Originally Posted by SAPB
Yes, just went out to look, since I'm thinking of doing the 13/42 soon...
The XR650L rear sprocket is also commonly available with 48 teeth.
In addition, the PBI C/S sprocket for the CBR250R/XR250R is available in sizes from 12T-15T.
Therefore, one could also employ a 48T/15T sprocket combination instead of a 13T/42T sprocket combination.
However, I think a 45T rear sprocket is a good choice. For technical off road riding one could employ the stock, 14T front sprocket with the 45T rear sprocket. Then, one could easily swap a 15T, PBI C/S sprocket for lower rpms during extended street riding.
The larger sprockets reduce wear on both sprockets as well as the drive chain, thereby extending the service life of all three components.
2005 XR650L: Shorai Battery Relocation, Spud Oil Cooler, XR650R C/S Sprocket, Reinforced Subframe, Chain Slipper Roller, Performance Design Lowering Link, Baja Designs Headlight, FMF Hi-Flo Header, ManRacks SD Rack, CST Surge I Front Tire, D952 Rear Tire, Tusk D-Flex Handguards, Uni Air Filter, No-Toil Evolution air filter oil