Simple Slider For Video Camera

Some shots needed to be taken as camera is sliding through the shot. i didn't want to go for a serious one for the time being. so i just built this little one using some simple tires (not bearings). after playing with it for a while i found out that  a surface should be very smooth for this one to take smooth shots otherwise it takes slightly shaking shots. To solve this problem i bought a pair of smooth aluminum flat rails each one 2m. so when i slide this one on the Aluminum rails it keeps recording very smoothly. but managing those 2m long aluminum rails are a pain in the stomach because i don't have enough space to put all these stuff. so i am thinking of kicking the the rails away and replace the tires with bearings, it might solve the problem, but for now i will use it anyway.