Dean V

I have Shimano hydraulic discs with Di2 on one of my bikes.
It does work very well but I am still happy to ride my other bikes with rim brakes and mechanical shifting too.

rpenmanparker 

You don't need acetone, which has a high flammability danger. Isopropyl alcohol works fine, is readily available, and is much safer.

elcruxio

I do those things too and I too live up north and have lived north of the Arctic circle. I've had a bike so full of slush the wheels would not turn, I've ridden in bogs and frequently do gravel roads, ride in the rain etc. I still don't clean the discs if they are not contaminatedwith oil. If they are, I loathe to clean them because the pad material on the disc is such a big deal. Adn it takes time to accumulate

So unless your bike is regularly dumping oil on the disc through broken seals (where I used to live it got so cold Shimano hydros would blow the seals and die) or your municipality has not substituted the use of road salt with WD40, there still is no point in stripping the disc of the accumulated pad material thus drastically weakening braking performance.

Essentially I very much see a point of disc brakes even on road bikes since the performance of a well bedded in disc brake (even mechanical) is just so far beyond even the most powerful rim brake. Because the better rim brakes also tend to be extremely grabby and people fly over the bars because of them. It's not all about power

Hypno Toad

There are threads (dating back to 2009) with strong arguments on both sides of this issue.

I've been using disc brake bikes since 2005; I've made a point of cleaning my rotors regularly and never had any issues with stopping power after cleaning.

Brand new brakes need bedding, however that's about aligning the pads and rotors.

My road bike tires lose traction before I worry about any issues with my rim brakes. Never had an issue with modulation.*

I love disc brakes, and my next road bike will likely have disc since it will be set up to ride gravel and blacktop.

* footnote (repeating): my road bikes don't go out in the rain; my area doesn't have long descents.

Edit/Afterthought: If you can post bike-specific expert information about the transfer of pads to rotors and the effect on stopping, I will be interested. However, if we are simply exchanging personal opinions and experiences... there's nothing more to be said about 'clear or don't clean' rotors.

noodle soup

6800 calipers and Green Swissstop pads work great for me, but I've never tried them with 6600 levers.

Maybe try some compression-less housings.

TenGrainBread 

99% of the time when somebody comes into the shop complaining "my brakes are weak and squishy", it's because they have the pads way too far away from the rims. Tightening up the brakes usually solves the problem.

But most bike forums members are probably loathe to admit that this was the problem ("Of COURSE my brakes are set up correctly!")

mcours2006

Cost might be a bit prohibitive.

nightshade18

Well I've just been out and cleaned the rims with some acetone and also gently keyed the braking surface with a scotch pad. I did get some black muck off, but then I've done 40 miles of commuting today. I wanted to rotate my bars slightly, so I did that too, followed by an adjustment to the reach of the leavers and then subsequent reset of the pads.
I can't get out got the next couple of days, but I'll report back if that's changed anything.

My housing isn't compression-less.... I think perhaps that's the only thing left to try? Although maybe it wouldn't be night and day.

RPK79

I'm going to switch to coaster brakes.

nightshade18

It's dark out so excuse the quality of the photo, but here's how they're sat. I said 1mm before, but looking again it's probably even closer. Wheels are bang on true, so I can run them pretty close which is how I like mine set up - I like the brakes to engage as soon as I start to squeeze the lever. They're not touching the rim

noodle soup

I'm using some Jagwire cables and housing now. They aren't the aluminum link style housing, but rather the same style as shifter housing.

It works well, and isn't stupid expensive.

Carbonfiberboy 

We get good results using rim brakes on our tandem with a 286 lb. team and a tandem weight of 40+ lbs. out the door. We use particular pads and rims. We are careful about our brake set up. We use Jagwire cables and housing. I clean our rims with alcohol after riding in the rain. The place we use compressionless housing is shift housing, between the levers and the frame braze-on. That said, there are hills we don't descend with only rim brakes: anything 12% or over with multiple turns or a stop at the bottom. On my single bikes, rim brakes are a complete non-issue.

For caliper brakes, if you're not happy with your stopping power, try Swisstop BXP (blue) pads. We run the GHP2 pads on our tandem because the BXP aren't made for V-brakes.

elcruxio

The fact that you've never noticed a deteoration of braking performance after cleaning the rotor, to me, seems like you've never experienced the power of a properly bedded in disc brake.
I can notice a definite decrease in performance, hence I tend to avoid disc cleaning like the plague.

The most expert opinions out there are about car brakes which function with slightly different parameters, but Avid states thus:
"All new brake pads and rotors should be put through a wear-in process called ‘bed-in’. The bed-in procedure, which should be performed prior to your first ride, ensures the most consistent and powerful braking feel along with the quietest braking in most riding conditions. The bed-in process heats up the brake pads and rotors which deposits an even layer of brake pad material (transfer layer) to the braking surface of the rotor. It is this transfer layer that optimizes braking performance."

I do admit that a quality disc brake without the pad material on the disc is still an impressive stopper, but like avid puts it, the pad material optimizes braking performance and at least to me that's the difference of completely effortless fully in control braking and braking that is a bit worrying. I started this whole cycling thing 10 years ago with disc brakes and have had some of the most powerful brakes ever made (Magura Gustav) to the suckiest rim brakes (Tektro cantilevers) and everything in between. I've used spoon brakes even.
With that experience I feel that rim brakes are always at least slightly worrying. Even while my CX has the most powerful brakes of all my bikes (mini Vees) they are still a lot worse than the discs I have on other bikes because of the inherent grabbiness of rim brakes and especially Vee brakes.
With discs and the long modulation combined with a lot of end power the worry just isn't there, except if I have a new system, new rotor or a cleaned rotor.

lyrictenor1

I don't know about cable pull compatibility, but I have a feeling that the cable pull ratios between the 2200 levers and the 6600 brakes may be mismatched. I don't know, though. Just throwing it out there.

nightshade18

Oh, ok. They're from the same era, so I thought they'd be OK..... we need an expert in such matters

pdedes

if you can't come a cropper with rim brakes, the problem is you

CliffordK

After years of running Universal side-pull callipers on my old bike, I now have 6800 callipers mated to Campy SR-11 levers. They'll send me flying over the bars if I don't pay attention. Not overly catchy, but very firm stopping.

The old Universals will stop me, but nothing like the 6800s (plus modern levers). It is a night and day difference. It really surprised me. It could be pads or something, but the brakes are GOOD. Next to try are Campy Skeleton brakes, but I do like the Shimano quick release/quick adjust option.

I'm not sure about 5800s, but also worth considering.

Hypno Toad

I understand and agree that new brakes needed to bedded in to get pads and rotors aligned (they are not fun to ride when brand new). However, the material transfer, I've not found any information about this; please do post a link, I'd like to see this in the source. For example, this 'transfer layer', how many braking events does it take to transfer? In city riding, it doesn't take more than a couple blocks to hit the brakes hard a number of time or mountain biking.

I have been riding disc brakes since 2005, with three different bikes, including the previously mentioned Kona Dew Drop. The Kona has over 15,000 miles on it. Additionally, I ride the Kona in extreme conditions, well beyond typical rider. I've never had a worry or issue about my brakes and the way I've maintained them.

Back to your first 'point', here's a GoPro clip from a morning commute with the Kona. I'm doing 30 mph and get the bike to a near stop in a very short distance. I felt the full power of these brakes and the control, the rear wheel is lifting off, but I can control the force to avoid going OTB. (WARNING: I use all the bad words in this edit):


I will not try to convince you that you need to clean your rotors, I promise... And I'll ask you to respect my experience and opinion.

Scarbo

My rides are always about going up and then going down--fast. I ride all of the Sierra mountain passes; when I lived in the SF bay area I'd ride Mt. Diablo all the time. Heck, I've even ridden down Old Priest Rd. (look it up) on, typical, rim brakes. I don't get what the supposed deficiency is. I have disc brakes on my MTB. I like them too. And, I like the fact that your rims can't overheat; but that benefit remains a bit in the ether and, therefore, theoretical to me because I've never had a tire blow due to heat on any descent before using standard rim brakes (but, then, I am not one to ride my brakes). I climb and descend. A lot.

Some rim brakes/pads combined with certain wheelsets are better than others.

Lastly, rim brakes have an elegant simplicity about them. They are easy to maintain. You can go anywhere in the world and they will be understood. We don't value simplicity enough, methinks.

SHBR

Such empty roads.

I would have cut left, and kept on riding, not worth the aggravation of stopping and almost having a collision.

In China it is common practice for left turning traffic to cut in front of straight through traffic.

Scarbo

Sudden left-hand turners are the bane of all motorcyclists, as well; and many are killed each year in the US due to this. I might point out that, unfortunately, a set of the nicest Brembos are not enough to keep most of us out of the morgue. As always, attentiveness is the ultimate answer in these types of situations.

Hypno Toad

Cut left? Into the path of over taking cars? These empty roads allow drivers to go much faster; therefore a quick move to the left has more potential danger than holding your line. Your post is base on local norms... I'll keep this in mind the next time I'm biking in China; however, in Minnesota, this is not the norm.

Chandne

I was told to bed in the disc brakes but to avoid constantly cleaning the discs. I suppose if they get muddy, that is fine but I'd just rinse them off and probably not use alcohol. I have never done that on my MTB till I got my Crux and Tarmac. When I did that a couple of times, the squealing was real. So I stopped doing that and did some hard braking on some hills. After 2-3 runs, the squealing went away on the Tarmac. I also called SRAM since my Crux was doing the same thing. The guy on the phone told me to stop wiping the discs with alcohol. I also decontaminated my pads since it looked they had got some oil or something on them from the bike shop. I took the pads, soaked them in 90% alcohol, and set them on fire (outside) to burn off any oils. They burned with a slight blue glow for a few seconds. They were HOT even a min after the flame went out...careful if you try this. I then sanded it down with very fine sandpaper, and eventually bedded them in on the bike with 2-3 long and hard runs downhill. No squeals anymore....thank goodness. Braking modulation is amazing...something I have never experienced with pads. I took it for granted on my MTBs (usually XT or XTR brakes, though have used SRAMs too) and never thought about having that on the road.

Bike Gremlin

Salmon pads (SwissStop, or KoolStop) work great when it rains.

While disc brakes give a bit better feel and modulation than rim brakes from the start, rim brakes have been very good for me, never had problems with them, and I ride all year long. The only problem with rim brakes is that when it rains, starting breaking (until the wheels make one turn) gives a bit smaller braking force, but no real problems.

Hydraulic discs are the best braking system I know of, but I'm quite happy with good rim brakes as well.

VNA

Discs are great or "almost" for MTB and rim brakes are also "almost" great on road bikes.

Almost because I melted the front brake once on my MTB--lots of long very steep grades where I ride!
And not so great when it rains while riding my road bike!

Not sure that discs will be ever accepted on certain pro races?