SRAM's new "wide" cranks (available on some 2x and XPLR (aka 1x) models) push the chainline out 2.5mm. They say this is compatible with existing cassettes, xDR hub bodies, 135/142/boost hubs. i.e. there are no "wide" rear components (hubs, hub body, cassettes, rear derailleurs). How did they make up this difference in the rear chainline? Or did they? Is the chainline now just off?
1 Answer
How did they make up this difference in the rear chainline? Or did they?
They didn't
Is the chainline now just off?
Yes
Why?
Standard road bike chainline is 45mm. This chainline was designed around for road bikes using slim tires. With the emergence of gravel bikes aka road bikes with wider tires, there can be problems with tire clearance of the chain and front derailleur. Coincidentally Shimanos gravel group GRX uses the same chainline as SRAM wide with 47.5mm. This chainline is designed for up to 700 x 45mm or 27.5 x 2.1″ wide tires.
MTBs have an even wider chainline of 49mm (SRAM) using standard non boost hubs with the same width as road hubs.
