Adding a "Secondary Brake" to Fixed Gear Bikes

Recently, while browsing websites, I came across some interesting designs on fixed gear bikes—they all coincidentally featured a disc brake system installed next to the crankset.

When it comes to fixed gear bikes, "brakes" are probably the most easily discussed topic. Pure enthusiasts believe that controlling the bike with your legs is the soul of a fixed gear bike, the most direct communication between rider and machine, and adding brakes is somewhat "against their beliefs." Many other friends—including myself—while having briefly tried fixed gear bikes, ultimately couldn't stick with them, although appreciating the extreme simplicity and direct road feel, have to admit: riding in the city, in sudden situations or on long downhill sections, relying solely on the foot brake feels a bit unreliable.

So when I first saw the crankset disc brake design, I was immediately impressed. It doesn't disrupt the frame lines, nor does it involve drilling holes in the fork or rear fork to install those somewhat obtrusive traditional C-clamps; instead, it cleverly hides the disc brake assembly next to the drivetrain. This isn't just a minor technical upgrade; it's more like a pragmatic "reconciliation"—preserving the original flavor of fixed-gear bikes while subtly increasing safety.

The most practical advantage is undoubtedly improved safety. The fun of fixed-gear bikes lies in the sense of control, but this control is extremely dependent on physical strength and skill. When you're in good shape, you can control the bike effortlessly, looking both stylish and smooth, but in an emergency, or after a long climb where your legs give out, you'll want extra protection. Disc brakes act like a reliable co-pilot in these situations, gently squeezing the lever for steady deceleration, providing peace of mind.

Moreover, this design hasn't ruined the fixed-gear's aesthetics. Those who love fixed-gear bikes are mostly drawn to their clean, sharp frame lines. Traditional brakes not only require drilling but also involve a bunch of cables and calipers, while crankset disc brakes are almost entirely hidden, visually uncluttered, and even add a touch of mechanical beauty to the bottom bracket area.

Of course, the new design is not without its controversies. For fundamentalists, a fixed-gear bike cannot have a handbrake; it's a matter of principle. Even if it's hidden next to the crankset, it might still be unacceptable—bicycle culture is diverse, and there's no absolute right or wrong.

From a modification perspective, crankset disc brakes are not easy to get started with. First, the right rear chainstay needs a disc brake mount—which usually requires aftermarket modification for most classic fixed-gear frames. Second, a matching crankset that can mount the disc is needed, meaning additional investment. Add to that the weight of the entire disc brake system, which contradicts the ultimate lightweight principle of fixed-gear bikes, and there's the occasional issue of disc rubbing.

However, ultimately, cycling is a very personal choice. If you enjoy the pure, direct feel of a fixed-gear bike but also want more composure in complex environments, then this crankset disc brake design might be an ideal and clever compromise.