Fixed Time Trial Bikes

I'm also thinking of putting together a fixed TT bike (also be my first TT bike). I'm going to be doing it on a shoestring, and have been looking at some frames or framesets like the dolan precursa or tifosi pista, would this be a good basis for a fixed TT....any thoughts?

Most people use a small track frame for fixed TT use. As an example, I used a 53cm Koga FPT, while I'd have bought the 56cm for sprinting. I've now switched to a 51cm Cervelo T3 with 60mm of spacers under the tribars to get the base bar lower and create a space between the wing and the elbow cups

For a budget build, I'd keep an eye on classifieds (not just here) for an older steel (531 ideally) track bike or frame. The thin tubes are stiff enough for TT use (really, they were stiff enough for Olympic track sprinters back in the day) and since nothing under £2k has been designed to be actually aero rather than cosmetically aero, you might as well stick to keeping the A part of Cd.A down. PNut uses an old steel frame and he has gone <20:00 for 10 miles.

Since you don't yet know what position you're going to adopt, and it will change with practice and development anyway, you're going to have to take a bit of a punt on the sizing. "Stack & Reach" is the sizing model you need to think about, and of those you need to concentrate on reach, since this will affect the handling. Stack can be fixed with stem angle and risers under your tribars, but fixing reach with extreme stem lengths messes up weight distribution and tiller geometry.