Why have disc brakes become so popular?

[amediasatex]

If you use cheap hydros, they are cheap enough to be reasonably disposable. A full set of basic Shimano brakes is around £25 with levers, hoses, calipers & pads.

Whilst true, and possibly making economic sense for the individual I find that an abhorrent concept in general.

Repair, recycle, replace

In that order of preference. I’d rather spend more money up front and have a repairable and servicable product. Most of my (hydro) disc equipped bikes use Hope because they are fully rebuildable and spares are available. I have a couple of sets of Shimano brakes and when they fail the only option is a complete new master/lever or complete calliper unit which is terrible considering most issues are down to easily replaced rubber seals which cost pennies, or basic parts like pistons which are easily swapped IF you could source them. I don’t care how cheap a whole calliper is to replace, I lament not being able to repair it instead.

[[XAP]Bob]

If you use cheap hydros, they are cheap enough to be reasonably disposable. A full set of basic Shimano brakes is around £25 with levers, hoses, calipers & pads.

Shudders at the waste...

Does anyone make hydraulic drum brakes?

[Brucey]

If you use cheap hydros, they are cheap enough to be reasonably disposable. A full set of basic Shimano brakes is around £25 with levers, hoses, calipers & pads.

Shudders at the waste...

Does anyone make hydraulic drum brakes?

not that I know of, not for bicycles. I wonder if the conventional arrangement for a hydraulic drum is really a good one in this case; any leak of fluid gets straight onto the linings. Maybe it would be OK (or better even) to think of some devious way of using a hydraulic system to replace the cable on a standard drum brake...?

cheers

[Cugel]

I take your point (XAP)......

I am well aware of emergency situations and as I have stated, in my opinion the best defence is conditioned reflex action through experience and practice. This, again in my opinion is a better defence than just relying on a little better equipment, in that even in an emergency, conditioned reflex action kicks in to modulate what you are doing given even a few seconds to juggle the controls. (And there is always that, no emergency situation in my experience occurs absolutely instantly.

........

Nearly all (including Brucey) seem to agree that disc brakes have a legitimate place in the range of effective bicycle brakes; and that all brake types have their advantages and disadvantages, varying with the conditions, type of cycling and habits of the cyclist.

All agree that risk compensation is a factor but most agree that an inclination to take more risk than a safety feature (such as brakes) offer may be curbed, especially with experience.

The one main point of contention seems to be on this business of emergency stops. Brucey in particular argues that "grabbing a handful" is a natural reaction that is likely to result in the rider skidding or going over the handlebars; and that disc brakes make this more likely as they require less grip-force than rim brakes. Others (including me and you) don't deny that this is a possibility but contend that experienced riders can and will (perhaps should) learn to induce in themselves another "natural reaction" which includes not "grabbing a handful".

All activities of the physical movement kind engender dangers to the person. Having to do an emergency stop on a bike is an example. Best, then, to understand that this is a risk and learn how to deal with it most effectively. The solution surely shouldn't include "brakes that don't work that well" but should rather concentrate on "inducing better instinctive reactions in oneself to various dangerous scenario-types".

Perhaps there should be compulsory cycling lessons, practical & theoretical, followed by a test and a license? When seeing many modern cyclists doing rather risky things (perhaps in pursuit if their Strava strive or in the belief that they are "riding like a pro") I often think that they need some serious lessons from someone who will curb their often infantile behaviours.

Cugel

[horizon]

Yes, well, I apologise to Brucey and , and will belt up (for a while. ) We all have strong points of view -that's life!

Thank you Peter but please do not restrict yourself - without strong views (politely expressed) I don't see how we can progress to the truth.

[[XAP]Bob]

If you use cheap hydros, they are cheap enough to be reasonably disposable. A full set of basic Shimano brakes is around £25 with levers, hoses, calipers & pads.

Shudders at the waste...

Does anyone make hydraulic drum brakes?

not that I know of, not for bicycles. I wonder if the conventional arrangement for a hydraulic drum is really a good one in this case; any leak of fluid gets straight onto the linings. Maybe it would be OK (or better even) to think of some devious way of using a hydraulic system to replace the cable on a standard drum brake...?

cheers

One advantage of hydraulics is the natural balancing that they can do (particularly thinking about trikes) - I do agree that having the piston outboard (i.e. replacing the cable) would be a better design. Just need to think about the mechanics - 'cos you don't want to be relying on vacuum pressure to apply the brakes...
Of course there might be an easy mechanical way to balance cable pulls as well - I just can't spot it in my head at the moment.

[Brucey]

a lot of upright trikes use linked front brakes; the usual arrangement is to balance the forces using a balance bar or a pulley. Not pretty but it works pretty well. In practice if the bike has a highish CoG the brake force balance doesn't have to be perfect; the road camber or the fact that you may be turning slightly means that one wheel will always lock up well before the other even if the force balance is perfect.

To convert standard drum brakes (and still leave the shoes leading/trailing as intended) it would be easy enough to flip the actuating arm and then use a slave cylinder to 'push' on it.

cheers

[iandriver]

The one main point of contention seems to be on this business of emergency stops. Brucey in particular argues that "grabbing a handful" is a natural reaction that is likely to result in the rider skidding or going over the handlebars; and that disc brakes make this more likely as they require less grip-force than rim brakes. Others (including me and you) don't deny that this is a possibility but contend that experienced riders can and will (perhaps should) learn to induce in themselves another "natural reaction" which includes not "grabbing a handful".
Cugel

No convinced that's how the human brain works. The panic instinct, emotional responses, work in a much faster part of your brain, the logical thought takes longer to catch up. Hence people can be made to jump them come around quickly once they've processed the threat.

Even top motorsport drivers or riders make mistakes and lock up wheels in real emergency responses. They've generally crashed and smashed up more machines than you can shake a stick at. That's quite of a conditioning curve, not one I'd care to go through.

To my mind, the argument about disc brakes now is "Are they now getting to be so efficient, that we are now beginning to see machines that are over braked?" rather than a generic statement about all disc brake systems on the market.

[reohn2]

At risk of sounding like a broken record,as I posted up thread and on other similar threads in the past,my preference for BB7 cable disc brakes stems from their performance in the wet which is same as in the dry,it's not that they're more powerful than V's or DP's it's that in the wet they're more reliable.

reohn2 (or anyone else for that matter, though I think you may be the only one who does): can you briefly say why you prefer cable over hydraulic?

Other than a short ride on someone else's bike,I've never used hydros so have no experience or opinion of them.

Cable discs in the form of BB7's tick all the braking boxes for me:-
Very good stopping power with superb modulation in ALL conditions.
Simple construction that can be stripped down and maintained or repaired easily,even by the roadside without any special tools or much mechanical knowledge.
Pads(sintered) that last waaaayyyy longer than rim brake pads,rotors,that unless bent,seemingly last forever.
The ability to be used with any standard cable lever so long as it's matched to the caliper,just the same as differing rim brakes are.

[Si]

I also chose cable over hydro for my new bike.

Reasons being, much as John has said:
- maintenance is much easier
- reliability may be the same but damage out on the ride is probably going to be less terminal
- I've had a BB7 on the MTB for ages and was very happy with it
- bigger choice of levers to use

TBH if V brakes had worked in the serious wet as well as the BB7 then I'd have been happy sticking with them...but they don't.

As yet I've not managed to accidentally do a 'stoppie'* or through my self over the bars with 18 years of disc brakes...although the first time I sued V brakes I did!

* not that that is possible as technically a 'stoppie' is a _deliberate_ use of the brakes to lift the rear wheel off the floor without going over the bars: it's a 'trick' not a crash...a bit of terminology that seems to have caused confusion up thread!

[reohn2]

........All have performed impeccably. Ironically the Cannondale is the worst (needs the most effort to brake)which I put down to the STis (a problem MickF had alluded to elsewhere with his Moulton & rim brakes)......

I can only say that there must be a problem as you and MickF have mentioned and it seems the ergonomics of the lever are at fault
Personally I haven't noticed any such problems and it was that tandem that introduced me to disc braking,I can only put it down to my oversized hands and strong grip which I mentioned in passing up thread.
I also mentioned up thread that I thought straight bar MTN BB7's were easier to operate than the road variant with drops,but I put that down to middle two finger(which are the strongest fingers)operation(I reserve thumb and index finger for gear-changing on flat bar STI's).
Hmmm,interesting......

[RickH]

........All have performed impeccably. Ironically the Cannondale is the worst (needs the most effort to brake)which I put down to the STis (a problem MickF had alluded to elsewhere with his Moulton & rim brakes)......

I can only say that there must be a problem as you and MickF have mentioned and it seems the ergonomics of the lever are at fault
Personally I haven't noticed any such problems and it was that tandem that introduced me to disc braking,I can only put it down to my oversized hands and strong grip which I mentioned in passing up thread.
I also mentioned up thread that I thought straight bar MTN BB7's were easier to operate than the road variant with drops,but I put that down to middle two finger(which are the strongest fingers)operation(I reserve thumb and index finger for gear-changing on flat bar STI's).
Hmmm,interesting......

I'm not saying that the brakes on the Cannondale are bad, far from it, just that they are the least good (in terms of the effort I find is needed to operate them rather than the outright performance) of the 3 sets of disc braked bikes that I ride. We can still stop quicker in extremis than most (possibly all) of the solo riders we ride out with regularly. That may be in part due to the more efficient back braking you have on a tandem.

[geocycle]

No convinced that's how the human brain works. The panic instinct, emotional responses, work in a much faster part of your brain, the logical thought takes longer to catch up. Hence people can be made to jump them come around quickly once they've processed the threat.

Yes, I agree. i mentioned up-thread that I, a very experienced, slow and careful rider, managed to lock the front wheel with powerful v brakes sufficiently to go over the bars. No amount of learning would have prepared me for the urge to stop when a car comes out of a side street right in front of me. It was a 1 in 40 year event completely out of the blue. If it had been very wet and v brakes less effective I might not have gone over the bars but could have hit the car...

[reohn2]

I'm not saying that the brakes on the Cannondale are bad, far from it, just that they are the least good (in terms of the effort I find is needed to operate them rather than the outright performance)

That's how I understood it,no worries.

of the 3 sets of disc braked bikes that I ride. We can still stop quicker in extremis than most (possibly all) of the solo riders we ride out with regularly. That may be in part due to the more efficient back braking you have on a tandem.

I reckon tandems with good brakes can stop as quick as solos because of that,put another way tandems effectively have two useful brakes due to the longer wheelbase and weight over the rear and the stokers weight on the rear end of it,whereas solos are far more front weighted during braking,effectively have just the one brake in extremis.
When we first bought the Cannondale I tested it's stopping power and despite warning Mrs R2 about the impending ES was able to lift her off the saddle and headbutt me between the shoulder blades.
I got told off for that

[Cugel]

No convinced that's how the human brain works. The panic instinct, emotional responses, work in a much faster part of your brain, the logical thought takes longer to catch up. Hence people can be made to jump them come around quickly once they've processed the threat.

Yes, I agree. i mentioned up-thread that I, a very experienced, slow and careful rider, managed to lock the front wheel with powerful v brakes sufficiently to go over the bars. No amount of learning would have prepared me for the urge to stop when a car comes out of a side street right in front of me. It was a 1 in 40 year event completely out of the blue. If it had been very wet and v brakes less effective I might not have gone over the bars but could have hit the car...

It was as a small child that I learnt not to lock brakes by "grabbing a handful". This "I" that learnt was initially the self-conscious "I" with the gravel rash and bruises but in time the alternatives to "grabbing a handful" became embedded in the sub-conscious "I" so that my instinctive reaction in an emergency is to do other things. I've not "grabbed a handful" in the last 50 years, despite hundreds of thousands of miles and a fair number of situations in which you and others might well have "grabbed".

The other things to do if the sudden possibility of a smack arises are primarily: "go for any gap, no matter how small"; "drop the bike and self to the ground, sideways-on the hazard"; "accept the coming smack and try to minimize its effects". There is no virtue in braking so hard that you throw yourself even faster at the coming hazard. Your sub-conscious can learn this.

Of course, in a true emergency, there is not just a lack of time to consciously plan a response but no time either for your learnt-and-installed new instinct to operate. You wake up (if you're lucky) not remembering a thing. This means that the best response to potential emergencies is to do your utmost to avoid them. This too is learnt behaviour that's installable into the sub-conscious mind, known as "acquisition of the cyclists' 6th sense".

But in the final analysis, anyone can be the victim of an unforeseeable and sudden event .... in which brakes or any other user-operated risk-reduction scheme are irrelevant because they never have a chance to operate.

Cugel