Why have disc brakes become so popular?

[[XAP]Bob]

I wonder if this type of bike shop even has staff with sufficient skill to build wheels?

That's one of the big issues. There isn't enough profit in replacing a wheel because a cheap hub and spokes is low cost compared with the labour of a relace/true.

The factory spoked and automatically trued wheels from the Far East will end up being less economically expensive than rerimming a wheel, at least if you ignore the potential change in hub quality.
Obviously if the hub has any additional features (dynamo, gears, whatever) then the economics change, but we no longer have enough people around who do rebuilds, so they become correspondingly more expensive as well...


It's a self fulfilling race to the cheapest possible hub, which now only needs a lifetime comparable with the rim...

[rmurphy195]

Why now? When I bought my previous tourer in the early 90's I bought the bike with whatever brakes were fitted (Galaxy with Cantis).

When I came to replace it in 2015, disc brakes were becoming available on tourers - cable ones, without the complexities of the hydraulic brakes of my son's downhiller.

Nothing to do with advertising beyond looking at manufacturers websites to see who offered a suitable bike with discs, or a suitable frame to build them into. To put it another way, the adverts didn't persuade me to go for discs, previous experience of the pros and cons of other types, and having a play with my son's Hope-equipped bike made me look for them

I was specifically looking for discs because of the obvious (to me) advantages (along with Brifters) and it became a criteria for choice of bike.

My original reply was based on the title and wording of the original post.

[Si]

We could also ask: why did V (parallel push) brakes become popular in the very late nineties given that they'd been around since before the war?

Anyway - another benefit of disc brakes.....just got in, totally knackered, thought I better lube my totally dry, dusty chain, massive dribble from chain, all over the rear rim....was I worried?

[Peter W]

I'm getting more depressed by the minute. (Thank you Brucey! ) It would seem that my 'super' bike with its wonderful and joy to use braking performance (and it is that) is just living on borrowed time which may be shorter than I'd imagined. I hadn't realised that Shimano road discs were less robust than MTB ones. I think I can take it for granted that if/when they do fail there will be no direct, more robust, MTB replacement disc of the same size and fitting!

As for rims, I used to lace up replacement ones myself when those earlier rim braked MTB rims exploded, since the relative durability of hubs and bearings and spokes still warranted doing so. But as Cugel and others have said, that is no longer necessarily the case. Specialised, for example fit alloy nipples to their MTB's which corrode and seize solid after a years use, before simply snapping at their base inside the rim. You often don'r realise one has gone while riding, except by the tyre giving a tell tale wonky patch. Replacing a single spoke and trying to re-true the rim simply snaps the equally corrode nipples of the nearby spokes, and so on. The only way is to replace them all.

Should the new disc Roubaiax turn out to be somewhat less durable, and refuse to remain the wonder bike it currently is, I won't burst into tears. I shall mount my old Stumpy triple chain ring (infuriating the fashion sheep with their single front rings, dinner plate sized cassettes, and gobs full of blather) MTB, and give adequate vent to my feelings to any herd of bovines who may or may not want to listen. And I've still got the older rimbraked Roubaix which is also a cracker of a bike -bar the braking, of course- to keep my spirits up!

[reohn2]

I have a neighbour who commutes on a mid-price hybrid. He's gone through two sets of rims in the last 5 years as he commutes 12 miles per day in all weathers & seasons, often down the canal towpath; as well as using his bike for general transport (shopping etc.). He gets me to do his maintenance when something goes wrong.

When considering the worn rims (which end up looking like Saturn's rings before I get to see them) I found that the hubs too (Shimano Deore) were knackered, since he does no maintenance himself, they don't get lubricated or adjusted or even cleaned. It was cheaper to buy another comparable wheelset for £69 in the sale.

Myself, I've never worn out a pair of rims or hubs, despite doing 10X the mileage my neighbour does. I suspect this is due to: regular cleaning, lubrication & maintenance; mostly fair weather cycling, not on the canal towpath or similar; better components. I have one pair of wheels now 30 years old that must have done tens of thousands of miles in their time but are still smooth i' the bearings with unworn rims and shiny spokes. They're Mavic ceramic rims on Shimano sealed bearing 600 hubs with 36 DB stainless spokes.

In short, different styles of cycling & bike-use on different qualities of components create different rates of wear and different effective replacement strategies.

I suppose you can make a case for a worn or damaged rim to be replaced if the hubs are good & well maintained and you can competently deconstruct and reconstruct a wheel. In my experience, many cyclists have mediocre wheels & hubs that came with the bike, which they never maintain; and no ability to build a wheel.....

Cugel

I take your point,though your post also illustrares perfectly why disc or drum brakes are the solution for certain applications

[Brucey]

I'm getting more depressed by the minute. (Thank you Brucey! ) It would seem that my 'super' bike with its wonderful and joy to use braking performance (and it is that) is just living on borrowed time which may be shorter than I'd imagined. I hadn't realised that Shimano road discs were less robust than MTB ones. I think I can take it for granted that if/when they do fail there will be no direct, more robust, MTB replacement disc of the same size and fitting!...

well a typical centrelock shimano ice-tech disc (road or MTB) srtarts life out at 1.75mm thickness and the minimum allowable thickness is 1.5mm. That is only 0.125mm wear allowance each side. I have seen them worn to 1.25mm without failing, but the owner of that bike wasn't riding big hills so the brakes didn't see the highest loads.

Non-ice tech discs run hotter but usually have more wear allowance in them. On MTBs they are often larger, too , so you don't need such high forces at the disc to slow the bike down; thus you get less wear, spread over a wider area. For reasons of weight and aero, small discs are often fitted on road bikes. I'm not sure a solid disc will work (at the same size) on a road bike and often fitting a larger disc is not possible on a road bike, because a larger disc would interfere with the fork blade.

Maybe I am being unduly pessimistic about it; you might get much more wear life than I fear you might. But I would suggest that you keep an eye on disc wear; the chap with the 1.25mm thickness discs had no idea they were so worn as that.

cheers

[The utility cyclist]

why?
Telling people they are a must have, telling porkies about the advantages (a bit like the porkies over remaining n the EU) promoting the heck out of them with those well known web sites/income based on how well we can promote products organisations promoting them, getting professional teams/riders to use them (on the back of pushing their new product) so if the pros are using them then they must be good/right, right?
Oh and reducing the line up/availability of non disc bikes/frames.
Because it dumbs things down, there's no skill or ability to concern yourself with ... apparently :roll

Funny how in the wet at high speed in the pro ranks it's not the brakes ability to work that is the problem, it's the tyres grip, poor line, poor decision making that is the deciding factor as to why they crash, that in turn is dictated in part by helmet wearing, it's not about modulation or ultimate braking power.

Discs are a step too far (I've explained previously why) unless you're bothered about rim wear, in which case more fool you because you just spent a shed load of money on a new bike and all your existing wheels are utterly useless for your new mchine so you have to spend even more money on new swap out wheels or simply get a new stable throughout.
Modulation, learn how to brake properly, learn how to anticipate/read the road and stop going too fast, travel at a speed you can stop well within the distance you can see to be clear, stop expecting to have things dumbed down, discs devolves skill/thinking ... it's exactly the same as motorvehicles/motorists.

[Cugel]

why?
Telling people they are a must have, telling porkies about the advantages (a bit like the porkies over remaining n the EU) promoting the heck out of them with those well known web sites/income based on how well we can promote products organisations promoting them, getting professional teams/riders to use them (on the back of pushing their new product) so if the pros are using them then they must be good/right, right?
Oh and reducing the line up/availability of non disc bikes/frames.
Because it dumbs things down, there's no skill or ability to concern yourself with ... apparently :roll

Funny how in the wet at high speed in the pro ranks it's not the brakes ability to work that is the problem, it's the tyres grip, poor line, poor decision making that is the deciding factor as to why they crash, that in turn is dictated in part by helmet wearing, it's not about modulation or ultimate braking power.

Discs are a step too far (I've explained previously why) unless you're bothered about rim wear, in which case more fool you because you just spent a shed load of money on a new bike and all your existing wheels are utterly useless for your new mchine so you have to spend even more money on new swap out wheels or simply get a new stable throughout.
Modulation, learn how to brake properly, learn how to anticipate/read the road and stop going too fast, travel at a speed you can stop well within the distance you can see to be clear, stop expecting to have things dumbed down, discs devolves skill/thinking ... it's exactly the same as motorvehicles/motorists.

I yam sending you some ice before your safety valve blows up with all that steam coming out of it.

One technique for avoiding brake problems, rim or disc wear, skidding and so forth is to not brake much. I've been doing this for years via learning to descend at remarkable speeds.

Accidental prangs, falls and tarmac-smacks? No, no - not wearing a helmet or having an ejection seat, I find that I carefully ride within the envelope of my competence albeit I like to expand that envelope a bit now and then. You could get a new woolly jersey and a matching hat in the envelope now (and I am a 44 inch chester of solid pork, so the jersey is a big one, as is the hat, for me big head)!

It's surprising how narrow a gap atween a hedge and a car you can get through if you have to. Mind, even I have to brake for the junction at the bottom of the 1 in 5.

Cugel

PS Do not try this if you are an habitual faller-offer, nervous type or have poor proprioception.


Cugel

[horizon]

Blah,blah,blah,blah,blah,yeah right,you must be right coz everyone else is wrong,blah,blah,blah,blah,blah...........
Do you never get tired of being wrong?

He does have some strong views and although others think him wrong, IMV those views do have some validity (quite a few points in fact). I know you and he disagree, but that's OK.

[reohn2]

Blah,blah,blah,blah,blah,yeah right,you must be right coz everyone else is wrong,blah,blah,blah,blah,blah...........
Do you never get tired of being wrong?

He does have some strong views and although others think him wrong, IMV those views do have some validity. I know you and he disagree, but that's OK.

It certainly is ok to disagree,however sometimes some folks opinions are just plain wrong.

Let's look at what TUC claims.

He claims someone(?) claims they're a must have.
Who claims that?

The line up of non disc brake frames being reduced.
Really?
There's plenty choice of both types on the market.

There's no skill in riding(presumably he means when using disc brakes)
Where's the proof in that?

He then blaims,poor decision making,poor line,helmet wearing,tyre grip, all on disc brakes use
Bonkers doesn't describe this theory!

Then he blaims a fault of discs as being a "step to far" unless you worry about rim wear,because it negates all your other wheels.
Oh yeah?
I got shed loads of wheels that don't fit my disc braked bike.... ... NOT!

Next we have,you don't know how to ride or brake and you also ride too fast if you ride discs and all this from someone who claims to cruise at 40mph!!!
Yeah,right,dream on.....

TBH I just get tired of the crap peddled by people who don't know the difference between Stork and butter .

If someone prefers rim brakes for whatever type of cycling they ride I have no problem with that,I do have problems with people posting crap and rubbish based on their own biased factually incorrect opinions about anything,this is such an occasion..

[horizon]

I think his point about incompatible wheels was good (it puts me off discs). I also think he has a point about braking - or at least an interesting view. I also like the way he puts his views over strongly - as I sometimes do, and you sometimes do . . .

It's all food for thought even if you disagree (and I can see why you do).

[Graham]

. . . unfortunately ( for the mods ) creating a tedious and unnecessary workload.

The same points can be expressed without the emphatic nonsense.

When confronted with emphatic nonsense . . . . .
1) Try to ignore it. In this way the offender eventually learns that their posts are being ignored for some reason.
or
2) Respond in a manner that helps the offender to learn a better way of expressing him/herself.
or
3) In extremis - use the report button.

[Brucey]

personally I don't have an issue with folk having their own opinions by and large so much as with the way they are expressed by some folk.


Regarding disc brakes; the assumption by many folk is that disc brakes will be more powerful and that this is "a good thing". I think if you want to do stoppies (in a planned way) disc brakes are not a bad way of achieving this. There are lots of brake characteristics (not all of them obvious) which to go to make up a good brake and a discussion of these could take ages, But the benefits of extra brake power are relatively easy to determine; you can stop more quickly, so that has to be good, right?
Well in lots of other vehicles that might be true, but bicycles are a special case. At high speeds and going down hills etc the brakes may be applied for several seconds and during this time the ability to modulate the brake up to the maximum power may well mean that you can stop and/or slow down more safely (ignoring the possible consequences of other riders near you having different brakes). Doing fast descents on an MTB with really good brakes is an absolute hoot, for example.

But a very common circumstance (esp when commuting or utility/town riding) is that you suddenly need to stop dead, from a speed of 20mph or a bit less. At this kind of speed the total time the brakes are on (in a hard stop approaching 1G) might be about one second. There is not enough time to modulate the brake usefully; having practiced a bit you might do a second or third stop very quickly and safely but the vital first (unexpected) one will be unlikely to exploit the full power of a very powerful brake; you are most likely to either throw yourself over the handlebars or to not apply the brake anywhere near enough to do this, for fear of doing so. Another possibility is that (in wet conditions) normally good disc brakes take about 1s to clear the water from the disc and to 'come on' noticeably. In this case you might take twice the time (with the brakes on) to stop; note also that the distance travelled in this case might be up to three times further. Even in the dry some brake pad compounds have poor cold bite (in order that they still work well when hot; it is a trade-off) and these don't give a high initial retardation even if you pull hard on the lever. This may prevent you from going over the bars instantly, but after half a second you may realise this and grab more brake just as it is 'coming on' by itself, and then you might well overdo it.

Arguably what would work better (and would be proof against grabbing a handful of brake in a panic) would be a brake that came on instantly, but didn't work so well that you could throw yourself over the handlebars. Some manufacturers have long realised this; for example shimano roller brakes are fitted onto a front hub that has a torque limiting clutch in it, to prevent an endo. Similarly their V brakes (for commuting and/or relatively unskilled leisure riders) have often contained a power modulator, typically consisting of a stiff spring in the noodle that modulates the brake force somewhat. These things are of some value rather than none, but are not perfect solutions.

By happy coincidence (or good design) it happens that 70mm Sturmey Archer hub brakes, once bedded in, are normally not quite powerful enough to allow a stoppie on a bike with 26-27" wheels. They are obviously completely unaffected by the weather, and the brake linings have good 'cold bite'. IME this means that in an emergency you can grab a big handful of front brake and reliably accomplish that near-mythic 1G, 1s stop from about 15-20mph. Thus even if they are not quite as powerful as disc brakes, and perhaps don't even modulate as well, IMHO 70mm SA hub brakes are a much better brake for town work and a much better brake overall than most folk give them credit.

BTW SA do a 90mm brake too; this is overkill for most bikes but has its place on loaded carrier bikes, tandems, and so forth. A recumbent tricycle fitted with two such brakes can (on dry tarmac, with grippy tyres) stop well in excess of 1G, and (despite the low CoG) even manage a stoppie (which has the unfortunate consequence of driving the chainrings and pedals into the tarmac). I doubt very much that (from speeds of 30mph or less) there are other vehicles on the road that could stop much quicker than that...

cheers

[reohn2]

I think his point about incompatible wheels was good (it puts me off discs).

Well it's true a dedicated disc brake rim can't be used with rim brakes but a rim with a braking track can be used with either and so can disc hubs.
if you're thinking of swapping over to discs in the future you could have wheels built with disc compatible hubs,either six bolt or centrelock which can be used with rim brakes.

I also think he has a point about braking - or at least an interesting view

In what way are better brakes with good modulation worse in bad conditions?
In what way are people who use discs worse riders or somehow inferior to people who ride rim brakes,preposterous doesn't begin to describe such a biased and unfounded view.

. I also like the way he puts his views over strongly - as I sometimes do, and you sometimes do . . .

I've no problem with a strong view if it's a correct view,but when it's based on biased trumped up bunkum such TUC has posted with regard to disc brakes,I'll respond equally strongly with fact based opinion garnered from a decade of disc brake use.

It's all food for thought even if you disagree (and I can see why you do).

Thank you

[reohn2]

Brucey's point about drum brakes may very well be a correct one and I tend to take his word for it,as I know he's used them a lot,personally I haven't so can't comment and confine my opinions to comparing brakes I have extensive experience of.
I have used single and dual pivot,cantis and V type rim brakes,used with a variety of different pads,and BB7 and Spyke cable disc brakes used with organic and sintered pads.
I've used all the above with both drops and straight bars with compatable levers in all manner of conditions.

As I've posted before on other threads those disc brakes I have experience of have better modulation than rim brakes,this isn't so much a crucial issue in dry weather as one adapts to any brake's slight differences in power and modulation when used for a while.
However in wet and or muddy conditions there's no comparison,discs win outright over rim brakes due to their reliable consistency of operation and modulation,that's a fact.