GRX 400 with 40t Cassette – 200km write up

I have now done about 200km on my 2x 11-40T experiment so I decided to make a little write-up.

Shifting quality is pretty good after a careful setup. It is a little bit more finnicky with the cable tension. But once that is dialed, it works perfectly well. I didn't notice anything weird. You can in theory even use both extreme gears without the risk of chain slack or the derailleur tearing off. No mods needed, the clutch can stay engaged and the B-Screw has some room left.

The range is pretty neat. Coming from 11-32T you notice the bigger steps. But the two extra bailout gears are great. Yes, you can grind out steeper stuff on "proper" MTB gearing that has like 20T difference. But I find that for anything that would need those gears, I am the limiting factor anyways. The bike is light and fast enough.

One nice side effect is that the new cassette has reduced cross-chaining for me. Ever since I moved to a region with more elevation, I ran more cross-chained gears than in the flat. The new cassette has fixed this, and I am back in my comfortable effort when running straighter chain lines.

Overall, would run it again in a heartbeat. We will see about how it holds up long term. But given the neglect the drivetrain has seen overall, this should not hurt it too bad.