サイクロイドのアニメーション

Animate[
If[t==0,dots={PointSize[0.006]};];
cycloid[t_]:={t-Sin[t],1-Cos[t]};
baseline=Line[{{-2,0},{10.5,0}}];

AppendTo[dots,Point[cycloid[t]]];
Graphics[{{GrayLevel[.5],Disk[{t,1},1]},(*disk*)
dots,Line[{{t,1},cycloid[t]}],(*spoke*)
baseline},{AspectRatio->3/12,PlotRange->{{-1.5,10.5},{-.5,2.5}}}],{t,0,3Pi,Pi/20},AnimationRunning->False]