We've had our Bike+ for less than a year and ride 5 to 7 days per week. Yesterday, my husband and I both rode and found the resistance calibration had changed markedly. Previously a cadence of 95 and resistance of 35 produced output of 100 joules or so. Yesterday I reached 100 joules with a cadence in the low 80s and resistance of 32. We have not done anything to the bike... not moved it or even jostled it. Don't know how this could have happened.