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From: wagner@uw-june (Dave Wagner)
Newsgroups: net.bicycle
Subject: Re: elliptical phrases
Message-ID: <395@uw-june>
Date: Thu, 17-Oct-85 20:17:50 EDT
Article-I.D.: uw-june.395
Posted: Thu Oct 17 20:17:50 1985
Date-Received: Sat, 19-Oct-85 04:02:07 EDT
References: <296@tekchips.UUCP>
Organization: U of Washington Computer Science
Lines: 25

> >Can anyone comment on elliptical chainwheels?
> >
> >I wonder about deurailler wear with one of those, since I understand
> >your mechanism would flex twice every revolution.
> 
> I have never held one in my hand, but I've seen one up close, in
> action. Surprisingly, the derailleur pulleys move only during
> shifts. (I never did get around to formulating a mathematical proof
> of this, but I've seen it happen).

It seems rather obvious to me, that at any point in time the chain is wrapped
around exactly half of the teeth on the chainwheel, regardless of its
orientation.   Think about it.


			Dave Wagner
			University of Washington Comp Sci Department
			wagner@washington.arpa
			{ihnp4,decvax,ucbvax}!uw-beaver!uw-wally!wagner

"The surest thing there is is we are riders,
 And though none too successful at it, guiders,
 Through everything presented, land and tide
 And now the very air, of what we ride."
	- Frost