G scale Sectional Track Note, the numbers below are APPROXIMATE, not exact, there is variation between manufacturers. Check the exact numbers on the manufacturer's site.Pick your R number "R" number LGB diameter feetPiko diameter feetTrain-Li diameter feet Train Line 45 diameter feet LGB radius feetPiko radius feet Train-Li radius feet Train Line 45 radius feet R1 4'4' 2' 2' R2 5' 6' 2-1/2' 3' R3 8'6'6'8' 4'3'3'4' R4~11-1/2' 8' 5-3/4' 4' R5 15'8' 7-1/2' 4' R6 R7 10-1/4' 5'+ Pick your diameter/radius Diameter Feet Radius Feet LGB Piko Train-Li Train Line 45 Aristo Craft USA Trains42R1R1 4'4'52-1/2 R2 5' 5'63 R3R3R2 6-1/2~3-1/4 6.5' 84R3R5 R4 R38' 8'94-1/2 9' 10 5 10' 10'10-1/4 ~5 R7 11-1/2~5-1/2 R4 11.5' 12-1/26-1/4 12.5' 147 14' 157-1/2R5 15' 168 16'16.5~8-1/4 16.5' 2010 20'20' Link to Piko track planning guide: https://cdn.shopify.com/s/files/1/1960/4221/files/99350_G-Track_Flyer.pdf?9757276037842777937 Link to LGB: Notes:There is no R4 curved track from LGBThere is no even numbered curved tracks from PikoWhat a mess huh?