My physics are rusty, or weren't that great to begin with, but I believe it's harder to power extra mass when it is on your wheel as opposed to on your bike somewhere else. There are specific terms for this I'm forgetting.
<br><br>
<div><span class="gmail_quote">On 1/7/06, <b class="gmail_sendername">Thomas John Vitolo</b> <<a href="mailto:tjvitolo@bu.edu">tjvitolo@bu.edu</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">I stumbled on this while looking up ways to<br>> generate power. <a href="http://www.freelights.co.uk/">
http://www.freelights.co.uk/</a> it seems to be a<br>> nice way to make your bike visible without making it more difficult<br>> to<br>> ride (friction and so on). The key is the magnet tumbles past one<br>> of
<br>> the magnets on the spokes and thereby creates electrical current.<br>> No<br>> physical turbine gets cranked, which seems amazing to me not being<br>> much of an electrician.<br><br>It still makes it more difficult to ride. After all, you've now got to (1) work
<br>harder because you've added weight to your wheel and have to "lift" it, and (2)<br>the magnetic force of when the moving magnet approaches the generator results in<br>resistance. Think of pushing a magnet toward another like magnet. Sure, it's
<br>not much resistance in either case, and you get the added bonus of recovering<br>nearly all of the force when (1) the magnets get to "fall" and (2) the generator<br>pushes the magnet away once it's past.<br>
<br>But, no machine is perfectly efficient, so there is a 100% chance that this<br>frictionless dynamo system makes it harder to pedal than no dynamo system at<br>all. How much harder to pedal? Probably not much.<br><br>
- stomv<br><br>P.S. Since your cycle will have more mass with the dynamo system on, you will<br>face more rolling friction when you ride, it's just that the friction isn't on<br>the dynamo, it's between your wheels and the road.
<br>Support a few technologists in Washington. Go to:<br><a href="http://actblue.com/list/stomv">http://actblue.com/list/stomv</a><br>_______________________________________________<br>Boston Critical Mass mailing list<br>
<a href="mailto:list@bostoncriticalmass.org">list@bostoncriticalmass.org</a><br><a href="http://bostoncriticalmass.org/list">http://bostoncriticalmass.org/list</a><br>To unsubscribe email <a href="mailto:list-unsubscribe@bostoncriticalmass.org">
list-unsubscribe@bostoncriticalmass.org</a><br></blockquote></div><br>