My hub shifts at ~6.6 miles/hour when it is set for a 16" wheel. That seems about right. But it shifts at ~7.8 miles/hour when it is set for a 26" wheel, which is way too slow. You would think that the programmers would have tried to pick the same rotational velocity, no matter what wheel size is set. Does anyone know how to change the shift speed, or do I just choose a 16" wheel and do the arithmetic in my head for actual speed and trip length?