The Bionicon C.Guide V.02 has to be one of the most obvious, duh, face-palm bike accessories ever. As soon as I saw it (2011 Interbike), I said, "duh," and slapped my own face. When you see it, you can't help but ask yourself why this wasn't done years ago. The $50 C.Guide is a perfect example of "elegant design." It's pure and simple, it works great and it's super light - less than 20 grams according to Bionicon. It also works on two or three chainring drivetrains. I'm not one of those weight weenies that own an electronic scale so no photos of the C.Guide on a scale. You're gonna have to take their word for it or buy one and weigh it yourself. However - just looking at it you can tell it's lighter than anything else on the market.
Bionicon sent me the C.Guide V.02 last spring and I've been using it for over a year now. It's mounted on my trusty Bionicon Golden Willow trail bike (Yes, I'm a happy Bionicon owner. And yes, "Golden Willow" is the lamest bike name ever.). I've done pretty much every kind of ride now using the C.Guide, short of full-on downhill, and it's been bombproof for me. The simple design makes it really easy to install, too. You don't have to worry about ISCG tabs or mess with your crankset and bottom bracket, both of which are standard procedure with other chain guides. You simply remove one screw to split the C.Guide's aluminum alloy body and the low-friction plastic guide tube, reassemble around your chain (Bionicon recommends adding a couple of chain links to compensate for the added tension), then zip tie the hanger to either your derailleur cable or your chainstay - depending on your bike's cable routing and rear triangle configuration. In the case of my Bionicon Golden Willow, I hung the C.Guide from the chainstay.
Early in 2012 there were some problems with C.Guides breaking and the mixed user reviews here reflect that (Bionicon C.Guide user reviews). I'd bet that most negative reports were for early 2012 C.Guides, though. Either the user bought them in early 2012, or the dealer put them on the shelf that spring. In any case, I'd seen reports of them breaking so figured as a good tester I should do my best to break mine - which I did on the first ride. The "universal mount" that attaches to the chain stay with zip ties, broke. To be fair, I did ride the bike as hard as I could on a super muddy, rocky trail with a bunch of stupid flat landing kicker jumps. You can get an idea from the mud in the photo below, what the conditions were like. And even when it was broken, the C.Guide didn't cause me any problems because it was still attached to the chainstay on one end. That's a good thing because if it did get totally ripped off, there's a high likelihood it would get jammed in and damage the rear derailleur. Thankfully, that didn't happen to me. Even though I broke the C.Guide, I didn't drop my chain once during that ride and even when my tires were so packed with mud that my rear wheel wouldn't turn, the chain still moved freely through the guide. When I got home I called Paul, the president of Bionicon USA, and let him know what happened. He told me they'd identified the problem and the mad scientists at Bionicon headquarters in Germany already had stronger, replacement pieces made.
As a control, I went back the next day and rode the very same trail without the C.Guide and I did drop my chain. However, I haven't dropped my chain once since reinstalling the C.Guide, over a year ago.
Bionicon sent me their new, stronger universal mount and I was on the trail again with the C.Guide within a few days. I've been riding with it for over a year since then and I haven't had any issues - not even on super rocky trails or jumping (small jumps - I suck). The drivetrain - a 2 x 9 setup with a bashguard - shifts fine and I haven't dropped the chain once since I installed the C.Guide. One thing that concerned me was the plastic guide tube. I was worried that maybe there would be too much drag on the chain. That hasn't been the case, though. Bionicon uses super slick plastic for the guide tube and I swear the C.Guide has less drag than any standard, bearing-mounted pulley-wheel chain guide I've ever used. Plus - there are no bearings to wear out, corrode or freeze up - just another example of how the C.Guide fits the "elegant design" aesthetic. Pulley wheels with bearings look good but for most riders on most trails, they're probably not necessary. And they do have parts that will eventually wear and fail. The plastic guide tube does wear and Bionicon recommends rotating it periodically to get the most out of it and keep it running smoothly. They also have replacement guide tubes if you do wear one out.
In spite of the mixed user reviews here, and complaints about the $50 price, I'm totally sold on the Bionicon C.Guide. I've abused mine thoroughly and it's taken whatever I've been able to throw at it - since I got the replacement part, that is. I wish it was possible to check when each C.Guide reviewed in our user reviews was made to see if they're the older ones with the weaker universal mount. That's what I suspect. Unfortunately, without e-mailing each reviewer, there's no way to know. All I can say is the Bionicon C.Guide has worked great for me. It's super light, it does what it's supposed to and it's easy to use. I think it's totally worth the $50.
To learn more about the C.Guide, visit the Bionicon C.Guide Web page.