[mauvehaus]

Yeah, the SRAM ones require two syringes and seven hands to bleed. And DOT fluid is great at removing paint if you spill it. I haven't done any Magura ones, but the Shimano ones were clearly engineered to be maintained by someone who isn't an octopus.

I recently learned that if you live in a place where Citroën LHM is readily available, it's a less-expensive and compatible substitute for Shimano mineral oil brake fluid. Conversely, if you're in a place where LHM isn't available for love or money, you can substitute Shimano mineral brake oil instead of going on a wild goose chase of the Citroën product.

[jaapz]

Wow wait, I basically live in bicycle land (the netherlands), but I've never heard of fluid breaks for bicycles. All I've ever seen are cable breaks. Fluid breaks on motorcycles, sure, but I'm pretty surprised they are used on regular cycles as well!

[mauvehaus]

They came on to the downhill MTB market 25-30 years ago now, spread into XC and from there into road and gravel. Sadly, they've now made their way down to the mid-low end of the hybrid/city/comfort market as well. Low-end hydraulic disc brakes are a huge downgrade from cable-actuated brakes.

The components range from OK to outright crap and the labor to screw around with them easily adds up to a significant fraction of the cost of the bicycle. What would've been a 15-30 minute cable and housing job can easily turn into a 60-120 minute hose and bleed job. Assuming you have the parts on hand to terminate the hose on both ends, that is.

In 10 years, there will be an absolute glut of bicycles that are basically fixable except for their totally unsupported hydraulic brakes.

The braking performance ranges from better than the equivalent price-point rim brakes to absolute crap. I hadn't ridden my mountain bike for a while, and was pleasantly surprised to realize that the 20 year-old Avid BB-7 cable-actuated discs on it compare favorably to most of the hydraulic systems on the market.

[lstodd]

Whoa are they that different from a typical motorcycle brake? Because I never had a problem with those, all the way from 1990s japanese scooters. They are simple, reliable and don't require much maintenance. They even work ok on 75% water-dot mix on completely weared-out pads if you can't fix'em on the road. Worst thing that can happen is hose rupture, which is extremely rare, good hoses just work forever, brakes becoming a bit mushy after about 10-15 years, which you adapt to.

I think hydraulics are overkill for bicycles, but apart from that what's the problem?

[lostlogin]

They can be very very fiddly.

They get contaminated fluid - presumably from shit cylinder seals. They can be difficult to tune (too much travel, not enough). They can be fiddly to change pads. The pistons stop working on one side (binding up), they can leak, etc.

Combine all that with an electronic, wireless gear shifter that’s in close proximity and the roadside repair in the rain can be miserable.

Don’t get me wrong, I like them a lot but most my shop visits are for brake repairs. I have to work on them every few weeks as I go though pads in as little as 6 weeks.

[mauvehaus]

I've never worked on a motorcycle, but I have worked on hydraulic brakes on several cars, including when I was recently given the opportunity to learn how to bend and flare rigid brake lines.

The problem on bicycles is that everything is small and light, and that nothing is really standardized at this point. You need a bleed kit for mineral oil, and a different one for DOT fluid. Each of those probably comes with a few different adapters for the various threadings. Barbs, olives, and flare nuts aren't standardized across manufacturers either. There are three or four different ways to just put a caliper on a fork or frame. There are a further three or four ways to put a rotor on a hub. That means you're stocking more hubs and pre-built wheels as well as rotors. There are easily a dozen common brake pads, probably many more if you start looking at the obscure stuff.

At the handlebars, the drop-bar brake and shift levers are super tightly packaged and integrated. At the high end of the market, you might be able to get rebuild parts, though I never had to do that. Otherwise you're replacing a pretty expensive component, assuming it's even available. The market is still moving pretty fast as we've gone from two-by to one-by drivelines.

Cheaper non-integrated flat-bar brake levers are relatively benign to replace if you have to, but you still have to chop and reterminate the hose and bleed them. On the flip side, you can probably forget about getting rebuild parts.

Compared to a car, and I assume a motorcycle, the tolerances on everything are tighter. The room for gaskets and O-rings is smaller so leaks develop more easily and water contaminates the fluid more easily. The size of the fluid reservoir is vastly smaller so there's less reserve if you have a small leak. You're moving less fluid overall, so the margin between mushy and useless is pretty small.

We've come from a world where you needed two types of cable (road and MTB), one type of housing, and generously a half-dozen kinds of pads for cable actuated rim brakes to this. It's all doable, but the amount of stuff and tools you have to have on hand in a bike shop has goddamn exploded.

[lstodd]

Well I can see where excessive minituarization of hydraulics makes it a mess. One can't really lower working volume past some threshold, and the rest of system gets very fragile.

I don't really get why it's even needed, it's not like you need to drop 80km/h from a 150kg bike every other minute.

[lostlogin]

I got back into cycling after 20 years off.

Good hydraulic disc brakes are just so good.

Sadly I need them more, I’m a chicken on the decent and there is a lot more of me to stop.

[bobthepanda]

now that e-bikes are so prevalent, I wonder if we will see more regenerative braking.

i live in a place with large hills that have long descents over miles, and it would be nice to not be wearing out my brakes physically while controlling my speed.

[mauvehaus]

To have regenerative braking, you'd need a hub motor or a bottom bracket motor with a fixed hub and the freewheel on the crank, which admittedly does exist, just not in conjunction with a motor in the bottom bracket AFAIK.

You'd also need some way of controlling the regenerative and friction brakes together. No, it cannot be separate levers. A lot of casual cyclists don't use their front brakes because they're worried that they'll go over the bars.