Whatever it is that's going on with that seat tube shifter, I love it. Google Translate isn't quite up to the task, what does it do?
I think it might be to engage and disengage the dynamo on the rear wheel just behind the bottom bracket.
Also too slow!
@rj started
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Whatever it is that's going on with that seat tube shifter, I love it. Google Translate isn't quite up to the task, what does it do?