Originally Posted by
cat0020
The 109% method do not compensate the difference if you're using differnet crankarm length. I use the test ride method and change my saddle height regularly according to my condition, different seat height and fore/aft position allow me to work on different muscles.
It's right in the calculation. If you don't subtract the crank arm length, you're not using the 109% method.
1.09 x inseam - crank arm length = BB to saddle height