I'm ordering a new frame on line to build up. I'm debating between a 53 and 55 size frame. I'm 5'10 and I have a bike that is a 54 that fits me better then any other bike I've ever had. I know the suggested theory is base off effective top tube length.
My current , great fitting bike has a 543mm eff tt. The new frame I'm looking at in 53 has 540mm level top tube/535 actual. The 55 has a 557mm level top tube/550 actual.
I have another bike with a 565mm effective top tube that definitely feels too big.
I like the feel of a smaller frame. 540mm level top tube should feel pretty close to 543mm effective top tube...right?