找到一些Speed drive的重量資料如下
Weight
Including spindle, bearings and spider, excluding chainring and cranks: 790g (46 tooth chainring with chainring bolts: 90g, cranks 180g each).
Please compare the total weight of speed-drive with the total weight of a triple chainring set including shifter, cable, derailleur. Example: Shimano Altus (48/38/28 teeth): weight incl. right crankarm: 1255g