The "ES" means 'extra smooth.' It might not be as quick handling as our Smoothie or other dedicated race frames, but it is still quite fast and you'll actually gain valuable stability on speedy descents and the ability to fit wider tires. An ideal choice for multi-day charity rides, centuries, credit card touring and fast commuting. For 2016, we have shaved the number of sizes a little, but have kept the hard to find 66cm size.. - Tange Prestige heat-treated butted CrMo steel front triangle; butted CrMo rear end - Road sport geometry - Rear rack & fender mounts - Designed with 57mm reach caliper brakes in mind. Fits some 32c tires with fenders - Optional carbon fork or steel fork available. Both have fender eyelets. (IRD Mosaic 57 Carbon fork has less clearance than our steel fork and only fits 28c wide tires with fenders) - 1-1/8" size headtube - w/ extra extension so you need less spacers - 27.2mm post size - 7 sizes: 48, 51, 54, 56, 58, 61, 66cm - 4.25 lbs. (51cm) - In Pacific Blue