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If that were the case, surely Tour de France riders would use wider tyres to gain more grip going around corners, especially in time-trials or stages with sprin
by louthy 5y ago
If that were the case, surely Tour de France riders would use wider tyres to gain more grip going around corners, especially in time-trials or stages with sprint finishes.
Doesn’t a greater surface area touching the floor means more frictional effects when pushing against the road?
- bretthopper 5y agoThe one caveat this article doesn't mention is worse handling but they replied in the comments about it. And handling matters way more at higher speeds, plus they commented the extra weight matters more for steep climbs too.
- Cockbrand 5y agoThis, and a wider tire also has a larger front surface, resulting in more aerodynamic resistance. As every watt counts in the pro peloton, this is an important factor. For us amateur riders, probably not so much.
- loeg 5y agoI was a little surprised: the weight difference isn't huge. It is about +27% between Conti 5k 25mm and 32mm, or 60 grams per tire. Aerodynamics are the only real reason, I think.
- mantas 5y agoThey're already using wider tyres than a decade ago.
- scoofy 5y agoYes. Much, much wider. I nearly passed by this comments section because i assumed everyone already knew this was true.
- at-fates-hands 5y agoI think you're exaggerating a bit. From 2018: https://www.businessinsider.com/tour-de-france-wider-tires-lower-pressure-faster-2018-7 https://www.businessinsider.com/tour-de-france-wider-tires-l... "It depends on the road surface, but 10 years ago the standard was 23mm tires at 8 or 8.5 bar, or 115, 120 psi," Brown said. "And now it's 25mm for regular road racing and 7 to 7.5 bar for front and rear, so a little less than 100 to 110 max on the bikes." 2mm and 10psi less is not that huge a difference.
- mantas 5y agoIt's pretty big when you take into account whole context. Stuck up "socks size is a rule" UCI, historical norms, technical limitations (25mm is a limit for caliper brakes), tire tech (wider tires used to be heavy).... My prediction is 27mm being the norm in next 5 years. Currently I'm riding a decade-old road bike. It was fancy at the time because it fit 25mm tires without issues. People would give me shit for "slow" tires on group rides. But 25mm tyres improved a lot in that time. Now I wish it could take 27mm :(
- loeg 5y ago25mm is not a limit for caliper brakes? No idea why you claim that. One of my bikes has calipers and can fit 33mm tires. Also 28mm is extremely common; 27mm doesn't exist.
- usrusr 5y agoThere are definitely calipers that can't take a 28. And the mounting bolt position isn't a precise norm, there are frames that put the brake considerably closer to the rim than others. And not without reason, the effective length of the caliper arms has an obvious influence in brake leverage.
- mantas 5y agoClassic road bike caliper breaks don't >25mm. 33mm would be cantilever CX brakes. Or a weird type of caliper.
- kazinator 5y agoRegardless of whether it is the case or not, Tour de France riders would not use wider tires to gain more grip around corners because ... wider tires do not add more grip. You get a larger contact patch from a wider tire, but that patch has less pressure. Grip (static friction) is coefficient of friction, times weight. The coefficient of friction is a constant which depends on the materials. Rubber on road is no exception.
- Retric 5y agoThat’s the first order effects, however substances deform under pressure which is just one of many complexities involved. For car tires on dry pavement you get maximum grip from racing slicks. Unfortunately they need to swap in the rain.
- kazinator 5y agoFirst order effects are the only effects which matter in cycling. This isn't aerospace. Racing slicks are a different material. In Formula 1 racing, you go through multiple tires in one race. In consumer driving, tires are expected to last 100,000 km or more. There is even the practice, in racing, of using chemicals to attack the rubber to soften it.
- carl_dr 5y ago> In Formula 1 racing, you go through multiple tires in one race. They could easily make a tyre which lasts the length of a race, but they mandate pit stops and two different tyre compounds to add interest - teams can use the mandatory pit stop to “undercut” or “overcut” competitors. In fact, IIRC, for the 2005 season, changing tyres mid race for anything other than safety reasons was banned. > In consumer driving, tires are expected to last 100,000 km or more. This is much closer to 25,000-50,000km, and peaking at 70,000km. Source: https://www.pirelli.com/global/en-ww/road/how-many-kilometres-can-a-tyre-cover https://www.pirelli.com/global/en-ww/road/how-many-kilometre...
- Retric 5y agoUsing a different material is in effect irrelevant, they still get maximum grip from maximizing contact area because of how rough roads are. Ultra narrow tries need higher internal pressures, which limits how much the deform and thus reduces grip. Also, F1 cars are going up to 246 mph and doing heavy acceleration and breaking throughout the races, which seriously heats up the tires. Normal road tires would actually die sooner under those conditions. Just read up on who long tires last when people are doing street racing, burnouts, etc.
- deleted 5y ago[deleted]
- carl_dr 5y agoFrom TFA: “ We tested our tires on smooth pavement at 29.5 km/h (18.3 mph), and found no speed difference between narrow and wide tires.” A professional peloton rides at 28-30mph on the flat and significantly faster towards the end of a flat stage - I bet at higher speeds, for professionals where every percent matters, it does make a difference. Certainly for my level (and I have ridden for an hour at 18mph average) it doesn’t.
- bmj 5y agoIt is worth noting that tires used by the pros have used slightly wide tyres over the years, and for events like Paris-Roubaix and Flanders, they absolutely use wider rubber on frames with more clearance.
- medstrom 5y ago"We tested our tires at the same speeds and found no speed difference". You don't say?
- periheli0n 5y agoThe problem is that wide tyres tend to eat lots of momentum in corners. When going mainly straight and/or on uneven ground, use wide tyres. When cornering a lot, use narrow tyres.
- outside1234 5y agoAlso, they have higher raw weight, so thinner is better uphill.
- mijamo 5y agoThis is actually not really true. Competition bikes have a minimum weight nowadays, and technology is that advanced that it wouldn't be a problem to add some weight here or there because the bike would stay the same weight in total as they have so much margin else to keep in track with the minimum weight. This is why most teams have switched to disk brakes btw, and that they can have all the electronics onboard with power meter, bike computer etc.
- localhost 5y agoBut there's rolling "sprung" vs. static "unsprung" weight (the examples you listed). You care a lot more about rolling weight as that affects the acceleration characteristics of the wheel - that's really important at the limits.
- oriolid 5y agoIf you bother to do the math, but simplify things so that all the mass of wheels is at the contact patch, you'll end up that rotating mass has twice the kinetic energy and takes 2x effort to accelerate and decelerate. Now if you check how large fraction of the mass of rider and bike the wheels are and how fast bikes accelerate, it's kind of insignificant.
- usrusr 5y agoTechnology was advanced to routinely end up with bikes beneath the minimum, but those days are over. With wider tires, disc brakes, excessive focus on aerodynamics and even wider gear ranges they are usually racing considerably above the limit. These days you'll find bikes in the range of 5000 euros advertised that are considerably heavier than what you would have got for 1500 ten years ago.
- dredmorbius 5y agoStatic friction being constant regardless of contact surface presumes a uniform surface consistency (uniform frictional coefficient). Large (an knobby) tyres are a statistical bet that there will be sufficient friction somewhere on the contact patch. When riding over nonuniform surfaces (dust, loose pebbles, twigs, mud, leaves, and embedded rock), that's a gamble the large and contoured tyre is far more likely to win. On a velodrome deck, not so much, and cross-sectional area, thermal losses from compressive deformation, angular momentum, etc., favour thinner tyres and higher inflation pressures.
- bernulli 5y agoIs the static friction what is going on with wheels? Why do race cars (dragster, F1, etc) have wide, smooth (un-knobby) tires if it's so disadvantageous (no gain, but higher weight and moment of inertia)?
- dredmorbius 5y agoFor your standard street-car tyres ... mostly, modulo variations in surface, rain, snow, mud, etc. On reasonably fresh dry clean tarmac though, yes. For racing tyres ... you're getting into a differet set of circumstances and uncomfortably far from my knowledge and experience, though my understanding is that the rubbers are specifically engineered to be sticky, more so at high temperatures (hence why drag racers spin out, it warms the tyres). That's no longer the domain of static friction. There's also the matter of thermal management, where tyres at high speeds generate a lot of heat. How much size affects and/or is determined by this, I don't know. I am aware that street-tyre speed ratings are based on thermal properties, however. Knobby tyres are most effective on non-uniform surfaces: dirt/rock and mod most notably.
- adrianN 5y agoIt is my understanding that race cars have wide tyres to shed more heat. Tyres melting is a problem at F1 speeds.
- saberdancer 5y agoSofter tires give more grip but are less resistant to shearing forces. Having a wider tire helps with that.
- taude 5y agoHere's a pretty interesting article discussing Le Tour slowly getting wider and wider tires, compared to a decade ago [1]. Granted their use case is going to be at a very different scale than most rec/serious non-pro riders. But I know that most all my friends and I ride 28s on our road bikes these days compared to 23s a long time ago. More comfort and more forgiving. My current road bike maxes out at 28, but I'd probably go a little wider if I could due to the nature of the roads around here (lots of potholes, chunks, crappy shoulders, etc...) [1] https://www.businessinsider.com/tour-de-france-wider-tires-lower-pressure-faster-2018-7 https://www.businessinsider.com/tour-de-france-wider-tires-l...
- bombcar 5y agoYou also have the theoretical perfect tire vs the actual best for the rider - the more comfortable tire may be better overall as it allows the rider to perform better and for longer.
- gameswithgo 5y agoTour De France riders do use wider tires than they used to these days. At some point the width starts imparting aerodynamic drag penalties that are worse than the handling gains.
- CalChris 5y agoYou can't really rely on the Tour de France peloton for guidance. They're pretty conservative and, to a degree, ruled by fashion and sponsors.
- carl_dr 5y agoI guarantee the masters of marginal gains, Sky (now Ineos Grenadiers), will have spent some resources on looking at which tyres are actually faster for them, regardless of fashion or sponsors. I think it’s safe to say that whatever they ride on are the fastest options - and every other team would follow - or that within a certain set of parameters, it doesn’t matter. I just tried to search to see if Ineos run different tyres on different race and stages, and found nothing conclusive.
- dropofwill 5y agoAccording to eurosport commentary they do change wheels and tires based on the race. That said they use rim brakes so probably never go over 28m tires.
- deleted 5y ago[deleted]
- idoubtit 5y agoCycling teams spend tens of millions each year, with Ineos going over € 50m some time ago. Are they conservative? They benchmark their material in wind tunnels. Sometimes they bend the rules with high-tech material[^1]. There's no way a team competing in Tour de France would choose fashion over performance. [^1]: https://www.theguardian.com/sport/blog/2017/jul/03/vortex-suits-team-sky-tour-de-france-marginal-gain https://www.theguardian.com/sport/blog/2017/jul/03/vortex-su...
- usrusr 5y agoAnd quite a bit of the money they spend comes from companies trying to sell gear to hobbyists. It's a rather wild mix between ride what makes you fast and ride to pretend that it makes you fast.
- dahart 5y ago> Doesn’t a greater surface area touching the floor means more frictional effects when pushing against the road? Good question because at first I thought it might be negligible due to the tire normally being in a state of static friction relative to the road. But some quick searches showed me that rolling resistance is related to how large the contact point is, like you suggest, along with a variety of other factors. https://en.wikipedia.org/wiki/Rolling_resistance https://en.wikipedia.org/wiki/Rolling_resistance I don’t know how reliable this is, but googling brought me to this site which compares bicycle tire brands according to rolling resistance on their test machine. Apparently, some 25s have all the 23s beat. If true, the variability range for bicycle tires is a lot wider than I expected. https://www.bicyclerollingresistance.com/ https://www.bicyclerollingresistance.com/
- Cockbrand 5y agoI've bought a few tire models after researching at bicyclerollingresistance.com, and while I certainly don't have the means to do proper scientific research, I feel like I did buy the right stuff.
- jeffbee 5y agoSame. I don't have any rational basis for it, but I've been happy with my tires. I think the best thing I learned from that site is even slightly larger sizes have a much bigger effect on puncture resistance than better construction.
- nchie 5y agoI love brr.com and have used them a lot, but in the context of this thread, it's important to consider that the surface they test the tires against do not have the kind of imperfections you see on the road. This means lower pressure will always perform worse in their tests, which goes against the more recent consensus in that each road has an optimal pressure depending on its roughness.
- davisoneee 5y agoOne thing every person has missed so far is that often the TDF riders are on rather narrow bikes with very little clearance. This helps give an aerodynamic profile. Even at a few watts, this is considered worth it. You would likely have to do a lot of research to go with bigger wheels, as that would been wider fork, and thus throw off aerodynamics. A bit daft, in my opinion, given that it's mainly the domestiques who are in the wind and the ones behind, and in the peloton, can be putting out significantly less energy. May even be better for recovery having a bit more comfort on the bike through wider tyres with a bit lower pressure.
- uoaei 5y agoPath Less Pedalled recently had a great discussion on this with Josh Poertner, the owner and president of Silca, the tire pump company: https://www.pathlesspedaled.com/2020/01/09/your-tires-are-lying-to-you/ https://www.pathlesspedaled.com/2020/01/09/your-tires-are-ly...
- adnmcq999 5y agoYeah I haven’t read the article yet but OP is making flat-earth level claims Even in Paris Roubaix (where there are cobbled sections) they ride 28s
- deleted 5y ago[deleted]
- AtlasBarfed 5y agoTour riders are EXTREMELY conservative, well they were back when Lemond pushed clipless pedals, more helmets, and aerobars. The nameless scapegoat who was totally the only person using EPO pushed more thorough full-system wind tunnel testing/aerodynamics and a lot more scientific testing, and even (gasp) clincher tires. Euro riders for a long time worshipped Eddy Merckx (who was totally clean and never doped) and thought you basically only needed an italian bike and nothing else and were culturally averse to change. Also, keep in mind the Tour riders are basically showcasing industry products, and those products aren't really that diverse in their sourcing, especially with globalization. They all run on whatever they are getting for free or at a vast discount from the two or three providers in each equipment category.
- lamby 5y ago> "If that were the case, surely Tour de France riders would..." Apologies for appearing to pick you out here, but your comment is representative of a number of eminently "logical" comments made here (as well as many analagous comments on HN in general). So, modern professional cycling is a sport with a 100+ year history, and in 2021 represents a bizarre fusion of the sports entertainment industry, the romantisation/revival of the past, celebrity culture, global cycling manufacturers, the mid-life crises of Wonka-esque team owners, the aestheticisation/fetishisation of the working class, the 'Olympics industry', lurking labour disputes, the fast fashion sector, the ad-hoc application of modern sports psychology, a looming confrontation with its historical emphasis on (mostly horrifically underpaid) white males, neoliberal economics, petty and bountiful financial corruption, widespread pharmaceutical corruption, and the influence of petrochemical money from several ex-Soviet states... All mostly filtered through the celluloid lens of France and Italy, two European nations that have an extremely complicated relationship towards their own history which comes out as a muted pageant of lukewarm national pseudopopulism that is not only is confused within its own borders, but is more-or-less unintelligible to those in the Anglosphere. To imply in any way that a kind of efficient market analysis can apply to decisions made within this sport (that has, if I remember correctly, strict rules about sock length), suggests an insufficient engagement with the background.