27
votes
Why did the hydraulic disc brake stop working when riding down a steep mountain?
What you experienced was brake fade. There are two reasons why it happens:
The fluid inside the brake boils releasing gas into the system which makes the brakes feel spongy and then non-existant.
...
19
votes
Accepted
How do I rebuild Shimano XTR brake levers?
This answer must be prefaced with the obvious: brake-related work is high-consequence and could be genuinely injurious if performed incorrectly. Please exercise your own judgement regarding your ...
18
votes
Accepted
V-brake vs hydraulic disk-brake - which is more environmentally friendly
We can assume that V-brake pads are essentially non-degradable. The same is true for resin disc pads. But are non-recyclable. Metal disc pads seem to be various copper alloys which are probably OK ...
16
votes
How to install pre bled brakes with internally routed frame
Usually what you do is disconnect it at the lever, install the lever to the bar, and run the hose up from the caliper end. Because it's sealed on the other end, no more than a few drops of fluid will ...
16
votes
Accepted
Is there way to fix a disc brake rotor if slightly bent?
Yes. Disc brake rotors can warp a little in use, or get bent from impacts and straightening them is routine maintenance.
The basic procedure is to find spots where the rotor is bent inboard or ...
16
votes
Is this bike suitable for a male
The Older Paradigm of Women's Specific Bikes
Argenti and Kaz both are correct, but let's dive a bit deeper into women's specific design (WSD). Their answers allude to an old paradigm of WSD. It ...
15
votes
Does this bike use hydraulic brakes?
If there are no signs of a metallic wire (often colored silver) exposed anywhere near either end of the black housing "tube" connecting the lever on the handlebars and the caliper on the fork, it ...
15
votes
Accepted
What is this stamped metal piece that fell out of a new hydraulic shifter?
Providing the 7900 is the same, I’m sure it is but someone more qualified can chip in if it’s different.
How did it fall out ? Shimano have a proper tool for removing them.
Info from here Fawkes
13
votes
Hydraulic Vs. Mechanical disc brakes
Cable discs rule if you are riding a lot of third world. I am a million miles away from a shop, access to the oil, etc. A hydraulic failure would be disaster, whereas the worst thing that will happen ...
12
votes
Can hydraulic brake levers get hot when brakes overheat?
No, the thermal conductivity of brake hose/fluid is way too low.
I've run the numbers on this -- very roughly to make the calculations simpler. I've assumed the hose isn't cooled by airflow for some ...
12
votes
Accepted
What causes and how to fix wandering bite point on Shimano hydraulic brakes?
Originally I gave a tentative answer to this question and proposed the solution without actually trying it (next three paragraphs), and now that I have tried it I expand the answer with a report on ...
12
votes
V-brake vs hydraulic disk-brake - which is more environmentally friendly
The world is full of perfectly good cantis, v-brakes, and rim brake wheels that sit unused since disc has taken over. Using what we've already produced for its actual full service life is pretty hard ...
11
votes
Accepted
why can't you use park tool shift cable cutter to cut hydraulic cable
The comments OraNob and Batman said are spot on. A cable cutter uses shear force (focused crushing) to cut through the metal wound wires in a cable housing but still requires some clean up because of ...
11
votes
Can broken caliper be fixed?
I highly doubt you'll be able to find a separate alloy casting to replace the one that broke. Even if you can you'll be faced with assembling the caliper which is not trivial.
Just buy a replacement ...
11
votes
V-brake vs hydraulic disk-brake - which is more environmentally friendly
The true answer is: It really doesn't matter. You are riding a bicycle, that is what matters. If you are truly eager to minimize your ecological footprint, caring about the break type on your bike is ...
10
votes
How do I get my hydraulic disc brakes working well again
Most likely cause if the disc and pads are contaminated. What did you wash it with? Many cleaners leave a residue.
Worst case the pads need replacing. The discs should be well cleaned before ...
10
votes
How can I reset hydraulic brake pistons without removing the wheel?
I believe it is not worth trying it. You risk contaminating, scratching, or bending your rotors, as well as scratching or cracking a brake pad.
Consider also whether there are bigger problems with ...
10
votes
Disc Brakes *Completely* Ineffective
I've had my fair share of hydraulic brake woes this year so I'll list the things I'd check - I am aware that you've done some already. Firstly some questions though:
Are these brakes using mineral ...
10
votes
Accepted
Is it safe to run disc brakes up front on a mountain bike that lacks a disc caliper mounting point in the rear?
A few years ago this was a reasonably common setup as sold. I've certainly ridden an e-bike set up that way, with v-brakes at the back and a mechanical disc brake at the front. I suspect this wasn't ...
10
votes
Brake disc sometimes touching brake pad when not braking
Rotors can and do bend, subtly. Have you checked it's flat? One of mine sounds flat (or rather doesn't sound) cold, but has a high enough spot when hot to sing.
Have you checked for play in your ...
9
votes
Can storing bicycles upside-down damage hydraulic brakes?
From Shimano Service Instructions:
When turning the bicycle upside down or on its side the brake system may have some air
bubbles inside the reservoir tank which are still there when the ...
9
votes
Accepted
Converting road hydraulic disc brakes to flat bar : Possible?
The official answer from Shimano as of now is no, as per their road hydraulic systems compatibility chart.
Someday there may be flatbar road hydraulic levers that make their way onto a new version of ...
9
votes
Accepted
Are disc brakes weak? And what is "bedding in"?
Bedding-in is a common process with new disc brake pads. Disc brakes were developed much earlier for motorcycles and cars, from which the technology and the terminology has been transferred to MTBs: ...
9
votes
Accepted
Brand new bike. Briefly removed the rear disc brake caliper, now it's too tight
As mentioned in comments you most likely applied the brake without the disc between the pads. The pistons advance and do not return all the way to their original position - this is how hydraulic ...
9
votes
Why are brake levers still bent in form to accomodate more than one finger?
TL;DNR - single finger levers have little (if any) advanatage and some disadvantages.
Most people do not start out cycling with XT/Ultegra quality bikes and therefore (do not) start out on bikes ...
9
votes
Accepted
Pros and cons of mixed hydraulic/mechanical brakes vs pure hydraulics
Background
For most of cycling history, we've actuated derailleurs and brakes by pulling cables. One of the possible disadvantages of cables in general is that as the cable housing exerts a bit of ...
9
votes
Can broken caliper be fixed?
It is a brake - a critical safety component. Just replace it.
Any fix or hack or bodge could fail you at the worst moment, endangering you and others around you. This one has already broken, who's ...
9
votes
Accepted
Shimano Deore hydraulic brake problem
The part that popped out is one of the pistons.
There should always be a bleed block in place between the pistons when bleeding the brake. Immobilizing them this way is what prevents overfill and also ...
9
votes
Heating of hydraulic oil with hardtail electric MTB brakes
pumping worked to no avail-which usually works
This is ringing alarm bells for me - it implies you encounter brake fade on a semi regular basis.
This is almost certainly down to poor braking ...
8
votes
Accepted
How do I tell the size of my braking discs?
The disc that you are talking about is in fact called the rotor.
Rotor size is measured by diameter, ie. edge to edge through the centre. The size may also be etched on to the rotor which would be ...
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