does that number increase when you get into the range of cyclists who pay for Di2?
It doesn't have to be a hard thing to change it. If your "sensing" idea didn't work for some reason (I think it's a good idea, but then you'd have to input your tire size anyway
), you could simply do something like
- Hold both buttons for X seconds until light flashes.
- Press button 1 the lower number of teeth times (12 for a 12tooth small cog)
- Press button 2 the number of times the big cog has.
- Press and hold both buttons until light blinks.
Obviously it'd be a bit more complicated for a custom cassette.
Sure, it'd require counting to ~30, but it'd take all of 45 seconds or so.
Alternatively, if you often switch between two cassettes, be able to have two different configurations in memory.