If you're overriding the bootstrap breakpoint (and using containers properly), adding this below the bootstrap breakpoint media queries in the bootstrap CSS file should work for you.
If using LESS
@media (min-width: @screen-lg) {
.container {
width: 970px;
}
}
OR, you can simply override the bootstrap container in your own CSS (just make sure you load it after bootstrap.css)
@media (min-width: 970px) and (max-width: 2500px) {
.container {
width: 970px;
}
}
OR you can find the media query in the bootstrap.css file on around line 1240 and simply change it there
@media (min-width: 1200px) {
.container {
width: 1170px; /* change 1170 to 970 */
}
}