The frame sizes are skewed in the table below are based on C-T to make things a little interesting which is .67 of inseam, so if you are using this table you will need to measure off the "A1" measurement in the diagram above which allows for 15mm of tube above top tube centre that you may have to allow for if more or less. If you want to run centre to centre you can use a calculation of Inseam x 0.65. Inseams toward the low end of the scale have size recommendations slightly smaller than what the strict ".67 * Inseam" formula would suggest, while longer inseams have sizes slightly larger than what the formula would recommend. Mountain bike table is adjusted back 10-12mm to allow for more stand over height clearance.
