Model RBEX29761 REEBOK RT 300 Bike Drive Belt Part 142056

I replaced both the belt and clutch pulley on my Reebok RBEX29761 upright stationary bike. When I first installed them, there was slippage after pedalling for less than a minute. Retightened the idler pulley arm and experienced the same problem shortly after adjustment. Checked other possible mechanical problems and found none. It turned out to be what appears to be simple stretching of the belt as it was flexed in operation. I wound up retightening the idler pulley tension at least ten times before the slipping stopped. The belt works just fine now (based on a ten-minute ride). Recommend that the the instruction paper that comes with the belt (and presumably all similar belts) inform the customer that stretching is expected and the idler pulley arm will have to be adjusted more than several times before the belt is fully stretched and stops slipping.