I am slowly building stamina and gear to do some bikepacking trips. I love my bike, but I wonder about brake issues in the middle of nowhere. Has anyone had an issue with hydraulics in the field and how did you handle it?
No one else seems to b responding, so I'll give it a try. In the worst case, you will be off the bike, walking it along - slow, but you will get there eventually.
When you are distant from a bike shop or repair services, it is up to you. Train and prepare accordingly
@MikeNWFL That's awesome that you're building up to start taking some bikepacking trips. I'm really stoked for you. Unless you're planning on a months long expedition to the most remote areas where access to tools, parts and repair could be an issue, I don't worry that much about my hydraulic brakes as long as you have your bike regularly serviced. With the exception of one set of brakes on a bike which were subsequently recalled and were not repairable (my brakes still worked, just not well) and although not impossible in the future, I haven't had any issues with any of my bikes' hydraulic brakes in the field. I typically only carry tools to address the most common mechanicals that I might run into - flats, a chain breaker or quick link pliers for a broken chain, multi-tool, etc.
Although I haven't done any bikepacking or truly long rides (yet), I also would not worry too much about hydraulics. As long as they are up to date on service, and the brake hose is secured well to the frame so that nothing can snag on it and rip it open, it's a closed system so dirt and contaminants shouldn't be able to affect it's performance. If you're particularly worried, couldn't hurt to have a fresh bleed done just before your trip (but also leave enough time to get a short ride or two in as well to confirm all is well after the service).
The one thing I might still think about is being mindful that your bike is heavier laden down with gear, and if you're on any significant downhill where you end up riding the brake, the excess heat buildup can result in brake fade where the fluid reaches it's boiling point and stops performing as well with a loss in power. But most bikepacking routes tend to be a bit mellower on elevation profiles so it's not a huge concern either. If you really anticipate it might be a problem, it can be mitigated with larger rotors if the frame can fit them or pads with cooling fins.
I would agree with everyone else here. I have not seen an outright hydraulic line failure and would add a story to reinforce that sentiment. While traveling with my bike on a platform rack I once forgot to secure the rear wheel and as I hit a bump the bike came flying out. Luckily, the hydraulic line hooked on the others handlebars and the line held with the bike being drug another 1/4 mile. It did leave a slight kink in the line but I continued to ride that line and never swapped it out. Hydraulic lines are very strong so I never worry about that aspect. If you are really worried you could always invest in a steel braided line but the line I described was the standard Shimano XT hose.
The one thing I do worry about is pad wear and pad glazing. This applies to both hydraulic and mechanical disc brakes. Before any significant trip I always check my pad wear to ensure I am within manufactures specs for wear. The second part is when replacing be sure to take the time to break in the pads, 30 medium slows to walking pace followed by 30 hard stops. Failure to do so may result in glazing. Once a pad becomes glazed it feels as though it will not stop no matter how hard you pull. I have seen this happen and during a 13 mile decent nonetheless. My friend basically had to walk or brake by foot the entire time.