A probably pointless discussion about watts/effort and bikes

[ripvanrando]

Did Lael really ever have the incorrect equipment?

Gear isn't why the top riders win.....the human side is very interesting.

I remember going up a longish climb at around FTP (around 300 watts) and Lael came by me like I was f^cking standing still. Being somewhat math nerdy, I then quickly calculated that she had the W/Kg of an elite rider. This was 2016.

A top rider can thrash most of us on an old schwinn with the wrong tires.

[marciero]

Originally Posted by cgates66

Just a quick timing point about wind. In a higher wind, for the same effort, and assuming you start and end at the same point with equivalent elevation etc. - you'll always be slower than light wind, and no wind is fastest of all.

The reason is that, for the same power, you'll spend more time on the leg into the wind than you'll save on the leg with the wind.

Suppose you have a 20MPH average speed on a course with no wind. With 5MPH wind on the same course, for the same power, you could maintain about 16MPH into the wind, and 24MPH against the wind - for an average speed of 19.2. For a 10MPH wind, it'd be about 16.8MPH - reason being that you spend more time at a slower speed.

This is a rough calc., but windy days for rides that finish where they started (assuming the wind stays the same!) are slower.

Excellent. The appropriate average is the harmonic mean, 2/((1/16)+(1/24)) = 19.2, rather than the arithmetic mean, which of course is just 20. A similar argument can be made for uphill outbound/downhill inbound.

[oldpotatoe]

Originally Posted by ripvanrando

Did Lael really ever have the incorrect equipment?

Gear isn't why the top riders win.....the human side is very interesting.

I remember going up a longish climb at around FTP (around 300 watts) and Lael came by me like I was f^cking standing still. Being somewhat math nerdy, I then quickly calculated that she had the W/Kg of an elite rider. This was 2016.

A top rider can thrash most of us on an old schwinn with the wrong tires.

"Eddy can win on my bike, I can't win on his".

"More races have been lost due to equipment than have been won"

"Don't pay for upgrades, ride up grades".

[rain dogs]

Here is some information for the OP that I think is relevant from tire experts (ie. those who make tires), don't shoot the messenger (me), but I am always surprised this is even debated. Yet again, lots of people saying "It's obvious wider tires are slower" and "Of course bigger tires are slower":

Quote: Continental Tyres:
Remember that wide tires of the same type and with same air pressure run better and more lightly than narrow tires.
https://www.continental-tires.com/bi...haracteristics

Quote: Schwalbe Tires
Wider tires roll better than narrower tires. This statement generally invokes skepticism, nevertheless, with tires at the same pressure a narrower tire deflects more and so deforms more.

They have a whole section on "Why do wide tires roll better than narrower tires?"
https://www.schwalbe.com/en/rollwiderstand

Quote: Vittoria Tires
What is better wide or narrow tyres in terms of rolling resistance? Why do professional road racers use narrow tyres?

In real life conditions, wider is better for rolling resistance. A wider tyre will have a shorter contact patch with the surface it is rolling over compared to a narrow tyre. This shorter contact patch causes less deformation of the tyre, which in turn leads to less rolling resistance. https://www.vittoria.com/ww/en/faq-tyre-performance

.....

Again, that's solely rolling resistance, in an "all things equal scenario". Obviously weight, aero resistance, bike setup etc are all at play. And those were three of the first four brands I looked up (Michelin doesn't say anything I could find)

But, if you put the same tire, on the same bike, with the same use, and you adjust the weight to be equal the difference will be miniscule if all you change is the tire width, and depending what compare against it may favor the wider tire. Now, a gravel bike will almost never have the "performance" of a road bike but that's mostly due to 1. body position (aerodynamics) and 2. weight (or 3. a totally different tire studded vs slick). It's pointless to compare tires with two or more different bikes - if you want to compare tires, compare with the exact same bike, exact same position.

[mtechnica]

Originally Posted by rain dogs

Here is some information for the OP that I think is relevant from tire experts (ie. those who make tires), don't shoot the messenger (me), but I am always surprised this is even debated. Yet again, lots of people saying "It's obvious wider tires are slower" and "Of course bigger tires are slower":

Quote: Continental Tyres:
Remember that wide tires of the same type and with same air pressure run better and more lightly than narrow tires.
https://www.continental-tires.com/bi...haracteristics

Quote: Schwalbe Tires
Wider tires roll better than narrower tires. This statement generally invokes skepticism, nevertheless, with tires at the same pressure a narrower tire deflects more and so deforms more.

They have a whole section on "Why do wide tires roll better than narrower tires?"
https://www.schwalbe.com/en/rollwiderstand

Quote: Vittoria Tires
What is better wide or narrow tyres in terms of rolling resistance? Why do professional road racers use narrow tyres?

In real life conditions, wider is better for rolling resistance. A wider tyre will have a shorter contact patch with the surface it is rolling over compared to a narrow tyre. This shorter contact patch causes less deformation of the tyre, which in turn leads to less rolling resistance. https://www.vittoria.com/ww/en/faq-tyre-performance

Again, that's solely rolling resistance, in an "all things equal scenario". Obviously weight, aero resistance, bike setup etc are all at play. And those were three of the first four brands I looked up (Michelin doesn't say anything I could find)

But, if you put the same tire, on the same bike, with the same use, and you adjust the weight to be equal the difference will be miniscule if all you change is the tire width. Now, a gravel bike will almost never have the "performance" of a road bike but that's mostly due to 1. body position and 2. weight. It's pointless to compare tires with two or more different bikes - if you want to compare tires, compare with the exact same bike, exact same position.

If bigger tires were faster then how come pro racers aren’t riding 38c tires? Why? Because the wind resistance is higher and rolling resistance on smooth surfaces especially climbs is, you guessed it, also higher. Also gravel bikes with gravel tires are mostly slower because of the tires not aero. 40-42c tires with a little tread roll way slower than road slicks do.

[rain dogs]

Originally Posted by mtechnica

If bigger tires were faster then how come pro racers aren’t riding 38c tires? Why? Because the wind resistance is higher and rolling resistance on smooth surfaces especially climbs is, you guessed it, also higher. Also gravel bikes with gravel tires are mostly slower because of the tires not aero. 40-42c tires with a little tread roll way slower than road slicks do.

Read the webpages its all in there. The OP's question was not about pro road racers/racing... my responses have never been about pro road racing. My responses have only been as per the above info, and my own personal testing which has confirmed it.

And road pros have changed from 700x20's to 700x28's, but that's not the OP's question (at least that I understand). He asked "Will a larger tire bike, with a higher stack and all of those other "gravel" characteristics, ever be as fast a true road bike?"

Of course not! But, that's principally because it's not as aero a position, then not as light a bike, the difference in tires will be miniscule compared to that. In fact, as per the tires experts, the wider tires may have less rolling resistance if they are wider. But the bike surely will be slower, because of "higher stack" and gravel 'characteristics'... which are often not "aero bike, as low as is comfortable and efficient" characteristics like with a road bike.

Again, if you want to argue. Argue with those brands, not me. I didn't write those webpages... I only linked them with the hope that the OP will get real information from experts.

[mtechnica]

The Vitoria link is pandering to Fred’s by saying comfort is not a factor. 28c tires at the correct pressure are extremely comfortable, and pros aren’t riding 6 hour days in discomfort.

[mtechnica]

Anyways forget it, if anyone here seriously think a huge tires roll as fast as road slicks then good luck to you and obviously you’re not racing.

[mtechnica]

Originally Posted by ripvanrando

Did Lael really ever have the incorrect equipment?

Gear isn't why the top riders win.....the human side is very interesting.

I remember going up a longish climb at around FTP (around 300 watts) and Lael came by me like I was f^cking standing still. Being somewhat math nerdy, I then quickly calculated that she had the W/Kg of an elite rider. This was 2016.

A top rider can thrash most of us on an old schwinn with the wrong tires.

She knows exactly what she’s doing gear wise and also is very fast. Did you guys ever watch the documentary with her? Jan Heine is in it. It’s interesting and has a few amusing moments (some at the expense of a certain someone).

[spoonrobot]

Originally Posted by mtechnica

Anyways forget it, if anyone here seriously think a huge tires roll as fast as road slicks then good luck to you and obviously you’re not racing.

+1

We've hashed this out several times and it never stops being fun. Nobody really believes unusually large tires are as fast, because if they did we'd have seen shakeups in races where their comfort, grip, and cornering ability advantage would be the deciding factor in winning. 650b would have lit the world on fire because 650bx42 is an excellent road racing tire.

On the dirt/gravel side: There have been bikes, capable of being set up very aero, that clear 60mm slicks, for several years. As well as very fast tires, and yet these bikes have gone nowhere as far as race results are concerned. Wider tires are slower, and the farther you ride, or the smoother surface you ride, the slower they get. There's no free lunch and most paved roads don't have enough vibration (the theoretical cause of most impedance) to overcome the aero, weight, hysteresis losses.

When I started gravel racing in 2015, any give race had half the field on mountain bikes with 2.1-2.3" tires. Within 2-3 years all those guys got gravel bikes on 38-42mm tires and never looked back.

It's helpful to remember the biggest player in this whole thing found that "wide tires aren't as slow as historically thought, when constructed correctly" and never found wide tires to be as fast as lightweight tires until he started contracting and selling his own tires.


Results from the Laboratory of the Road
Pavement:
19mm tires are slower than 21mm tires are slower than 23mm tires, many of which are slower than some 25mm tires, many 25mm tires are faster than 28mm tires, most 28mm tires are faster than 32mm tires, 32mm tires are faster than 35mm tires, 35mm tires are faster than 38mm tires, etc.

Gravel:
33mm tires are slower than 35mm tires are slower than 38mm tires, many of which are slower than some 40mm tires, many 40mm tires are faster than 42mm tires, most 42mm tires are faster than 45mm tires, 45mm tires are faster than 48mm tires, 48mm tires are faster than 52mm tires, etc.

Ride what you like, Race what will help you win.

[rain dogs]

Originally Posted by spoonrobot

+1

We've hashed this out several times and it never stops being fun. Nobody really believes unusually large tires are as fast,

...

Results from the Laboratory of the Road
Pavement:
19mm tires are slower than 21mm tires are slower than 23mm tires, many of which are slower than some 25mm tires, many 25mm tires are faster than 28mm tires, most 28mm tires are faster than 32mm tires, 32mm tires are faster than 35mm tires, 35mm tires are faster than 38mm tires, etc.

Gravel:
33mm tires are slower than 35mm tires are slower than 38mm tires, many of which are slower than some 40mm tires, many 40mm tires are faster than 42mm tires, most 42mm tires are faster than 45mm tires, 45mm tires are faster than 48mm tires, 48mm tires are faster than 52mm tires, etc.

Ride what you like, Race what will help you win.

Again agreed. Race what will help you win.

I've never said anything to the contrary. And you yourself have justed posted that 28's are faster than 19's (that's 9mm wider is faster) in a road scenario and you've posted that 40's more or less are faster than 33's for gravel (about 7mm wider being faster.) *more or less.... tire dependant etc. And I've posted info from tire makers which support that skinnier does not always equate faster.

And, it stands to reason, that 42's, if slower, are almost immeasureably slower than 44's yet 48's would be more significantly slower than 44's and so on. I posted the same in the first place: "that tire width will make very little difference in speed" and the response was outrage, mtechnica saying he needed to stay out of the forum over such absolutely ridiculous comments. I mean, come on, 'take my toys and leave' That's hilarious.

If you race road or gravel, you'll know that you don't race road on 48's AND you also don't race gravel on 23's. But that's where the counter-point has been "Anyone who seriously thinks HUGE tires roll as fast as road slicks etc". "Unusualy large tires" It's comedic. Do you actually believe I think fatbikes are the future of the Tour de France?

So, if, like the OP was asking about bike position AND tire width, the difference between a 38mm and a 42mm "will be miniscule or make very little difference" (as I said) The more important place to be looking for racing gains in racing scenarios is aero position over stressing about small differences in tire width. Of course a 48mm tire isn't as fast as a 25 in a mirror smooth velodrome or whatever, but no one is racing real gravel on 25's so that's kinda not applicable to the OP question, no?

Go back into my comments and tell me where I've said anything different! You guys are making the same argument, some are just a little "behind" to realize it.

[marciero]

Originally Posted by spoonrobot

Results from the Laboratory of the Road
Pavement:
19mm tires are slower than 21mm tires are slower than 23mm tires, many of which are slower than some 25mm tires, many 25mm tires are faster than 28mm tires, most 28mm tires are faster than 32mm tires, 32mm tires are faster than 35mm tires, 35mm tires are faster than 38mm tires, etc.

Gravel:
33mm tires are slower than 35mm tires are slower than 38mm tires, many of which are slower than some 40mm tires, many 40mm tires are faster than 42mm tires, most 42mm tires are faster than 45mm tires, 45mm tires are faster than 48mm tires, 48mm tires are faster than 52mm tires, etc.

You're missing the air quotes around "Laboratory of the Road"
Not sure what to make of terms such as "many" and "most" tires. Why not compare tires using the same, or at least similar construction? Also, if speed were not simply a decreasing function of width, as you are suggesting, it would be very surprising if global max of 25mm for speed were independent of rider weight.

In fact I find detailed anecdotal accounts, such are ripvanrando's, more compelling than these "why arent the pros riding them" type arguments.

[spoonrobot]

Originally Posted by marciero

You're missing the air quotes around "Laboratory of the Road"
Not sure what to make of terms such as "many" and "most" tires. Why not compare tires using the same, or at least similar construction? Also, if speed were not simply a decreasing function of width, as you are suggesting, it would be very surprising if global max of 25mm for speed were independent of rider weight.

In fact I find detailed anecdotal accounts, such are ripvanrando's, more compelling than these "why arent the pros riding them" type arguments.

The loss factors exist in isolation of rider weight. Tire size is more relevant to comfort than speed, for a rider's weight. Big guys still need skinny tires to be fast for racing.

I've ridden and raced every major wheel and tire size since 2013 (26", 27.5 & 650b, 700c & 29"). I'm probably the only guy in the world to seriously attempt road racing on 650bx42, among other experiments. Tire width makes a huge difference in speed and is as important to the individual rider as is aero or weight. There's no reason to discuss only one thing at the expense of the other. If a racer is to care about aero, they also need to care about tire width - Cda as well as Crr.

[txsurfer]

Originally Posted by spoonrobot

The loss factors exist in isolation of rider weight. Tire size is more relevant to comfort than speed, for a rider's weight. Big guys still need skinny tires to be fast for racing.

I've ridden and raced every major wheel and tire size since 2013 (26", 27.5 & 650b, 700c & 29"). I'm probably the only guy in the world to seriously attempt road racing on 650bx42, among other experiments. Tire width makes a huge difference in speed and is as important to the individual rider as is aero or weight. There's no reason to discuss only one thing at the expense of the other. If a racer is to care about aero, they also need to care about tire width - Cda as well as Crr.

That is another factor Im working on. At what point do I want to give up speed for comfort, mileage or time wise?

The weather on the ETS was horrendous and my BMC Monstercross disc ate it up and was comfortable to the finish. In dry weather, I wonder if I could have hammered the 280 out on my Bowman Pilgrim's (road +) on 32-35c gravel tires. It would have been fast and potentially bone jarring, but less time in the saddle.

[rain dogs]

Originally Posted by txsurfer

That is another factor Im working on. At what point do I want to give up speed for comfort, mileage or time wise?

The weather on the ETS was horrendous and my BMC Monstercross disc ate it up and was comfortable to the finish. In dry weather, I wonder if I could have hammered the 280 out on my Bowman Pilgrim's (road +) on 32-35c gravel tires. It would have been fast and potentially bone jarring, but less time in the saddle.

You initially said you "just want to have a conversation about what I could be missing, ways to improve speed on the gravel." So, In regards to tires if you're going to obsess about things it's:
1. tire pressure, tire pressure and tire pressure.
2. then tread and (course dependant) side wall protection.

I know it seems like I am the lone voice that everyone is arguing against (it surprises me too, but I think people just lose the plot) but think of it this way:

If you totally botch tire pressure and tread (and on some courses sidewall protection unless you're lucky) your day can be ruined. If you absolutely nail pressure and tread but "botch" the question of 35's vs 40's, just trust me (or better, test it yourself controlling everything the same including weight and only change the 5-8mm width) You will hardly notice any difference no matter what theoretical stats or fancy numbers people type up (or make up??) on the internerds.

Tire pressure is a far greater influence on comfort and performance than 5mm of width variance ever will be for your scenarios/usage You can make a 50mm tire more uncomfortable, handle worse and have worse traction than a 35 with totally wrong pressure in the 50 vs correct pressure in the 35, even though "in general" everyone will say a 50mm tire will be more comfortable, handle better and provide more traction than a 35mm. Similar can happen with speed, but the other way round.

Now, you also are making it more difficult with two BIG variables at play - you're asking about tires AND you're asking about two different bikes. The performance differences between the bikes are seperate than between the tires. In theory you could have totally different tires and wheels options for the same bike, or vice versa. You need to sort the bike questions *that will be where the HUGE performance differences lie*, but I'm only focusing on tires now. There is no reason (or few reasons) a day on 32-35's on your bowman needs to be "bone-jarring" with the correct 'low' tire pressure while still being high (or, yes, higher) performance.

The gains to be had by 5-8mm of tire width variance is so far down the list of priorities (and will have such small performance gains/losses vs pressure and tread) in equipment selection a gravel event. Tire pressure. Tread selection.

The responses/irrelevant concepts in this thread are whack... ask a cyclocross rider (pro or otherwise... heck I'd think even a beginner) about how much more important tire pressure is than 5-8mm of width, if you don't want to take my word for it.