I am building a new e-fatbike with Tongsheng tsdz2 48v 500w with 100mm b/b widht,,,,,OUPS did not fit my frameneed a 120mm so i put it on my wife trike. Nice install with the 20amp batt on the side frame. The 120mm is on is way with a new 20h batt in a soft bag for a better attachment between the frame tube.