In 1978, Clench was asked to join
Bachman–Turner Overdrive to replace
Randy Bachman, who decided to start a solo career. Clench was with BTO until its first breakup in 1979, appearing on the albums
Street Action (1978) and ''
Rock n' Roll Nights'' (1979). In addition to playing bass, Clench shared lead vocal duties with
Fred Turner and wrote multiple songs for these two albums. Shortly afterwards, Clench also appeared as a guest musician on
Bryan Adams's 1980
debut album. In 1980, Clench formed and toured with his own group, 451 Degrees. They released one album in Canada only. A video of their hit song, "Don't Walk", is available on YouTube. Clench also appeared in
Loverboy, who made their live debut opening for
Kiss at Pacific Coliseum in Vancouver, British Columbia, on November 19, 1979. Shortly after this show, Clench was replaced by
Scott Smith. == With April Wine (second run) ==