Most folks prefer to stack headset spacers beneath their threadless stem in order to minimize the drop from their saddle to their handlebars. Keep in mind that if your steerer tube is made of carbon fiber that you can generally stack your steerer no higher than the diameter of your steerer (check your fork owner's manual for exact guidelines for your fork). For a 1" steerer this means you can have an approximate stack of 2.5cm. For a 1-1/8" steerer you can have an approximate stack of 3.0cm. We sell our spacers in quantities of 3cm, and you can choose the denomination of this stack. Wheels Manufacturing spacers are free of logos.