Shimano GRX 12 speed 1x crankset: FC-RX820-1 (40T)
Compatible chain: HG 12-speed; Chain line (mm) = 49.7; P.C.D. (mm) = 110; Spider/gear arms = 4; Q-factor (mm) = 151; Weight = 544g; Price = $215 (may be on sale for less)
· 30mm spindle
· Color option: Silver
· Extractor cap option: Silver
· Lengths available: 165, 170, 172.5, 175, and 180
· Compatible White Industries chainrings: TSR 1X/singlespeed (From 28 teeth to 48 teeth in 2 tooth increments)
· Compatible with 8/9/10/11/12 and 12 flat-top chains. Shimano 12 speed chains must use a SRAM Eagle 12-speed PowerLock connector
· Designed around a 91mm OBW (Outer Bearing Width).
· Designed to fit 68mm or 86mm bottom bracket shells
· Weight: 570g (175mm length w/spindle)
· Q factor: 158.5mm [vs 151mm on Shimano GRX] [vs 171mm on G30 crankset]
· Chainlines:
o 1x standard TSR ring (3mm offset, facing inward): 46.5mm
o 1x Boost TSR ring (0mm offset/flat): 49.5mm [Vs 49.7mm on GRX]
https://www.whiteind.com/product/mr30-tsr-1x-chainrings: $100.90 From 28 teeth to 48 teeth in 2 tooth increments
· Price: $366.40 (>$150 more than GRX)
Total = 366.40 + $100.90 = 467.30 (Compared to Shimano = $215; $252.30 more)
Conclusion
The most similar to GRX seems to be the R30 with a 1x Boost Ring
· Shimano: Chainline = 49.7mm; Q factor: 151.0mm
· White Industries: Chainline = 49.5mm; Q factor: 158.5mm
Why? (1) Option for different chainring sizes (e.g., 36, 38); (2) Option for 165mm crank arm; (3) Silver rather than black
§ Gear inches: [36T = 19-97] [38T = 20-102] [40T = 21-108]