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"Colnago EPS Carbon Fork & Tubing diameters: Colnago’s new EPS has a 35mm seat tube diameter that uses a 31.6mm seat post. The EPS also features the all new Colnago NewStar carbon fibre fork that was specifically developed for the C-HS1. It features improved steering and stability thanks to the new fork blade shape, and maximum strength to absorb shocks. The EPS NewStar fork blends smoothly with the new 1 ¼” diameter at the bottom of the head tube."