Why have disc brakes become so popular?

General cycling advice ( NOT technical ! )
Debs
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Re: Why have disc brakes become so popular?

Post by Debs »

I believe choosing a new bike with disc brakes to buy will remain a consumer option, as will choosing a new bike with rim calliper brakes or cantilevers will also remain an option, and for donkeys years to come.
Mainly because the bicycle exists for most cyclists as an uncomplicated transport machine that avoids the extensive bureaucracy and legal requirements that is commonly attached to owning/driving motor vehicles [licence,tax, MOT, insurance, professional service need etc] and the overwhelming majority of ordinary cyclists who ride a bike will prefer one that's less complicated, easier to understand & service with rim type brakes, and not to mention the lower price of the bicycle.

The evolution of disc-brake bicycles is not to be feared, but rather marvelled at the engineering achievement [if the performance is top draw] and this regardless if one choosing a disc brake bike or not.
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The utility cyclist
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Re: Why have disc brakes become so popular?

Post by The utility cyclist »

reohn2 wrote:
The utility cyclist wrote:So far several posters are doing exactly as predicted, taking more risks and going faster. You'll end up running out of road and thinking time sooner rather than later. That unexpected occurrence you'll have less time and tarmac to deal with it, but it won't be the brakes fault you had so little, good luck to you when it occurs.

The facts still stand as to why they've increased in sales, well done to the marketing/decisionmakers restrict and nombard, it's helmets all over again.

So far we have a warning of going faster from someone who claims to "cruise" at 40mph!

Two(myself and Cugel) out of the three people who've mentioned faster descending have done so with regards to bigger tyres at lower TP's not disc brakes

Now you're just deliberately distorting what has been said, suggest you check back and retract :twisted:
You seem to be rather wound up, enough to distort what was said, by the fact that firstly I can cycle/descend downhill faster than some, oh and do that on my way to the supermarket, that must grate, and for me to do that safely on mere rim brakes too!

You're also confused, I haven't said I go faster, it's the speed I've always done, actually I cycle slower now than I used to, despite better tyres and bikes, I ride within myself.
It's you and others that are saying that through more confidence due to using disc brakes over rim brakes you're going faster, basically risk compensation, you're a crash waiting to happen.
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Cugel
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Re: Why have disc brakes become so popular?

Post by Cugel »

The utility cyclist wrote:
reohn2 wrote:
The utility cyclist wrote:So far several posters are doing exactly as predicted, taking more risks and going faster. You'll end up running out of road and thinking time sooner rather than later. That unexpected occurrence you'll have less time and tarmac to deal with it, but it won't be the brakes fault you had so little, good luck to you when it occurs.

The facts still stand as to why they've increased in sales, well done to the marketing/decisionmakers restrict and nombard, it's helmets all over again.

So far we have a warning of going faster from someone who claims to "cruise" at 40mph!

Two(myself and Cugel) out of the three people who've mentioned faster descending have done so with regards to bigger tyres at lower TP's not disc brakes

Now you're just deliberately distorting what has been said, suggest you check back and retract :twisted:
You seem to be rather wound up, enough to distort what was said, by the fact that firstly I can cycle/descend downhill faster than some, oh and do that on my way to the supermarket, that must grate, and for me to do that safely on mere rim brakes too!

You're also confused, I haven't said I go faster, it's the speed I've always done, actually I cycle slower now than I used to, despite better tyres and bikes, I ride within myself.
It's you and others that are saying that through more confidence due to using disc brakes over rim brakes you're going faster, basically risk compensation, you're a crash waiting to happen.


It's true that any technology that offers improved safety when using a vehicle tends to result in many of the users taking more risks than are justified by the technology involved. It's happened with always-on sidelights, seat belts, air bags, ABS brakes and a host of other such stuff. There are more "accidents" as a result, although the risk-hungry who are involved are often themselves better protected from their stupid actions - even if others involved who are outside the vehicle, such as cyclists and pedestrians, suffer more.

So, would you decry seat belts, air bags et al? After all, they do "save lives" of the users, even if part of the cost is taking someone else's life.

Personally I prefer to keep the technologies if we must have the vehicles in which they're used .... but I believe it would be better if the manufactures and sellers were forced to point out, in no uncertain terms, the danger of taking more risks than the new technology justifies.

The alternative is to ban all human-controlled technologies that can achieve a certain degree of speed and/or momentum, on the grounds that people are too stupid to be trusted to use them properly. We do it with guns (those bullets have lots of momentum). I would do it with cars and all other free-roving motorised vehicles in which a human does all the driving. Bikes, trains and planes only. Would you like to howl at this notion? :-)

Cugel.
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fastpedaller
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Re: Why have disc brakes become so popular?

Post by fastpedaller »

reohn2 wrote:
fastpedaller wrote:My worry with disc brakes and other 'improvements' like 10 speed freehubs is that those of us who would like to stay with the 'old' technology will have the choice taken away from us (eg production stopped of rim-brake capable rims). :(

10sp freehubs are in fact the same as 8/9sp hubs,which are a vast improvement on screw on freewheels wouldn't you say?
But you can still buy freewheels up to 7sp possibly 8sp and qualty hubs to suit.

Rim brakes won't become obsolete IMHO,though disc brakes may yet improve further.
I'm happy with my BB7 cable discs they've proved their worth time and again,but my mind is open as to whether further improvements are possible.


I'm unable to buy my choice of 7 speed close-ratio cassette any more (luckily I have some stock). Just because some 8 speed freewheels or cassettes are available doesn't necessarily mean the choice we had 10 years ago is the same now. Yes, I agree the freehub/cassette is an improvement on the old freehubs - however they aren't as durable re chain wear :(
reohn2
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Re: Why have disc brakes become so popular?

Post by reohn2 »

The utility cyclist wrote:Now you're just deliberately distorting what has been said, suggest you check back and retract :twisted:

If you mean by claiming you've claimed to "cruise" at 40mph then you're are wrong and that statement you made on another thread,go check it for yourself unless you've amended it.

You seem to be rather wound up, enough to distort what was said, by the fact that firstly I can cycle/descend downhill faster than some, oh and do that on my way to the supermarket, that must grate, and for me to do that safely on mere rim brakes too!

I couldn't care less what you claim for yourself.

However what does concern me is the posting of misleading and downright silly statements about disc brakes by people who claim to know what they're talking about,which their posts clearly show they don't

You're also confused, I haven't said I go faster, it's the speed I've always done, actually I cycle slower now than I used to, despite better tyres and bikes, I ride within myself.
It's you and others that are saying that through more confidence due to using disc brakes over rim brakes you're going faster, basically risk compensation, you're a crash waiting to happen.

If you read my posts you'll see how wrong you're in your claims,I suggest it's you who are confused.
Last edited by reohn2 on 25 Jul 2018, 2:35pm, edited 3 times in total.
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Brucey
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Re: Why have disc brakes become so popular?

Post by Brucey »

Cugel wrote: ….It's true that any technology that offers improved safety when using a vehicle tends to result in many of the users taking more risks than are justified by the technology involved. It's happened with always-on sidelights, seat belts, air bags, ABS brakes and a host of other such stuff. There are more "accidents" as a result, although the risk-hungry who are involved are often themselves better protected from their stupid actions - even if others involved who are outside the vehicle, such as cyclists and pedestrians, suffer more.....


yup. IIRC at least one engineer who worked on both seatbelts and later, airbags, in the US car industry, has suggested that because of such 'risk compensation' effects, the only way of slowing motorists down might be to deploy what is known as 'Tullock's spike'.

The most commonly accepted view is that despite risk compensation effects, there is usually a net benefit arising from things that improve safety, but that benefit is liable to be reduced somewhat. This does not allow for

1) the fact that it is not only the people who are subject to the effects of risk compensation who are likely to be affected; e.g. motorists might be perfectly safe in their metal boxes, but increasingly put pedestrians and cyclists at risk and

2) the possibility that there may be something that merely appears to be an improvement in safety, thus engenders risk compensation effects without any actual benefit. In this case the net outcome is worse.

Arguably a really safe brake might be one that feels like it might be terrible but actually works rather well when needed. It might be that those who see no value (or negative value) in disc brakes do so in part becuase they think that disc brakes have the reverse characteristic of this, i.e. they feel great but actually don't offer much real benefit in an emergency.

Upthread i explained why it is that in a typical bicycle emergency stop from ~15-20mph, a very powerful brake that modulates well and feels great is actually of no benefit whatsoever; it merely gives an illusion of control that in fact you don't have enough time to usefully exploit when you really need to stop quickly. You would be better off with a brake that was less powerful but that could be safely applied with maximum power, instantly.

Conditions on a fast descent are not quite the same but it is still possible that in some cases risk compensation effects are greater than any real benefits offered by tyres, brakes, steering etc that 'feels better'. Slick tyres are another case in point; they grip better than treaded tyres on dry roads but in wet/greasy conditions they are (IME) more likely to transition into a skid, and to do so without much warning. You don't have to spend much time riding on roads with such characteristics before the net outcome is likely to be worse, even though the tyres are notionally 'better', even without allowing for any risk compensation effects.

cheers
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horizon
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Re: Why have disc brakes become so popular?

Post by horizon »

reohn2 wrote:However what does concern me is the posting of misleading and downright silly statements about disc brakes by people who claim to know what they're talking about,which their posts clearly show they don't



In which case you can safely ignore them. But, without shooting the messenger, silly ideas have their place: the idea of risk compensation with disc brakes is to me a new idea. I might dismiss it but it's all grist to the mill. What I like about this thread is that it isn't censored by commercial interests, it's based largely on real knowledge and experience (not mine, but certainly yours), has got some passionate if slightly left-field ideas (cue TUC) and is IMV a far broader assessment of disc brakes that you could ever hope to expect either from a commercially sponsored article or even a single well-informed engineer. As a result of this thread I would certainly look at discs on my Sardar but feel very happy with rim brakes on my other bikes and feel I understood at least partly why.
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Cyril Haearn
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Re: Why have disc brakes become so popular?

Post by Cyril Haearn »

I feel sure risk compensation is relevant, for example in the group of riders with different brake types
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reohn2
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Re: Why have disc brakes become so popular?

Post by reohn2 »

horizon wrote:
reohn2 wrote:However what does concern me is the posting of misleading and downright silly statements about disc brakes by people who claim to know what they're talking about,which their posts clearly show they don't



In which case you can safely ignore them.

I can ignore them because I know they're unfounded and silly.However inexperienced cyclists who may read such silliness may take it as truth, that's why such opinions need to be shown up for what they are,baseless nonsense.

But, without shooting the messenger,

The messenger is the perpetrator What is one to do but resist such silliness.

silly ideas have their place:

They do,in the bin!


the idea of risk compensation with disc brakes is to me a new idea. I might dismiss it but it's all grist to the mill.

An idea if taken to it's logical conclusion,that if better brakes are bad then poor brakes must good.
As I posted before that is the logic of the madhouse but which a couple of contributors maintain to be sound judgement
I'll leave it to you to decide the difference between daft and sensible :wink:

What I like about this thread is that it isn't censored by commercial interests, it's based largely on real knowledge and experience (not mine, but certainly yours), has got some passionate if slightly left-field ideas (cue TUC) and is IMV a far broader assessment of disc brakes that you could ever hope to expect either from a commercially sponsored article or even a single well-informed engineer. As a result of this thread I would certainly look at discs on my Sardar but feel very happy with rim brakes on my other bikes and feel I understood at least partly why.

I only ever post of my experience of any kit,and my experience of cable operated discs in the form of the two types I've used(BB7's both MTN and Road,and Spykes)over the past 10 years,and 50+years of various rim brakes,discs have been very positive experience,especially on tandems,which is a good test of any brake's performance.

That is all I can offer,of course others may post their opinions without such experience and so their opinions are baseless and serve no one,but only serve to cause confusion in the minds of people who maybe thinking of buying a disc brake bike.
Last edited by reohn2 on 25 Jul 2018, 2:45pm, edited 1 time in total.
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fastpedaller
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Re: Why have disc brakes become so popular?

Post by fastpedaller »

horizon wrote:
reohn2 wrote: the idea of risk compensation with disc brakes is to me a new idea.


This reminds me of when a work colleague was driving his old Triumph Herald with an Institute of Advanced Motorists instructor as a passenger.....
IAM passenger "I'm pleased to see you leave a good distance between yourself and traffic in front"
Colleague "That's because the brakes on this car are s**t"
reohn2
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Re: Why have disc brakes become so popular?

Post by reohn2 »

fastpedaller wrote:
reohn2 wrote:
fastpedaller wrote:My worry with disc brakes and other 'improvements' like 10 speed freehubs is that those of us who would like to stay with the 'old' technology will have the choice taken away from us (eg production stopped of rim-brake capable rims). :(

10sp freehubs are in fact the same as 8/9sp hubs,which are a vast improvement on screw on freewheels wouldn't you say?
But you can still buy freewheels up to 7sp possibly 8sp and qualty hubs to suit.

Rim brakes won't become obsolete IMHO,though disc brakes may yet improve further.
I'm happy with my BB7 cable discs they've proved their worth time and again,but my mind is open as to whether further improvements are possible.


I'm unable to buy my choice of 7 speed close-ratio cassette any more (luckily I have some stock). Just because some 8 speed freewheels or cassettes are available doesn't necessarily mean the choice we had 10 years ago is the same now. Yes, I agree the freehub/cassette is an improvement on the old freehubs - however they aren't as durable re chain wear :(


My choice of 8,9and 10sp cassettes aren't available so I'm forced to either accept what's on offer or select cassettes I can split an make up the ratios which suit my taste :wink:

But the point I was making was that disc brakes won't ever be the only brake system on offer,rim brake will always be available for a very long time to come IMO
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Cugel
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Re: Why have disc brakes become so popular?

Post by Cugel »

Cyril Haearn wrote:I feel sure risk compensation is relevant, for example in the group of riders with different brake types


The different brake technologies don't make any difference to a group's braking behaviour in the course of straightforward riding, when keeping off a back wheel just in front, approaching a junction or otherwise riding along steadily. However, it is possible for the hydraulic disk braked riders to go down the bendy steeps a bit faster yet safely, as they really can control their braking better-enough to allow a little more speed if there are no speed-averse dangers such as blind bends with gravel drifts and the possibility of lurking tractors.

For example, we disc-braked lads can more easily stop, in a controlled non-skidding manner, at the bottom of a fast descent where there's a road junction. We can go a bit faster down a really steep hill knowing that it won't take the grip of Desperate Dan to haul hard and long enough on the levers in order to stop as that road junction approaches; or to slow in a hurry when Gerty the sheep appears, munching at the verge.

But in descending that little bit faster, we effectively encourage others with perhaps lesser (rim) braking control to do the same. They find that they are going too fast as the descent develops. They cannot stop in time at the junction; or they do so but find they're skidding a bit as their modulation is less fine as they have to haul manfully on the levers, whilst we disc brakers merely caress the levers with two fingers.

Of course, anyone with any sense takes the braking ability they actually have in to account, no matter what the fellows in front might be doing. Not everyone is sensible.

Cugel
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Brucey
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Re: Why have disc brakes become so popular?

Post by Brucey »

or it might just seem like that....

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Vitara
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Re: Why have disc brakes become so popular?

Post by Vitara »

How I wish I had all this wisdom about how unnecessary and dangerous disc brakes are before I bought my replacement Audax bike.

I suppose I'd better get rid of it & go back to rim brakes.

Or, having ridden several thousand Km on and not experienced any of the problems quoted here perhaps I'll keep it a bit longer :D
Airsporter1st
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Re: Why have disc brakes become so popular?

Post by Airsporter1st »

Vitara wrote:How I wish I had all this wisdom about how unnecessary and dangerous disc brakes are before I bought my replacement Audax bike.

I suppose I'd better get rid of it & go back to rim brakes.

Or, having ridden several thousand Km on and not experienced any of the problems quoted here perhaps I'll keep it a bit longer :D


You must have got some magic discs, which were accidentally covered in fairy dust during manufacture. I think I have some from the same batch.
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