Single chainring setups seem to become more and more popular, and it's not hard to see why. Assuming you can get away with the reduction in possible gear options, a "1 by..." setup can be lighter and require less maintenance than a system with a front derailleur. If this is the route you are taking than Race Face's Narrow Wide rings are one of the best options out there and are now available in 130mm BCD.
Made from aerospace grade 7075-T6 aluminum, these rings are strong and light, perfectly at home off road and totally suitable for the weight conscious. Their stiff, I-Beam construction also helps transfer loads without flexing, so no power is lost when you drop the hammer.
The feature of these rings that really sets them apart from the traditional single ring is their narrow wide profile. This method of shaping the teeth of the chainring acts as a chain retention device, effectively removing the need for a chain guide, especially when used in conjunction with modern, clutched rear derailleurs.
The 130mm Narrow Wide Chainring is available in 40, 42, or 44 tooth versions. 130mm BCD. 56 grams weighed (40 tooth version).
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A guide to understanding and calculating bicycle gear inches.