Billski's point: a few % of power loss - all convert to heat (only 1% to 2% losses).sorry, you missed Billskis' point: there is no way a transmission set-up on a bike (or car/truck etc) can have more than a few % of power loss. There is simply no capacity to shed that generated heat without a cooling circuit and forced cooling. The only transmissions that do have forced cooling are automatic transmissions and some heavy-duty pullers. Most electric kettles are 2.4kW, I use that often to get the message across about heat energy and power. Having several of those kettles in your transmission system would cook the whole lot in no time.
My point: a lot of % of power loss - some convert to heat others are different (two figure % losses).
No, I am not missing that some losses turn to heat. Am I missing something?