tomato coupe

A lot of cyclists would pay lots of money for tires that gave them an extra 1 mph.

dim

they are kak .... if you want a tyre as puncture resistant, and which has better grip in the wet than gatorskins, and which are less harsh, get Durano Plus

aliasfox

You're right, it's not robust testing - considering that testing is my profession, I will readily admit that it's not large sample, single variable testing. Heck, the difference could have come from the fact that I was wearing full finger gloves in 2019 and therefore had a better sense of how much I was modulating the brakes. Or maybe I happened to cruise down a drier patch of road in 2019 when I went down the same hill.

However, my personal conclusion, after riding that bike that day, was that those tires were doing me no favors.

indyfabz

Uncorrect.

seypat

They are good material to make boots out of.

WhyFi

Ha ha - good one. I thought that you were being serious there for a second, until you wrote this and made it obvious that you were joking. Kudos.

Dancing Skeleton

I found them to give a very harsh ride, they also felt very slow & didn't grip the road well in wet conditions.

BoraxKid

You must be a newbie, so I'll cut you some slack. A 1 mph change in speed can happen when the wind changes speed or direction during your ride, or when you start getting more air resistance because you sat up a little while pedaling and that increased your coefficient of drag. In fact, changes in the wind can easily account for +3 mph while riding. This is why most serious riders will focus on their cadence and power output instead of just speed.

To take this a step further, the post I was referring to cited a 1 mph difference at 20+ mph. If you are riding above 20 mph, then 1 mph is less than a 5% difference in speed, which is something that is likely not going to be noticed. If you are still a beginner (as I suspect you must be) riding at 12 mph, then sure, that 1 mph matters a lot because it represents a bigger change as a percent of your speed. I recommend you spend more time lurking before posting again, mmkay?

Bah Humbug

I...

Wait, what? It seems like you’re serious, but you can’t possibly be serious.

HTupolev

I'm familiar with the discussion around drum testing. Like, I literally have a Bicycle Quarterly subscription.

The main criticism with traditional drum testing is that it does not detect the effects of suspension. However, it does measure hysteresis loss of the tire rolling against the drum, which is fairly analogous to the hysteresis loss of a non-over-pumped tire rolling on a road. It's not an exactly precise representation of a road surface, but tests that have compared between drum results and real-world results have generally concluded that tires that perform well on the drum generally also perform well on the road.

No, it's actually the opposite. Look at this chart from Jan Heine comparing tire pressure versus performance across 3 different tires. The performance difference between the two faster tires and the slower tire is actually smaller when all the tires are over-pumped, than when they're all pumped to their optimal pressures.

Many people would disagree. I mean, I sometimes say that there's "not that much" difference between my Emonda...



...and my Stumpjumper...



...because I typically see less than 1mph between them on solo road rides. In terms of how the two bikes look and their versatility, a kph or so is "not that much" compared with the expectations that most people have when they look at the two bikes, and considering the use cases covered by each bicycle.

However, when we're talking about changing a single part of a performance-oriented road racing bike, that's a different context. For instance, if it were determined that Look Keo pedals were 1mph faster than Shimano SPD-SL pedals, this would be absolutely astonishing and a huge deal, and even people who preferred the feel of SPD-SL would flee to the Look Keo infrastructure.

BoraxKid

You've read that chart wrong. It shows that the least amount of power was needed to maintain 17 mph when each of the three tires was inflated to 80-90 psi; for the two CX tires the minimum is at 80 or 85 psi, the Rubino minimum is at 90 psi. And that exactly proves my point, and the entire tubeless tire industries point: you don't need to be over 100 psi to go fast.

I understand your misreading of that chart because it is not constructed very well. But it clearly is meant to show for a given tire pressure, what power is required from the rider to maintain 17 mph. The caption explains it (poorly).

HTupolev

No, you misread my post. I wasn't claiming that you need to be at high pressure to go fast. I was pointing out that the performance differences between the tires was larger when they were pumped correctly than when they are over-pumped. If all three tires are at 9bar (~131PSI) the chart only shows ~10W between the slowest tire and the fastest tire. But at 6 bar (~87PSI), there are about 17 watts between those two tires.

In other words, as people settle on lower tire pressures, Gatorskins are likely to be at a greater disadvantage compared with fast tires than they were in the past. The advantage of fast tires becomes larger when people select appropriately-low pressures.

WhyFi

Yeah, a 1 mph difference matters less and less the faster you go - ha! The jokes - they just keep coming!

MoAlpha

You mad, bro?

WhyFi

I'm enjoying this man's comedic stylings!

BoraxKid

Oh okay, so you just over-extrapolated some poorly presented data to try and prove your point. Got it.

Gatorskins are not shown on that chart, so they cannot be included in whatever inference space that data might have provided. Your post would be the equivalent of me showing data from the latest Space-X launch and trying to extrapolate it to explain why Peter Sagan was able to accelerate better while wearing Oakleys instead of 100 Percents.

The chart you provided shows 2 CX tires and one "Rubino" tire, and when you look at clincher vs clincher, the difference between the two tires changes at each pressure tested. Clearly there is more going on than what that chart shows, as there is likely some run-to-run variation and some variation from one sample of the same tire to the next sample. Of course, since you didn't provide any details of test methods, it's impossible to see how well the test was designed and how applicable (or not) it might be to real-world conditions.

BoraxKid

Explain how I'm wrong. At 10 mph, 1 mph = 10%.

At 20 mph, 1 mph = 5%.
At 30 mph, 1 mph = 3.33%.

The percent change represented by 1 mph literally gets smaller as speed increases. Why is this so difficult for you to accept? It's just basic maths.

So, if a tire causes a 1 mph reduction in speed when riding at >20 mph (which Gatorskins DO NOT, but I'm entertaining an argument here), that is an insignificant change in total speed.

asgelle

Yes, but I feel like I'm watching a cat play with a captured mouse.

HTupolev

It's from an old Bicycle Quarterly, but I referenced it from this blog post. Heine's test methodology involved measuring power while holding a constant speed riding laps around the asphalt apron inside of the track at Marymoor Velodrome.

My observation was that the stiff slow tire gets less benefit from being reduced to optimal pressure than the two suppler tires did.

This result is also intuitive. When all tires are pumped far too stiff to function properly as suspension, there's no obvious reason that a slow stiff tire would suffer more loss from bumping over road irregularities than a supple tire. But slow stiff tires do suffer greater losses from deformation when pressure is lowered. So whatever disadvantage a slow stiff tire has at too-high pressure, it makes sense that the disadvantage would grow when pressures are lowered to more optimal levels.

Obviously without testing this directly on Gatorskins I cannot make a totally confident statement on the issue. I do not dispute this. That is why I qualified my statement with the word "likely." It agrees with current theories about rolling resistance, which agree with what on-road data exists, but it's true that this exact case has not been directly tested in data that I've personally looked at.

WhyFi

You joker, you!

rubiksoval

Oh, look, you're making stuff up again.

Seattle Forrest

Since going tubeless, the only flat I've had was that one day I used tubes.

Seattle Forrest

This pretty much sums up my experience with Gatorskins.

rubiksoval

Awesome. Now explain how much power it takes to increase your speed by 1 mph at 10 mph, 20 mph, and 30 mph.

It's just basic maths, right?

BoraxKid

So now you're just making assumptions and treating them as fact. Nice. You've assumed that the Gatorskins are a "stiff slow" tire, when in fact they are neither slow nor stiff. As plenty of people in this very thread and out in the real world have reported, Gatorskins are actually a fast, supple tire when properly inflated, and they have the added benefit of a more puncture-resistant tread than their in-class competitors. You can't even point to a single, fair test of Gatorskins to prove all the hogwash that people have been bandying about for all these years. Hence, your claims are dubious and show an obvious bias.