Racing Dan

If you are heavy you need wide (and tall) tyres if you want to ride in reasonable comfort, or you bottom out and get a snakebite.

MoAlpha

They are also highly suggestible, they have huge biases, and virtually no human testing of bike products is blinded, making it next to worthless. That said, even I can tell the difference between Gatorskins and 4000s, even GP4Ss.

TakingMyTime

I like the tires I have on my bike now. I'm sure I'll like the replacements I put on mid-summer. If not, I'll replace them with another tire.

rubiksoval

Rolling resistance is one of the most important attributes of a tire if you're worried about speed. And the more important speed, the more important rolling resistance.

It might be important to you, but it's not important in the real world comparatively.

BritishV8

Strava makes it convenient to compare tires.


By comparing segment times on otherwise similar rides, it's quite clear I lost quite a lot of speed when I swapped from GP 4000S II (28mm) to GP 4-season (32mm) tires back in December. I'm slower everywhere, and I can easily feel the difference too. The swap was largely motivated by a particularly inconvenient flat, and because with winter I was riding in darkness and inclement weather more. I haven't had any flats since, but with longer days and fair weather back I'm delighted to ditch the "4-season" tires. (They're not even much different from the Gatorskins on my commuter.) Aerodynamics and weight could be factors, though Strava segment times and feel seem to match wattage numbers on bicyclerollingresistance.com.

RChung

We can actually calculate the difference in weight that's equivalent to a difference in rolling resistance. That difference will depend, of course, on whether you're riding on a flat road or up a hill, and what your total weight is.

Suppose you weigh 72 kg, your bike weighs 8 kg, and you're comparing a Conti 4000S with a Conti Gatorskin. On a steep 10% slope, the 4000S saves you the equivalent of 2 kg of weight (that is, a 10 kg bike with 4000S tires will take as much power as an 8 kg bike with Gatorskins). On a middling 5% slope, the 4000S saves you the equivalent of 4 kg of weight.

If you're not a powerful rider and you care about weight, you should definitely care about rolling resistance. People fret about a difference in weight of a hundred grams. Rolling resistance is worth thousands of grams.

Racing Dan

At an accent speed of 1000 m per hour, 1 kg is worth 2.72 W. Its not as much as ppl make it out to be. Rolling and wind resistance is more important than saving a few hundred grams.

Carbonfiberboy 

IME this is absolutely true. Slow tires suck the life out of my legs. They never stop sucking. A very experienced friend of mine tried Gatorskins on a metric century event ride. Back at the cars, she said she was throwing them away. Our used tandem came with Gatorskins. After 2 rides, I threw them away. We've run 4KIIs in 28mm the past 2 winters, fewest flats we've ever had on any tires. I have a pair of 5000s for when we wear the current tires out. I'll be interested in how wide they are inflated on our 23mm (outside) rims. Maybe I should have ordered 32s.

We like speed.

Yeah, we've had a sidewall cut on the Contis, but that was captain error, not tire error. Stupid to hit a sharp rock. I don't ride them on gravel.

woodcraft

The difference could also be accounted for that it was winter and you were riding through denser air.

Iride01 

While I've always liked the comparison data of BRR it still leaves much that we'll always be able to argue about. Their tests, according to their Standard Test Procedure are done with a load of 42.5 kg. This is 92.7 lbs. If you assume it's the rear wheel then on a road bike this probably equates to a rider of 140 pounds or less. Not realistic for me.

Yet by not giving this info to the reader of the tire article, it causes a lot of people to think they need to inflate their tires to what is shown in the article and what to me are dangerously low levels for their actual ride weight and probably result in a lot of the "why did I flat" and "I need a tire that grips in a turn" postings.

TimothyH

I'm not talking about Gatorskins. Gatorskins are ****.

I'm talking about Michelin Pro 4 (or whatever they are called nowadays) vs Corsa vs Rubino Speed vs GP4000 vs Turbo Cotton vs whatever high end road bike tires are out there.

All have pretty good to excellent rolling resistance. I like speed too but I think people are splitting hairs.

As an example, how a tire behaves when braking hard and deep into a turn matters. In this situation I'll take a supple Vittoria over a nervous, twitchy and unforgiving Michelin any day, even if they have a slightly higher rolling resistance.

Unless you do TT's in a straight line on flat ground every day, rolling resistance only tells part of the story about how a tire behaves at speed in the real world


-Tim-

canklecat

Among the various mostly affordable road bike tires I've tried, I can *feel* a difference in perceptions of responsiveness and comfort, but I don't see any consistent differences in my times over familiar routes that I've ridden dozens of times. Some of my fastest times were on cheap Vittoria Zaffiro wire beads and pricey Schwalbe One V-Guard HS448 folders. And Conti Ultra Sport 2 folders in 700x23 and 25. And an old pair of Specialized Transition wire beads.

The better tires feel better. But it doesn't show in my times. Any differences can be attributed to other factors -- mostly how I felt that day. On the 5-20 mile loop circuits I ride, wind and elevation are negated as factors, so my average speed and times are roughly the same on calm days as on days with 20+ mph winds. I don't count single direction routes since they're subject to wind, and even a small breeze can influence perceptions of how a tire performs.

But on my hybrid, yup, I've noticed significant differences that definitely show in my average times. I suspect there are much larger differences in the potential for hybrid/touring tires, vs road bike tires where manufacturers seem more competitive for best performance within value constraints.

For a couple of years I preferred Continental Speed Rides on my hybrid (700x42 nominal, measures closer to 700x38). Just great all around tires, smooth and quick feeling on good pavement, comfortable on busted up pavement and chipseal, grippy on dry gravel and grass. The specs weren't impressive but the sidewalls felt compliant and supple and the ride showed it. Depending on the engine I averaged 14 mph, closer to 16 if I put some effort into it. And every ride was a pleasure.

Back in the autumn I wanted to put fenders on the hybrid. The old SKS fenders I had in the closet were too narrow for the Speed Rides, so I ordered a set of Conti Sport Contact II when Nashbar blew 'em out for $20 for the pair. I figured the 700x32 would fit the fenders, still be reasonably wide, and should ride about the same as the Speed Rides since both weighed the same.

Nope, not even close. The Sport Contact II felt harsh at full pressure, sluggish at lower pressure and never as compliant or supple or whatever that means. Squeezing the unmounted tires, they felt like Gatorskins I've squoozed in the LBS -- like lead filled garden hose. The sidewalls were rigid. My average speeds were much slower and every ride felt like a chore. I switched back to the Speed Rides and the old magic was there again -- faster speeds, more pleasant rides.

But I haven't found comparably significant results with the handful of road bike tires I've tried. Sure, they feel different. But it doesn't show in my speeds, not at my modest level of power and ability. Any slight differences on smooth, flat roads are negated by the more frequent chipseal, striated concrete and slow-feeling pavement.

Conti Ultra Sport II have been a reasonable compromise for me. Reliable, durable, good resistance to punctures and cuts, comfortable at the right pressure and I don't feel like the tires are holding me back. Sure, I'd rather ride the old Schwalbe HS448s, but only if someone else was paying because those things nicked and cuts a little too easily, although they were otherwise reasonably durable and puncture resistant.

on the path

I also tried the Rubino Pro Speed. Great tires. They're light, they grip, they roll great. Best of all they inspire confidence in cornering. I feel the tires will allow me to lean the bike over further than I'd really want to. And yep, about 1200 miles for the rear tire and it was done. I'll replace them with Conti 4000s because of price and longevity. I hope the sidewalls of the Contis hold up.

asgelle

Given the non-linear nature of aero drag, this doesn't make sense. If your times are the same on calm and windy days, there's something going on to offset the increased drag from the wind.

Spoonrobot 

Even if you assume wind/elevation are not a factor (erroneously IMO) air density and road surface temperature are still huge factors. The latter can account for double digit percentage change in rolling resistance time for a given segment, based on my own personal testing and testing done by Bicycle Quarterly, among others.

The more I read about rolling resistance the more it seems the most knowledge institutions are the ones who've said nothing. Professional mountain bike racers and the companies who develop their tires probably have a deeper understanding of the applications of rolling resistance with respect to all the other factors that go into a tire than anyone else.

Personally rolling resistance is the more prominent factor for a given tire for reasons already mentioned; it's always there. On pavement - no matter how well a tire corners the time spent doing so is minuscule compared to the time spent riding in a straight line. Saving a few seconds in a corner doesn't mean much to me if it's costing minutes over the course of the ride. Thankfully, the best cornering tires are often the fastest rolling tires.

RChung

We know that additional bike weight doesn't matter when it's flat, so you can add a lot of extra weight to a bike on flat terrain without costing you much in power. We know that as the road gets steeper weight matters more so a smaller difference in weight penalizes you more. Meanwhile, differences in Crr apply whether you are on the flat or on a steep hill (or even while descending). We know how to convert a difference in Crr to an "equivalent" penalty in mass.

Here's a comparison of the old Conti 4000S II and the new Conti 5000 in terms of "equivalent mass penalty." Both are good tires with low Crr: .0039 for the 4000S and .0032 for the 5000 -- neither are anywhere near a Gatorskin. Even at a steep 10% slope, that small difference in Crr is equivalent to more than 500g in additional bike mass. If you care about weight you should care even more about Crr. Weight weenies should be rolling resistance weenies.

Sy Reene

Presuming you don't need to factor in the time a trip to the ER takes due to sliding out while cornering, you'd be correct.

Sy Reene

Interesting chart.. but it looks the curve has no finite end for mass penalty. Ie. is there one at 0% slope? What does curve look like going downhill?

f4rrest

Theoretically, additional mass doesn't matter on flat ground, so there could be no equivalent mass great enough to offset the rolling resistance on flat ground.

As for negative slope, I would expect that you'd reflect the curve around both x and y axes, which suggests infitely negative mass at tiny negative slope.

Sy Reene

hmm ok.. but if you're riding up only a .5% slope, there's a really really large mass penalty?

asgelle

Unless we're careful with language, statement like this (which is qualitatively correct),
lead to ones like this,
Which are incorrect.

Theoretically mass does matter even on flat ground. Mass appears in the rolling resistance force term, https://www.recumbents.com/wisil/Mart...%20cycling.pdf Eq. (5). The fact that mass appears in the rolling resistance force just as it does in the gravitational force is what allows us to convert Crr to slope. (I should have given credit to Robert earlier for pointing this out.)

DrIsotope

All I know for sure is when I swapped out the 700x28 Conti Gator Hardshells for 700x28 Michelin PRO4 Endurance, I got over 1mph faster overall-- and that was over thousands of recorded miles. And the PRO4 isn't even a super-fast rolling tire. The Hardshell just might as well be a LEGO® brick.

noodle soup

I thought you were a tubeless guy,

I used Michelin PRO4 Endurance tires for years because they were smooth riding and reasonably durable( + inexpensive).

Did you ever find them to be "twitchy and unforgiving"

DrIsotope

The PRO4 were my last tubed tires before going to tubeless. I had relatively good luck with them flats-wise, but for me the great failing of the PRO4 is that they would be fine for a few thousand miles, then suddenly it was 3 flats in a week, or two in one day. They were the lithium battery of tires. The rolled better that the Contis, and they handled better as well, but they were really just a slightly different flavor. My first tubeless were Schwalbe ONEs, which were not long lasting by any measure, but after all those thousands of miles on armored tires, it was like going from a Flintstones car to an F1.

noodle soup

I know what you mean.

I went from 25mm Pro 4 Endurance tires, to 30mm Schwalbe G-One Speed(tubeless).

It's like riding on a cloud, and not a bit slower.