Does anyone else notice that it seems to take more strokes to pump up the TPU tubes? Seems like there is a higher volume of air inside these tubes. On my Look bike I have a TPU tube in one wheel and a regular butyl tube in the other. I can say for sure that the butyl tube loses more air over time. Or I should say the butyl loses more pressure over time. Maybe they both leak the same amount of air, but since the TPU tube held more air to begin with, that same leakage amounts to less pressure loss.