There is a video compilation here that seems to show him switching something on under the left side of the saddle. https://videos.marca.com/v/0_r7kcp809-el-ges

There is a video compilation here that seems to show him switching something on under the left side of the saddle. https://videos.marca.com/v/0_r7kcp809-el-gesto-en-la-nalga-que-puede-delatar-a-armstrong-por-el-uso-de-motores?uetv_pl=0&count=0 https://videos.marca.com/v/0_r7kcp809-el-gesto-en-la-nalga-q... I don't really see this being possible at the time, the required power from such a small motor just wouldn't be available. It's alleged the motor was hidden inside a frame tube leading it to be maybe 30mm OD max.