i changed my back tyre size the other week only just the width.. so instead of 195/60/15 its not 205/60/15.. i also changed my disks on the front as well as new pads.. but ever since then i now have a shuttering when i accelerate but as soon as i either back off or put into neutral its stops and drives smooth again.... what could it be because its doing my head in..

any suggestions would be great...