<telerik:RadSlider ID="RadSlider_Ticks" runat="server" MinimumValue="0" MaximumValue="5"
                                        SmallChange="1" LargeChange="1" ItemType="tick" Height="40px" Width="400px" TrackPosition="TopLeft"
                                        AnimationDuration="400" ThumbsInteractionMode="Free" AutoPostBack="True"
                                         Skin="Metro"      RenderMode="Classic"  >
                                    </telerik:RadSlider>

When scrolling the page and the finger is on the slider, the slider value changes.

The following code prevents the scrolling when you scroll from the slider.

function pageLoadHandler() {
    $telerik.$(".RadSlider").on('touchstart', function (e) {
        e.preventDefault();
    });
}
Sys.Application.add_load(pageLoadHandler);