Typically in shorter or lower budget stage races there will be severe limitations in TT equipment - "standard road bikes" etc. In Tour of PA (U23 race held just one year) you had to use UCI approved mass start equipment, i.e. bike, wheels, helmet. This way teams from Europe or Africa wouldn't be penalized for not having insane resources on hand like the Felt guys had. 1080s that year were not approved so Felt and them got by with 808s. Most of the riders used pretty much totally normal equipment, with only aero bars as a concession to aero. That afternoon they did a circuit race on pretty much the same course on pretty much the same equipment, minus aero bars.