i have owned this bizango for just over three years.i have just changed all the drive train.new bb. new cassette. new chain. new jockey wheels. and new chainrings.i have now been having problems with my front shifter it will not shift from the 22t to the 36t properly.the original chainrings were suntour which i found imposssible to get .the new rings are shimano.any help would be appreciated.