As stated above, not to worry about rewind time, the most important thing is the accuracy of the instrument. So far as my experience goes, each clock will have its own "recycle" time depending on how it is assembled, lubrication of parts, etc. Just for a point of reference, I timed a VDO clock from a 911 that is lying on my bench - 2 minutes, 22 seconds between rewinds. Nothing else close at hand to time and it's too cold to walk to the garage.