Why are bike companies telling consumers that disk brakes are maintenance free?

meanredspider

ugo.santalucia wrote:

mamil314 wrote:

you seem to have missed the point of his post - there are people out there to whom the disc brakes are sheer simplicity and foolproofness.

Not many though...

Actually I'd disagree. There's a vocal minority who post on here who can't get them to work. Then there's pretty much the entire MTB population who get on with them.

ugo.santalucia

meanredspider wrote:

ugo.santalucia wrote:

mamil314 wrote:

you seem to have missed the point of his post - there are people out there to whom the disc brakes are sheer simplicity and foolproofness.

Not many though...

Actually I'd disagree. There's a vocal minority who post on here who can't get them to work. Then there's pretty much the entire MTB population who get on with them.

those work fine... I am sure the hydro road work fine too... post mount issues aside

DeVlaeminck

meanredspider wrote:

earth wrote:

These are all very impressive points, a fine argument. So why is it that disc brakes are so shoot and rim brakes just work?

Much to my mum's chagrin, when I was a kid my rim brakes were "shoot" and I relied on the soles of my shoes...

The reason why people have trouble with disc brakes is because people simply don't know how to set them up. I've always maintained that, if you aren't mechanically competent (and, unfortunately, that applies to some LBS bike mechs) discs aren't for you. I'm sure it'll get better as designers realise that road bike riders aren't too handy with an Allen key and they make disc calipers more "user-proof". In the meantime, these people should stick to rim brakes (I've resisted a Darwin comment )

Why bother with the aggro though. Rim brakes are just as good in most circumstances unless you lack the fine motor control to use them properly - maybe this is your problem?

ZMC888

meanredspider wrote:

earth wrote:

Couldn't agree more. Pad wear alone is at least double that of rim brakes. I had mechnical discs on a CX bike and they were full time maintenance. Now I have a MTB for the odd occasion that has hydraulic disks. The rear caliper is dragging on the rotor like a vice and I thought hydraulics were suppose to self-align.

The caliper needs to be aligned at least to the disc - the calipers can't defy the laws of physics. But, provided this is done properly once, there's no reason it should need to be done again unless it gets a bash hard enough to misalign it.

People seem so easily bamboozled by discs.

In this case there is probably some binding.
Remove caliper, take out the pads, clean the inside on the caliper.
Partially eject the pistons to check if they are uniformly moving inwards at the same rate. If they are working properly push the pistons back into their bores with a plastic tool and use a realignment tool https://www.amazon.com/Hayes-Brake-Rotor-Alignment-Tool/dp/B002SQTRXK to get things straight when reassembling. If the pistons are not behaving well eject them from their bores a little more but be vigilant not to go to far - by pumping the brakes a few times, clean and lightly grease with silicone grease, but probably any grease is OK.

Remember to pump the brake after reassembly to get the pads to sit back in the correct position.

Yes, anyone can learn to self maintain disk brakes, but it is not that straightforward.

meanredspider

DeVlaeminck wrote:

unless you lack the fine motor control to use them properly - maybe this is your problem?

This had me laughing out loud - thank you

The thing is, I'm not criticising rim brakes - they've served bikes well for a very long time (just like changing gears with a ratchet and bit of twisted cable and a spring) but the world moves on and, for all the reasons I've listed above, disc brakes are just better brakes. Of course, you need to use them fully to appreciate this difference. What's interesting is that many people that claim disc brakes aren't needed don't even understand the dynamics of braking :roll:
How much of the last two points applies to you, I'll let you decide

Anonymous

apreading wrote:

Carbonator wrote:

meanredspider wrote:

Carbonator wrote:

Stoping a spinning wheel at the hub requires more force than at the rim.
Its as simple as that, and discs only work if hydro.

Loving all the pseudo science and engineering in this thread.

Ore could just skip the basic laws of physics (as people love to do on this forum) and go back to real life experience.......... cable discs are shite

The basic laws of physics are that it requires the same force to stop an object of the same mass, regardless of where that force is generated. What you probably meant was that it requires more FRICTION for a given surface area to generate that force from a smaller circumference surface (disc) as opposed to a larger one (rim). FORCE is the same.

So you could lift a bike off the floor and stop a spinning wheel at any given speed, with your hand, just as easily at the disc as at the rim (put some rubber on the disc if you like)?

ugo.santalucia

meanredspider wrote:

The thing is, I'm not criticising rim brakes - they've served bikes well for a very long time (just like changing gears with a ratchet and bit of twisted cable and a spring) but the world moves on and, for all the reasons I've listed above, disc brakes are just better brakes. Of course, you need to use them fully to appreciate this difference. What's interesting is that many people that claim disc brakes aren't needed don't even understand the dynamics of braking :roll:
How much of the last two points applies to you, I'll let you decide

I did believe that it was the end of the road for rim calipers too... however, the 5800 are a significant step forward over their predecessors... I don't know how many pivot points you can meaningfully add to make them even better, but the point is that there is still life in the old dogs.

Is there more life in the hydraulic disc brakes? Are 2017 XT significantly better than say 2012 XT? Are the next generation of hydros going to be better than 685, or it will become an exercise of changing the shape of the STIs to make them look different.

I don't see disc brakes of the next decade being much different from the ones on offer now. Of course there are interesting things that could be done, including having an integrated ABS, but is anyone going to do it? Progress in bicycles is painfully slow... what was prototyped by Mavic in 1992 only became a commercial reality around 2012... it's all happening at snail pace and I don't think rim brakes are going to become obsolete in the next 5-10 years... if you say 20 years, then maybe, so long as they prove themselves in the racing circus

fat daddy

ugo.santalucia wrote:

Is there more life in the hydraulic disc brakes? Are 2017 XT significantly better than say 2012 XT? Are the next generation of hydros going to be better than 685, or it will become an exercise of changing the shape of the STIs to make them look different.

oh god I hope so ..... road hydraulics are just crap compared to MTB hydraulics ... the throw of the lever is far too long compared to a flat bar lever.

There is still to come, decent throw, adjustability, noise reduction in the wet .. and ultimately the price. .. you can get a sealed leaver + caliper for £34 in the mtb world that is better than any of the sti based hydraulics !

meanredspider

I don't see that disc brake calipers need to change much. After all, they've hardly changed on road cars for the past 50 years. They will tune the materials - caliper, pad, disc. As I've said elsewhere, though, I think there's a lot you could do to the rest of the bike:

Wheels: optimise the design to take into account a lack of brake track
Brifters: with no cables on hydro Di2, why would you make them the same shape?
Frame: build pipes into structure
Mounts: standardise and eliminate all adjustment (none in cars)

Let's get a bit of creativity into road biking: a world where adding another gear to a 10 speed cassette or fitting a 52-tooth ring instead of a 50 or 53 is seen as "innovative" - give me a break (brake? )

ugo.santalucia

fat daddy wrote:

ugo.santalucia wrote:

Is there more life in the hydraulic disc brakes? Are 2017 XT significantly better than say 2012 XT? Are the next generation of hydros going to be better than 685, or it will become an exercise of changing the shape of the STIs to make them look different.

oh god I hope so ..... road hydraulics are just crap compared to MTB hydraulics ... the throw of the lever is far too long compared to a flat bar lever.

There is still to come, decent throw, adjustability, noise reduction in the wet .. and ultimately the price. .. you can get a sealed leaver + caliper for £34 in the mtb world that is better than any of the sti based hydraulics !

I don't see them getting cheaper... for as long as the lever is integrated, you'll pay premium. Electric shifting could in principle make them cheaper, but I suspect it will always be sold as a luxury product instead.
I tried the levers in a shop... they are a bit long, but not too bad compared the HyRD.

Is it just me or the long distance between the loading point on the bike and the rotor means there is always a bit of flex in the fork/ wheel under braking?
With the front brake locked, I can make the bike wobble forward and back, which I cannot do on rim brakes bikes... I thought it was a feature of straight alloy steerers, but it happens even with tapered carbon ones just the same

meanredspider

ugo.santalucia wrote:

Is it just me or the long distance between the loading point on the bike and the rotor means there is always a bit of flex in the fork/ wheel under braking?
With the front brake locked, I can make the bike wobble forward and back, which I cannot do on rim brakes bikes... I thought it was a feature of straight alloy steerers, but it happens even with tapered carbon ones just the same

Almost certainly float in the pads - they need some clearance to ensure free return. It's not an issue as you only brake in one direction. Rim pads obviously don't though there's often some flex in the caliper itself - it's not a very stiff system.

ugo.santalucia

meanredspider wrote:

ugo.santalucia wrote:

Is it just me or the long distance between the loading point on the bike and the rotor means there is always a bit of flex in the fork/ wheel under braking?
With the front brake locked, I can make the bike wobble forward and back, which I cannot do on rim brakes bikes... I thought it was a feature of straight alloy steerers, but it happens even with tapered carbon ones just the same

Almost certainly float in the pads - they need some clearance to ensure free return. It's not an issue as you only brake in one direction. Rim pads obviously don't though there's often some flex in the caliper itself - it's not a very stiff system.

Ah, I see, never thought it could be float... no, it's not an issue, just couldn't work out what it is.

Never noticed any flex in the rim calipers, if there is, it's well hidden. First time I picked some speed today (nearly 50 mph) so I could see how the 5800 brake at speed... pretty awesome bite, I'd say on par with the HyRD when the latter had a good day.. they scrub speed very quickly indeed

meanredspider

Whilst we're on the merits of either system, I problem I've had with the cheap-ish Tekro rim calipers on my Paddy Wagon is that, as the block wears, its position on the rim changes (the movement of the block describes an arc). Unless I keep an eye on this (which I haven't - my fault- it's a cheapish commuting singlespeed) the block starts to contact the tyre and wrecks the side wall. The first time I was aware of it was when the tyre exploded in my apartment!

Now, as I take up wear through the cable adjustor, I also need to realign the pads.

meanredspider

What pads do you use, Ugo? It's been a while since I've bought any Salmons or the like and the price shocked me. I know you think hydros are expensive but a few sets of those high-end brake blocks and the occasional wheel rim and hydros start to look cheap.

ugo.santalucia

meanredspider wrote:

Whilst we're on the merits of either system, I problem I've had with the cheap-ish Tekro rim calipers on my Paddy Wagon is that, as the block wears, its position on the rim changes (the movement of the block describes an arc). Unless I keep an eye on this (which I haven't - my fault- it's a cheapish commuting singlespeed) the block starts to contact the tyre and wrecks the side wall. The first time I was aware of it was when the tyre exploded in my apartment!

Now, as I take up wear through the cable adjustor, I also need to realign the pads.

Yes, if they are already close to the rim edge, that can happen, if they sit close to the middle of the rim or lower, that shouldn't happen. It's also down to how much wear you allow before you replace. I've always played it safe with pads, both disc and rims and binned them before they got exceedingly worn... I have seen people around with 3 mm of rubber left still going strong.
I seem to recall the RRP for Shimano is 12 quid, so not worth scrimping... of course if you have carbon rims and use pads that cost 40 instead, the temptation is to run them for longer

ugo.santalucia

meanredspider wrote:

What pads do you use, Ugo? It's been a while since I've bought any Salmons or the like and the price shocked me. I know you think hydros are expensive but a few sets of those high-end brake blocks and the occasional wheel rim and hydros start to look cheap.

High end pads for alloy rims are a con... standard black Shimano are very good, same for standard Campagnolo pads

meanredspider

ugo.santalucia wrote:

meanredspider wrote:

Whilst we're on the merits of either system, I problem I've had with the cheap-ish Tekro rim calipers on my Paddy Wagon is that, as the block wears, its position on the rim changes (the movement of the block describes an arc). Unless I keep an eye on this (which I haven't - my fault- it's a cheapish commuting singlespeed) the block starts to contact the tyre and wrecks the side wall. The first time I was aware of it was when the tyre exploded in my apartment!

Now, as I take up wear through the cable adjustor, I also need to realign the pads.

Yes, if they are already close to the rim edge, that can happen, if they sit close to the middle of the rim or lower, that shouldn't happen. It's also down to how much wear you allow before you replace. I've always played it safe with pads, both disc and rims and binned them before they got exceedingly worn... I have seen people around with 3 mm of rubber left still going strong.
I seem to recall the RRP for Shimano is 12 quid, so not worth scrimping... of course if you have carbon rims and use pads that cost 40 instead, the temptation is to run them for longer

Yeah - mine were set low on the track but it was my "zero maintenance" (by me, not claimed by anybody) Amsterdam city commuter. Lots of start-stop I guess and before I know it I've wrecked an Open Pave :shock: :roll: :oops: (Pave? AMS is wet and lots of cobbles)

ugo.santalucia

When I lived in Amsterdam in 2004 I was riding a brown Gazelle lady bike with back pedal brake... I think I paid 50 Euro for it... probably less than one of your tyres :-)

meanredspider

ugo.santalucia wrote:

When I lived in Amsterdam in 2004 I was riding a brown Gazelle lady bike with back pedal brake... I think I paid 50 Euro for it... probably less than one of your tyres :-)

And probably weighed more than me!

Anonymous

ugo.santalucia wrote:

High end pads for alloy rims are a con... standard black Shimano are very good, same for standard Campagnolo pads

So Swissstop set out to defraud cyclists?

Not sure con is anywhere near fair.

Either they make a better compound that works better (as a lot of people seem to feel) or Shimano over engineer their standard pads and waste money by giving away stuff most people would not appreciate (seems unlikely).

Is 'very good' as high as your breaking standards go?

£20 seems a cheap upgrade to me.
Worth a try I would say. Just pop the black ones back in when they wear down and see if you notice a difference.

ugo.santalucia

if they are better, then they last less... it's one or the other and Shimano are a n excellent compromise at an affordable price.

I had a pair of organic swiss top disc pads... they were good but lasted a month

meanredspider

ugo.santalucia wrote:

if they are better, then they last less... it's one or the other and Shimano are a n excellent compromise at an affordable price.

I had a pair of organic swiss top disc pads... they were good but lasted a month

I got through 3 sets of disc pads in a night on the MTB.

ugo.santalucia

meanredspider wrote:

I got through 3 sets of disc pads in a night on the MTB.

Which is another downside of discs, but that's another story

meanredspider

ugo.santalucia wrote:

meanredspider wrote:

I got through 3 sets of disc pads in a night on the MTB.

Which is another downside of discs, but that's another story

Better to destroy £15 of pads than £600 of wheels

robbo2011

ugo.santalucia wrote:

if they are better, then they last less... it's one or the other and Shimano are a n excellent compromise at an affordable price.

I had a pair of organic swiss top disc pads... they were good but lasted a month

Not sure you are right here, the best rim brake pads I have used are Swissstop BHP pads, cost £20 for a pack of four and last 15k-20k km.

ugo.santalucia

My point is that arguing that rim brake ads are expensive is pointless, given the standard SHimano are very good indeed. If you then can spend marginally more to get marginally better pads fair enough.

I just don't see the point in spending 40 quid for some silly compounds that promise miracles, when there is no need for such miracles.

Even assuming there is a pad that halves the stopping distance... what's the advantage? It just means the guy behind you will ram you from the back... you are probably more likely to end up in A & E as a consenquence.

Standard pads don't fall short of performance, period.

If you then are worried about your wet commute in traffic, get disc brakes

apreading

But doesnt the same apply to 5800? Why did you spend money on them when there was no need, 5700 was good enough?

apreading

I think the diversity of opinions is down to people's upbringing.

If you have made your way through years of rim brakes, you have got used to them, convinced yourself that they are OK and learned to live with it, without yearning for more.

If you come from mountain bikes though, rim brakes are SCARY and you feel like you are going to die every time you go out.

meanredspider

apreading wrote:

I think the diversity of opinions is down to people's upbringing.

If you have made your way through years of rim brakes, you have got used to them, convinced yourself that they are OK and learned to live with it, without yearning for more.

If you come from mountain bikes though, rim brakes are SCARY and you feel like you are going to die every time you go out.

I've mostly ridden rim brakes all my 52 years (well, 48 of those year and versions of rim brakes). I just know a better brake when I use it.

ugo.santalucia

apreading wrote:

But doesnt the same apply to 5800? Why did you spend money on them when there was no need, 5700 was good enough?

You silly... it wasn't an upgrade... I did need a pair of rim calipers as I didn't have any... initially I did want 5700 to match the STI, but firstly I could not find them and secondly I read the 5800 were better and same price, so no brainer...