Britain have named only six riders, rather than eight, after falling outside the top-10 ranked nations.
Thomas will be joined in the road race by Ben Swift, Owain Doull, Tao Geoghegan Hart, Ian Stannard and Adam Yates.
"We have such a talent pool of elite men's road riders in this country that final selection was quite tricky even though the course is so challenging," said Matt Brammeier, British Cycling's elite men's road coach.
"Looking at the time trial, we have selected two very experienced time trial riders this year in G (Thomas) and Alex, both of whom suit the course and as such we can expect to see good performances from them both.
"G will then stick around to compete in the road race on the Sunday, and will no doubt be a valuable asset to the team in the final laps."
The elite men's road race is a hilly 284.5km course starting from Leeds and taking in seven laps of the Harrogate circuit. The time trial is a 32.5km course from Ripon to Harrogate. (Reporting by Martyn Herman, editing by Ed Osmond)