See Jan's 1984 Bicycling Magazine Buyer's Guide , for the advertisement for the Durham elliptical chainwheel !
Hey Jan , have a scan you could send to Dan ?
Seriously , you want the greatest amount of chain to be engaged , thereby yielding maximum effective gear ratio , as your foot descends , and you have the greatest amount of muscle power .
Happy Trails ,
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.