Im running middleburn 7s on my decade virsa 1×9 with an uno chainring. The Paul chainkeeper fouls the crank arms when you have it set in the correct posistion over the chainring. Had to take as hacksaw to the out flange of the chainkeeper to allow it to clear the crank arm which was a bit of a shame but seems ok now. Saying that I havn't but it back on yet but run the chain quite short (plus 1 link rather than 2) and havn't dropped the chain yet even over rough s.wales rocky natural trails.