The bike should always run smoothly shouldnt it? when i put my bike on a stand and the back wheel is lifted and not touching the ground and i turn the bike on and put it in gear the wheel or chain dosnt always run smooth. i dont feel any vibration while on the road but when its going slow in first gear theres a wierd vibration or something stops the chain from spinning.

would anybody be able to help me out and check out the video if i were to post one up to show ou what i mean?