I started my bike i then let it warm up and i went to ride it and the rear brake was fine for a few minutes and then i went to press it and then there was a barley any pressure the pedal gs al ; the way down and barley stops the bike ive looked up issues like this and it looks to be a common issue my bike only has 612 Miles on it and with it being the rear brake i believe this should be a safety issue and needs to be looked into