Lrdchaos

My rim brake, alloy wheeled road bike would always hang upside down by the front and rear wheels feom
the ceiling. With the new hydraulic disc and carbon wheels, what is the best way to store the bike?

PepeM

MoAlpha

Seems like a good way to get air in the brake lines.

DrIsotope

MoAlpha

Or move to the Southern Hemisphere, whichever's easiest.

DrIsotope

Yeah, if you opt for down undah', I always just assumed there would be a huge spiderweb capable of holding up the bike, or maybe some cooperative serpents.

I just rotate our bikes around, so there's never a need for the hydro bike to be hung upside-down.

Zaskar

Some will say it'll be fine upside down. And, some bikes will be fine like that. I've had mtn bikes (disc) breaks leak at the MC and leave a puddle when hung upside-down. Now, all of my bikes hang by the front wheel - two of which are disc. They've been fine this way.

WhyFi

You don't want to hang hydros upside down. I assume that the issue is air in the reservoir making its way in to the line. I don't remember why, but I had to orient my bike somewhat upside down for a short time; I had to pump the brakes for a minute or two to get them to work afterwards. If upside down for longer and a bubble made it someplace where it might "stick" when upright (past a bend in the BB area or maybe a nook or cranny in the caliper itself), it could be a pain in the ass.

OUGrad05

My hydro mtn bike has been hanging upside down for 7 years, no issues, sometimes for extended periods of time. That's interesting that you had a brake issue, not sure it was related but maybe it was? You could hang them against the wall like one of the other posters was doing.

WhyFi

Probably the position of the reservoir given the different ergonomics. FWIW, Shimano explicitly states that road hydro bikes shouldn't be put upside down.

edit:

I haven't had any issues whatsoever transporting my bikes on their sides, though, even with 1500+ mile road trips.

OUGrad05

Well damn, I had no clue, glad I read this thread. I don't yet have a hydro road bike but one is in my future.

Zaskar

Both mtn bikes that leaked when upside-down had Shimano brakes

cthenn

Hang it by one of the tiny holes in the disc rotor

jackb

I don't see how air can "work its way" into the brakeline if it is a sealed system. In order for air to get in, there would have to be a leak, in which case fluid would leak out. My wife hangs her bike upside down with no problem.

superdex

Your posts:bikes ratio is way too low.

WhyFi

So you're under the impression that reservoirs are always perfectly tippy-topped-off with fluid and that there's no air anywhere inside the system?

Okay, cool.

Zaskar

As I said way up ^there^, some bikes do just fine hanging... and some don't. That your wife's is fine in bat-mode, doesn't negate the fact that others leak, drip, get spongey... Maybe it's a Shimano (mine are and they protested) vs SRAM thing.

WhyFi

Thinking about it a little bit, I wouldn't be surprised if some systems have air in the reservoir by design, rather than by accident. There's (at least) two things to consider: fluid expansion/contraction with temp changes and pressure behind the piston when braking.

Expansion/contraction is pretty self-explanatory - if the volume changes, you need to address it somehow. Having a bladder, the back side of which would be open to atmosphere, would do that, but so would bubble of air in the reservoir that can expand/compress.

Pressure behind the piston is an obvious problem too, when you think about it. Once you're braking and the piston cuts off the reservoir from the rest of the system, you'll essentially have two sealed systems - one in front of the piston and one behind. In front of the piston, the pressure increases and the calipers push out, squeezing the disc, obviously. What about behind the piston, though? If that sealed mini-system were rigid and completely filled with fluid, the lever wouldn't move because that fluid wouldn't be able to meaningfully expand. Again, a bladder would address this, and I think that they do this on some MTB systems, but I don't know that they do it on road systems; it would certainly be more complex and costly than leaving an air pocket in the reservoir, though, and the only downside is that you have to tell people not to turn their bikes upside-down.

rumrunn6

2 hooks in the ceiling, maybe? just measure first to get the spacing correct

OUGrad05

I reached out to a few friends this morning in light of this thread, they don't hang any of their hydraulic bikes upside down. Air in the reservoir can migrate when hanging.

I would assume hanging vertical against the wall as shown above is ok though? Looks like when I get an hydrualic road bike I'll need to find a different hanging arrangement.

Lrdchaos

I appreciate the feedback. I have a steady rack for my mountain bike, I’ll buy another for my road bike.

Atlas Shrugged

I can speak from experience after flipping my Dura Ace Hydraulic bike upside down to facilitate a roadside repair a bubble worked its way into the rear braking system and I lost braking and needed to bleed the brakes once home. A thing similar happened to front brake after a flight and needed to find a bike shop to bleed brakes, luckily it was in a location with quality bike shops available to do the work.

It was when the bike was new and perhaps the reservoir was not completely full making the system more susceptible to the problem.

jackb

I didn't say that. If it is a sealed system, nothing can get in or out unless a leak develops. It there is no leak and air is in the line, it stays until bled out. If there is no air in the line, the line will remain airless unless a leak develops.

As for migrating air bubbles as someone suggested, why wouldn't these migrating bubbles migrate back to where they came from when the inverted bike is placed right side up?

DrIsotope

That would rely on a perfectly sealed system. The pistons move through seals, which is where contaminants get into the fluid. If the seal was absolutely perfect, the pistons couldn't move.

Imagine a typical internal combustion automobile engine. Properly maintained, sitting inside a car in the driveway, it doesn't leak oil, coolant, or fuel. Now turn it upside down.

WhyFi

I take it you've never bled a system. Brake lines don't always run downhill the entire length between the levers and calipers. Mineral oil is thicker than water. Bubbles stick and often need to be coerced. Until those bubbles are back on the other side of the piston, though, you could have some seriously compromised braking.

It's great that you/your wife haven't experienced any issues, but you're completely mistaken in thinking that it's a non-issue.