The Shimano Ultegra RD-6700-GS is a rear derailleur designed for road cyclists seeking a balance of crisp shifting and reliable performance across a broad range of gears. Its medium-cage (GS) design allows it to handle larger cassettes—officially up to a 28-tooth largest cog with a triple crankset or for improved chainwrap, but some users report successful adjustments for cassettes up to 30 teeth, especially with careful setup. It is constructed from aluminum with stainless steel hardware for durable but lightweight function, weighing in around at about 200 grams.

The RD-6700-GS is compatible with Shimano 10-speed groupsets, including Ultegra 6700, 6600, 5700, and Dura-Ace 7800/7900. It is intended for riders who require wider gear ranges, such as those who ride hilly terrain, tour, or prefer a single setup for both training and racing. The bolt-on mounting type ensures compatibility with most modern road frames using standard mounting points.

One of the main reasons to choose the RD-6700-GS is its ability to accommodate large cassettes and chainrings, making it versatile for different riding styles. While not the lightest option in the Shimano catalog, it is lighter than most mid-cage derailleurs from previous generations and provides robust shifting performance. This derailleur is a solid choice for riders who want dependable, low-maintenance shifting across a wide gear range without requiring the latest electronic components.