one hell of a bang when they go

as others have said not seen one go bang yet – thankfully, used to get cheapy rims on my commuter and they went pretty slowly, normally braking would get pulse-y as the rims started to deform then a couple of weeks/months later when cracks started to appear I’d get around to replacing them 🙂

MAMIL’s with more money than sense will lap it up

you’ve really got it in for disc brakes huh? repeatedly chucking in the mamil reference just sounds like trollage. On my (looked after) road bike rims and brakes last for ages, that’s fair enough. On my neglected commuter rims lasted a couple of years tops, pads didn’t last long at all and when I switched to grittier NCN routes pads lasted a week and rim wear accelerated. Disc brakes are definitely a good move commuter wise, maybe less so for roadies until weight decreases but not sure I’d get a new road bike without them.

my first shimano brakes lasted 8 years before a seal went, and that’s without road salt/grime attaching them

TBH 8 years doesn’t sound too bad IMO, pity seals aren’t officially* replaceable on shimano brakes, seals went on one brake in cold weather got a new xt caliper for about £35. But yeah the salt thing will be an interesting one to watch for.

*dunno if it’s bodgeable

Just replaced my front open pro after 4 years and about 25,000 miles, I guess it depends on where you ride as too how long a wheel will last.

impressive wear rate (and mileage) mrmo, was that road rides or commuting? Think people who do long undulating country road routes with little braking (and nice weather) will get a lot more out of their gear than stop start heavy traffic riding in rainy manchester, YMquiteobviouslydoesV

D0NK – Member
one hell of a bang when they go
as others have said not seen one go bang yet – thankfully, used to get cheapy rims on my commuter and they went pretty slowly, normally braking would get pulse-y as the rims started to deform then a couple of weeks/months later when cracks started to appear I’d get around to replacing them

As you say, you’ve not had one go. They don’t do this IME.

I’ve seen a few threads on road discs which point to MAMIL’s chomping at the bit to get them. However most of the MAMIL’s I see seem to be chasing the full pro peloton look*. So until they are on the pro’s bikes, will they bite?

* by this I mean team kit and top end bike, although often top end bike is the ‘comfort’ geometry model or has a hefty collction of spacers under the stem 😉

by this I mean team kit and top end bike, although often top end bike is the ‘comfort’ geometry model or has a hefty collction of spacers under the stem 😉

And an extra chainring… 😉

you’ve really got it in for disc brakes huh? repeatedly chucking in the mamil reference just sounds like trollage.

I’ve not got it in for disk brakes in general, they’d be fine (if overkill) for a commute or touring. But I still think they’re overkill for a problem that doesnt really exist.

The mamil referance I’m just refering to that section of the bike buying public who buys £2k bikes while the tours on telly, tells everyone who’ll lsiten they rode 30km at the weekend, then put’s it in the shed only to re apear on ebay in 18 months time. £600 di2 brakes are tailor made for them*.

On my neglected commuter rims lasted a couple of years tops, pads didn’t last long at all and when I switched to grittier NCN routes pads lasted a week and rim wear accelerated. Disc brakes are definitely a good move commuter wise

Agree entirely, commuter bikes fine, road/race replica bikes (which £600 Di2 brakes are clearly aimed at), why?

*and people who take cross seriosuly, but I suspect that they’ll be a minority of who ends up buying these.

I’ve not got it in for disk brakes in general, they’d be fine (if overkill) for a commute or touring. But I still think they’re overkill for a problem that doesnt really exist.

I’d say a premium for improved brake modulation and reduced rim wear is worthwhile – the question is only how much extra I would be prepared to pay.

I’ve not got it in for disk brakes in general, they’d be fine (if overkill) for a commute or touring. But I still think they’re overkill for a problem that doesnt really exist.

Drum brakes worked fine on cars, why have they all got discs now?
V-brakes worked fine on MTBs, why have they all got discs now?

There are loads of benefits to discs:
takes the braking away from the rim so you can have lighter/stronger/stiffer/more aero rims without the weight penalty or the structural integrity issues.
allows much more intricate hose routing – hydraulic hose can be fully internal, can turn corners which cables can’t.
much less servicing required – maybe a bleed and pad change once every 18 months or so.
and the usual one: more consistent stopping power, more modulation

road/race replica bikes (which £600 Di2 brakes are clearly aimed at), why?

new technology innit, always comes out at the top then filters down. As others say, it’s probably the future, but maybe still a bit portly at the moment for mass uptake. I’d guess there’ll be more uptake for winterbikes once it comes down to lower groupsets then, once they’re lighter and wheel tech builds on the advantages, the race bikes too. But I’m just guessing, who knows what goes on in a roadie’s head 😉

Drum brakes worked fine on cars, why have they all got discs now?

Because generaly car’s with drum brakes had <30hp and weighed <500kg. Modern cars are at least 2x the weight and 3x the power. I know I mentioned MAMILS but calling them too fat for calliper brakes is just offensive 😛

Donk, both, most mileage is commuting, but i currently have a 16mile pan flat rural commute, there are a couple of lights where i might have to use the brakes!

As for your comment about what goes on in roadies head, will it make me faster!

Brakes, well they are designed to make you go slowly, so why spend money on them?
tyres, wheels, gears, frames, etc things that make you go quick is where you spend money.

My brakes work well enough, are reasonably cheap, are reliable and, if we go by the standard threads, don’t need a weekly bleed!!!!

I have to say I kind of agree with TINAS on this now to a certain extent, the prime markets right now for a hydraulic STI are Drop-bar commuters, CXers and possibly some Tourers; all looking for less maintenance, servicing, better reliability and sensible pricing, but also not really the target group for Di2 either so as a product Di2 shifting/hydraulic braking STIs don’t really make that much sense IMO

Serious roadies will be sticking to rim brakes for the forseeable future and aspirational “MAMIL” types will seek to emulate their hero’s, and hence will adopt Di2 Ultegra/Dura Ace on High price point bikes, but won’t want discs cause it’s not what the pro’s are using…

takes the braking away from the rim so you can have lighter/stronger/stiffer/more aero rims

Disc rims can be lighter, but add in the weight of the rotor and heavier hub and they are pretty much the same. No radial lacing on wheels so spokes are longer (less aero?), longer hose routing, then add in the extra material to locally strengthen the frame and fork and suddenly discs become a much heavier option than rim brakes.

allows much more intricate hose routing – hydraulic hose can be fully internal, can turn corners which cables can’t.

I’ve never had a problem with any bike routing the brake cables, road bike cable routing is really quite straightforward.

much less servicing required

Seriously? I guess you’ve never seen the sticking pistons, contaminated pads, brake fade, boiling and warped rotors threads which crop up on here regularly?

One of the main drawbacks though is that from an aero point of view they are gash, the caliper (particularly the front) is basically a big lump of metal exactly where you don’t want it. I think it was Cervelo that did some testing and found that they were terrible.

irelanst – Member

Disc rims can be lighter, but add in the weight of the rotor and heavier hub and they are pretty much the same. No radial lacing on wheels so spokes are longer (less aero?), longer hose routing, then add in the extra material to locally strengthen the frame and fork and suddenly discs become a much heavier option than rim brakes

You’re moving the material needed to strengthen the frame/fork, not adding it. Slightly longer hoses, but much lighter, as they don’t have a steel cable in them.

As for the aero side, nobody’s tried to address that for road discs yet – integrating them better with forks will improve that.

On the aero thing, start with a rim that is 50mm deep design it for disc brakes an design it for rim brakes and how much difference is there actually going to be? you might be able to remove a little mass as there is no wear from braking, but you can’t remove that much as the wheel still has to hold a tyre at upto 150psi. It still has to be able to cope with minor potholes etc.

I don’t actually see any slightly deep wheel getting lighter, infact i can see them getting heavier as the hub and spokes have to be speced to take the extra load.

As for the aero side, nobody’s tried to address that for road discs yet – integrating them better with forks will improve that.

on the aero thing, a rim that doubles as a braking surface will be better than having another surface bolted to the hub. Remember the UCI rules on farings and non structural components.

make a disc this aero?

And it’s not really “Just” £600, comes to ~£880 once you bung another £280 on for their wheels;

And don’t forget you also need their really cheap electronic rear mech and front mech too…

You’re moving the material needed to strengthen the frame/fork, not adding it

No you’re not, the loading on a disc caliper is far higher than on a rim brake and is transmitted into a single fork leg / stay. Using a fork as an example, in a rim brake the braking forces are transmitted directly into the fork crown which is stiff and supported by the headset, in a disk brake almost the entire length of the fork leg has to withstand the torque generated at the caliper.

Because generaly car’s with drum brakes had <30hp and weighed <500kg. Modern cars are at least 2x the weight and 3x the power.

Aside from your wild exaggeration, speed limits remain the same, and modern cars can stop in a far shorter distance than they did BITD.

The weight arguments are a bit of a red herring TBH, it must be possible to build a disc braked road bike at the magic 6.8kg mark (IMO) then neither method of deceleration presents any real weight advantage in competition…

The Aero points have more merit but are still debatable IMO.
While a chunky, angular MTB caliper might well be an aerodynamic nightmare, that shape can be monkeyed with and improved upon no end, and of course once you remove the rim brake caliper from the fork crown and top of the seat stays you can start to look at re-profiling those areas for some co-responding aero improvements perhaps, all of those images above seem to show a consistent effort being made to “blend” a rim brake and minimize it’s apparent Aero disadvantages, so the current preferred solution still ain’t “perfect” clearly…

Realistically though the last lot you’ll persuade are the serious Amateur and Professional roadies, the closest you might get right now is talking them them into trying disc braked “Winter bikes” maybe?

But then these aren’t the only people who buy or ride road bikes.

Realistically though the last lot you’ll persuade are the serious Amateur and Professional roadies, the closest you might get right now is talking them them into trying disc braked “Winter bikes” maybe?

But then these aren’t the only people who buy or ride road bikes.

which leads neatly to a point made earlier, why Di2 Disc brakes, how many roadies are going to have Di2 on the winter hack? How many commuters tourers are going to use Di2?

Mind you the same applies to SRAM, how many are going to buy the red22 discs? I can see some people buying the hydro calipers just not the discs.

with disc brakes, a fork has to be stiffer, which will impact ride quality no matter the argumuments about carbon ‘property placement’. plus most roadie tyres aren’t up to reaping the power benefits of a half-decent disc brake, and a decent road rim brake doesn’t lack modulation.

so here’s how I see it: Mr MAMIL buys latest hot-snot bike with £600 hydro brakes. crashes first time it spits. Hey presto, cheap hydrau-compatible levers available on the secondhand market without the need to wait for trickle-down to 105 (or sora, which is more realistic in my case).

everyone’s a winner!

with disc brakes, a fork has to be stiffer, which will impact ride quality no matter the argumuments about carbon ‘property placement’. plus most roadie tyres aren’t up to reaping the power benefits of a half-decent disc brake, and a decent road rim brake doesn’t lack modulation.

💡 that is why they are pushing 25mm tyres, nothing to do with performance, convince people that the next bike has to have bigger softer tyres and discs, you hide the fact that the bike is less comfy etc.

One other point tinging discs!!! every set of disc brakes i have come across will at some point rub!!!!!!

mrmo – Member

…that is why they are pushing 25mm tyres…

get you, posh mr ‘la-di-da’ with your smooth new tarmac, and predictable road surfaces.

round ‘ere its 2000 year old cobbles, and potholes so deep you can swim in them.

our potholes are so big, they’ve got potholes in them.

it’s all about 28’s now.

(except they don’t go through the brake callipers, which is another reason why discs are great)

Loving all the condescending talk about commuters and MAMILs. Well done.
Good to see it’s not just mountain biking that can be snooty and elitist. 😕

fwiw I am a commuter and having just bought my first road(ish) bike at 38 and opted for a comfortable CX frame with 28mm tyres and discs I guess I qualify as a MAMIL too.

The uptight “road bikes must only ever be used for racing or training to race – never for transport or, heaven forbid, fun” crowd should try to relax a bit. Maybe straighten out that hunch a bit. It’s all “riding bikes” and it’s all good.

Discs suit me. (BB7s on my bike). I couldn’t care less if the aerodynamics and extra weight mean I’m pushing an extra half watt – or if i have one too many spacers under my stem. Because I ride for pleasure not trophies.

that is why they are pushing 25mm tyres, nothing to do with performance, convince people that the next bike has to have bigger softer tyres and discs

Except almost all the riders on the tour this year are on 25c…

Like a lot of other teams Leopard Trek have largely gone for 25mm tyres and that’s what Schleck has on his Bontrager Aeolus 3s too.

and Corsica’s roads looked pretty smooth to me?

As a side note does anyone ignore all the UCI rules and come out with 5kg* aero faring-ed normal shaped** bikes for your average punter? Dunno if there’s a business case, I assume the minted ATGNI guys want race replicas and the serious guys will need race regs bikes. But 99% of my road riding is solo and not in any competition and I’m sure I’m not alone.

*not that I could afford a bike that weighed 5Kg, just hypothetically speaking here
**I know recumbents and preying mantis bikes are quicker but bit not practical on busy roads.

GrahamS – I guess I qualify as a MAMIL too.

you posted the pic, we know you are 😉

Fair point D0NK 😆

D0NK, commuting to work on his mtb…

As a side note does anyone ignore all the UCI rules and come out with 5kg* aero faring-ed normal shaped** bikes for your average punter?

They are already available, triathalon bikes, designed to go fast for loners 😆

As for the OP, I’d buy a bike that had them over one that didn’t, though I wouldn’t upgrade the one I have by putting them on.

Except almost all the riders on the tour this year are on 25c…

and at the Giro most were on 23’s… and i have seen a few comments that 25’s aren’t as common as is being made out. Consider also that most pros are on tubs not clinchers.

GrahamS, no issue with commuters, i am one, my only issue is whether Di2 is the place to start with disc brakes and generally not convinced they offer enough advantages compared to calipers.

Discs on MTB no brainer imo, better mud clearance for a start. On a road bike, higher speeds, more faff, etc.

GrahamS needs a hug. But not while he’s in his lycra please 😉

btw I hope 38 doesn’t qualify as middle-aged!

btw I hope 38 doesn’t qualify as middle-aged!

as someone at work said to me,

age at death for a man is 85,

divide this by three, so you have young, middle aged and old.

your young till your 28, middle aged till 56 and then old.

As the average male life expectancy in the UK is 78 then 38 is close enough to be called middle-aged I would say.

your young till your 28, middle aged till 56 and then old

NNNNNNOOOOOOOOOOOOOO!!!!!!!!

😥

Tomhoward
DOB 23.3.85

I’d get them if they were cheaper. I hate my road bike brakes, they are shit. Ok if you are braking gently in the dry but coming down a 1:4 in the Valleys approaching a roundabout in heavy rain, they do pretty much nothing.

tomhoward – Member

your young till your 28, middle aged till 56 and then old

NNNNNNOOOOOOOOOOOOOO!!!!!!!!

Tomhoward
DOB 23.3.85

+1
DOB 28-11-1980
DOMA 28-11-2008

[desperation] okay, in Mayan culture, I believe, you don’t pass out of childhood until 33 and you’re still not a man until 52. if average age of death is 78, then you are not into your second trimester of manhood until 60yrs 8months.

congratulate me, I stop being a child this year! [/desperation]