The Great Braking Debate Thread (Disc/Rim/Cantilever/Fixie/InsertNewTechHere)

[openwheelracing]

With all the improvement going to disc in the next years, I fear consumers are simply being trained to think disc is always better even though there is no clear distinction. One day disc wheels might be as light or lighter than its rim counter part. I also think it's a bit disingenuine to distinguish them as disc vs rim. Rim brake is technically disc brake. One is symmetrical while the other is assymetrical. Motorcycles use two discs, maybe bikes can move that route one day?

[tomato]

Yes, a 15k bike has more margin than a 5k bike. Anyway you look at it.

I think maybe you're unclear as to what a profit margin is and how it's calculated. In case you forgot, or didn't know, it's expressed as a percentage.

[Etienne]

In case you forgot, or didn't know, it's expressed as a percentage.

It's not mandatory ... as a matter of fact, many activities don't express the profit margin in % but in value, just because the expenses are paid in value and it's far easier to work like this.

I'd say that % is only interesting when comparing product lines, activities, etc ... it's a tool, no less, no more.

[tomato]

In case you forgot, or didn't know, it's expressed as a percentage.

It's not mandatory ... as a matter of fact, many activities don't express the profit margin in % but in value, just because the expenses are paid in value and it's far easier to work like this.

I'd say that % is only interesting when comparing product lines, activities, etc ... it's a tool, no less, no more.

Sure, nothing is mandatory. But, the standard usage is profit in dollars (or other currency) and profit margin (or margin) as a percentage.

[RyanH]

@tomato give it a rest.

[tanhalt]

The out-and-out best braking you can get is a Magura HS33 on an alloy rim. Nothing is evenly remotely close in regards to modulation, feel or power.

As good as that is, I would add that the "out-and-out" best with the HS33 is not just an alloy rim, but one with the Hed Turbine Track treatment braking. Truly unbelievable. I prefer it to the braking on my disc equipped bikes. I would bet on this combo "beating" any road disc setup in regards to total power, and more importantly modulation, in the dry OR wet. Would love to see a lab test of that...




P.S. Despite >10k of pavement use on those wheels, and now >2500 miles of mixed surface use (heavily skewed to dirt), there's still no discernable wear on the brake tracks. The radial grooves in the aluminum brake track appear to be quite good at "cleaning" the pads and preventing brake track wear. Despite that, pads seem to last quite a long time (no new pads within that 2.5k miles, and not close to needing replacement)...definitely longer than disc pads under the same use case

[maxim809]

Something different.

The debate surrounding RvD isn't about "pros vs cons" anymore.

We all already know. We've flipped every stone.

I don't know about you, but I haven't heard anything new that has made the pros vs cons list any bigger. How you ride, where you ride, how much you weigh, how much it weighs, maintenance, durability, noise, brake feel, so-on and so-on. Followed by personal anecdotes validating personal experience for days.

In recent years, RvD has been about the imminent death of rim brakes.

The barely legible writing on the wall 5 years ago has become more pronounced with each passing year. The people who are impacted the most are the ones who have invested the most time & money into filling out their rim brake knowledge. This isn't about which tech is better. It's about mourning the loss of all that domain knowledge for those who have invested heavily into rim technology.

And everybody would do better to emphasize.

Hardcore disc brakers could recognize that rim brakes fit the bill for people who are not like them. Some of these people have gone thru enormous trial & error to select the best pads, obsessing over cable routing, trying different wheels surfaces, and cycling thru various calipers to perfect modulation and bite. The Holy Grail of perfect rim braking is achievable, and lightweight rim brakers wants everyone to know it! However, that investment is about to become obsolete. To no fault of that person. How could they have known, especially if they started before road disc was even a thing?

On the flipside, hardcore rim brakers should recognize that disc is a great advancement for The People. Rim brakes are especially awful at the entry level. Newcomers to this sport just want their shit to work off the rack. Test 100 entry level rim and 100 entry level disc. Yes, there will be a few on both sides that will exhibit problems (#statistics). But ignore those exceptions and focus on the quality of braking. Head to head, a no-name 3rd party spongy brake block with no-name calipers on cheap ass wheels will never compete with the consistency of disc. Hydraulics is price agnostic.

You need to be especially dedicated and perhaps lucky to achieve the Holy Grail of rim brake perfection. Ain't nobody got time to search thru dozens of permutations of rim brake setups. That's an unreasonable expectation. I suppose you could flip it once more, and say the same about those who have perfected disc maintenance who feel that rim brakers should "Just move on, like me." That's missing the point. Or plot-twist: maybe the emerging point is why are BOTH technologies still riddled with the issues they carry? That's a diff topic.

...

Anyway, I wrote a fkking book. And I don't know how to close this. So I'll just say. At WW, there are very knowledgable people on both sides of the curve. And it can be really hard to see the middle when it is pointy-end fighting against pointy-end. And even harder to see the opposing pointy-end. But it is clear that one side is about to have their choices taken away, and washing away alongside with it is the value of their knowledge and experience. Nobody would be talking if both standards had healthy robust choice. But in the end there can only be one.

So all of this strife and animosity just seems completely natural to me.

Btw, I am excited to announce that I just bought my first disc bike. I licked the rotors and now it's doing something funny; can somebody please send help. I am just a bag of problems and I don't know why I'm even here.

[tomato]

@tomato give it a rest.

No problem. I would be more than happy if profit margins were never again mentioned in this thread, by myself or anyone else.

[GregR]

<snip> I fear consumers are simply being trained to think disc is always better even though there is no clear distinction. <snip>

I just feel like you keep circling back to the tired idea that we are not purchasing disc for good, well thought out reasons. The same sort of fallacious accusations could be thrown back at the rim crowd, but why bother? I have a rim bike that I like so I'd just be insulting myself.
As noted elsewhere, we all ride in different places, and encounter different challenges. Specific to this "discussion", the main variables are how much climbing is done, length and grade of climb, surrounding environment, road surfaces, wheel material, and weather. I have undoubtedly missed some.
All of these affected my decision to go to to disc. Of all, weather was the least important tbh. I find the focus on weather as a disc "pro" puzzling as the rain disc scream is annoying af to the point where I feel like taking the rim brake bike out in the rain. (not riding in the rain fixes this!)

[GregR]

@maxim809

[JWTS]

With all the improvement going to disc in the next years, I fear consumers are simply being trained to think disc is always better even though there is no clear distinction. One day disc wheels might be as light or lighter than its rim counter part. I also think it's a bit disingenuine to distinguish them as disc vs rim. Rim brake is technically disc brake. One is symmetrical while the other is assymetrical. Motorcycles use two discs, maybe bikes can move that route one day?

I'm sorry, but this is nonsense, and parsing words to the extreme.

In every other application known to man, "disc brakes" refer to a disc separate (that is not used to attach the tire). What's disengenous is this "rim brakes are really disc brakes" trope.

[tanhalt]

With all the improvement going to disc in the next years, I fear consumers are simply being trained to think disc is always better even though there is no clear distinction. One day disc wheels might be as light or lighter than its rim counter part. I also think it's a bit disingenuine to distinguish them as disc vs rim. Rim brake is technically disc brake. One is symmetrical while the other is assymetrical. Motorcycles use two discs, maybe bikes can move that route one day?

I'm sorry, but this is nonsense, and parsing words to the extreme.

In every other application known to man, "disc brakes" refer to a disc separate (that is not used to attach the tire). What's disengenous is this "rim brakes are really disc brakes" trope.

Actually, it's not nonsense, but technically correct. The only difference is that the "braking disc" for a "rim brake" has been integrated into the rim surface. How they operate physically and mechanically (i.e. clamping brake pads onto a disc shaped surface) is the same.

IMO, for a better distinction of the technologies, the division really shouldn't be "disc vs. rim" braking, but hub-based braking vs rim-based braking. That better expresses that one type of braking uses the spokes to transfer braking torque (and thus requiring additional spokes and/or structure) while in the other that load path is bypassed and the braking torque is transferred directly into the rim. What is typically referred to as a "disc brake" (but not universally, as you assert - see below) is really just a type of hub brake (along with, for example, drum brakes)...but, disc brakes can also be rim brakes as well.

For example, there's a relatively well-known performance motorcycle brand that touts the innovation of attaching the braking disk directly to the rim rather than the hub, in order to be able to get the same performance as a dual front disk setup while also being able to lighten up the rest of the wheel structure, for an overal net mass loss (~6lbs/3kg IIRC) and thereby reducing unsprung mass and increasing performance. If performance motorcycles ran tires as narrow as road bicycles, the next logical step would be to integrate the braking surface into the rim and have the caliper reach around the tire itself.

[tjvirden]

With all the improvement going to disc in the next years, I fear consumers are simply being trained to think disc is always better even though there is no clear distinction. One day disc wheels might be as light or lighter than its rim counter part. I also think it's a bit disingenuine to distinguish them as disc vs rim. Rim brake is technically disc brake. One is symmetrical while the other is assymetrical. Motorcycles use two discs, maybe bikes can move that route one day?

I'm sorry, but this is nonsense, and parsing words to the extreme.

In every other application known to man, "disc brakes" refer to a disc separate (that is not used to attach the tire). What's disengenous is this "rim brakes are really disc brakes" trope.

No, openwheelracing is correct on this one - from the point of view of engineering design, what we all know as "rim brakes" are a type of "disc brake". A subset of disc brakes no less - that's why they work as well as they do! The rim is the disc - about 622mm in diameter

Canyon's concept disc-brake road bike used twin discs, but it's overkill for well designed carbon forks.

Edit: Ha....beaten to it!

[TobinHatesYou]

But again, openwheelracing is going off on an irrelevant tangent because arguing profit margins wasn’t working out. No one actually cares about the mechanical similarities of rim brakes and disc brakes, only the differences in the current implementations.

“Haha disc brake havers, you’ve been fooled! Rim brakes ARE disc brakes!” … not a useful statement.

[tanhalt]

But again, openwheelracing is going off on an irrelevant tangent because arguing profit margins wasn’t working out. No one actually cares about the mechanical similarities of rim brakes and disc brakes, only the differences in the current implementations.

“Haha disc brake havers, you’ve been fooled! Rim brakes ARE disc brakes!” … not a useful statement.

It's "useful" in pointing out the fallacy that what's typically referred to as "disc brakes" is somehow a more evolved braking technology than what's typically referred to as "rim brakes" (just from the reasoning that other vehicles went from hub drum brakes to hub disc brakes), when in fact it's just a difference of implementation (i.e. hub disc vs rim disc).

When folks claim that bikes finally are upgrading to a superior technology, it's useful to point out that in actuality bicycles were already using a form of that technology (just in a more integrated fashion) ever since performance bikes moved on from "tire spoons" and hub drum brakes and skipped the whole hub disc phase altogether...and, it might be useful to point out, that when implemented correctly, it actually may be the best overall solution for system performance for road cycling due to the unique use case and performance factors of a road bicycle as compared to those other vehicles.