Disc Brakes in the Tour de France

This year’s Tour de France has had its share of drama, and the winner won’t be the one most observers predicted. Among the sporting achievements, the technological innovation was easy to overlook: Finally, the UCI approved disc brakes, and the Tour is the first big stage race where they’ve been used.

Reading the previews of Tour bikes, it sounded like all racers would make the switch. Just in time for the big race, several big bike manufacturers rolled out new race bikes with disc brakes that approach the UCI-required minimum weight. With no weight penalty to speak of, adopting disc brakes seemed like a no-brainer.

After all, brakes are maybe the most important components of a racing bike. When Mafac introduced their first centerpull brakes in 1952 (above), it didn’t take long until almost all racers adopted them, so superior was their performance. It didn’t matter whether they rode for French, Italian or even the ‘International’ teams – braking hard before the corners was more important than allegiance to national sponsors. And when Campagnolo rolled out their sub-optimal ‘Delta’ brakes, racers refused to use them. Campy backpedaled and resurrected their old sidepulls in a hurry. With disc brakes being heralded as the most important innovation in decades, most expected shiny metal circles to appear on the hubs of the entire peloton.

And indeed, during the first stages, most teams rolled out on bikes with disc brakes (above the finish of Stage 5). Ironically, most of the disc brakes were on aero bikes used for flat stages, where brakes make no difference in the bike’s performance.

As the race continued, most racers quietly switched back to rim brakes. The yellow jersey contenders had used rim brakes from the beginning. Why?

The racers were concerned about flats. Through axles require extra time during wheel changes. Worse, the inevitable manufacturing tolerances change the alignment of the disc rotors on different wheels, even if the same model of hub is used. Unless the disc calipers are adjusted, the new wheel’s rotor will rub. (We realized this during our most recent tire tests, where we thought we could speed up the changes between different wheel sizes, but had to adjust the disc brake calipers after every run.)

BMC Racing found a work-around solution to the problem: When a rider flats, they don’t change wheels, but the entire bike. However, this also means they no longer can use neutral support. Most other teams weren’t willing to run that risk.

When the Tour entered the mountains, many observers expected the racers to switch back to disc brakes.

If disc brakes have an advantage, it’s on the vertiginous descents of the Alps and Pyrenees. Since racers have moved to wider tires with more grip, descents have become much more exciting, with higher speeds and more attacks than in the past. Braking is more important than ever. And yet, there was hardly a disc brake in sight.

What happened? I asked a former mechanic of the French national team. He indicated that the introduction of disc brakes was due to sponsors’ demands. With the big component and bike makers pushing discs, it was useful if pro racers used the new technology.

So why did the racers use rim brakes when their sponsors wanted them to use discs? If discs were superior, racers would have used them, especially in the mountains. After all, a real advantage on the many descents of this year’s Tour would have outweighed the relatively small risk of losing time due to a wheel change.

The answer is simple: Really good rim brakes stop just as well as even the best disc brakes. And many riders find that rim brakes offer superior feel: The brake lever is directly connected to the rim via a cable, rather than having the feedback dulled by the wind-up of the spokes and by hydraulic fluid. It’s refreshing that even today, where bike racing has become big business, winning races still is more important than pleasing sponsors.

In the future, I expect that the problems with wheel changes will be overcome by standardizing the disc location. A friend has already done this, using thin washers to make sure all his wheels fit all his bikes without adjusting the brakes. It’s a lot of work, and team mechanics will not be happy…

Rotors will also have to be standardized – currently, teams use both 140 and 160 mm on the front – to simplify neutral support. And then, the sponsors finally will be able to showcase bikes with disc brakes in the Tour. For now, it’s clear that disc brakes don’t offer a big advantage over the best rim brakes.

Back in 1952, it was different: Centerpull brakes swept through the pro peloton. With their pivots placed next to the rim, they offered greatly superior stopping power and modulation to previous brakes. In fact, the rim brakes that dominated the 2018 Tour de France use the same principle – only the actuation is different to eliminate the need for straddle cables and cable hangers.

Further reading:

Photo credits: A.S.O./Tour de France.

About Jan Heine, Editor, Bicycle Quarterly

Spirited rides that zig-zag across mountain ranges. Bicycle Quarterly magazine and its sister company, Compass Cycles, that turns our research into the high-performance components we need for our adventures.
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65 Responses to Disc Brakes in the Tour de France

  1. Rod A Bruckdorfer says:

    Professional cyclist ride what they are told to ride by their sponsors.

    • It makes their life easier, but they also need to win. There have been many instances of disguising ‘incorrect’ equipment, from custom frames painted like production bikes to rubber covers to disguise Simplex Retrofrictiom shift levers on ‘all-Campy’ bikes. The lack of disc brakes is difficult to hide, though…

  2. Paul says:

    “Your old bike is garbage, you need a new bike.”
    –The Bike Industry

    • Greg Parker says:

      Precisely!!

      Marketing 101, especially when your target demographic is the same enthusiasts to whom you already sold nine other types of bike!!

      • Luis Bernhardt says:

        Exactly why my current bike uses a front disc only (you just need to buy a new fork and not an entire bike or frame, plus it’s lighter without a rear disc that hardly is needed anyway on dry pavement, plus I can continue to use my existing 130mm rear wheels) and why I still use a 9spd cassette (chains and cassettes are much, much cheaper and just as – if not more – reliable). Take advantage of the bike industry, there are lots of good deals as well as useful innovations out there; don’t let them take advantage of you.

      • Greg Parker says:

        Well-said. Absolutely, there are advances that one can adopt (like wider, faster tires!) while still avoiding the marketing hype. We have this somewhat odd “I need a new xxxxx” syndrome (as opposed to your current, not-new one), here in the USA. It pervades the markets, up to and including homes! I am always amused at folks that just HAVE TO own a new car, not a good used one, and must own a new home, not an existing one. Right where I live, a new home is less desirable than a “vintage” one. The new homes just don’t have one-tenth the craftsmanship in them, compared to the 80-125-year old ones.

        By the way, there are of course prototype 12-speed-cassette drivetrains out there now!

  3. kurtsperry says:

    Look at the tiny diameter of the discs used at the TdF vs. the wheel diameters. On motorcycles and cars, effective, high performance disc brakes have evolved diameters near the rim diameter where the calipers have favorable leverage. Rim brakes are already there. Motorcycles also use two discs to maximize both the braking torque and keep the reactive forces acting on the forks laterally symmetric. On a bike, an optimized disc design would be prohibitively heavy. Marketers, however, don’t care about the engineering niceties, they just want “features” for brand differentiation, create demand, and to make writing their ad copy easier. Bikes have become so optimized and developmentally mature over so much time that at this point there is very little remaining scope for significant performance gains. Marketing rather than engineering or performance is the primary differentiator between competing brands. Human powered road bikes 100 years from today are unlikely to be significantly faster or more efficient than today’s, that’s just the nature of stuff that is mature in its development process.

  4. Bryan Willman says:

    Fair enough – but do note that just as the TdF doesn’t really inform other aspects of bicycle design, it doesn’t really inform brake design all that much either. Even as a cyclocross and MTB racer (never road racer) the pace of wheel changes with through-bolt axles is acceptable. And they make a stiffer more secure wheel attachment. (Some have claimed that liability issues will force the whole world to through-bolt, we’ll see.)

    Yes, cable rim brakes work (at least in the dry), but I personally have had FAR less trouble with the hydraulic discs I switched my whole little herd of bicycles over to last year. (But my competition riding is MTB and Cyclocross where mud shedding, etc. are obviously a huge deal – and since I’m not a road racer speedy wheel changes by people in a neutral support car are irrevelent.)

    And no rim brake scheme is going to allow switching between 700c and 650b wheels. TdF riders don’t do that, I do.

    • No doubt, disc brakes have their place. It’s just that the industry tries to suggest that they’re better in all situations, including road riding…

      • Monty says:

        I have many bikes. Today I was out on one of my road bikes and some of the gradient was 14% on very rough roads and let me tell you I really missed having one of the bikes with hydraulic discs. Jan, I hear what you say, but, in our club (400 members) people are moving to discs for their better performance in more conditions. TdF is one thing, but, most of us need the better braking that discs provide for recreational and club riders.

    • Greg Parker says:

      I think you’ve mentioned the two best applications for disc brakes. Perhaps tandems as well. But on a single road bike? They are misapplied to that application, imo.

    • MarkMin says:

      Surely there’s a way of testing at least some aspects of braking alternatives—eg, ultimate stopping power, effectiveness in the wet, fade, modulation, durability &c? Then there might be more than just an endless exchange of opinions based on personal preferences and different experiences. And surely the major manufacturers must have done some testing (there would be liability issues) whatever the nefarious activities of marketing departments. Can that data be got? Or am I naive? As to what pro cyclists do: on the one hand, we’re told that professional bikes are more or less irrelevant to everyday/non-racing riding—too fragile, over-geared, tyres too narrow, wrong geometry &c (btw, I agree); on the other, suddenly what professionals do with their brakes is. Don’t different conditions, expectations, and experiences dictate a range of reactions, decisions, and compromises?

      • Even a 185-pound rider can lift the rear wheel with a good modern racing or centerpull brake in the dry – which means that it has more braking power than you can use. The same applies to a hydraulic disc, so neither provides an advantage in pure stopping power. That means it comes down to other aspects of the entire bike, and this is where preferences differ. There is no ‘right’ or ‘wrong,’ but many good (and some bad) choices among all types of brakes.

  5. Sebastian says:

    The following sentence simply is not correct: „The brake lever is directly connected to the rim via a cable, rather than having the feedback dulled by the wind-up of the spokes and by hydraulic fluid.“

    The brake lever is directly connected to a brake caliper via a cable, definitely not to the rim! Such a system also has delayed feedback, caused by the squirm of the brake pads and brake cable stretch for example. I never felt a wind-up of spokes on a bike with disc brakes which wheels were built to a minimum standard level and the hydraulic fluid of a properly bled system offers a very instant and clear feedback as I can tell from my experience with hydraulic disc brakes.

    It‘s not that I‘m a disc brake advocate, I ride both systems on different bikes and never felt the described disc brake issues.

    • I don’t think you can feel the windup of the spokes (unless you lock the brake and rock the bike back and forth. It’s surprising how much the bike moves even though the hub doesn’t turn).

      What you do notice with a really good rim brake is the clarity of the feedback. You really can feel when the wheel approaches the point of locking up. With disc brakes, I’ve never felt that, and inadvertently locked the wheels on gravel. I think part of the ‘grabbiness’ of disc brakes is actually the reduced feedback.

  6. Gerald says:

    Are you sure that through axles require extra time during wheel changes? A TV commentator noted that fork ends have to be equipped with lawyer lips according to UCI rules. With that I don’t think wheel change with quick release is faster than with through axle. Also making sure that the bike stands straight while it’s between the legs of the rider who might be still connected to one pedal is quite difficult and costs extra time whereas a wheel which is held by a through axle can’t be out of position.

    • On Bicycle Quarterly test bikes, I’ve found that aligning the hub on thru-axle hubs depends on how deep the recesses on the rim are. On some bikes, installing the thru-axle wheel is neither quick nor easy. Also, some thru axles don’t slide easily into the hubs. I am sure the pro teams make sure before the race that all their hubs have holes that aren’t on the tight side of the tolerances, but still…

      With quick releases, the lawyer lips complicate things a bit, but since the entire team will be on the same forks, a mechanic can set all the quick releases at the same distance, so they clear the lips and then require just a pre-set number of turns to be ‘just right.’

      I can’t help but think of the old days, when all dropouts had the same thickness (they were standardized around 1950 to allow the widespread use of quick releases). Just slap in the wheel, turn the lever, and push off your racer.

  7. Fantastic article. It’s nice to see that centerpull brakes are still preferable in certain race conditions. If UCI WorldTour racers ever adopt, say a 32-42mm tire or so, I wonder if a Compass style centerpull brake will ever be the “new” norm, or if discs will gain prevalence, or if it will be a bit of both as it is now . . .

    I’m still not sure disc brakes, as they are now are entirely safe to use in a peloton, because of the modulation and also the safety hazard of the disc itself . . .

    When GCN interviewed UCI WorldTour racers about their opinion on discs, many liked their braking performance, but thought they were undesirable in a “mixed peloton” meaning a peloton with both discs and not.

    Also if everyone were riding discs, (and if discs had more precise tolerances across different wheels) the time penalty for a wheel change should be the same for all . . . GCN also mentioned that some team mechanics are experimenting with using a drill bit with a pre-set torque setting to make installing thru-axles a bit quicker.

    • John Irvine says:

      “Also if everyone were riding discs… the time penalty for a wheel change should be the same for all.”

      But not everyone needs a wheel change, so those that do are still penalized. I noticed Bardet using rim brakes, and he needed – what: four wheel changes in a single stage? Add say 15 seconds to each and he’s a minute lower on GC. I did think the descending in this year’s TdF was pretty spectacular, and was to some extent a factor in at least stage wins. Roglic and Alaphilippe were fantastic, and both were on rim brakes. Sagan was on discs when he crashed on stage 17. Not sure about Gilbert, though it looked like with his approach to the turn, no brake could have helped.

      What I don’t get is, if the industry wants to sell new bikes with new features, making your old bike obsolete, why aren’t they pushing the pro teams to adopt frames that will fit larger tires? “Your old road frame won’t fit 34mm tires” is as good a sales pitch as pushing discs.

      • Good point about wheel changes. Having raced for 10 years, I can tell you that every additional second lost in a wheel change requires a huge extra effort when chasing back on. It’s like an all-out attack, and you have only one or two per race in your legs and lungs.

      • Ian says:

        A sprinter either comes in first, or loses. A wheel change could take 15 seconds or 15 minutes, on a sprint day, same thing. But to the GC contenders in the later mountain stages, a few seconds could be a big difference, wheel changes need to be fast.

        As far only doing what sponsors tell them: More or less, of course. But in the photos above we see Gavira on discs and Alaphilippe on rim brakes, and they ride for the same team.

      • Indeed many good points here John . . . interesting point on what would have happened to Bardet’s time in the GC just from wheel changes with a disc bike

        Especially since (forgive my generalizations here) braking force is limited by the amount of traction/friction you have between the tire and the surface (right?), and rim brakes should be more than powerful enough to exceed that limit on a UCI WorldTour bike (with better modulation/ fine tuning of the braking force, at least in the dry) that rim brakes are preferable even before considering their better wheel changes . . .

    • Greg Parker says:

      Two thoughts: those aren’t centerpulls, but rather dual-pivot sidepulls, and 32-42 mm tires in the top Pro Peloton is a Quixotic thought! Would that it were so….

      They have moved from 21 to 25 mm in some cases, though, so there is that….

      Maybe even 28s occasionally might be possible? Like the totally tubular days, when we had the bellissima 29 mm Campionato Del Mondo Seta. Those were the days, my friend, we thought they’d never end! We’d sing and dance, forever and a day….

      • What matters for brakes is where the pivots are located, not where the brake cable runs above the pivots. That is why the accepted terms ‘sidepull,’ ‘centerpull’ etc. are misleading. Both the modern ‘dual-pivot sidepulls’ and ‘centerpulls’ have the pivots in the same location (next to the rim) to keep the lower arms as short as possible, which minimizes flex.

        When you compare that to a classic sidepull (with the pivot on the fork crown), you can see why the modern brakes are so much more powerful. The pivot on the fork crown means that the lower arms are very long and flexible. The first-generation dual-pivot brakes were a strange hybrid with two pivots that were in different locations. I often wondered about that, but the newest designs finally have moved both pivots to the best location – just where Mafac already had placed them in their first centerpulls way back in 1952.

  8. cschick3 says:

    Very informative article! I often start discussions with people about disc brakes on road bikes. I can’t seem to conclusively finish these discussions because I get to talking about disc brakes on the professional level and realize that I don’t know why they do or do not use them. Thanks so much for writing!

  9. canamsteve says:

    Good points, but just how popular are rim brakes in MTB racing now? I’m not really sure, since I tend to ignore racing of any sort, but I doubt rim brakes are very popular. In cyclocross, an essentially made-up use for a bicycle, they still exist, I believe, But that’s like saying fish in an aquarium are a miniature version of the ocean. Not actually real-world.

    As a simple recreational and touring cyclist, the TdeF is about as relevant to me as F1 Grand Prix is to my commuter car. That Is, very distantly. The TdeF has apparently also “proven” that carbon fibre is the only suitable frame material (we can’t pick and choose our line of argument to suit) but I tend to ignore that as well.

    Rim brakes are simple and effective. Pads are cheap and in most case setup is easy. They work less well (at least for me) in the rain and muck, but that has never been an issue for my style of riding. They do mean that a worn rim requires a complete wheel rebuild, and that can be sooner than you might expect if used in wet and gritty conditions. It’s often cheaper to buy a new wheel than have one rebuilt, unless you have a dynamo hub where the hub is the major expense.

    You can’t easily switch wheel sizes with rim brakes (say 700c to 650B) but that’s dead easy with disc brakes. Disc brakes work as well as rim brakes for my style of riding (possibly better) and the cost is comparable. The weight differences between disc and rim brakes are insignificant for my uses. I believe disc brakes for bicycles are still in evolution and eventually will sort themselves into effective standards. In the meantime, I use classic rim brakes on classic road bikes and new bikes that emulate them. I use disc brakes on MTBs and touring and adventure bikes. It doesn’t have to be one or the other – even, apparently, in the TdeF.

    • They do mean that a worn rim requires a complete wheel rebuild

      Replacing rims does not require a complete wheel rebuild. It’s relatively easy to swap rims – Jobst Brandt described how to tape the two rims next to each other, and then just move over the spokes one by one.

  10. Tom larson says:

    I have no road bikes with disc so not drinking the koolaide but I have used Shimano hydro road and it’s amazing. Trust me if the pros bikes with disc weighed the same as caliper ( I don’t think they can quite get to I I minimum with disc ?) and wheel change was not an issue , the large majority of pros would be on disc for performance reasons over caliper. End of story. The reasons they don’t use them are not performance reasons.

    • Nobody says that hydraulic discs don’t offer enough performance. There are other disadvantages – including the ones you mention – that make many of us prefer rim brakes. At least for now, this includes pro racers, despite pressure from their sponsors.

  11. Luke says:

    Is the only real advantage of disc brakes just better performance in the wet? This year’s tour was pretty dry, but I wonder if we would’ve seen more disc use if there were more wet stages?

    • Good rim brakes work fine in the wet. Wet weather does show up the deficiencies of poor rim brakes: They simply don’t have enough clamping force to cut through the film of water on the rim. You get no braking power at all until that film has been removed. Discs clamp the rotor harder to make up for the smaller rotor, so they tend to work better in the wet.

      • Dr J says:

        Plus on top of that rim is close to the road and gets quickly dirty from all the sand, mud, etc. while discs remain relatively clean, being further away from road’s surface, which is another reason why disc brakes tend to work better in wet/muddy conditions.

      • Reuben says:

        Good rim brakes, on carbon rims, in the wet, work just as good as discs?

      • There are too many different disc and rim brakes to generalize. This article is about pros in the Tour de France preferring rim brakes over disc brakes despite their sponsors clear preferences for discs, and the reasons that have been reported for this preference.

  12. John Duval says:

    I don’t recall any time in the past where the public was less concerned about imitating the professional racers. Disk brakes seem to have been adopted in mass by the public some time ago, and the shear number of different bike niches that have no professional racing equivalent. On the other hand, bring up something like center pull brakes in any public forum, and you will be diluged with claims that they are “no longer used, for good reason”, which is an assumption with no evidence behind it.

  13. Good thing I don’t race in the Tour so I can keep using my disc brakes!

  14. Antoine says:

    Add overhauling constraints: circuit draining once a week + changing discs after each mountain stage due to overheating. You understand why team mechanics don’t like disc brakes!

    • Sebastian Taege says:

      Circuit draining once a week? You mean they bleed the brakes weekly? Why should they do so?

      DOT brake fluids are hygroscopic, I know, but it takes a few months until the brake fluid needs to be changed. A critical overheating of the rotors and brake pads might lead to a „boiling“ brake fluid, that causes bubbles of gas inside the system which might cause the brake lever to bottom out, but these temperatures are very high for DOT4/5.1 or the new Bionol introduced by Trickstuff for example. Descents cool down the rotors, as long as your are not descending with 8km/h on a 22% descent…

      The change of a disc brake rotor on a wheel takes less than a minute, even with the 6-bolt standard. They are quite happy to just swap the rotors and pads instead of the rim and pads after a mountain stage with unexperienced and/or heavy team members. Well, I don‘t think the mechanics do rim swaps at all, as they have plenty of spare wheels in their team trucks.

  15. GuF says:

    I do not care about pro tech/choice. Sadly I do weight more than 100 kg plus bike plus gear … the only way to get this system stopped properly is a disc brake with 180mm rotor. I do use mechanical DB, so much easier to adjust than V-brakes, so much better braking than road rim brakes and it is a “rim-saver” (aka money /risc saver), because no matter how often you use your brake (even in bad weather conditions) braking does not wear out the rim … I will never ever buy a new bike without DB again, for no reason.

  16. Tim Cupery says:

    New trends in road bicycle components usually come first to the pro peloton, and trickle down to the average user from there. “What the pros use” is often a selling point.

    But in the case of disc brakes, the pros seem substantially behind the average, non-racing users. Which makes me wonder whether manufacturers actually have so much incentive to get pros riding disc brakes. Adoption by the general consumer has been happening even as the pros still largely ride rim brakes.

  17. Martin Lemke says:

    As I understand disk brakes on his Venge didn’t really help Sagan to negotiate the corner when he crashed on Stage 17, or, as he put it, “I was braking but it wasn’t enough”. I wonder whether the Sagan’s mistake was caused, – at least partially, – by an overestimation of the disk brakes power.

  18. Sim Richards says:

    Thank you for bringing this to our attention Jan. Not having the luxury of a team car with a rack of spare wheels or a mechanic to true my wheels at the end of the day or adjust my pads after a long decent or clean my rims after a wet ride or rebuild my wheels when the rims wear through I’ll stick with my hydraulic disks which suffer none of these issues. Those of us who are not pros are simply choosing disk brakes because they’re better in our world meaning lower maintenence and safer to use.
    I’d also suggest that any grabbiness that Jan suffers can be overcome with the finesse that comes with practice.
    I’ve never noticed any spoke wind-up but if it is the case, it would serve to decrease the sharpness of the brake. In the early years of ‘V’ brakes Shimano used to insert springs into the front brake pipe (noodles) because they were so much sharper than the cantilevers they were replacing and people were simply not ready for the improvement in performance and Shimano worried about folks going over the handlebars. We don’t have to do this anymore and in the same way we’ll get used to the improved braking offered by disks in time.

  19. Rick Harker says:

    Amazing how advocates of either braking system will argue their back teeth in favour of what they use and find fault with the other. Mostly petty issues in the real world of cycling enjoyment.

  20. Chris V. says:

    There is no doubt to me that with proper research and development disc brakes on road bikes will overtake rim brakes! This article states the very obvious reason why the majority of the pro peleton is not on discs……because of the lack of support and uniformity among manufactures and neutral support vehicles. In a race where seconds count and millions of dollars are at stake, the teams are going to use what will give them the greatest advantage of winning. Rim brakes have been the standard for many, many years. So they have been R&D’d to the point of near perfection. But wasn’t there a time when racers wanted carbon rims, and standard rim brakes did not play well with this technology? So manufacturers created special side walls on the carbon rims to help with brake fade and such.

    The old argument “the bike industry is pushing new stuff on us to make more money” is short sighted! The rim brake vs. disc brake debate has been going on for years among mountain bikers who love to argue on internet forums. If you want your V-brakes back, I say have fun. I’l get to the bottom of trail much quicker and with much less fatigue. Hydro discs are standard now on most decent quality mountain bikes. I wouldn’t even consider riding a mountain or rode bike with the best cable actuated discs!!

    As for pro riders and their descending speeds. I say that has much more to do with the rider, and much less to do with the bike.

    • My experience on mountain bikes is limited, but disc brakes make sense there. Road bikes, even those for gravel riding, are very different machines, and it appears that the jury is still out which braking system is better.

    • Tom says:

      Amen to this. Not just with descending, hasn’t most everything been mainly about the rider?

      I recall reading somewhere, maybe here, that after 50 years of technological advancements in cycling, the TDF average speed increases were minimal from the 1960’s forward. This seems to resonate in that vintage photo of Bobet. Of course many will debate the wide array of TDF conditions from year to year preventing a sound comparison, yet the latest disc benefits seem to play into this recurring notion.

      For you golfers, I’ve heard the same story with ball technology. Despite major design changes, why no marked distance increases? A major golf ball manufacturing CEO was asked, then what are you selling? Hope…he said.

  21. reuben says:

    with all this discussion, there are 2 huge factors left out (so far):
    1) Carbon rims, which have different braking performance than metal
    2) Riders weight;

    combine a heavier rider (i’ll say, over 190 lbs), carbon rims and a bit of rain and you can see a clear advantage for disc brakes, especially for the amateur ranks.

    Sure, you write: “The answer is simple: Really good rim brakes stop just as well as even the best disc brakes.” – but assuming carbon, this also means a USD 2500+ retail wheel-set (one that brakes great); and even then, if you’re over 190 lbs, the braking is still often compromised.

    • In the past, carbon rims didn’t work well with rim brakes, but this now seems to have been resolved to the point where disc brakes no longer provide a clear advantage.

      You are right that heavy loads require better brakes. However heat buildup is usually the biggest problem, and disc brakes are fat worse in this respect. Many disc pads fade quickly once they overheat, and the sudden loss of braking power is quite disconcerting.

  22. John.J says:

    Magura hydraulic rim brakes, the best of both worlds.

  23. Archetype says:

    Disc rotor brakes are superior in their ability to stop with more consistency, less fade and power.

    • I think it’s hard to generalize. There are so many disc and rim brake designs out there…

      I haven’t yet found a mechanical disc brake that can lift the rear wheel of the bike. I had Shimano disc brake pads fade to the point where the bike continued to roll at low speed on a 15% hill no matter how hard I pulled on the levers. And I’ve had more than one disc brake suddenly reach the optimal temperature in mid-corner and grab much harder than before.

  24. Vlad Luskin says:

    Please don’t badmouth Campy Deltas. Properly set up, they worked better than Super Record. Set up was a huge pain, however, and it was the difficulty of working on and adjusting them that led to the rebellion, not any perceived functional deficiency.

    • Thank you for adding that information. My experience with Campy Deltas is limited to one bike, where the brakes were so hard to use that my hands weren’t strong enough. Due to the limited experience, I just wrote ‘sub-optimal’ without further details. I think we can all agree that the brakes were sub-optimal, whatever the reason.

  25. Greg says:

    For road bikes…
    In wet conditions both tires and rim brakes lose traction. Disk brakes do not lose traction in the wet – making it much easier to lock up wheels, lose control and crash.

    Disk equipped tandems have had problem with over heating warping 200 mm disks.

    Center splined disks cannot be shimmed.

    Disks are easy to damage and should be removed from hubs on bikes which are to be shipped.

    Yes I love the disk brakes on my gravel and mountain bikes but I’ll stick to rim brakes for the road.

  26. John C. Wilson says:

    This spurred me to view some video of the 1952 Tour with all the coureurs on their new Mafac. Completely different roads. Sometimes roadway just 2 meters wide. With running meltwater and gravel. Much better graded than a typical American farm road but still not pavement. Only glimpses because the camera car not able to get the best shots in the high mountains.

    What riders are doing with their brakes is different and new. Not long ago, even in a car, if the grade was long and severe the likely course of action was to pull over and enjoy the view while the brakes cooled. Descents that ruined a rim in a single ride were places that bikes did not go. So product development will happen.

    Those 66 year old Mafacs are still useful and desirable. Disc brakes have not appeared that check all the boxes immediately.

    • Yes, the old races were quite different from today. Even so, I don’t think TdF racers stopped in 1952 to let the brakes cool. But then, bikes reach much lower terminal speeds than cars, and on most descents, even on gravel, only little braking is needed. It’s only when you reach a turn that you have to slow down. On gravel, tire traction limits your braking, and almost any brake is powerful enough. On pavement, you can brake much, much harder, which is why descending on pavement requires much better brakes. In fact, it may well be that the paving of the mountain roads in the 1940s led to the development of better bicycle brakes, culminating in the 1952 Mafac.

  27. cbwesq says:

    So the pros in the Tour all switch to rim brakes in the mountain stages because they are better than discs. Winning is most important. The sponsors be damned! (Coincidentally good for Compass – the seller of fine rim brakes.) I am with you so far. So why are none of the pros in the Tour riding anything wider than a 26mm tire? Haven’t you given us BQ readers reams of “science” that says wider is better despite the extra weight (encouraging us to buy wider, heavier Compass tires)? I thought we all just agreed the pros will use the best regardless of anything else because winning is most important…

    • I understand that your comment is intended tongue-in-cheek. In this post, we’re just reporting facts – if you doubt that most racers in this year’s Tour used rim brakes, check the online photos. A good source is the official Tour de France web site. I had a hard time finding a photo of racers on disc brakes to illustrate this post.

      As to wider tires, Bicycle Quarterly‘s tire tests have shown that on smooth roads, tires wider than 25 mm are neither faster nor slower than wider ones. So there is little incentive for pros to go wider than 25 mm on the smooth roads of the Tour, especially since their sponsors make bikes that don’t easily fit wider tires. Coincidentally, Compass offers 26 mm tires, so we don’t need to convince you that wider tires are better.

  28. Martin Petersilka says:

    What kind of brakes were used in racing before MAFAC introduced their centerpulls back in 1952?

    • Most racing brakes in the 1940s were sidepulls. Many of them were cast, not forged, and technical reports in Le Cycle mentioned brakes breaking as a serious problem. The Mafacs were forged, making them far stronger. That is why they were labeled with the words ‘Forge Dural’ instead of the model name ‘Racer’ at first.

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