Technically, track buying advice

964cup Posts: 1,362
edited June 2015 in Road buying advice
Assuming I fall between a 56 and 58 ETT for road bikes, what would the assembled company recommend in track bikes? Assuming I need to get low as all f**k, and so need to bring the drops towards me to keep my elbows bent, do I do this by using a shorter stem, or by shortening the top tube? They have same ultimate limiting factor in terms of knee/bar interface, but a shorter TT will also mean a shorter wheelbase and more toe-overlap, plus more exposed seat post. Is there a general rule of thumb?

I'm 185cm, and ride 78.5cm BB to saddle top and 76cm saddle nose to hood diagonal with an 11cm saddle to bar drop on my main road bike, which is effectively a 56 - it's a Cervelo R5Ca, so actually a 58cm ETT, but with an inline post and a slack seat-tube angle. Previous bike was an R5VWD, which is a conventional 56 with a 565mm ETT and a setback post.