Your Reformer has Side Wheels (some people call them Guide Wheels), which control the side-to-side motion of the Reformer carriage. This means that under each carriage there are usually 8 wheels.
Studio Reformers have side wheels that must be adjusted so that there is very little or no side-to-side motion of the carriage. If there is too much side-to-side motion, the carriage can ride on the tracks crooked, causing the wheels to wear more quickly, leave black marks on the rails, and if the angle is great enough, scrape the side of the carriage on the inside of the wooden rail.
Allegro 1 and Allegro 2 Reformers do not need to have their side-wheels adjusted. Because the carriage rides above the rails, there is little danger to the side of the Reformer rails. Despite having some side-to-side motion, these carriages tend to find a track along the rail and stick to it. As long as you DO NOT add silicone spray to the rails to clean them, you’ll be fine. Silicone spray will make the rails very slippery and cause the carriage to slide in every direction- the opposite of what you want!