I have an 8 speed touring bike and recently noticed that when I have selected the fourth largest ring on the rear block (excuse me for not using correct terminology) and pull up at lights and then back pedal to move the pedal in position to pull off the chain drops down onto the next smallest ring on the block. As soon as I start pedaling forward it moves back up to the gear I selected. Also there is a really annoying tick tick noise when I am pedaling under load. I have checked the pedals and their is no movement as well as the bottom bracket.
Advice is most welcome
Advice is most welcome