Like many sites who announced this, Shimano could have simply tweaked their existing lineup, slapped “gravel” on it, and called it a day. But it looks like they made some serious considerations in the design of this groupset. Lots of subtle details to consider when looking at this groupset. This is the part that caught my attention the most though:
Shimano’s road shifters may work with the new GRX drivetrain components, but you’ll certainly be missing one of GRX’s most notable advantages. Shimano’s research concluded that you’re more likely to descend and ride rough terrain in the hoods than the drops, and GRX’s shifters offer greatly improved braking from higher up.
As a result, the brake lever pivot point has been raised by 18mm in an effort to improve the braking leverage offered from the hoods. The lever blade has been overhauled too, and there’s now a scalloped flat part for your finger to rest when braking from the hoods – it’s a wonderful update compared to the slippery lump that your finger sits on with current 11-speed road shifters. Additionally, the blade is given a matte-finish for better traction.
The smaller chainrings is the only thing I’m concerned with. With a Shimano 105 groupset, I would likely go with a 34/50 crankset. With the GRX, I would have to choose between a 31/48 or 30/46. I’m not a speed demon so, honestly, I can probably live without having a 50t chainring. For the most flexibility, I might choose the 31/48 just so I can maintain some capabilities for speed in the upper-end of the gears.
Aside from that, this is a very interesting announcement. Gonna have to consider this as an option when it comes time to upgrade my groupset. :D
Checkout the Shimano Gravel website for more info.