![GRX 400 (10 Speed) x2. Looking to upgrade to GRX 400. Has anyone got experience of what the optimum cassette size to use in the rear? Looking to get a low bail GRX 400 (10 Speed) x2. Looking to upgrade to GRX 400. Has anyone got experience of what the optimum cassette size to use in the rear? Looking to get a low bail](https://preview.redd.it/rg0sapqcq5r81.jpg?auto=webp&s=9fbe2d0195c410ec872f8398ee35b1143ad3ec03)
GRX 400 (10 Speed) x2. Looking to upgrade to GRX 400. Has anyone got experience of what the optimum cassette size to use in the rear? Looking to get a low bail
![SHIMANO GRX Rear Derailleur 10-speed, Sports Equipment, Bicycles & Parts, Parts & Accessories on Carousell SHIMANO GRX Rear Derailleur 10-speed, Sports Equipment, Bicycles & Parts, Parts & Accessories on Carousell](https://media.karousell.com/media/photos/products/2021/10/24/shimano_grx_rear_derailleur_10_1635068790_530e4968.jpg)
SHIMANO GRX Rear Derailleur 10-speed, Sports Equipment, Bicycles & Parts, Parts & Accessories on Carousell
![Shimano GRX component series is the first dedicated gravel group w/ 10 & 11 speed options - Bikerumor Shimano GRX component series is the first dedicated gravel group w/ 10 & 11 speed options - Bikerumor](https://bikerumor.com/wp-content/uploads/2019/05/Shimano-GRX-11-speed-road-product-matrix-rx600-rx810-rx812-rx815-rx817-hydraulic-road-gravel-di2.jpg)