kshapero

Advantages?
Disadvantages?

wolfchild

The biggest advantage of discs is that they will prevent your rims from wearing down. This is very important in winter time when there is a lot of salt , sand and grit on the roads. Disadvantages are that it may be difficult to mount racks unless you get the disc specific racks. Unless you live in the snowbelt and have a lot of crap on the roads you don't really need them. I have two bikes with discs and one with rim brakes.

kshapero

Thanks

Leebo

Less cleaning, better braking.

calamarichris

Pro:
~Supreme feel and control (even better IMO than Dura Ace 7800 brakes, which are really all the feel & control anyone really needs on a bicycle)
~The neat sound they make under hard braking

Con:
~Weight
~Shortening hydraulic brake lines a PITA for shop, and pretty much impossible for me, since I'm unwilling to buy the special tool to work with the little-bitty hose fittings.

Referring to the Tektra brakes that came on my Glove Live 3:

pallen

My commuter bike came with disk brakes. Its my first experience with them and I have been very pleased. More stopping power if you carry a lot of weight. No degradation of braking ability when riding in rain or going through deep puddles. After more than 2000 miles, I haven't touched them. Getting the wheels on and off has been easy. I cant really think of any downsides for a commuter. Weight is a little more and frames designed for disk brakes generally have stiffer/heavier forks. I wouldnt spend a bunch of extra money for them, but I'm glad I have them.

Arcanum

Pros:
More reliable braking in bad weather and otherwise wet conditions
No wear on the rims.
In the case of hydraulic brakes, more power and control.

Cons:
A little more expensive.
If the frame is poorly designed, can require specially-designed racks, or special adapters.
Fork needs to be strong enough to support the additional strain. (Not usually a problem; more a weight concern.)

IMO, discs are the way to go for a commuter bike.

exile

Are they easy to repair, replace, or adjust if necessary?

AsanaCycles

I haven't owned a car for at least 7 years.
I've been using Avid Mech disc brakes since 2000

the deal is:
consistent braking performance

thompsonpost

This was beat to death on another tread two days ago.

gitarzan

Marketing?

canyoneagle

I have Avid BB7 mechanicals on my commuter, and the answer is YES.
My wife's bike has Shimano Alfine hydraulics, which (IMO) have a better feel and modulation. I haven't had to do anything with them yet, so can't report on the maintenance side of things.
The BB7's were easy to set up and are a snap to work with.

Main advantages are rim wear avoidance and superior bad weather braking performance. Main disadvantage is the possible need to utilize a special spacer or disc-specific rack / fenders. I found this to be a non-issue (very easily accommodated). The Planet Bike Cascadia fenders come with the necessary spacers, and many racks are designed to be disc compatible. I used a second PB spacer in back for my Civia Rack.

sebnukem

I still stops the bike in snow, mud, water.

alan s 

Disc brakes are not for Luddites. For the rest of us, they offer significant advantages in all-weather stopping and rim wear.

tatfiend 

If you ride in snow conditions discs also are less likely to ice up or get bound up due to snow buildup on rims and calipers or pads.

dersan

if you dont ride in the snow you wont need it.I ride my commuter on every weather condition with no problems.
People telling that discs are heavy oh come on you are commuting you carry lots of equipment with you 300 grams wont kill you even my cellphone is 300 grams.If you like to buy just buy it there is no disadvantages its just expansive rhan v brakes thats all

paul2432

I use V-brakes. I've never had an issue stopping and I ride in all conditions (snow, rain, ice, etc). Granted, I don't ride in traffic conditions that require emergency stopping (I can't recall slamming my brakes once in the last two years).

Here is what Thorn (maker of high end touring bikes) has to say about discs:

There is no doubt that hydraulic disc brakes are
preferable to V brakes in the deep, muddy
conditions often found in UK mountainbiking.
They are, however, very easily damaged
(especially in transit) and a bent rotor is much
more difficult to straighten than an “out of true”
wheel. Indeed, if the rotor is warped enough, the
wheel will not even turn! Don’t compare the 8 to
10mm thick, cast rotors, found on modern cars
and motorcycles, with the 2mm thick, stainless
steel plate, rotors found on bicycles.

For everything, apart from full-on
mountainbiking, we prefer the
simplicity, ruggedness and ease of
maintenance of V brakes. We even
prefer the “feel” of top quality V
brakes. We have rims available, with
a tungsten carbide braking surface,
which provides fantastic braking
combined with exceptional longevity

Please don’t ask for a
disc brake on steel forks,
we simply won’t do it!

We use raked blades, these are exceptionally
comfortable, they will withstand the forces of
cycling (and have done so for generations) but
raked forks will not withstand the forces
generated by a disc brake, which are very
different to the forces generated by V brakes,
even at the same rate of ***********. We have
seen 3 ways that other manufacturers have
“accomplished” this, they all seem stupid to us
(1) We have had customers complain that a
well known custom builder’s raked steel forks
have permanently bent under braking.
(2) We have seen hideously uncomfortable,
thick walled, straight blades used by another
manufacturer, these forks don’t fail, but I
expect that an owner’s hands and elbows
soon would!
(3) The most ridiculous “solution” of all, is a
heavy left blade and lighter right blade. The
different blades must have different elastic
properties (isn’t that supposed to be the
point?) and therefore the axle must twist, when
a bump is hit. If the axle twists, then so must
the front wheel. If the front wheel twists, then
the bike consequently alters course.

Isn’t hitting bumps comfortably and safely
the main function of a bicycle’s fork?
Why compromise comfort and safety, in
order to fit a brake, which is inferior, in the

conditions that the steel fork will be used in?

Seattle Forrest

Very consistent stopping power in any weather, as much as your tires allow. It's not that the rotor is higher than the rim and less likely to be splashed: even when it's raining sideways, disc brakes are night and day compared to rim brakes.

Crashing Finn

All the benefits that have been mentioned (no rim wear, weatherproof etc).. Got hydraulics on the MTB and love them.

Having said that, I specifically chose rim brakes for my commuter. The pads (and even the whole brake if needed) will cost a fraction of the price of disc brake pads. And there are a zillion different kind of disc pads, V-brake pads are locally available practically everywhere. And well adjusted rim brakes with decent levers will have sufficient stopping power for commuting purposes.

sauerwald

I do not believe that disc brakes make sense for a commuter bike. I am an engineer, and that may show through in my reasoning:

First is the physics of the design - to stop the bike, your tires need to exert a negative force on the pavement. In the case of a traditional brake, the mechanism that does this is to apply pressure directly to the rim of the wheel, which translates the pressure to the tire and then to the pavement - all pretty straightforward.

With a disk brake, the calipers apply pressure to the disk, which in turn applies pressure to the hub, which applies the lateral pressure to the rim and then the tire through the spokes. The spokes (especially on a front wheel) are primarily designed to apply radial, not lateral pressure, so in order to accommodate the braking forces, you will want to use a lacing pattern which takes this into account. The net result will be more, longer, and beefier spokes on the front wheel than you would otherwise need.

The next issue is again one of physics - the pressure that needs to be exerted by a traditional brake pad on the rim of the wheel is approximately equal to the pressure that the tire is exerting on the pavement. For a disk brake, the disk is much smaller than the diameter of the wheel, so the amount of pressure that needs to be exerted is multiplied by the ratio of the disk diameter to the rim diameter - which can easily be 8:1 or more. This large force is applied to the fork near the dropouts, so the design of the fork needs to accommodate this as well, meaning that to support the disc brake you will need a heavier, stronger front fork.

The next issue is one of thermal dissipation - when you are slowing your bike, you are doing so by converting the kinetic energy of the bicycle to thermal energy, mostly in the brake pads and the braking surface. In the case of a traditional brake, this heat is generated in the rim of the wheel, and there is a lot of area over which it can be distributed, and dissipated. With a disk brake, all this thermal energy is transferred into a relatively small disk.

There are some advantages to disk brakes primarily when riding in wet conditions where the distance between the braking surface and the road helps to keep the brakes drier, but I believe that this is more of an advantage in mountain bikes than on road bikes. And for a commute bike, traditional brakes work just fine, also, for a commute bike, where you expect to put a lot of miles on it, the cost and ease of replacement should come into play, and again, here the advantage goes to the rim brakes.

no1mad 

I have no experience with disc brakes or physics, but it seems to me that the enhanced stopping power that the disc brakes (mechanical or hydraulic) more than compensates for the added mass.

Rhodabike

I think it depends on your riding conditions. If you live in a very hilly city in a wet climate - say, Vancouver - then they are better. If you ride in snow all winter they'll be better. If you live in a dry climate, have few hills, and don't use the bike in winter, it may not be worth your while.
I have them on my commuter because it's what it came with (the bike was on sale). I have to say, when I ride a bike that doesn't have them, the braking feels feeble and spongy until I get used to rim pads again.

rnorris

My most recent commuter came with disk brakes. After more than a year of riding with them in wet conditions, I'm a convert. I ride on busy urban and suburban arterials with large hills, and not having to wait for wet V brakes or cantis to reluctantly engage the rims (even with Kool Stops) is a boon. I find them actually easier to adjust than V brakes, and far less fussy than calipers. I'll agree that they're probably overkill in some cycling applications, though.

FunkyStickman

I'm going to build a 700C road bike with drum brakes. Just to irritate the guys in the 41.

CB HI

Regardless of all the engineering, physics and some bike builder discussions, the imperical data says disk brakes are working out just fine.