The gear drive is hidden inside the down tube and lithium battery packs are designed in water bottles. I guess the officials are walking the line pulling the bottles out of their cages before the race begins.
The gear drive is hidden inside the down tube and lithium battery packs are designed in water bottles. I guess the officials are walking the line pulling the bottles out of their cages before the race begins.
This thread on eng-tips.com has more details on bike motors - plus a link to the longer article with other comments, plus an alternative scheme where the magnets are inside the hub around the rim, rather than using a small geared motor hidden inside the tubing.
http://www.eng-tips.com/viewthread.cfm?qid=402911
Hmmm... Mr Bean rides...
https://www.youtube.com/watch?v=5cioiZ54s2k