57
votes
Accepted
What is the difference between I.S., post, and flat mount disc brake mounting standards?
IS mounts (also frequently called IS tabs, disc tabs, etc) are unthreaded 6mm eyelets 51mm apart that bolts run through parallel with the hub axle. In almost all cases the brake caliper is then bolted ...
- 87k
31
votes
Why are disc brakes (disc & caliper) always installed on the left side of the bicycle?
On the rear, the disk rotor is on the left side of the bike to keep it away from the contaminants around the chain and cassette. This is why QR skewers have their levers on the left side of the bike ...
- 129k
29
votes
Accepted
Is this brake mounted incorrectly?
The brake pads are too high and barely contacting the rotor, which is wrong. It's also dangerous and the bike shouldn't be used in this condition. If the wheel in the picture is properly in place in ...
- 87k
28
votes
Accepted
6-bolt vs centre-lock: pros and cons?
Centerlock largely exists because since the beginning of modern disc brakes for bikes, Shimano has more or less alone had a weird cautionary take on the physics of rotor bolts theoretically being able ...
- 87k
24
votes
Accepted
Disk brake cables wear out too often - can I do something?
I think this is a design failure for this particular brake model.
Many of the mechanical brakes I've used have a sort of rounded "landing" surface for the cable, and the cable is rolled into ...
- 12.8k
21
votes
Is disk brake effectiveness mitigated by tyres losing traction under strong braking?
Ideally, the brakes should be able strong enough to break traction otherwise you will not be able to brake maximally (i.e., just before the threshold of losing traction). Rim brakes can do this, even ...
- 30.7k
20
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 ...
- 61.4k
19
votes
Accepted
How to install round brake pads
You got the wrong pads.
While it's possible to mix and match some pads, this is usually not the case. When replacing pads, keep track of:
Pad material and what your rotor is compatible of. Some ...
- 5,708
17
votes
Why are disk brakes not completely round on the outside?
For the brakes to self clean and remain effective, the surface of the pad must transition from metal to void at least once every revolution across the entire pad (i.e. no continuous line of metal). ...
- 52.4k
17
votes
Accepted
Do we need to repeat the bed-in process for disk brakes after replacing only the pads?
Yes. The bedding in process also prepares the brake pad's surface at the same time.
No need to make it complex, just do a set of hard but controlled stops down from a decent speed to stopped. Avoid ...
- 129k
16
votes
Can a bike have both rim and disc brakes?
If you are asking one of each type on the bike, yes. As disc brakes were becoming popular, many companies produces bikes with a disc in the front and a rim brake in the rear.
If you are asking ...
- 10k
16
votes
6-bolt vs centre-lock: pros and cons?
Advantages of 6-bolt:
Not being patented by Shimano means more vendors offer compatible wheels/disks.
Torx bolts require a smaller tool which is often included in many multi-tools so one can always ...
- 14.3k
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 ...
- 75.9k
16
votes
Accepted
I know I am missing a rotor but I don't know what to attach it to
You will need a wheel with a hub that is rotor compatible and fits your bike.
There are two main ways to mount a disk brake rotor to the hub.
A Shimano centerlock design has splines on the hub to ...
- 23k
15
votes
I mistakenly put WD40 for my disc brakes and now pads not anchoring as well as before. Any solution?
Disc brake pads are very sensitive to contamination. You can clean the disc rotors with rubbing alcohol, but that's about it. Anything else will contaminate the pads.
You may not be able to restore ...
- 30.4k
15
votes
Can't get enough braking power after lots of adjustment
Render R's are very susceptible to the arm being over-actuated. They don't hit a physical stop like some of their peers, but they reach a point where the cable anchor location is hanging in space and ...
- 87k
15
votes
Accident from front wheel locking up on brand new bike
Re:
When I tried to spin the front wheel, it just popped out of the frame. I was NOT applying any force and it just came straight off
This suggests the quick release was not properly attached or ...
- 2,845
15
votes
Accepted
How do bicycle brake manufacturers balance their products' physical limitations?
There is more to it than the 3 factors you describe beyond just the conversion of one force to another. A few others:
The deflection of the linkages in braking. A flimsy brake caliper will ...
- 12.2k
14
votes
6-bolt vs centre-lock: pros and cons?
A couple more pros of centre lock:
Finned rotors
One big difference is that you can't get the finned Shimano Ice-Tech rotors used on the road bike groupsets in a 6-bolt configuration. E.g:
or
I've ...
- 301
14
votes
Accepted
Why are bolts of brake discs using Torx sockets?
The magic of lobes allows Torx to handle a given torque value with a shorter bolt head than the alternatives, and some frame/fork designs need the clearance in this area. That's the only reason for it....
- 87k
14
votes
Can my fork support disc brakes?
In order to fit a disc brake, you need a compatible fork and a compatible wheel, plus a compatible brake lever.
Your fork does have a disc brake mounting already designed in, it is an International ...
- 12.9k
14
votes
Disk brakes swap on a new road bike with rim brakes
Can I put disk brakes on it?
No. You cannot effectively convert a rim brake frame or forks to disc brakes.
(Alternative answer:
do I need to replace parts?
Yes, the frame and forks.)
Seriously ...
- 75.9k
14
votes
Is it normal that front wheel bends when front disk brakes are applied?
No, not normal at all. You should have a bike shop look at it for a safety check if you are new to the sport and bike.
One thing that can cause a wheel to bend is poor spoke tension. A good bike shop ...
- 2,547
13
votes
How to replace Avid BB7 brake pads in "new" calipers?
There is a trick: The pads need some "persuasion" to get past the spring clip. Here is a side view of the pads and the spring clip showing how the pads nest within the steel clip. This should make ...
- 471
13
votes
Are rotor bolts designed to shear?
Low-profile button-cap socket screws do have a design weakness. The button reduces the amount of material around the head and the recessed hex or Torx socket also does the same, exactly at the ...
- 29.4k
13
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 ...
- 35.3k
12
votes
Is there a wheel which can use both disc brakes and rim brakes?
Rim brakes need an appropriate braking surface on the rim -- if you apply rim brakes to a rim which doesn't have an appropriate braking surface, it'll wear down the rims quickly to be unsafe to ride ...
- 46.4k
12
votes
Accepted
Can I convert a rim brake wheel to a disc brake wheel?
The hub for a disc brake wheel has the mounting for the brake rotor machined into the left side, and has shorter spokes that side to make room for the brake.
If the eBay wheels are for rim brakes, ...
- 12.9k
12
votes
Why do my bicycle brakes get worse and feel more 'squishy" over time?
On most cable disc brake systems there's a moving pad and a fixed pad. The moving pad presses against the rotor and bends it slightly towards the fixed pad. The rotor is made of rather springy steel,...
- 61.4k
12
votes
Accepted
Removing wd40 from disk brakes
The rotor needs thorough degreasing, finishing with alcohol to ensure there is no residue. The trick is that when there's actual oil on it, you should use something nasty like brake cleaner, but then ...
- 87k
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