sfrider 

They also don't use tail lights in the TdF. Doesn't mean I'm not going to.

guy153

In theory they can dissipate it much better because you can allow them to get much hotter. The hotter something gets the better it is at spitting out heat (it's the 4th power of the absolute temperature). Rims can only get so hot before the tyre blows off so that dictates the range you can work in.

There's no reason why you couldn't allow disks to become red hot but you need a pad material that works both at that temperature and also when the brakes are cold.

But it seems in practice disk brakes on road bikes do have issues with overheating. It looks like what happens is you reach a temperature where the pads stop working properly so the brakes lock up.

I don't like them on road bikes. The top of the fork. And the SS bridge are just much better places to transfer braking forces, on the centreline of the frame and in places where it's strong anyway. With a disk it's all happening at the end of one fork leg, the worst possible place, which means the whole fork has to be made bigger and stiffer. On an MTB this is a non-issue because the fork needs to be big and stiff anyway.

They're also heavier and less aero. Neither of these matters for MTB. The brake feel however is much better which does matter for MTB but less for road. And rim brakes on an MTB get covered in mud.

Then there's the speed of wheel changing which matters for racing. And don't get me started on thru axles.

If they actually worked a lot better on mountain descents they might be justified for pros and you would actually see them gaining time. But it doesn't look like they are achieving this yet.

tomato coupe

No really relevant, as blackbody radiation is not the primary mechanism for dissipating the heat.

guy153

True. But it will also lose heat to the air at a higher rate if it's hotter.

Iride01 

So what is the fuss? Do we all have like and use the same type brakes?

Am I going to be chastised if I ride with those that use a different brake?

WhyFi

Personal preference is all well and good, but vomiting up BS excuses while making broad generalizations is pretty lame.

colnago62

Which is really the crux of the statement made by Chris. His statement applies to him in a professional context. Disc brakes are fine for me. His issues with them are not mine. He is not wrong and neither am I.

surak

Froome is well within his rights to nitpick his setup, but let's be real, he spent the off-season in SoCal (hardly challenging weather conditions) and hasn't ever raced on disc brakes.

How about Matteo Jorgenson, who has fewer TdF victories than Froome, but has at least raced on and even had his leg sliced by discs?

SoSmellyAir

Since I only ride recreationally, the chances of me trail braking into a late apex to overtake someone through a turn is pretty slim. But I do look forward to my first disc brake bike, so I can one finger brake from the hoods without hooking my thumbs behind the bends.

tomato coupe

How about a rider that has slightly better results than Jorgenson:- B. Hinault

Andy Somnifac 

Pshaw... What does Bernard Hinault know about bikes?

Wait, I'm getting a phone call...

"Hello? Yes? Oh, that Bernard Hinault? He won the TdF how many times? OK, thanks..."

Never mind, carry on.

iterax

by the time the brake tracks on my wheels are worn out, lightweight alloy wheels for rim brakes may no longer still be offered

I so hope you are wrong.

Snotrub

As I watched the TdF and Vuelta this past year, I noticed that the majority of the racers were running disk brakes. The only ones that weren't were the main GC contenders. The commentators mentioned several times that they were not running disks because of wheel changes in crucial stages. I'm going to go out on a limb and predict that 99% of the racers in this years grand tours will be running disks. The speed of disk wheel changes by the mechanics on the side of the road wasn't much slower that a rim brake wheel. They had electric compact wrenches to quickly remove the through axle which made the change much quicker and looked very proficient toward the end of the TdF and down right experts during the Vuelta.

guy153

I hope so too but I think they'll be around for a while. We used to be worried 10y ago that you wouldn't be able to buy separate hubs and rims any more and it would all be pre-made "wheel systems". But these parts are still widely available.

tomato coupe

Not 99% yet, but I think Team Ineos will be the only team on the world tour with rims brakes this year.

merlinextraligh

If it weren’t for UCI weight limits, which completely erase the weight penalty of discs, and marketing considerations which lead sponsors to strongly encourage discs, I doubt very many pros would ride discs.

Drop the UCI weight limit to 11 pounds and watch what happens to discs. For those of us who are not subject to UCI weight limits, have to rely on a neutral wheel truck for a wheel change, and don’t have a team car with a complete replacement bike to whip out for us, discs make little sense if you’re competing, unless you’re subject to UCI rules, and have professional support.

WhyFi

It's funny that you think that it's not worthwhile to race discs unless you have professional support and I would look at it as the only sensible thing unless you have deep-pocketed support. I'd rather have discs for my everyday bike and wouldn't want to spend money on a race-only rig and wheels, 'specially if it meant investing in (IMO) a dead-end standard.

Different strokes.

merlinextraligh

Benard Hinault is a paid sponsor for Look; has an ownership interest in a group trying to resurrect Mavic; works for ASO. A little digging I’m sure would reveal more commercial interests in the bike business. Discs are the product the bike industry has to sell, and there is a lot of money to be made getting us all into to new disc brakes bikes, and selling us new disc compatible wheels.

merlinextraligh

I race a Willier Zero 7, now 8 years old. It weighs 12 pounds. It does everything I need. A new disc braked bike won’t touch that weight, and won’t even be close without spending a fortune.

and the new disc bike will have thru axles that wil, make it much harder to get neutral support in time to recatch the pack in a road race.

These considerations don’t apply to a UCI pro team because they can’t ride a 12 pound bike due to UCI weight limits, and they have team cars that can switch out full bikes quickly. As an amateur without the constraint of UCI limits, and without the benefit of professional support, IMHO, discs make no sense for racing.

Admittedly, as the weight penalty gradually comes down, it’s a closer issue, but they aren’t there yet

surak

Nah, every manufacturer and non-niche LBS owner that I've read discussing discs have said discs already vastly outsell rim to the point that keeping rim brake options in their lineup hardly makes sense. Factor has said that 93% of their bikes sold that are offered in both disc and rim options are disc braked.

Just because there's a vocal number of anti-disc posters on the Internet doesn't mean that there's an equal or majority who want them IRL. It's time to put the conspiracy theory that disc brakes on road bikes are an industry plot to bed, along with every other conspiracy theory that doesn't hold water with real evidence.

WhyFi

Blink twice if Big Bike is holding you hostage until you've delivered their pro-disc propaganda to their satisfaction. We'll send help.

mack_turtle

BF never disappoints when it comes to laughable conspiracy theories.

merlinextraligh

and that’s kind of my point , and my problem. It’s pretty clear that disc brakes have won this argument. I only care to the extent it will limit my available choices going forward.

I think however this is an unfortunate result that is driven by an artificial UCI rule that doesn’t even apply to us.

it shouldnt matter what the Pros ride, but in practice it does. So the pros riding disc brake bike where the weight penalty doesn’t matter, and the wheel change hassle doesn’t matter due to the level of support ends up driving demand for bikes that may be a poor choice if you want the lightest fastest cheapest most convenient bike.

WhyFi

This fight was over when pros on discs were a small minority.

surak

I want a bike that can stop consistently in the rain and allow for wider tires. Like the vast majority I don't race and therefore see no point in getting the lightest bike out there. What the pros don't care about are things like carbon rims getting destroyed and wider tires. You miss all these reasons when you reduce discs in the public down to "because that's what the pros ride, durr."