Shimano Soraa - Modern functional technology for sports and fitness riders
The Tiagra is based on the technology of the top groups, but has its own, unmistakable identity. Its slim design and optimised ergonomics are complemented by a new level of performance.
HG cassette sprockets
In combination with Shimano HYPERGLIDE (HG) chains the HG cassette sprockets provide fast, precise indexing function. The special, computer-designed sprockets feature particular tooth profiles and specifically positioned climbing aids that optimise the chain guide during shifting. Conventional sprockets let the chain ride on the tooth tips before it sits on the sprocket. HG sprockets guide the chain directly and without riding onto the next sprocket. This results in fast, smooth and noiseless gear changes.This version of the CS-HG50-9 cassette is recommended by Shimano for road bike applications.