Second-year player Grimes, along with first-year pair Conca and Helbig, have agreed to terms for contract extensions at "Tigerland".
Grimes, who was coming out of contract at the end of the season, has signed a new two-year deal with the Tigers.
Conca and Helbig, who still had one year remaining on their two-year deals, have recommitted to the Club until the end of the 2013 season.
“We’re delighted to have re-signed this trio of young players, who we believe will develop into an integral part of our playing group moving forward,” said Tigers general manager Craig Cameron.
“They possess the necessary qualities, both on and off the field, to play a key role in the team’s rise over the next few years.”
Grimes, 20, was a standout in defence during his seven appearances for Richmond this season (eight games all-up in his league career).
He earned particular praise for his desperate spoiling work, before suffering a severe hamstring injury in the Round 9 ‘Dreamtime’ victory over Essendon, which has sidelined him ever since.
Conca, 18, has played 15 of the Tigers’ 16 games so far this season, averaging more than 16 disposals per game, and winning an AFL Rising Star nomination.
Helbig, 19, has played 10 games in his debut league season, impressing with his hard-at-it approach and long kicking.