I reached 47.6mph down the String Road in Arran; I wouldnt be surprised if braver folk than me could get to 60mph there. The fastest Ive been this year was 38.8mph going down the Braunston Road to Oakham.
Garmin Connect says I done 48.7mph but I doubt it, it was wet all our ride and snowing at one point Garmin TC says 32.6mph (somewhere on the road from below the A1 to Empingham) that's more realistic
Edit: Had a closer look at the gps, it was
here today, that'd be right, not too steep, totally straight (good visibility) and with a steep uphill to slow me down