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64

I think it mostly comes down to one primary thing: disc brakes weigh more and road bikes are supposed to be light. Also, you need a heavier wheel and heavier fork to handle the forces of disc braking, which compounds the weight. Additionally, the advantages to disc brakes (working better in mud/dirt, easier to work with a suspension, work with really wide ...


34

Keep it Simple Not everyone knows how to setup and maintain disc brakes. I know that it does not take a lot of work to read the manual but people sometimes prefer to stick to what they know and are hesitant to purchase a bike they do not feel they can confidently work on. Flawed Technology Disc brakes are far from perfect. We all should know that the ...


20

Check out this link for a recent post by ex frame-builder Dave Moulton about disc brakes. He discusses the reverse-directed stress to the spokes due to disc brakes as a potential problem. He also points out that the standard caliper brake can be viewed as a disc brake with a much larger diameter disc (the rim) and without the problem of transferring the ...


18

Usually, singles need to have horizontal dropouts so you can take the chain slack by adjusting the rear axle position. That means that any brake that is attached to the frame will "go out of position" when you adjust the rear axle position. That is, by the way, the reason why some horizontal dropouts are not quite horizontal, but diagonal: to be ...


16

Your frame and fork already have disc tabs, which is the first step. The second is a disc wheelset, which it does not appear that the stock wheels are. Disc hubs come in two varieties: the common six-bolt ISO and the proprietary Shimano Centerlock, the former are identifiable by a large six-bolt-hole protrusion on the left (non-drive) side of the bike. ...


15

Hydraulics are used on higher end systems, cables are a certain sign of a cheap brake set, so your observations are correct regarding "professional" bikes. Cables have the disadvantage of friction that hydraulics virtually eliminate. It is significantly easier to modulate hydraulic brakes, you get more force delivered to the pads, hence more stopping power ...


14

Look at any high end bike and you will find hydraulic disc brakes. There will be people who argue the pros/cons of hydraulic vs mechanical disc brakes but it's hard to deny what the entire industry is putting on their most expensive rigs. For ease of stoppage, minimal brake fade and ease of modulation - the hydraulic disc brake wins hands down. You can ...


14

Since bikes are usually shipped to the dealer with the wheels disassembled from the frame, the disc calipers often each have a plastic separator pressed into them that serve to prevent lock-up during shipping. The Hayes company even puts their brand logo on theirs. Since these are removed during assembly, you might be able to ask a repair person at your ...


14

One of the most advanced disk rotors are "floating rotors", made of 2 different materials and connected together. Look like this: These are exceptional brakes rotors. They are very rigid, won't bend sideways easily. Overheating problem is much less of a problem for these boys. But if they are going overheated, they don't bend that much because of the ...


13

I've used a (clean) drywall putty knife. The blade is wider than a screwdriver, so there's less chance of gouging the pads. Slide the knife in between the pads, twist and pry a bit, and they open right up.


12

As mentioned try a blunt bladed instrument (A large flat blade screwdriver will do) to pry the pads back in. Just put the screwdriver between the pads and lever the pads apart evenly! Just be carful though as sometimes the pistons that push the pads out can come out too far resulting in the pistons being slighly out of line, however if the pads have plenty ...


12

For use at home, there's no question that separate keys are more useful and more economical. A multi-tool has limitations that make it cumbersome to use in tight spots because all the keys are attached to the tool. Separate keys suffer no such limitation. Separate keys can be bought and replaced individually and very inexpensively -- not so with a ...


11

It isn't wise to install disc brakes on a frame and fork that weren't designed to withstand the unique forces that disc brakes generate, and you'll just damage your bike in the process. If your Haro does have disc brake mount tabs, then you can install them but likely only with smaller disc rotors. Remember that you'll have to get new wheels too, ...


11

They squeal because water acts as a mild lubricant. That's why things are "slippery when wet" ;) The water makes it harder for the pads to grab onto the rotors. They'll grab for a small fraction of a second and then let go again, and they do this really fast. Imagine the squeaky sound that a your finger makes when your run it over a smooth wet surface, or ...


11

In addition to @mattnz's response; most cable disk brake systems work by operating one pad only - and squeezing the rotor onto a stationary pad. This means that as the pad wears down, you typically have to wind in the moving pad (usually the outside one) to keep the right bite point. Hydraulic systems usually have opposing pads that self adjust for central ...


10

One thing that hasn't been mentioned, and probably trumps any mechanical advantages or disadvantages of disc brakes, is the fact that the UCI currently doesn't allow disc brakes in professional road races. This has a trickle down effect to you and me. Most, if not all, of the national racing federations follow the UCI's lead on equipment rulings. This ...


10

For a city commuter bike, don't bother with disk brakes - go for simple rim brakes. You'll want the reliability over all else. You don't need disks for most types of road cycling, as the limiting factor for grip is likely to be your tyre anyway. As regards shifters, go with whatever is comfortable for you. I like the combination of brakes and gear levers in ...


9

You should just pull the pads out and see how worn down they are - or if they are really dirty. Sometimes it helps to get some rubbing alcohol and clean the pads and rotors.


9

I think the LBS is partially correct, that bikes with disc brakes aren't generally designed to hold a rack. That said, I think there's a few solutions (other than getting a bike built to have disc brakes and a rack): Get a seat-post (or similar) mounted rack. Downsides: very low weight limit, often not good at holding panniers, and probably prone to ...


9

You want the correctly sized Torx driver. When I had to swap to a new wheel set I used a T25 driver. I just found a Park Tool TWS-2 that has 9 different sizes. You can probably find just a T25 driver at a hardware store.


9

I have or have had bikes with mechanical rim brakes, mechanical disks (shimano deore), hydraulic discs (also shimano deore) and recently hydraulic rim brakes (Magura hs33). The experience I had says that: The force you have to apply depends on brake-system preload / elastic constant (lever spring + actuator spring), cable friction, and actual, braking, ...


9

I commute every day in SF with drop bars. It's not an issue for me. You quickly adapt to the hand position, if you bike is set up in a way that is comfortable for you. The real safety issue you should be worried about, IMHO is not braking itself, but rather the "heads-down" position you can be in on the bike itself. You have to get used to looking around ...


9

An unaligned caliper (the unit that sits over the disc) is far more likely than a bent rotor. It's more exposed and susceptible to being knocked. You should first try to realign your disc brake caliper as this will quickly show if it is a rotor straightness or caliper alignment issue. This is a simple job and will only require the correct sized hex wrench. ...


8

I like disc brakes for these reasons: they're easier to keep oil off than rims bent wheels don't rub easier to adjust easier to get wheels in and out my rims don't wear out oh yes, they stop well too, but that's my last reason, not first!


8

You've met a mechanic that either wants you to buy more brake pads from his/her shop or doesn't know what he/she is doing. There's really no good reason to resurface your disc brake pads, let alone on a monthly basis. All that's doing is decreasing the life of your pads and temporarily decreasing your braking power until your pads bed back into the rotors. I ...


8

Disc brakes are very precise and the pads run very close to the disc even while not braking. Due to this, even small misalignments might make the pads (or even the caliper) rub against the disk, producing the noise you describe. A simple test would be to lift the wheel (or turn the bike upside down) and spin the wheel slightly. If it stops quickly, the ...


8

Simply put a bigger rotor provided better braking, and a four pot caliper provides better braking - better meaning more, and more control (Everything else being equal). For the same force between the disc and pads, a bigger rotor generates more torque on the wheel - i.e. more stopping force. It is running though the pads faster, generating more friction ...


7

The only way that I've found to get them to stop squeaking is to burn the water off. Big steep hill and stop at the bottom. As for performance, I don't notice any difference in the feel of my BB7's in the wet vs. the dry after a couple seconds of use. Even in rain puddles up to the bottom bracket.



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