Road Cycling - Finally...a road bike with disc brakes

I'm not sure why it has taken so long for this concept to move from mtb bikes to road bikes. Looks like Giant now has a road bike with disc brakes.

Giant Bike (http://www.giantbicycles.com/us/030.000.000/030.000.006.asp?bikesection=8830&lYear=2003)

Is there really the need for a road bike with disc brakes. Whats wrong with the normal ones that I have now? They stop me fine. The disc brakes will add extra weight.

Personally I view this as a marketing ploy on their part... Are their any real world advantages to this over the present offering of brakes for a road bikes? On the down side I would guess it will add a little weight over reg. road brakes as well...

They are good for winter riding and muddy CX style trails, work better than cantis or Vs with road brake levers, free up some room for tyre and fender clearance and save your rims from wear.

Do they have to make the fork stiffer to work with one-sided braking ?
Can the frame take a full sized touring load (which could benefot from disksc) or is it for light-touring only ?

Its an interesting concept, a bit outside the box, so full marks to Giant for experimenting.

get used to it. Discs are going to become standard soon. The new XTR is only 100grams heavier than V brakes.
Benefits are obvious, like the other poster listed. But also, less fade, more modulation, control, less lockup, alot safer-especially in the wet or rain where calipers don't work.
They already use them in cyclocross and they will become standard in XC. Once the weight drops, I see them standard on road racing bikes. Maybe within 2 years.
There is more discussion on this in the cyclocross section too.

edit;
yes, they can take full size loads as any other bike. Full carbon forks with disc mounts are in our future!

Ummm... are discs even race legal in road and 'cross? I think that would delay the penetration of the technology in the road market.

Personally, I don't like discs, but I don't know if that's my retrogrouchiness showing...

I have heard and understand the advantages of disk brakes.
Surer stops in bad weather.
Braking independent of wheel trueness.
Wheel size becomes independent of frame setup, for whatever that is worth.

My first thought was wheel interchangability. I'm not sure how big an issue that is.

I remember when I thought indexed shifting was something I could never aspire to having, back in 1984 or so. Now it's almost universal. Will discs be the same way?

Frankly, I don't like my Shimano XT hydraulic front disc at all, and I'm intending to get rid of that rubbing, howling, underpowered, overweight, difficult-to-work-on piece of highly-advanced technology and go back to some V-brakes and a normal front wheel with a 24" brake rotor (26" nominal) that I can true myself to within a tenth of a millimeter if I so desire. Sorry to pout in the pro-disc-brake thread... hey, anyone want to buy a disc brake? :)

I think the V-brakes will at least remain as an option for many years to come, unless they're supplanted by a more-advanced rim brake.

If you think about it a bicycle rim IS a disc brake.

if you'll notice, that wasn't a pure "road" bike, it was a "touring" bike. If It was just a normal road bike (training,racing use) then I couldn't see. But riding a touring bike with 40 lbs worth of stuff loaded on it must be hard to stop, thus the disks w/ the extra power.
I dont think that discs will ever be commonplace on road bikes, though, b/c there is the extra weight of the disc brake itself, and the extra material required to strengthen the fork and rear triangle.

Originally posted by velocipedio
Personally, I don't like discs, but I don't know if that's my retrogrouchiness showing...

hmm maybe I agree....

personally I don't like the way they look (sorta ok on a mtb but not on a road IMHO) but then again I would not have index shifters on my road bike, if I didn't have my campy ergo. too many cables with those shimano ones (was index shifting for a while there) I don't know I think the road bike in general should be sleek, it is such a machine that looks like was made from one piece, not seperate components... I don't know but they probably will become popular in a few years...

Doesn't seem like a good idea to me on racing/fast training bikes. There's no reason for them, IMHO. Too much power. You'll be sending people over the bars left and right. At the very least, folks will be locking up their wheels and sliding a lot more. I understand the argument that there's more modulation, but I would counter that with the opinion that disc brakes have too much power at the top for road racing and fast training.

Just my $.02.

One man's opinion. . .

Discs will make it on racing bikes in spite of the weight. Why? Manfacturers can already build a bike lower than the UCI minimum of 15.5 lbs., so adding another 150-200 g for better stopping won't be a big deal - even if only on the front wheel.

I went on rain ride the other day and was reminded how long it takes for the calipers to scour the water from the rim before they start to grab. Another disc advantage that bad-weather riders will appreciate.

Once forks start coming with disc mounts the move will begin.

Originally posted by velocipedio
Ummm... are discs even race legal in road and 'cross? I think that would delay the penetration of the technology in the road market.

Personally, I don't like discs, but I don't know if that's my retrogrouchiness showing...

Ummm...yes

But riding a touring bike with 40 lbs worth of stuff loaded on it must be hard to stop, thus the disks w/ the extra power.


I don't think world tourists will ever accept disc brakes because the parts could be hard to find in third world countries.

Originally posted by RacerX
Ummm...yes
:D

I still wonder if discs would be race legal under UCI regulations. I can't find anything that explicitly excludes disc brakes from sanctioned races, but regulation #1.3.004 requires an application and approval process for the acceptance of "technical innovations.":

No technical innovation regarding anything used, worn or carried by any rider or other license holder during a race (bicycles, equipment mounted on them, accessories, helmets, clothing, means of com-munication, etc.) may be used until approved by the UCI Executive Committee. Requests for approval shall be submitted to the UCI before 30 June of any year, accompanied by all neces-sary documentation. If accepted, the innovation will be permitted only as from 1 January of the following year.

As fart as I know, no one has applied to have discs made race-legal, so I think it's fairly safe to say that, as an innovation, they aren't legal for road races, and won't be for the near future. Considering the UCI's intransigence on Camelbaks, I suspect it'll be a long time before they accept disc brakes.

I also understand that discs aren't race legal for mass starts. In any event, despite the popularity of discs on MTBs, no one at any UCI-sanctioned mass-start MTB race whose picture I've seen lately seems to have used them... Even at Kaprun, where I imagine they would have been useful.

Why are UCI regs important? Well, the road bike culture and industry is very sensitive to UCI. Maybe it's just that more roadies are aspiring or actual racers than MTBers. Having discs on your bike means having an unraceable bike [for now at least]. Hey, a lot of roadies don't use 'baks because they're not UCI legal, whether they actually race, or not...

I might be way off the mark here -- and if I am, please correct me -- but I think the odds are stacked against discs on the road...

Oh, c'mon-there have been disc brakes available for touring bikes for about 15 years! This ain't nothing new! I even considered cable-operated discs for my heavy-duty C'Dale touring bike a couple of years ago, but didn't think it would be worth the extra weight.

what do u need disc brakes for? my bike stops... i guess ill spend some extra money so i can add a little more weight so i can stop again...

I wouldnt have thought the continual drag of a disc brake would be acceptable to a roadie. Its no problem for a DH. For heavy weight touring rim overheating can be a problem, but I think an airbrake/spoiler would be better for dissipating energy on a long downhill.

Originally posted by AndrewP
I wouldnt have thought the continual drag of a disc brake would be acceptable to a roadie. Its no problem for a DH. For heavy weight touring rim overheating can be a problem, but I think an airbrake/spoiler would be better for dissipating energy on a long downhill.

We already have that. It's called the rider. |8^) Just sit up and open the full-length zipper of your jersey on the next long downhill.

I can see disc being used on tandems. Ever try
to stop a tandem on a long descent? (me neither! :lol: )
but I hear its a bear. Given the weight and momentum
built up disc brakes make sense on a tandem.
I don't see them being used in a sanctioned UCI road race.
watch the big rides, hardly any braking is done and if
they do brake its just feathering the brakes on long
descents.

Just my .02 worth.
Marty

Many professional racers ditch dual pivot brakes in favour of lighter, weaker single pivot models (often from down the groupset range) for their lightweight mountain stage bikes.
I dont think you can persuade them to add more metal to their wheels.
For tourists, tandemists and winter riders its a whole different case.

The actual mounting of the calipers to delicate road bikes may be an issue.

Imagine the huge amount of torque acting against ONE of your nicely sculpted chainstays, or your trick lightweight carbon fork.

Cannondale has a Cross bike with discs this year, but it has a beefy fork and chainstays.

I haven't spent a lot of time contemplating disc brakes, so bear with me. But... Isn't the disc mounted to the hub? How rapidly can one change out a wheel with a disc? Wouldn't wheel changes be slow in the middle of a race? Especially with neutral support. That alone would make them slow to be accepted by racers.

The mountain bikers seem to get their tires changed pretty quickly in races these days. But, road racers tend to be really picky about equipment. I think it would take a while for disc brakes to catch on in the pro peloton. I can see how they'd be helpful in some applications, but the racing scene would probably be slow to accept them widely. Just an opinion.

A horse and buggy worked fine.

Technology will always move forward. Often step back in more subtle ways.

Would rotor use lead to lighter rims? Less rotating mass? faster mountain stages?

I'm personally not in any rush to fit disks onto my road bike.

I suppose it could lead to lighter rims, as you'd eliminate the need for any braking surface out there. Also, maybe there'd be a little less stress on the spokes when stopping. I don't see the disc itself as detrimental areodynamically. The caliper maybe somewhat problematic, but bringing it around behind the fork reduces this greatly. Also, maybe with the increased efficiency and the ability to modulate the brakes more effectively, you may be able to eliminate the rear brakes altogether. Hmm, food for thought.

Yep Tech marches forward again.

Maybe I'll get em on my next road bike.
But by then they'll probably be old news.


ChipR

Originally posted by ChipRGW
Also, maybe there'd be a little less stress on the spokes when stopping.ChipR

Actually, all the force would be on the spokes with a disk.

With the current rim brakes, none of the force is added to the spokes as the friction surface of the pad and the rubber of the tire are mechanically one.

With a disk, the two (hub and rubber) are separated by the spoke. Mountain bike spokes, hubs and tires a way more beefy than a typical road bike. Than again, the terrain resisting against the rubber of the tire of the mountain bike is less stable.

D'oh!


Oops, my bad