Bell, 29, was in the final year of his three-year, $9.3 million contract that included $4.3 million guaranteed when he was released in a move that freed up $2.5 million in available cap space for the Lions.
In 2015, Bell appeared in 13 games for the Lions and ran for 311 yards on 90 carries (3.5 YPC) to go along with 22 receptions for 286 yards receiving and four total touchdowns. Pro Football Focus has him rated as the No. 27 running back out of 68 qualifying players.
Bell, 30, originally signed on with the Bills as an undrafted free agent out of Wayne State back in 2010. After brief stints with the Eagles, Colts and Saints, Bell signed a two-year contract with the Lions towards the end of the 2011 season.
Bell spent four years in Detroit before he was released back in February. The Bears elected to sign him too a contract close to a month ago.
IN 2106, Bell has appeared in four games for the Bears and ran for six yards on three carries and no touchdowns.