base2 

JFC 23's at ~10&1/4 watts against 32's at 11&1/3 watts.

...All this over 1&2/25ths watts.

Yan 

Yes, for a Continental GP5000. But we don't actually tour on Conti GP5000s, do we? When we look at touring tires, the Schwalbe Marathon is 21W, the Marathon Plus is 26W, the Vittoria Randonneur is a whopping 32W. That's per single tire and bikes have two tires, so multiply by two.

Now all of a sudden we are in the region of 50W disappearing into the tires. Considering the average touring cyclist is chugging along at a mere 100-120W total output, we are not laughing anymore, are we?

mstateglfr 

https://www.bicyclerollingresistance...terra-speed-45

https://www.bicyclerollingresistance...on-32-37-40-47

https://www.bicyclerollingresistance...-gravelking-35


Pick these apart and wiggle around to justify your narrative.

Yan 

Is this a joke? Did you even read these pages before you linked them? Conclusion quoted from the test you linked:

mstateglfr 

You asked for exams where wider tires of the same brand and model roll faster than narrow tires.
I provided examples.

I am not claiming those options are ideal for touring. I am not claiming g they are bad for touring.
I am not claiming anything, just providing examples.

As for your Marathon tire ramble, yeah I know the tester thinks the 32mm is a different material. Again, I provided examples where a wider tire rolls faster than a narrower tire when the brand and model are the same.
The Marathon testing showed a 37 was faster than a 32 at proper psi(for me, at least. I don't know what your proper psi would be).



Once more, even if the rolling resistance is the same between widths when proper psi is accounted for, air resistance for a 37mm tire vs a 32mm tire is so dang minimal that it isn't worth the handwringing. You are touring- nothing about the activity is aerodynamic. Tire aerodynamics is not even in the top 10 of what I would want to try and focus on for aero gains when touring.

Question for you - how much of an aero penalty, in watts, is a smooth 40mm tire vs a smooth 32mm tire? Source it.

Yan 

That wasn't my ramble. That was a direct copy and paste from the conclusion section of testing article you linked yourself. Now I know for a fact you never actually read it.

The Schwalbe Marathon is a different material in 32mm because this tire is not just one of the most popular touring tires in the world, it's also one of the most common commuter tires in Germany. And because Schwalbe doesn't want its reputation trashed, it wants every tire under the Marathon marque to meet a minimum threshold of endurance, which the narrow variant can't achieve without using a harder wearing compound than the wider variants. It's actually a completely different tire stuck under the same name by Schwalbe's product manager.

Which circles back to the same mistake you've been making this entire time. If you want to talk about the merits of different tire widths, you need to experiment using different widths of the same tire. If you compare different tires, your whole experiment is out the window.

If seeking evidence for your position requires you to scrounge the internet until you've found a marketing gimmick in the naming conventions of one particular brand, and then triumphantly yelling, "haha!" That's not exactly shedding a good light on you, is it? Did you also know that the Toyota Camry used in NASCAR isn't the same Camry your mom drives? Crazy stuff.

But anyway, circling back to the widths variations which ARE actually the same tire, why would I bother writing my own argument when bicyclerollingresistance.com has already written it for me?

And that's all there is to it. What else needs to be said?

I have no doubt you have immaculate credentials in whatever it is that you make a living with in your own life, but pardon me for choosing to believe in the conclusions of an independent testing lab over the opinion of some random nobody on the internet. No offense.

base2 

Can you drum me up a scenario where 2&4/25ths of a watt in total will have a real world impact on the outcome of any cycling activity not performed on a laboratory test equipment?

Apples to oranges bull with GP5000 vs Marathons and Marathon vs Marathon Plus is hogwash and you know it. Of the same series of tire, the Rolling resistance difference between size "A" and size "B" is within the error bars. That is to say: Negligible.

What does "negligible" mean? It means that in the real world with a variety of variable surfaces the larger (of the same series) tire at the appropriate pressure can and often does come out on top and almost always has the more comfortable ride while doing so. The rougher the surface, the more likely this is so.

Learn a new thing, Yan.

Yan 

There is no need to speculate. If you go to the Schwalbe Marathon testing report linked previously and look through the chart, you'll see that going from the old school touring width of 37mm up to the newly fashionable width of 47mm loads you with an extra 8 watts of drag across two tires at typical pressures. For surface quality, that lab uses a patterned drum to approximate rough pavement.

Now the question is, what exactly is "error bars" according to you? What exactly is "negligible"? For the typical touring cyclist peddling along at 100W cruising power, 8W would be 8%. In the opinion of Base2, is 8% "negligible"? And if 8% is negligible, then how much slower would Base2 have to be riding before he is able to notice a difference? 10%? 15%?

End of the day, is 8% power a worthwhile sacrifice for the additional comfort of going from 37 to 47mm? It's a personal preference and not a question that has a correct answer.

By the way the standard Marathon uses a steel bead and the 47mm variant weighs a whopping entire kilogram per tire (holy smokes), so it's worthwhile to consider a more expensive kevlar bead alternative if going for that size. At least get the weight down even if one doesn't mind the rolling resistance.

And coming back to this thread, because this is a stem topic thread and we shouldn't get totally sidetracked: the Redshift stem in question weighs 280g for the 10cm size, which is about 100g heavier than a typical aluminum road stem. For that extra 100g non-rotating weight, you get a stated 20mm of suspension travel, in my experience more like 15mm with the medium elastomers I put in. 15mm of suspension is the equivalent of going from 37mm to 52mm tires. If you install the softer elastomers to get that full 20mm suspension, you'd get the equivalent of going from 37 to 57mm tires, which is full blown mountain bike tire territory. Very few touring frames can even fit that width of tire. My own frame tops out at 50mm clearance. The stem costs about the same as a pair of decent tires.

And that's the gist of it.

Which is better, chunky tires vs Redshift stem? Personal decision. You could even get both and it'd be like riding a fat bike. There are very few completely free lunches in the world. Personally I think given the affordability of the stem and the very light 100g static weight penalty, it is very close to getting a totally free lunch.

mstateglfr 

Now do the Panaracer and Conti examples.
I provided 3 that met your criteria and you clearly dislike one of them.

john m flores 

Insightful framing. Thanks.

base2 

News flash: Marathons are terrible tires from a high performance perspective. But even if they weren't, the low rider power and high weight of the scenario you offer were specifically chosen to make the rolling resistance difference between the various sizes of these tires specific tires look more significant than they really are as a percentage of rider power.

8 Watts. You lose as much with a dirty cross chained drivetrain. You lose as much in aero with exposed shifter & brake cables or simply by looking up or with a partially unzipped rain cape. The wider Marathon still offers better comfort and better protection against pinch flats and more conformance over sharp objects (less puncture risk) over rougher surfaces than the skinnier marathon. How much time do you lose fixing flats? The wider Marathon is the winner...Even if touring tires don't scale as flatly as high performance, supple sidewalled road tires.

https://en.m.wikipedia.org/wiki/Error_bar

Tourist in MSN

I can't tell if my dyno powered lights are on or off from the additional drag to produce the power in the lights. If I recall correctly, turning on my lights adds about 5 watts of drag.

Thanks for posting those results that show that all tire widths are so close in rolling resistance, that only a racer would care about tire size.

That does not say how much weight is on the tires, I assume that the same weight load is used in each test, the tire pressure is varied to produce the desired tire drop.

The last brevet I rode with 32mm tires, had some expansion joints in the concrete every 25 feet or so, was very rough riding for several miles with a jarring bump about every second. Was glad I did not have skinny tires on that stretch of road. My road bike with 28mm tires would have had a much rougher ride.

phughes

It is amazing how one person can take a thread about a stem, and turn it into a personal diatribe about tire rolling resistance. That particular individual makes reading Bike Forums feel like riding a bike with too much rolling resistance. Hovering over the ignore function, and yet strangely hesitant due to the same force that beckons one to watch a bad movie just to see how bad it really is.

john m flores 

This is pretty eye-opening for me. One of my bikes has Vittoria Randonneur Trail tires, which are likely even slower than the Randonneurs listed here. As Yan has pointed out previously, these result are per tire. If I can save 25 watts of output by simply changing tires, that's about a quarter of my average wattage. Not insignificant.

mstateglfr 

Yes, those are absurdly slow. I had a new pair from a used bike I bought and donated them after 1 ride. They felt like I was riding in peanut butter.

Yan seems to think you can't compare tires from different brands, but look at what you did with that screen shot- you managed to compare.

All seriousness, yes a Gravel King tire that you can get for under $40, or any number of other options also for less than $40, will save a bunch of rolling resistance for you.
Easy win, really.

john m flores 

LOL but I lowkey love the Randonneur Trails because they provide surprisingly good grip on gravel and dirt and in the mud. That said, I'll try another tire when I wear them out as I need all the watts i can get.

I don't think Yan is saying that at all. When making comparisons you try to freeze all the variable that you can except the one that you are comparing. Makes sense to try to freeze brand when comparing the relationship between tire width and rolling resistance.

Yan 

100W cruising isn't an artificially low number. That is indeed a typical cruising power. The power number everyone talks about online, what you are thinking of, is FTP, which is a one hour max effort. You can't ride an entire day at anywhere near that. And touring cyclists don't ride at the max possible day long effort either. That would be a racing context.

Marathons are not performance tires, but they are one of the most popular touring tires for a reason. In a touring context, we have to look at what people actually use, not some fantasy racing tire. Schwalbe's best selling tire isn't even the Marathon. It's actually the even slower Marathon Plus. That's what people are using in the real world. This tire is a total behemoth that weighs 1.1kg per tire in the 47mm size. You want to talk about a massive penalty for sizing up?

Drivetrain loss is in the range of 2 watts.

You are right that 8 watts isn't a deal breaker. Afterall, anyone who rides a touring tire is making a speed sacrifice for durability. We are all already making a decision to de-prioritize speed. But you have a set amount of power to work with. 8 watts here, 8 watts there, 8 watts in a third place. If you care about absolutely nothing, small numbers will eventually add up to larger numbers. We are already losing 6 watts to the dynamo, 10 watts to durable tires, 30+ watts to pannier air resistance. That's all before we get into the heavy weight we are lugging around. I try to avoid flappy clothes for example. Eliminate the lowest hanging fruit first. The Redshift stem is a low hanging fruit.

Yan 

I can't tell as those two are hidden behind a paywall and only the very low pressure results are shown for free. Do you have a paid subscription you can share?

phughes

Really? I'm still here. Sorry, but it is a huge thread drift, and you are, and I'll be nice here, overzealous in your opinion regarding tire width affecting rolling resistance, saying wider tires have more rolling resistance, despite evidence to the contrary. You chery pick data that disregards tire construction, which has a great affect on rolling resistance. The fact is, a wider tire of the same construction, has a lower rolling resistance, all things being equal, because it has a shorter, rounder contact patch than a narrower tire, which has a longer, narrower contact patch. THe wider tire's shorter, rounder contact patch rolls more easily over surfaces, and the tire can be run with a lower pressure, absorbing bumps and imperfections on the road.

Now despite the cycling community as a whole accepting this now, based on studies, and science, you are stuck in the old days, which I grew up in, and you still believe what we did back then. Back then we went narrow because it was fast. What was actually the case whas there were no real studies done, and there were not a lot of wider tires available for road bikes, and those that were available were heavy. That has all changed.

There are reasons that competitive cyclists choose a narrow tire today, and much of that has to do with aerodynamics and weight, and nothing to do with rolling resistance.

Anyway, I have considered the Redshift stem for my touring bike, and this thread has put that bug in my ear again. Hopefully my wallet hasn't heard because I really don't need to spend any more on my bike right now.

Yan 

We must be living in different universes because if you read that bicyclerollingresistance.com test report being discussed above, it supports what I'm saying and goes against what you're saying.

I "cherry picked" data? I'm only reading a lab test report on the most popular touring tire line in the world. LOL!

You talk about relying on studies and science. Ok. Whatever you say I guess. If you think they are a disreputable lab and they are lying, fine. Which lab is your preferred lab? Which lab in your opinion isn't lying?

phughes

You evidently didn't read what I wrote. You missed the fact I said you cherry picked your data. You went off one test, one, when multitudes of tests have shown the opposite over the past few years. The most important thing people in the touring community can take from this though, is that differences are negligible for the most part, and in the world of touring, there are other things that make a bigger difference from a touring point of view, such as durability, flat resistance, and comfort, comfort being what this thread is actually about, in case you missed it, and that comfort comes from running a wider tire, which will soak up bumps better than a narrow tire. Now, couple that with a Redshift stem and you've got something.

phughes

You also skipped this from the same site, showing the GP 5000 32 has lower rolling resistance than the smaller width GP 5000 tires using a latex inner tube. And carefully read their conclusion, "From the results above, we can quickly draw the same conclusion that we got from our test from 4 years ago: At the same air pressure, a bigger road bike tire has a lower rolling resistance." Also, and this is important, "We've decided to use a latex tube to minimize the influence of the inner tube on the total rolling resistance." In other words, all things equal, the wider tire has lower rolling resistance. That is not to say there are not differences between tires, or that some narrow tires have lower rolling resistance than some woder tires, but it sayd that all things being equal, a wider tire has lower rolling resistance at a given air pressure.

base2 

From Bicycle Rolling Resistance:
Can you show me a real human 42.5kg person that cruises at 28.8kph at 100 watts?

That only happens in a polished wood floor velodrome subject to the vacuum of space, going down hill...with a tailwind.

Your made up scenario magically arriving at 50 (or whatever) watts loss...Which is really only 8 watts difference between sizes at 18mph which is not a touring speed of 9-12mph to justify the skinny high pressure you seem to have an unhealthy obsession with is hogwash.

When you scale the 8 watts actual difference in Marathon tire size extremes down to the touring speed of 9-10mph it's like only 4-5 watts or so. A meaningless difference by most accounts.

4 Watts isn't now, or ever going to make or break a day on a tour.

...And while we're at it: Nobody buys Marathons of any variety for their stellar "performance." So, any discussion concerning their rolling resistance is, by definition moot.

Yan 

Yes, if you inflate the wider tire to the same pressure as the narrower tire.

But did you miss the part a little further down on the very same page where they said that if you inflate the wider tire to the same pressure as the narrower tire, then the wider tire is actually LESS comfortable than the narrower tire, completely defeating the purpose of running a wider tire in the first place?

Did you also miss the part on the very same page where they said they ignored the rated safety maximum pressures during the tests, and that in real world use, you cannot actually safely inflate wider tires to the same pressure as narrower tires?

Yeah, you missed both.

This is the problem with you parrots who have drunk the marketing Kool aid. You saw one chart and never paused to realize that in real life, wider tires need to be run at lower pressure than narrower tires.

Yan 

Holy smokes I already reminded you about this before so how did you forget again???

These tests are on one wheel. Bikes have two wheels. If you and your bike weigh ~80kg, then each tire carries about half the weight, therefore, ~40kg.

They are not screwing around with you by cheating with some fake light weight. It's simply because bikes have TWO wheels. What's hard to understand about this? HELLO???