The job of a chain guide is relatively straightforward: to keep your chain connected to a chain ring while your bike is bouncing over the ground at speed. Despite the simple goal, most chain guides are relatively complex, with a mixture of derailleur-like guides at the top and rollers or jockey wheels on the bottom to maintain chain tension. The Straitline Silent Guide is a simple design: a 7075 T6 aluminium backplate (almost twice as strong as 6061 T6 alloy) with a matched bashring. What sets the Silent Guide apart is the way it’s built—there are no rollers or jockey wheels, but instead a pair of vibrant green elastomeric guides that ensure the chain stays in place. The guides (especially the lower one) will wear with use, but replacements are available for RRP $27 in red, white, blue and black if green isn’t your thing. Out of the box, the Silent Guide met all requirements. Installing it was a breeze; it took just 10 minutes. The guides are available in ISCG and ISCG ’05ROYstandard fittings, and the box includes a range of plastic spacers and easy-to-follow instructions on fitting to most bottom bracket sizes. The box doesn’t include chain ring bolts however—I needed to buy a set of dual-ring bolts to mount the included bashring. The Silent Guide is lighter (at 197 gm including mounting hardware for the 36 tooth version) than the competition at the downhill racing end of the market. In use, the Silent Guide is almost silent. Rattle and slap from the chain is noticeably reduced, and there’s none of the noise from rollers that you get with many other guides. Most importantly, my chain has never dropped or jammed while the Silent Guide has been on the bike. If you’re looking for a reliable, almost maintenance-free chain guide, the Silent Guide is definitely worth considering. JONO BADDILEY