Road bike disc brake wheels - possible solutions

Do you need special wheels for disc brakes?

To use disc brakes you'd need a different wheel hub than on standard rim brake wheels, and the fork would need brake mount tabs to accommodate disc brakes.

We are constantly being hit by statements about the superiority of disc brakes. Bicycle manufacturers say discs are the future. To be fair, a lot of cyclists say discs are the future, Well, be the future, but do we know why? We are told that discs provide better braking performance, but then critics will say we don't need better brakes on racing bikes , You need better tires that give you more grip, because you can lock your wheels up easily with rim brakes if you want to.

Today's critics say a-ha, it's not about performance, it's about modulation. And then I realized that I don't really have any facts to back it up, it's all based on that, the feeling is of course completely subjective. So we were wondering if you could actually analyze disc brake performance versus rim brakes.

Generate some real data for both wet weather and dry weather to see if disks actually brake better. So how do we do a su pro science, so? Well, first of all, the bikes. We have two Orbea Orcas here.

One with SRAM RED eTap HRD disc brakes and one with mechanical SRAM RED rim brakes are important points, so the geometry of the frames is the same. My position on the two wheels is also the same, and then the contact patch, the tires are also the same. They are Continental GP 4000 IIs, 25 mm wide, and run at the same pressure, i.e. 75 PSI.

Then what do we do with them? Well, we've brought them to the Alta Badia Dolomites region and are currently standing on the incredible Pordoi Pass. Down there in the background lies nine kilometers of winding asphalt. One of the greatest descents I've ever ridden and I will ride it four more times, twice on each bike.

Once in the dry and then again in the wet. In terms of the data we are going to collect, the first thing we have is our GPS data that we receive on our Wahoo ELEMNT. That will be able to tell us our actual time of course, but then we will also need to see detailed entry and exit speeds on corners.

That may not sound too scientific now, but we will back it up with power meter data. And we have a heart rate monitor, but I'm not sure that will tell us anything. But then it gets really really interesting with that, that can only be a phone but it has an app that makes it really accurate accelerometer so all right, this will tell us how strong I am on a dicc bike compared to brake on a rim brake bike and how hard I can lean in corners.

See? Science, Big Data. Good, then let's go. Disc wheel first, in the dry.

Record, let's go. (dramatic music) So run number two, rim brakes. I'm a bit more familiar with the downhill so this might work out in their favor.

Right, run number three. Rain with a bit of snow, on discs. Ready, let's go.

Oh God, the things we do for science. Then run number four. Rim brakes when wet. (Brake) it squeaks) Then it's time for some data.

And there are actually quite a few of them. We recorded 688,000 data points from our accelerometer alone. So it takes a little bit of time and more than a lot of help from GCN team legend and brain, Daffyd Thomas, so thank you very much to him.

Exactly then the million dollar question: Were disc brakes faster? Yes. And also no. In the dry there wasn't much to separate, and in fact the rim brakes were a bit faster, even by two seconds.

However, when it was wet, the results were reversed. The disc brakes were significantly faster, by eight seconds. If you transfer that to the road, at 50 kilometers an hour, that's about 120 meters between the two.

So that's not to be despised, I think. But that's just the top line. Let's take a closer look at the data, right? We've had enough of it, at least.

We have isolated an important section of the road. It's 2.2 kilometers long.

It has 11 corners, some of them super fast and some very tight. If we superimpose the speed of each bike through this section in the Dry, then we can see again that there isn't much to separate the two. Disc brakes are in blue and rim brakes in red.

championship cycling

Now the GPS data is a bit patchy in places, but if anything, it looks as if the disc bike is going around corners a little faster on the straights, but also a little slower. The performance data were the same, the average was 175 watts for each run and the peaks were also roughly the same, 804 watts for discs and 811 watts for rim brakes. To see if we were really fast on the straights and slow on the corners, we took the speed data and plotted it in a histogram.

Each bar represents the number of seconds in each run that the bike reached a certain speed . So if the bike was traveling consistently at higher speeds, we would expect to see taller columns on the right side of this graph showing a short curvy section, there isn't really anything to separate the two, but if we look at the data over the whole Looking at the run, we can actually see that the wheel with rim brakes is consistently reaching much faster speeds. And that's kind of puzzling.

So we thought about the big picture. Although the wheels are almost identical, you can actually guess that the rim-brake bike has the aerodynamic advantage. If nothing else, it has the slightly faster Zipp 404 NSWs as opposed to 303s.

So a significant part of the faster speeds could possibly be due to pure aerodynamics. Then what about when it is wet? Well, disc brakes seem to get a bit faster on the straights and then a bit slower in the corners. But this time, if we actually plot that data in a histogram, we can actually see that this is actually true, disc brakes seemed to go a little faster on the straight.

So this is food for thought, and we'll come back to that in a moment after looking at our acceleration data. Now I'm not going to lie, that was a massive pain in my butt, I was a little worried at first that the data would just get too loud as the bike's top tube is likely to be pretty bumpy at 70 kilometers an hour. And indeed.

But don't let that put you off. We got the data from the y-axis, which records the force in the direction of travel, and then Daff set about looking into a certain corner with a super-fast entry. Can we see the difference Uh One thing, however, was the vibrations at the bottom of the graph, they were the only pattern that repeated throughout the descent.

And we can see it quite a lot. So we plotted that against GPS data and it turned out that I was actually getting off the saddle and sprinting up to speed again. Kind of cool.

Not very relevant to braking, but still kind of cool. In any case, by the noise, I think you could argue that there is definitely more activity on the disc brake bike when entering the corner. It looks like I'm braking harder than the rim brake of the bike.

Nowhere is there less activity until I grip a handful of brakes in the middle of the curve. Which isn't exactly textbook stuff, I know. And then these big spikes, by the way, they are actually bumps on the road, like this one.

If that's the summary of the data, what does it all really mean? Well, there's not much to separate when it comes to dry-land performance - that fact can really make it stand out, other than that our rim-brake bike might do a little better aerodynamically. Things are a lot more interesting in the wet, however, thanks to the fact that there is actually a difference between the two, especially the faster top speeds on the straights, which I think is due to the fact that wet braking is much more controlled with disc brakes. From our acceleration data we can see that I was able to brake much harder and therefore brake faster.

I don't have a grip on the tires anymore, I think that just depends on more predictable braking. Do that for each curve and you can see where the time really adds up. The reason I slowly turned the corner on the disc bike in the wet was probably one that made it my first ride down the mountain in the rain.

And so in the second run I was a little more familiar with the grip the road offered. And the same applies in the dry, the disc wheel came first and the wheel with rim brake came second. While it wasn't my first mountain run, I was a little more familiar with the road, especially on some key sections where I knew I could completely release the brakes.

In the introduction to this article, I said everything we were in ever really speaking of the disc brake debate is the feeling. So after forever collecting data and then going through it, I am a little embarrassed to feel that we are going to come back now. But then maybe that is actually one of the most important things when we ride our bikes.

I was more confident when I stepped off a bike with disc brakes in the wet, and actually I was a little more confident in the dry, if I'm completely honest. And of course I didn't make optimal use of the bike. I didn't push the tires to their limits.

And then I think that depends on the limitation of the test. I haven't ridden enough to get rid of any kind of bias, run one versus run two, and be more familiar with the road on the second run. So more time to run tests.

And while we're at it, why not do tests on different descents, that can change the results, as can different riders. What if you weigh 60 pounds as opposed to mine 73 pounds, and what if you weigh 80 pounds or even 90 pounds? It certainly brings with it the difficulty of actually measuring the differences between bikes; often, what we find significant is actually hard to quantify on the road. Before we start, one more thing must be said that our little test track of the best five and a half kilometers of the descent from the Pordoi Pass in the Dolomites was one of the best descents I've ever ridden, and it has on every bike, regardless of the brakes fantastic fun and i think that's very important to mention.

Now, of course, we would like to hear your thoughts on this. Have we missed something in our data? And the fact is, which side of the fence are you on in this big debate: disc brakes versus rim brakes. Let us know in the comments section below.

It's very easy and free, just click world and now if you want even more content we have two old but very much good articles about disc brakes. Are you ready for road bikes? It's just there.

And how much faster can you stop with disc brakes? one is just there.

What is the best wheelset for road bike?

Narrator: These are the brand new Zipp 303S wheels that are more affordable, lighter, and apparently faster than the 302 wheels they are replacing. That doesn't seem to do them justice, as Zipp says they've improved the overall efficiency of this wheelset to the point where the performance surpasses the classic 303Firecrest, which hit the market back in 2016 and costs twice as much. In all honesty, I want you to know how Zipp did it, so let me fill you in.

First, yes, I'm still largely confined to my house, but amazingly, I've got my hands on some hot new technology. Many thanks to Zipp for sending me and also for patiently answering all of my questions so that I can give you the juicy details. Reminder of Zipp's balance bike range, which covers the entire depth spectrum from the flat 202 series to the all-rounder 303 series, the 404 to to the 808 and the disc wheels.

Most depths have different models and prices. I have the Firecres t, the classic zip with its characteristic dimples that are used and abused both on and off the road. The NSW that boosts performance even further, and then you had the 302, which simplified all of the carbon and aero knowledge and distilled it into a more affordable wheelset.

Now we have the even cheaper, lighter, and faster 303 S. Disc- specific, happy off-road, as well as on and tubeless ready. So what's up? For the most part, they got a new logo, for a start.

Let's talk about these benefit entitlements first, shall we? Zipp says this 303 S is 10 watts more efficient than what their 2016 303 Firecrest is at 40 km / h. Leaving aside for a moment that these are faster than their more expensive brethren, I think it's also very important and interesting to note that Zipp is rapidly changing the way it is quantified, and that's because Zipp says they are from just wind tunnels to holistic real tests that not only include aerodynamics, but also tires, dynamics too. Its data collection techniques are so advanced that you can now get accurate and repeatable results outdoors with an aero stick that measures wind and atmospheric data in real time.

The Zipp engineers basically had to spend countless hours driving up and down stretches of road at 40 km / h. How do these stack up in the wind tunnel? I don't know. Zipp says they're not that fast either, and instead points point out that it's your real-world data that shows you are 10 watts more efficient at 40 km / h on slippery roads, because on rough surfaces that difference seems to increase even further.

How? Zipp has designed these so that they are aerodynamically optimal for 28 millimeter wide tires. That's a really big part of this overall increase in efficiency because wider tires roll with little resistance and can also be driven at lower pressure, which also increases rolling efficiency. Viewers will find that there is less of a difference than there is between the outside and the inside, and yes you are right because these are hookless.

A traditional rim has a little hook on the top of the inside of the rim sidewall, but with the latest developments in tire technology, you no longer need that. You can get rid of it and get a whole host of benefits from it. One of them is aerodynamics.

Hookless means a much smoother transition from tire to rim that creates less turbulence than you cut through the air. Since the inner rim width can be wider, the tire blows less over the rim, which also creates less turbulence. The rest of the rim profile has also changed accordingly, old 302, 45 millimeters, but the rim is much less blunt at the nose than on the Zipp predecessors.

What about the weight then? They're 165 grams lighter than the 302s that came before them, which means they're only 1,530 inches in total for the backpack. That's 710 in the front and 820 in the back. Granted, that's not a stupid, stupid light, but for a bike of this depth, strength, and price, I'd say it goes pretty well.

How are you? Much lighter then? Zipp says advancing the construction process, mold design, and carbon layup has allowed them to be more efficient with less material. One of the big steps forward was, surprise, surprise, go without a hook; you could change the way they shape the rim base. You're switching from a soft mandrel to a metal shape that allows for more even compression.

You can basically use less resin and less carbon in this part of the rim. If strength is your concern, you don't have to be. I think it's fair to say Zipp has always been risk averse when it comes to construction In the impact test, they are as strong as their predecessors, but these even now have a lifetime impact and damages policy that covers all damage while driving.

How are you? Well, these are the first carbon Zipp wheels to be made outside of the U. S. SRAM, the parent company of Zipps, has its own carbon manufacturing facility in Taiwan and it has completely replicated the production of Zipp Indianapolis Process over there, but then Zipp also says that by making these refinements in the building process, such as hookless, they were able to make it more efficient.

They also say that because they're lighter, there's just less raw materials in here. You don't often hear manufacturers say something is cheaper because it's lighter, but high-five all round. It takes a while to get back to it but it's like a lot of cool things have happened but one of the most obvious differences from the new wheels is the new stickers.

The classic Zipp logo changes from this to this one. Eagle enthusiasts will of course have noticed this not only on the mountain bike wheels that were launched last year, but also on the wheels that the Movistar team used earlier this year. Two last points should be mentioned first the hubs say they have the same bearing axle and freehub as the ones used on the Firecrest wheels in recent years, but here the difference is actually in the spokes and the way they enter the hub .

These use J-bend spokes, whereas the Firecrest uses straight-pull spokes. Finally, a very important note about the tires that you use with them. It's important that you use tubeless ready tires on these rims as the higher tolerances and stiffer bead of tubeless tires mean they don't need that traditional hook design to work.

ww1 bicycle

You can of course use an inner tube here, but you will need these tire-ready tires. We'll soon have another article for you to dive into Zipp's new test protocols. because it's a big break for the brand and they've definitely found some super interesting and also super useful insights, some of which can actually already be found on their new tire pressure calculator, on which an algorithm is built on all of their recent research I had a bit of play.

I think it's super cool. We'll include a link to it in the description below this article. That's a very brief overview of the new 303 S.

They're available in stores at just under $ 1,300 or just under £ 1,000 for the pair which, as I said at the beginning, makes them some of the cheapest carbon zipps to date. Be sure to let us know what you think in the comments section below and please give this article a big thumbs up.

Are disk brakes better on a road bike?

Disc brakes offer better modulation than rim brakes, meaning it's easier for the rider to precisely meter out how much clamping power is generated. Peak stopping power occurs just before the point of lock-up, and disc-equipped bikes are better equipped to flirt with that edge without crossing over.

Can I use rim brakes on disc wheels?

Short answer: no. Disc brake rims generally don't have a brake track designed for rim brakes, and you will damage the rim quickly.

Can you put disc brakes on any bike?

Disc brakes can be fitted to any mountain bike so long as the bike is equipped with two things: Hubs that have the fittings for a disc rotor.

Are disc brake wheels different?

Manufacturers often try to minimise the difference but don't forget that disc brake hubs are heavier too, and disc brake wheels are often built up with more spokes of a wider gauge, although the lack of a brake track means that disc-specific rims are generally lighter.

Are road bike wheel upgrades worth it?

Perhaps the most underappreciated advantage of upgrading your road bike wheelset is leveraging the latest trends in rim width. In summary, a wheelset upgrade allows you to access multiple performance advantages in a single purchase: better rotating efficiency, ride quality and aerodynamics.

Why do road bikes not use disc brakes?

Disc wheels are not going to work in your current bikes, and vice versa. There is also the risk of problems with heat dissipation on long descents. Small discs may not cool down quick enough, heating the hydraulic fluid, and therefore reducing feel and stopping power.