Osymetric chainrings are appearing on more and more professional athletes bikes because they increase effectively gear size while reducing lactic acid build up. Yes, they look a little strange, but they really work!
For the 52-42 combination the 52 actually feels like a 49 at top dead center but delivers the effective gear of 54 while in the strongest part of your pedal stroke between 1 and 5 o'clock. The 42 is the smallest chainring that can be used on a 130mm bolt circle but it will feel like a 39 tooth at top dead center and deliver additional power through the power portion of the pedal stroke.
The 54 tooth feels like a 51 so you will be able to turn it over. Then when you are in your power phase the Osymetric ring will act like a 56, giving you plenty of power and the ability to ride 4 seconds per kilometer faster than your competition. The matching 44 gets you over the climbs as well as any ring out there, but the secret is that it helps you ride faster while producing 10% less lactic acid. The 44 rides like a 41 at the top dead center, and like a 46 when you get into the power phase.
The 56 in the 56-44 combination feels like a 53 at the top and a 58 through the power portion of the pedal stroke. Select 52-42, 54-44, 56-44 for 130mm bolt circle Shimano/Sram compatible cranks or 50-38 for 110mm compact cranks.
Extremely difficult installation and set-up. Front derailleur shifting is less than stellar. Why no ramping pins?
These chainrings have made it so I can push a minimum of one bigger gear on the local climbs. My teammates are cursing the day I bought them. highly reccomend