Originally Posted by
azza_333
Why wouldn't the rear derailleur cage not take up all the slack, by my calculations it should (47t capacity)
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I ask B & M already about the battery, when they say small they really do mean small only 100mah. Its supposed to get fully charged after the first 10-15min of riding. I don't see how a variation in output will effect my results, since I can look at the total mah output over 1 hour.
I made the comment on the derailleur cage possibly not taking up the slack because I use an older XT rear derailleur. With a 52/42/24 crank and 11/32 cassette, when I used the 24T chainring the 11 or 12T sprockets on the cassette did not work as the derailleur cage did not take up enough slack. With a little bit of chain stretch, the 14T sprocket also became problematic. Maybe your derailleur which is newer will have a longer cage and take up more slack. But since those gears are quite cross-chained, I would not use those gears anyway so it was a non-issue to me. If yours works, great.
Your comment on USB output was:
"Once its built I also want to do a bunch of testing on the SON28 hub, to see how much USB amps I can get out of the socket at different speeds. I will post the results as well." I took that to mean that you planned to ride at several different speeds and note what your USB output measured at at those different speeds. And my point was that if you change your speed your USB port output would not immediately change because your battery would buffer short term variations. My USB charger has no battery to buffer variation, thus I get instantaneous change in output at different speeds. I can't predict how your battery system will affect output with different speeds. Will an hour at a different speed be enough to come to a new equilibrium? I do not know.
I am not trying to start any arguments here, I was just trying to alert you to a couple possible minor issues.