It’s no secret we make chainguides - accordingly, we are pretty enthusiastic about keeping chains on. For the best chain retention with a minimal weight penalty, we still recommend a guide with an upper slider like our TRS+ guide, Guidering M notwithstanding.
As a new drive train ages, several factors can reduce the retention capability of the Guidering M including chain wear/stretch, ring wear, and rear derailleur clutch friction deterioration or failure.
For everyday riding, the Guidering M provides an exceptional level of chain retention when used with a clutch derailleur. Come race day, a 70g weight penalty for an TRS+ is a small price to pay for absolute peace of mind.