During a recent move, I rummaged through bins containing a slew of parts spanning nearly 20 years. These mountain bike fossils opened my eyes to how quickly our machines have evolved, along with the level of sophisticated integration required to make all the moving parts play nice. I exhumed a small fortune in chainguides from Mr. Dirt, MRP, e13, Gamut, Blackspire, and a sweet, one-off titanium device given to me by a handy friend, Denzil, who had an affinity for machining bike parts in his Long Beach garage. Although chainguide mounting standards existed at the turn of the millennium, variations in frame design and componentry resulted in some head-scratching installations. I credit many late-night bike building sessions for sculpting me into the Michelangelo, or perhaps more likely the Bob Ross, of the Dremel tool.
The introduction of clutch-style rear derailleurs and narrow-wide chainrings has pretty much eliminated chain drops, but many riders still appreciate the peace of mind provided by a chainguide. I've spotted a handful of the minimalistic, two-bolt style top guides on the market, and to my knowledge the Specialized Mini Chainguide was one the first. It comes stock on Stumpjumpers and Enduros, and is available aftermarket for $33.
This minimalistic retention system was designed to be easily mounted to a frame without requiring the removal of cranks or chainrings. If you have a 4mm hex wrench, you're in business. The mounting plate slides behind the front chainring and mounts to two ISCG 05 chainguide tabs. The aluminum backplate mounts to the plastic guide, which is adjustable vertically to accommodate for a range of chainring sizes. Small spacers may be required for proper chainring spacing. The Mini Chainguide is available in two sizes, one for 28- to 33-tooth chainrings, and the other for the 33- to 36-tooth variety.
I've been running the smaller version on my trail bike with a handful of crank configurations. The guide hovers above the chainring and chain, and unlike devices which run the chain through or over a pulley there's no noticeable drag. The chain doesn’t make much contact with the guide once it’s set up right, which is why mine shows little wear after years of use. Riders sensitive to noises coming from their bikes may notice the chain contacting the guide during rough descents, but I was able to mute the clatter by adding a small piece of Velcro the inside of the plastic guide.
You don’t need a chainguide on today’s trail and all-mountain bikes, just like you don’t need an insurance policy to drive a car. You can get away without one, until you can’t. At that point, $33 starts to sound like a pretty good deal.