chain is tight and secure. i can‘t figure out what is going on since nothing appears to be loose.
How's the tire pressure? sounds low. Good luck.
Either a bad wheel bearing or a broke belt in the tire itself.Are you checking it with the rear of the bike off the ground?
How tight is the chain? There should be some free play otherwise it will snap and damage something, possibly you. First thing to check Is the tyre pressure correct? Has the wheel been balanced? If it has, have the weights have fallen off? Check the condition of the wheel, is it distorted, if it is wire-spoked, tap them with a spanner they should ring like a bell, it is a tricky job to tighten them as too tight will pull the wheel out of shape. Put the bike on a centre stand, have somebody support it for you, grip the rear wheel and the swing arm and try to move the wheel sideways (wheel bearings need replacing), now grip the swingarm and try to move it sdeways (swingarm bearings need replacing). EDIT: Is it possible when you tightened the chain that you left the axle at an angle – the marks on chain tensioners are not always accurate?
