In the early days of fat bike development, complete bikes came spec’d with mechanical disc brakes. It was my understanding that the story behind that was hydraulic disc brakes were unreliable at arctic temperatures. I rarely get the opportunity to ride in true arctic temperatures, so when I built my Corvus, I chose a pair of hydraulic disc brakes and have been running hydros ever since. I’d had good experiences running Hayes Disc Brakes on my mountain bikes before fat bikes. I didn’t have to bleed those brakes after the initial setup. The only thing that they required was a new set of brake pads now and then.
For the last several years, I’ve been riding hydraulic disc brakes from the two S companies and they haven’t had a failure due to cold temperatures. However, I would not call them trouble-free either. After a couple of out of the box failures, I switched from Sram to Shimano, on both of my fat bikes and I’ve realized that neither one of the S’s hydro brakes is cutting the mustard. The ride performance of either of the S’s hydros is not the problem. The issue that I have is with the maintenance required. Both the Sram and Shimano hydros have required multiple bleeds per calendar year. More recently, I fought a slow leaking caliper that deposited traces of brake fluid onto the pads and rotor for a couple of months. The supply chain issues didn’t help the situation. The result of contaminated pads and rotors made my hooptie whip sound like a flock of geese. It’s kind of embarrassing to be the bike mechanic with horrible-sounding brakes. I think that working at a bike shop has influenced the way that I evaluate componentry. Honestly, After working on bikes at the shop all afternoon, I just want to go ride without having to bleed, replace parts or file a warranty claim on my f’ing brakes. It was time for a change.
I decided to go back to running a set of mechanical Avid BB7‘s that I found in one of my parts bins. I’m pretty sure that they were the brakes that had come with my first Fatback, Otis. I installed the new/used BB7’s and was surprised at how well they measured up to the performance of the XT Hydros that they replaced. I’m not saying that they were as smooth or as powerful as hydraulic brakes, but the difference was closer than I had remembered. Most notable was the complete absence of any honking with the BB7’s. That silence was music to my ears. I’m not saying that BB7’s are the best choice in mechanical disc brakes either. This set was just something that I had laying around. I’m going to have to try a set of TRP Spyke brakes as well to see how I like them.
If I were a politician, I would get called a flip-flopper on the issue of disc brakes. A few years ago, I broke with the Alaskan tradition of running mechanical brakes. I’ve been running hydro discs for about five years now, and I’ve flip-flopped back to mechanicals. If there were a hydro brake out there that doesn’t need to be bled every few months, I’d be tempted to give them a try. I’ve got a set of the new Hayes Dominion hydraulic disc brakes on order for my next build. If they can last a calendar year without needing to be bled, I may flip-flop again! For now, I’m going to run what works and what doesn’t honk like a goose… that would be Avid BB7’s till something better comes along.