The thing that puts me off discs is that looking at them, I think they must make repairing a puncture much more time consuming. Is this true ?

A DISadvantage is all the OP asked about. Ugly is enough to be a dealbreaker 4 me.

No, you dont have to do anything.

I run an Avid BBDB (probably a relic by todays standards) but adjustment is super simple and super fine.

They stop on a sixpence(and my commuting weight is around 280-90), they last longer than rim brakes and they dont get crap stuck in the pads that score your handbuilt rear wheel

As for adjusting, when the brake isnt stopping so great, one turn on each caliper screw and you are back to uber performance.

If my frame would take a rear I wouldnt hesitate for a second.

The originals on my bike from new were Grimmica (sp) what a pile of junk. After reading up on the review sites I got the Avid's. 10/10! They are absolutely superb!

I Posted this in the Touring Forum about two weeks ago...

"I had canti's on one tour,V-brakes on another and disc on a third...the V's stopped better than the caniti's,but the disc (for me) is the way to go. No problems if you bend a wheel or break a spoke,better modulation,MUCH better stopping power when loaded."

DISadvantages of disc brakes? NONE!!

After using them for commuting on a road bike for two years; the only disadvantage I can think of is that currently you still have a limited number of forks and road frames that come with disc brake tabs. It makes your selection harder but I think that is slowly changing especially with cross bike frames.

Some people have questioned the safety of disc brakes.

https://www.ne.jp/asahi/julesandjames...quick_release/

I'm not bothering with retrofitting my existing bikes with discs right now. When I buy a new high-end mountain bike, it will be a different story altogether.

One bike I have will take a lot of retrofitting to get disc brakes on there properly, almost to the point where I might as well save that cash for a new bike. I may have to replace the fork, definitely the front hub and rebuild the wheel, and the back wheel will need an adapter for the frame and perhaps a hub/wheel rebuild as well to get discs operable.

The other bike I bought last month which is my commute bike, I'm not bothering with discs no matter how easy it would be to retrofit, mainly because discs are a thief magnet.

I think with almost any decent bike brakes you can go over the handlebars easily. I was about 14 and riding a mates new mountain bike, which was the first bike I ever road with cantilever brakes. I put the brakes on and went over the handlebars.

Not really.
When you take the wheel out just undo the axle quick release and drop out the wheel, no brake release necessary.
When you reinsert the wheel take a little care to line up the rotor with the caliper as you insert the wheel. There should be no other adjustment necessary.
I think they would be a nice addition to a commuter, an excellent idea for an off-road bike but overkill for a road bike. As has been mentioned disc brakes are heavier and require a heavier frame, and they are more expensive. For commuting they do make fitting a rack and fenders more difficult but by no means impossible. For this expense you get better braking that is less effected by weather and grime, longer lasting brake pads and no wear on your rims. If you live in SoCal or AZ don't bother, if you live in the NW seriously consider.
For me cheapness won out over the disc brakes. My summers don't have alot of rain to ride through and my winters mean lots of road salt which eats components. A disc brake frame and brake is too expensive for me to expose to Cleveland winters and is not needed for the summers. But my off-road bike does have disc brakes and I wouldn't have it any other way.
Craig

I think discs major disadvantage is on low-end discs. Low end (x-mart type) disc brakes can suck, be hard to adjust etc. I don't know that that's really an argument against them though because the same quality v-brake/canti/calipers also suck.

The only reason I don't have disc brakes is expense. I already have cantis/v-brakes. If I want to upgrade to discs I need a new fork, new brakes, new wheel (at least hub) etc. I don't even have tabs on the frame so I can't upgrade the rear. canti's and v-brakes work fine. I'm not saying they are as good as discs, but they work fine so I can't see spending the $$$.

Um...I don't see any powercranks on that bike!

My bike came with discs and other than weight, there really is no DIS-advantage to disc brakes.

There may be issues people have with disc nrakes, some real and some perceived, but there is no disadvantage to disc brakes as per the question by the OP.

Changing tires is easier with discs as they don't need to be released. In fact, you can spin the tire before you close the QR and confirm it is seated properly.

They are also extremelt adjustable with no tools required (mechanical brakes, I have no experience with hydraulic brakes).



Would I put discs on a new road bike? No. Do I see any reason to take them off my current bike, absolutely not.

1...2...character reply

I think you will be very happy with this setup. Your right that rear brakes don't do a lot.

I found that a week was about the adjustment interval needed for v-brakes. Disc brakes require much less frequent adjustment, and adjustment is much simpler.

I didn't realize there were other options. I stand corrected. Even so I think the front conversion is more important, and that would still be $$$. I guess my point is that I agree that Discs are great solutions, and for most utility/commuting folks they would be a better choice than rim brakes, but they are not enough better that I am willing to shell out more for them.

It rarely rains here. No need for them on my roadie which is what I commute on. I carry a shirt, underwear, socks, cell phone and wallet in a backpack so there is very little extra weight on my bike when I'm commuting.

cool - now I just need someone to knock me off my hobby horse

I still love disc brakes, but there are some disadvantages:

1. have to remove disc's if break a rear spoke on the wrong side
2. most road bikes don't have a strong enough fork to handle the extra forces generated by a fast stop
3. few CF bikes have strong enough forks
4. many race wheelsets are CF and are not strong enough to handle the faster stopping of disc brakes, i.e. Zipp and HED

[5. claimed problem raised on tri forum: not as aero as rim brakes. But I'm not convinced, looks like about the same frontal surface area to me. ]

6. roadies think they are uncool and riders with them are probably lame

Only other negatives are perception negatives and not real negatives:
a. weight - it's not a speed issue but a safety issue, especially for commuters
b. cost - it's not a toy, but rather a transportation vehicle. Cheapest forms of transportation are
1-- walking
2-- running
3-- using a manual 2 wheeled scooter or skateboard
4-- biking
5-- motor scooter
6-- motorcycle
7-- economy car
8-- car
9-- small truck/suv
10-- suv
11-- large truck
12-- dump truck
13-- semi
14-- tank

As far as I'm concerned the only real downside to discs is having to MacGuyver fenders on(and I fault the fender companies for this). Discs blow rim brakes out of the water. Longer pad life,less adjusting,cleaner wheels,plus the obvious advantages in bad weather. When I decided to sell off a couple bikes(finally ran out of room ) the rim brake ones were the first to go.

Disc brakes just make more sense for commuters. All weather,longer lasting,less maintenance.

I find i use my rear discs a lot more than the front vees.

Less noise, better contol of speed/braking. I can haul it down pretty quick with just the rears.

Although fronts are a better position to handle braking force, don't dismiss rear discs outright - they are a major improvement in braking over rear vees. Before the rears seemed like nothing, but now i have BRAKES.

I have disc brake on rear only mostly because i didn't want to shell out for a new fork for this bike, plus i figure rear discs compromise the rear wheel strength little to none, while putting discs on front would clearly reduce front wheel strength due to the dish required to accomodate them. This is probably a moot point since front wheels have excess strength anyway, and have to handle only ~1/3 of the total load.

Also, I'm building another bike from a non-disc frame - and it's getting the front disc brakeset...

Having had crap or moronically adjusted V-brakes doesn't justify buying discs.
Any halfway decent V-brake (properly adjusted) has enough braking power for any and all situations (possible exceptions: in a tropical downpour, alpine descent at 100+km/h, 220+pound rider). Grab a handful of my front V, and I absolutely guarantee that you fly over the bars like a cannonball. Same with the rear. If you grab it full force, it skids regardless of conditions. And mine are not remarkably good brakes at all, just average.

Thanks for that clever, useful reply. I'm going out to the garage now to start rebuilding my bikes so i can have 1993-technology brakes. I'll be sure to call you before I buy any parts, or actually install or adjust them myself, since I apparently lack the intelligence to perform these acts.

Actually, I have the disc on the rear so i can a) stop in pouring rain and b) stop in a controlled (skid-free) fashion and NOT fly over the bars of my bike like a cannonball (i have the impression that this has happened to you one too many times).

All I see so far is why V brakes are not worse than discs.

There is no questions discs stop better, the OP question was are there any disadvantages to discs and based on the replies in here, I'd have to say NO.

I think the mechanical drag inherent in a disc system is the biggest disadvantage for disc brakes. It's my biggest gripe I have about my bike.

1 I never flew over my bars
2 you were the one who wrote that a V didn't provide enough stopping power. I told you it can, for any rider and situation.
3 we all know that grabbing a handful is not the proper way for a panic stop. But it illustrates whether a brake has sufficient stopping power.

Discussion over.

Edit: why do I even answer someone who has a disc on the rear only? Mysteries of the universe...

Good systems don't drag. I can set up my Avid BB's and Shimanos for zero drag. My Hayes MX-2's will because you can only adjust the inner pad.