8 ms·

Unless you're on the ProTour, choose riding comfort over rolling resistance. Also see https://www.renehersecycles.com/12-myths-in-cycling-1-wider-tires-are-slo

Unless you're on the ProTour, choose riding comfort over rolling resistance. Also see https://www.renehersecycles.com/12-myths-in-cycling-1-wider-tires-are-slower/ https://www.renehersecycles.com/12-myths-in-cycling-1-wider-... for a related myth-debunking of the impact of tire width (which contributes to rolling resistance) on speed.

ActorNightly 2y ago
>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement road usually doesn't require less than 60 psi, and above 60 psi the rolling resistance of wider tires is about the same as narrower tires, but watt savings from aero can be significant. I got a gravel bike to replace my old road bike because everyone was raving about it, and I absolutely hated riding it. Sure, at slow recreational speeds, it was more comfortable, but when getting places, it just didn't roll as well down hills, making me having to pedal more over extended times to get uphill. Now I ride an aero road bike with TT bars, with 28c tires, and even when running them at 60-70 psi for rough pavement, the aero gains from the narrower wheels are significant, as I can pick up speeds over 30 mph on some descents which carry me way further uphill.
- bradfa 2y ago
  It depends on what kinds of roads you ride on. If you're always riding nice smooth asphalt, then yes, high pressure narrow tires are going to be faster pretty much always. But if you're riding on really crappy asphalt, chipseal, or on dirt or gravel roads, then a wider more supple tire may be just as fast but a whole lot more comfortable due to the ability to run lower pressures. The power losses on a perfectly smooth road are aero and rolling resistance. But once you get onto bumpy surfaces, now you also need to consider the power losses of the bumps on the bike AND on the rider because the rider is the one supplying the power, even the power which does not transmit through the cranks. Although I do agree with you partially, if you're racing, ride what ever makes you fastest. Energy efficiency isn't paramount, getting to the finish first is. But if you're not racing, then really consider if the tradeoff of comfort is worth it. The BRR website's test protocol uses a fairly smooth metal drum for testing. This is good for testing rolling resistance but not for testing total system losses over rough roads. So although BRR is a great resource, take it with a grain of salt.
  - wink 2y ago
    The real eye-opener for me were that my kinda knobby MTB tires apparently have nearly the exact rolling resistance as my Schwalbe Marathon Plus on the Gravel Bike. So although they're a lot thinner, nothing is gained here at all. (If you assume enough pressure in the MTB tires on asphalt).
    - ip26 2y ago
      I regularly clock 21+ on my knobby, slack MTB on flat pavement, but struggle to break 20 on many other bikes…
- tleb_ 2y ago
  The article from renehersecycles.com does not really agree with your comment, and explains why.
  - ActorNightly 2y ago
    28 to 32 is negligible aero wise for most people, I don't disagree. 30 mph (or slower into the headwind for an air speed of 30 mph) will start to matter a little bit though, math doesn't lie. But saying wider tires are better as a blanket statement implies that you can run like 45c gravel tires and still have the same aero drag, which is by far not the case. https://www.hambini.com/cycling-aerodynamics-wider-tires-and-rims-examined-in-engineering-detail/ https://www.hambini.com/cycling-aerodynamics-wider-tires-and...
- arghwhat 2y ago
  On descents you can also pick up a lot of speed by getting a heavier bike and supersizing your meals at McDonalds. Speed on descents isn't really that relevant - you're descending, so unless you're racing it's practically effort-less. What matters for people biking normally (i.e., not recreational road bike racing) is assistance in the 10-15mph regime, on flat terrain or climbing. Large changes in rolling resistance matters here, like going from an almost 40W tire to a 20W tire. But aerodynamics have a very minimal effect here, and going below 20W tires won't really make a meaningful difference in biking effort compared to the effect on your butt and wrists.
  - bluecalm 2y ago
    Going from 20W tire to 10W tires is going to be massive even more so for recreational not so fit riders. Such a rider may output 120-150W on average. Getting 20W free (there are two tires) results in a difference comparable to installing a small motor on your bike.
    - arghwhat 2y ago
      No: A 20W tire is a 20W tire at 18 mph. At 10 mph, it's roughly a 10W tire (rolling resistance should be mostly linear at these speeds). Going from 20W to 10W tires therefore only saves you 10W total at those speeds. At 120W, you are idle pedalling. You do not really pedal lighter, so saving a few watts mean an increase in speed, but as both rolling resistance and aerodynamic drag goes up with speed the gain becomes small. At normal climbs - the time where you'd wish pedalling was easier - you're either 1. spend in the area of 200-300W maintaining the same speed without increasing rolling resistance, making rolling resistance a smaller part of the load, or 2. drop to a granny gear, going very slow to maintain your 120W and thus making the rolling resistance negligible with any tire. In either case, rolling resistance matters much less in climbs.
  - ActorNightly 2y ago
    Yes if you bike slowly, wider tires are better. However I mentioned that in my post. A lot of people who are into biking are in the fitness zone where they are going into speeds where aero starts to matter way more. This is especially true when you consider wind.
- basil-rash 2y ago
  If your primary goal is minimizing work, you can also try an electric bike, or driving! Tongue in cheek, but isn’t fitness the point?
  - grayrest 2y ago
    While it's certainly possible to have a throttle most electric bikes require pedaling and therefore some degree of exercise. In many cases it gets people riding that would not be riding otherwise. For people that are actually interested in fitness it's a lot easier to maintain zone 2 on real roads with electric assist without the impulse to push it a bit up the hills. I did far more aggressive rides when I had access to my electric road bike than I do on other bikes because I knew I had a bail out if I pushed too far. Nobody's going to congratulate an e-bike rider on their feats of endurance or power but there are lots of points between a normal cycling effort and no effort at all.
  - ActorNightly 2y ago
    Same fitness on a more efficient bike = longer distance or higher speed.
    - basil-rash 2y ago
      To what end?
      - seadan83 2y ago
        Travel far, see more. Sometimes people riding bikes are in a rush (eg: morning meetings and commuting. [And no, drinking is not always a solution, in my situation it's a 30 minute drive or bike ride either way, and driving then costs $30/day and the time to find parking makes it slower. The drive Honda will be usually faster but has to be after 6pm, otherwise it is an hour to get home. This is a 10 mile commute I'm describing, and fir about 6 hours out if the day it's a traffic jam half of the way)
      - ActorNightly 2y ago
        Lots of factors. For example, i get way less tired riding a road bike in the heat than a mountain bike, because the airflow at speed helps me keep cool.
- bluecalm 2y ago
  Gravel bikes are going to transform in coming years as now they are neither very comfortable nor fast. It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain. The reason is that soft casing is way more important than knobs when it comes to rolling resistance and MTB tires can be made soft because all the additional rubber coming with width while gravel tires are usually harder and thus slower (and less grippy and less comfotable). Notable exception is Continental Terra Speed but it's still not as good as Race King and way more puncture prone. The problem with most current gravel frames is that they don't fit wide and fast MTB tires so you are stuck with the worst of both worlds - slow, not comfortable and still not grippy/soft enough to go fast off-road unless it's a very well maintained road.
  - latchkey 2y ago
    I absolutely love my Lauf with their weird suspension front fork. Bike is super comfortable to ride. Also has plenty of width room for wider tires. I run WTB Nano 40c, which are a great mix for road/gravel.
  - ActorNightly 2y ago
    >It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain. ...except when you are going fast. But I do agree that honestly, full on XC MTB are better than any gravel bike for mixed terrain. Modern race XC bikes are not only lightweight, but have enough suspension travel front and rear to tackle super rough trails, which means you don't have to rely on tire pressure for compliance (although QC on the carbon frames is questionable even from the bigger brands). That being said, when it comes to road, ultimately, aero bikes are still king for efficiency if you are least moderately fit.
  - pandaman 2y ago
    Gravel bikes are much more comfortable and fast than road bikes on unpaved roads, which is what they are designed for. Wider wheels will add more weight and more angular momentum, making it harder to climb and harder to steer so you might need to replace the drop bar with the MTB flat bar and without the drops you can move the saddle into a more comfortable position as well... ending with a hardtail w/o the suspension fork.
- aayjaychan 2y ago
  it's always wild to me hearing what pressure people use. on my road bike with 28c and inner tubes, 60 psi is what i use on _good_ road surface. maybe the roads are just shit here, but even 55 psi feel rough. i usually run on around 50 psi, 40 in winter. there was a time i lost my track pump and i just pump the tyres using a mini pump without a guage. later i discovered i was running on something as low as 30 psi. i have never had a pinch flat. i don't think i'm particularly light. full load when doing groceries is probably 85 kg. is it just that my pressure juage is woefully inaccurate?
- pmontra 2y ago
  28 mm tires used to be huge tires. Pros didn't ride anything wider than 23 mm in the 90s. 25 mm would be for special occasions. 21 mm on tracks, sometimes even 19 mm. I think than Valverde used a 28 mm in a Roubaix and at the end of the race said that it was too much and not worth of the extra weight and front section. Every pro is riding on 30 or 32 mm now. Of course the rims are totally different and wrap those tires in a way that the old metallic rims could not do, hence the aerodynamic gains. Edit: I've got a gravel bike with 42 mm tires and a 28 mm set. I use the 28 mm when going in the hills on asphalt. I'm with you on that: it's a day/night difference. On mixed mostly flat terrains the 42 mm tires are the best compromise.
  - bennyelv 2y ago
    Unfortunately you cannot discount the “sponsor effect” here. Wheel manufacturers have been pushing wider rims because it helps them sell another set of wheels to everyone. In the days of rim brakes a wheel had a finite life (the length of time it took to wear down the braking surface). Then shimano and the frame builders pushed everyone to disc brakes, so the wheels now last for ever. What do you know, 2 years later all the wheel manufacturers are claiming “wide is better” and flogging everyone new wheels. I’ve not seen any clear evidence that they’re right, and there’s lots of intuitive reasons to think that wider tyres will be slower (aerodynamics!). I remain sceptical, but genuinely hopeful that someone who thinks that wider is faster can provide me with some solid evidence…
    - mariusor 2y ago
      I feel that any marketing strategy that relies on the niche of a niche formed of the people that would buy the cutting edge cycling gear just because it's presented as an improvement over the status quo, would hardly bring any benefits to any wheel maker. I am 100% sure that in this age of "marginal gains", the pro tour teams would not go for anything that doesn't give them it unless severely hamstrung by sponsorship deals. And I doubt that the wheel sponsors don't have multiple sizes available. And I think you're severely overestimating wheel life span for modern models, at least due to the fact that carbon is more brittle than more pedestrian materials. Just look for Pogacar's fall earlier last week in the Giro to see how a simple flat tire makes the whole wheel a risk.
- edmundo 2y ago
  >Speeds over 30 mph on some descents All that aero is probably not working so well for you. Even on my mountain bike with grippy and wide tires I get over 40 mph. On my gravel I can hit over 50 mph, and thats with 45mm tires.
  - dbrowne 2y ago
    I can get close to 50 mph (safely) downhill on my 30 year old steel framed 8 speed bike with 20mm tubular tires pumped to 120 psi. No problem with riding at 20 mph on the flats and I'm close to 60 years of age. My "aero" CF bikes with deep carbon rims are minimally faster. Speed is irrelevant unless you are racing. Enjoy the ride and stop relying on equipment for minimal performance gains.
  - ActorNightly 2y ago
    Its totally possible to hit over 40 mph on steep hills on an MTB, especially if you weigh more. I was more referring to slight grades with just pure rolling without pedaling. Im in Austin so I frequent COTA Bike nights on Tuesdays on the track. Coming down the hill from turn 1 with other riders is a very good test of aero efficiency, because there is a slight uphill after the bend. Couple of my friends ride gravel bikes, one of them is heavier than me, and its pretty clear that that my bike is more efficient.
    - garphunkle 2y ago
      Shout-out to Violet Crown, PHENOM, Breakfast Club, UNITED, Night Owls, and all the other great cycling clubs in Austin! Wonderful community that I still miss. Have you tried swapping bikes with your buddy? Are you two the same height/weight? Who has the more flexible spine? It would be fascinating to measure aerodynamic efficiency for two riders on the same bike. Is the more variation within populations, or between populations?
- YuukiRey 2y ago
  Aero also matters at low speeds since you spend more time on the course
wink 2y ago
If you look at the tires (let's ignore road bikes for now) the vast majority is between 15ish and 28ish Watts (I usually look at Gravel and MTB tires). Then look at the methodology: > The total rolling resistance of an average rider with a total bike + rider weight of 85 kg / 188 lbs that averages 28.8 km/h / 18 mph will be double the rolling resistance you can find on our website. If you're heavier than that or average higher speeds, the total rolling resistance will increase roughly linearly with the increase in weight or speed. All I can say is that I am a lot heavier than 85kg with my bike and that I am usually riding at 20-25 km/h. So let's say the lower bound they mention would 2x15 and the upper bound 2x25. Let's assume 127kg with luggage, that scales linearly to 3x15 - 3x25, but the speed is only 2/3, so we can dial it back. My napkin math now says the difference between a good pair of tires and a bad one is 30 vs 50. And I'm still not sure if that translates 1:1 to the assumed typical 100 Watts of an average rider.. I found https://www.gribble.org/cycling/power_v_speed.html https://www.gribble.org/cycling/power_v_speed.html though and if I plug in my numbers, the coefficient of rolling resistance is our variable, and 0.00465 -> Rolling resistance is working against you with 5.79 (N) of force, or 50.15 watts of power. 0.00273 -> Rolling resistance is working against you with 3.40 (N) of force, or 30.01 watts of power. So the tires make about 2-3 kph, which fits what most people have posted when I was researching this.
deleted 2y ago
[deleted]
Arnt 2y ago
What's riding comfort? I let both of my kids try things and choose, both choose tires with fairly low resistance. One more so than the other, but both clearly regarded high pressure as somehow comfortable: Apply pressure to pedal, feel bike move. Responsiveness.
kohlerm 2y ago
Riding is more fun with less resistance, it just "feels better". That alone is an argument to choose the correct tire (there are trade offs obviously). From my own experience (MTB) I can say that the difference in rolling resistance are very noticeable.
wffurr 2y ago
I choose flat resistance over either. Schwalbe Marathons or equivalent on all my bikes, but I use my bikes as my primary mode of transportation in the city. I really don’t want to deal with flats when I have to be on time. Edit: after browsing the site, the Marathons are the lowest rolling resistance touring tires too! Double bonus for an excellent tire, which I can now recommend without reservations.
- bgribble 2y ago
  Marathons have been my tire for about 15 years of city and road riding, and I have only flatted once -- direct hit on a nail IIRC. I am always amazed at their longevity and reliability.
- fenazego 2y ago
  I like the Marathons for the same reasons. Only in cold weather it‘s like the rubber of the tyres gets quite a bit stiffer (more so than other tyres), and provides less grip, just when you need it.
scott_w 2y ago
BRR is not promoting harder tyres to lower CRR. What it lets you do is compare CRR across different tyres at similar pressures. Generally, wider tyres with lower pressure gives better CRR than narrower tyres at high pressure. Happily, this is also more comfortable.
MrSkelter 2y ago
You can have both. Wider tires are faster and more comfortable. It’s only at the point aero becomes a limiting factor that things change. In the real world most of what we “know” about tires is a myth (and the linked site isn’t doing real world testing)

ActorNightly 2y ago

>Unless you're on the ProTour You don't have to be on the Pro Tour to benefit from aero gains with narrower tires. Even moderately fit people usually can sustain 15 mph on flat, at which point aero gains start to matter. Even more for hilly terrain where you can easily pick up over 20 mph on descents. The wider tires roll more efficient at lower psi (when you have to air down for comfort). But roughness of pavement road usually doesn't require less than 60 psi, and above 60 psi the rolling resistance of wider tires is about the same as narrower tires, but watt savings from aero can be significant. I got a gravel bike to replace my old road bike because everyone was raving about it, and I absolutely hated riding it. Sure, at slow recreational speeds, it was more comfortable, but when getting places, it just didn't roll as well down hills, making me having to pedal more over extended times to get uphill. Now I ride an aero road bike with TT bars, with 28c tires, and even when running them at 60-70 psi for rough pavement, the aero gains from the narrower wheels are significant, as I can pick up speeds over 30 mph on some descents which carry me way further uphill.

bradfa 2y ago
It depends on what kinds of roads you ride on. If you're always riding nice smooth asphalt, then yes, high pressure narrow tires are going to be faster pretty much always. But if you're riding on really crappy asphalt, chipseal, or on dirt or gravel roads, then a wider more supple tire may be just as fast but a whole lot more comfortable due to the ability to run lower pressures. The power losses on a perfectly smooth road are aero and rolling resistance. But once you get onto bumpy surfaces, now you also need to consider the power losses of the bumps on the bike AND on the rider because the rider is the one supplying the power, even the power which does not transmit through the cranks. Although I do agree with you partially, if you're racing, ride what ever makes you fastest. Energy efficiency isn't paramount, getting to the finish first is. But if you're not racing, then really consider if the tradeoff of comfort is worth it. The BRR website's test protocol uses a fairly smooth metal drum for testing. This is good for testing rolling resistance but not for testing total system losses over rough roads. So although BRR is a great resource, take it with a grain of salt.
- wink 2y ago
  The real eye-opener for me were that my kinda knobby MTB tires apparently have nearly the exact rolling resistance as my Schwalbe Marathon Plus on the Gravel Bike. So although they're a lot thinner, nothing is gained here at all. (If you assume enough pressure in the MTB tires on asphalt).
  - ip26 2y ago
    I regularly clock 21+ on my knobby, slack MTB on flat pavement, but struggle to break 20 on many other bikes…
tleb_ 2y ago
The article from renehersecycles.com does not really agree with your comment, and explains why.
- ActorNightly 2y ago
  28 to 32 is negligible aero wise for most people, I don't disagree. 30 mph (or slower into the headwind for an air speed of 30 mph) will start to matter a little bit though, math doesn't lie. But saying wider tires are better as a blanket statement implies that you can run like 45c gravel tires and still have the same aero drag, which is by far not the case. https://www.hambini.com/cycling-aerodynamics-wider-tires-and-rims-examined-in-engineering-detail/ https://www.hambini.com/cycling-aerodynamics-wider-tires-and...
arghwhat 2y ago
On descents you can also pick up a lot of speed by getting a heavier bike and supersizing your meals at McDonalds. Speed on descents isn't really that relevant - you're descending, so unless you're racing it's practically effort-less. What matters for people biking normally (i.e., not recreational road bike racing) is assistance in the 10-15mph regime, on flat terrain or climbing. Large changes in rolling resistance matters here, like going from an almost 40W tire to a 20W tire. But aerodynamics have a very minimal effect here, and going below 20W tires won't really make a meaningful difference in biking effort compared to the effect on your butt and wrists.
- bluecalm 2y ago
  Going from 20W tire to 10W tires is going to be massive even more so for recreational not so fit riders. Such a rider may output 120-150W on average. Getting 20W free (there are two tires) results in a difference comparable to installing a small motor on your bike.
  - arghwhat 2y ago
    No: A 20W tire is a 20W tire at 18 mph. At 10 mph, it's roughly a 10W tire (rolling resistance should be mostly linear at these speeds). Going from 20W to 10W tires therefore only saves you 10W total at those speeds. At 120W, you are idle pedalling. You do not really pedal lighter, so saving a few watts mean an increase in speed, but as both rolling resistance and aerodynamic drag goes up with speed the gain becomes small. At normal climbs - the time where you'd wish pedalling was easier - you're either 1. spend in the area of 200-300W maintaining the same speed without increasing rolling resistance, making rolling resistance a smaller part of the load, or 2. drop to a granny gear, going very slow to maintain your 120W and thus making the rolling resistance negligible with any tire. In either case, rolling resistance matters much less in climbs.
- ActorNightly 2y ago
  Yes if you bike slowly, wider tires are better. However I mentioned that in my post. A lot of people who are into biking are in the fitness zone where they are going into speeds where aero starts to matter way more. This is especially true when you consider wind.
basil-rash 2y ago
If your primary goal is minimizing work, you can also try an electric bike, or driving! Tongue in cheek, but isn’t fitness the point?
- grayrest 2y ago
  While it's certainly possible to have a throttle most electric bikes require pedaling and therefore some degree of exercise. In many cases it gets people riding that would not be riding otherwise. For people that are actually interested in fitness it's a lot easier to maintain zone 2 on real roads with electric assist without the impulse to push it a bit up the hills. I did far more aggressive rides when I had access to my electric road bike than I do on other bikes because I knew I had a bail out if I pushed too far. Nobody's going to congratulate an e-bike rider on their feats of endurance or power but there are lots of points between a normal cycling effort and no effort at all.
- ActorNightly 2y ago
  Same fitness on a more efficient bike = longer distance or higher speed.
  - basil-rash 2y ago
    To what end?
    - seadan83 2y ago
      Travel far, see more. Sometimes people riding bikes are in a rush (eg: morning meetings and commuting. [And no, drinking is not always a solution, in my situation it's a 30 minute drive or bike ride either way, and driving then costs $30/day and the time to find parking makes it slower. The drive Honda will be usually faster but has to be after 6pm, otherwise it is an hour to get home. This is a 10 mile commute I'm describing, and fir about 6 hours out if the day it's a traffic jam half of the way)
    - ActorNightly 2y ago
      Lots of factors. For example, i get way less tired riding a road bike in the heat than a mountain bike, because the airflow at speed helps me keep cool.
bluecalm 2y ago
Gravel bikes are going to transform in coming years as now they are neither very comfortable nor fast. It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain. The reason is that soft casing is way more important than knobs when it comes to rolling resistance and MTB tires can be made soft because all the additional rubber coming with width while gravel tires are usually harder and thus slower (and less grippy and less comfotable). Notable exception is Continental Terra Speed but it's still not as good as Race King and way more puncture prone. The problem with most current gravel frames is that they don't fit wide and fast MTB tires so you are stuck with the worst of both worlds - slow, not comfortable and still not grippy/soft enough to go fast off-road unless it's a very well maintained road.
- latchkey 2y ago
  I absolutely love my Lauf with their weird suspension front fork. Bike is super comfortable to ride. Also has plenty of width room for wider tires. I run WTB Nano 40c, which are a great mix for road/gravel.
- ActorNightly 2y ago
  >It turns out that wider MTB tires are both faster (when it comes to rolling resistance) and way more comfortable and safer than gravel tires even on tarmac, let alone any kind of terrain. ...except when you are going fast. But I do agree that honestly, full on XC MTB are better than any gravel bike for mixed terrain. Modern race XC bikes are not only lightweight, but have enough suspension travel front and rear to tackle super rough trails, which means you don't have to rely on tire pressure for compliance (although QC on the carbon frames is questionable even from the bigger brands). That being said, when it comes to road, ultimately, aero bikes are still king for efficiency if you are least moderately fit.
- pandaman 2y ago
  Gravel bikes are much more comfortable and fast than road bikes on unpaved roads, which is what they are designed for. Wider wheels will add more weight and more angular momentum, making it harder to climb and harder to steer so you might need to replace the drop bar with the MTB flat bar and without the drops you can move the saddle into a more comfortable position as well... ending with a hardtail w/o the suspension fork.
aayjaychan 2y ago
it's always wild to me hearing what pressure people use. on my road bike with 28c and inner tubes, 60 psi is what i use on _good_ road surface. maybe the roads are just shit here, but even 55 psi feel rough. i usually run on around 50 psi, 40 in winter. there was a time i lost my track pump and i just pump the tyres using a mini pump without a guage. later i discovered i was running on something as low as 30 psi. i have never had a pinch flat. i don't think i'm particularly light. full load when doing groceries is probably 85 kg. is it just that my pressure juage is woefully inaccurate?
pmontra 2y ago
28 mm tires used to be huge tires. Pros didn't ride anything wider than 23 mm in the 90s. 25 mm would be for special occasions. 21 mm on tracks, sometimes even 19 mm. I think than Valverde used a 28 mm in a Roubaix and at the end of the race said that it was too much and not worth of the extra weight and front section. Every pro is riding on 30 or 32 mm now. Of course the rims are totally different and wrap those tires in a way that the old metallic rims could not do, hence the aerodynamic gains. Edit: I've got a gravel bike with 42 mm tires and a 28 mm set. I use the 28 mm when going in the hills on asphalt. I'm with you on that: it's a day/night difference. On mixed mostly flat terrains the 42 mm tires are the best compromise.
- bennyelv 2y ago
  Unfortunately you cannot discount the “sponsor effect” here. Wheel manufacturers have been pushing wider rims because it helps them sell another set of wheels to everyone. In the days of rim brakes a wheel had a finite life (the length of time it took to wear down the braking surface). Then shimano and the frame builders pushed everyone to disc brakes, so the wheels now last for ever. What do you know, 2 years later all the wheel manufacturers are claiming “wide is better” and flogging everyone new wheels. I’ve not seen any clear evidence that they’re right, and there’s lots of intuitive reasons to think that wider tyres will be slower (aerodynamics!). I remain sceptical, but genuinely hopeful that someone who thinks that wider is faster can provide me with some solid evidence…
  - mariusor 2y ago
    I feel that any marketing strategy that relies on the niche of a niche formed of the people that would buy the cutting edge cycling gear just because it's presented as an improvement over the status quo, would hardly bring any benefits to any wheel maker. I am 100% sure that in this age of "marginal gains", the pro tour teams would not go for anything that doesn't give them it unless severely hamstrung by sponsorship deals. And I doubt that the wheel sponsors don't have multiple sizes available. And I think you're severely overestimating wheel life span for modern models, at least due to the fact that carbon is more brittle than more pedestrian materials. Just look for Pogacar's fall earlier last week in the Giro to see how a simple flat tire makes the whole wheel a risk.
edmundo 2y ago
>Speeds over 30 mph on some descents All that aero is probably not working so well for you. Even on my mountain bike with grippy and wide tires I get over 40 mph. On my gravel I can hit over 50 mph, and thats with 45mm tires.
- dbrowne 2y ago
  I can get close to 50 mph (safely) downhill on my 30 year old steel framed 8 speed bike with 20mm tubular tires pumped to 120 psi. No problem with riding at 20 mph on the flats and I'm close to 60 years of age. My "aero" CF bikes with deep carbon rims are minimally faster. Speed is irrelevant unless you are racing. Enjoy the ride and stop relying on equipment for minimal performance gains.
- ActorNightly 2y ago
  Its totally possible to hit over 40 mph on steep hills on an MTB, especially if you weigh more. I was more referring to slight grades with just pure rolling without pedaling. Im in Austin so I frequent COTA Bike nights on Tuesdays on the track. Coming down the hill from turn 1 with other riders is a very good test of aero efficiency, because there is a slight uphill after the bend. Couple of my friends ride gravel bikes, one of them is heavier than me, and its pretty clear that that my bike is more efficient.
  - garphunkle 2y ago
    Shout-out to Violet Crown, PHENOM, Breakfast Club, UNITED, Night Owls, and all the other great cycling clubs in Austin! Wonderful community that I still miss. Have you tried swapping bikes with your buddy? Are you two the same height/weight? Who has the more flexible spine? It would be fascinating to measure aerodynamic efficiency for two riders on the same bike. Is the more variation within populations, or between populations?
YuukiRey 2y ago
Aero also matters at low speeds since you spend more time on the course

wink 2y ago

If you look at the tires (let's ignore road bikes for now) the vast majority is between 15ish and 28ish Watts (I usually look at Gravel and MTB tires). Then look at the methodology: > The total rolling resistance of an average rider with a total bike + rider weight of 85 kg / 188 lbs that averages 28.8 km/h / 18 mph will be double the rolling resistance you can find on our website. If you're heavier than that or average higher speeds, the total rolling resistance will increase roughly linearly with the increase in weight or speed. All I can say is that I am a lot heavier than 85kg with my bike and that I am usually riding at 20-25 km/h. So let's say the lower bound they mention would 2x15 and the upper bound 2x25. Let's assume 127kg with luggage, that scales linearly to 3x15 - 3x25, but the speed is only 2/3, so we can dial it back. My napkin math now says the difference between a good pair of tires and a bad one is 30 vs 50. And I'm still not sure if that translates 1:1 to the assumed typical 100 Watts of an average rider.. I found https://www.gribble.org/cycling/power_v_speed.html https://www.gribble.org/cycling/power_v_speed.html though and if I plug in my numbers, the coefficient of rolling resistance is our variable, and 0.00465 -> Rolling resistance is working against you with 5.79 (N) of force, or 50.15 watts of power. 0.00273 -> Rolling resistance is working against you with 3.40 (N) of force, or 30.01 watts of power. So the tires make about 2-3 kph, which fits what most people have posted when I was researching this.

deleted 2y ago

[deleted]

Arnt 2y ago

What's riding comfort? I let both of my kids try things and choose, both choose tires with fairly low resistance. One more so than the other, but both clearly regarded high pressure as somehow comfortable: Apply pressure to pedal, feel bike move. Responsiveness.

kohlerm 2y ago

Riding is more fun with less resistance, it just "feels better". That alone is an argument to choose the correct tire (there are trade offs obviously). From my own experience (MTB) I can say that the difference in rolling resistance are very noticeable.

wffurr 2y ago

I choose flat resistance over either. Schwalbe Marathons or equivalent on all my bikes, but I use my bikes as my primary mode of transportation in the city. I really don’t want to deal with flats when I have to be on time. Edit: after browsing the site, the Marathons are the lowest rolling resistance touring tires too! Double bonus for an excellent tire, which I can now recommend without reservations.

bgribble 2y ago
Marathons have been my tire for about 15 years of city and road riding, and I have only flatted once -- direct hit on a nail IIRC. I am always amazed at their longevity and reliability.
fenazego 2y ago
I like the Marathons for the same reasons. Only in cold weather it‘s like the rubber of the tyres gets quite a bit stiffer (more so than other tyres), and provides less grip, just when you need it.

scott_w 2y ago

BRR is not promoting harder tyres to lower CRR. What it lets you do is compare CRR across different tyres at similar pressures. Generally, wider tyres with lower pressure gives better CRR than narrower tyres at high pressure. Happily, this is also more comfortable.

MrSkelter 2y ago

You can have both. Wider tires are faster and more comfortable. It’s only at the point aero becomes a limiting factor that things change. In the real world most of what we “know” about tires is a myth (and the linked site isn’t doing real world testing)