Although clutch equipped derailleurs have largely negated the need for chain devices for the everyday rider, for racers or rowdy huckers, the extra security and peace of mind that one affords is invaluable.
So good… OneUp’s guide fits 28-36t chainrings, including oval rings. Three stoutly built bashguards (and a spare upper guide) are included — weight is just 88g with the medium bash and 80g with the smallest.
Small shims allow the upper guide to be spaced out precisely without removing the cranks, making set-up simple. The upper guide is nice and stiff and keeps the chain on without fail, as well as accommodating the full gearing spread without rub.
No good… The upper guide isn’t tool-free, but that’s about it.
So good… The AMg accommodates the full spread of gears easily without rubbing, and keeps the chain in place really well. Even when the chain partially derailed when backpedalling, the stiff upper guide kept enough of it on track to allow us to pedal it back on.
The softer plastic inside the upper guide silences chain noise, making the MRP the quietest option here after the Gravity Grid. Sump-outs are shrugged off without fuss by the stout skid plate.
No good… At 128g it’s fairly heavy for an upper-only guide. Pricey too.
So good… Even on bikes with a clutch mech, the Grid’s lower guide noticeably quietens the chain and stops it coming off when backpedalling. This means you can switch the clutch off on Shimano mechs to improve suspension sensitivity.
Construction is solid. Inside the lower guide is a jockey wheel, which is quiet and low on drag. The lower guide can be removed easily if not needed and the upper swung up to remove the cranks.
No good… At 167g it’s the heaviest here, but sans lower guide it weighs 119g. The quick-release pins are fiddly to remove without a pick or screwdriver.
So good… Blackspire’s bashguard is really solid and took every sump-out we threw at it without flinching. The upper guide covers a large part of the chain and is stiff enough to ensure top derailments are virtually impossible.
No good… The upper guide is a tight squeeze so it requires careful set-up to ensure the chain won’t catch under full suspension compression or at either end of the cassette. Because the bashguard sits quite far outboard, the chain rattles against it over rough ground. At 134g it’s heavy for an upper-only guide.
So good… E*thirteen’s three-in-one shims make fitting the TRS+ a lot less fiddly than traditional washers, and the tool-free upper guide attachment makes it a cinch to remove the cranks.
Two sizes of bashguard are included, which cover 28-34t rings without any unnecessary weight or overhang. Weight is decent, at 94g with the bigger bash.
No good… The chain rubbed slightly on the bash in the first, second and third gears on our Mondraker Dune test bike. While the chain stayed on through brutal testing, the upper guide feels a bit flimsy.