Originally Posted by
wrk101
Craziest gearing I have ever seen was on a Peugeot I picked up. Stronglight double crankset, 51/49 tooth chain rings. Thats right, a drop of two teeth. It visually looked like the two chainrings were the same size....
...a two tooth difference on chainwheels is something I have used to set up something for flat course Criterium gearing, where you've got very close cogs in the back, with maybe a one tooth difference in the rear. It's an old school attempt to give a lot of variations in a small range, to allow for cadence adjustments. Some of the older cottered crank chainwheel sets were so geared. Gives you a very easy and reliable front shift, assuming you don't require a wider gear range.
I have it on a few bikes.