Dan asked:
> I'm expecting a 46 tooth Thanet eliptical chainring to be shipped soon for
my Jack
> Taylor fixed gear with a bolt circle that fits the Cyclotourist, Nervar,
Stronglight arms
> with the really tight bolt circle. My question is: How does the wide
part orient itself
> to the crankarm? I can have it perpedicular or in any of four other
orientations. Its
> enameled and I'd just as soon get it right the first time. Does anyone on
the list have
> experience with these? Hilary said that these were quite popular in the
'30's and '40's.
> I expect mostly for time trialing, but I'd like to know more.
I don't have any direct experience with such chainrings but it strikes me as rather odd to put an elliptical chainring on a fixed gear. It would seem to me that this is an invitation to throw the chain. Perhaps the ellipse is small enough that the ideal chain length at the largest and smallest part of the ellipse do not vary sufficiently to allow for chain slack?! Personally, I wouldn't put anything other than a perfectly round and aligned chainring on a fix (or on the timing chain of a tandem) because of the possible dire consequences of a thrown chain.
Hopefully somebody else has more immediate knowledge.
Steven Maasland Moorestown, NJ
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