Great tire test article!

[simplemind]

http://www.bikeradar.com/road/gear/article/best-performance-road-tires-lab-tested-49101/

[weisan]

interesting....ok, maybe I should give those schwalbe pro one tubeless tires mounted on the pacenti wheels a try again this weekend. :D

[Bwana]

Pretty disappointed they didn't have the Corsa's in 25c. :(

[ikecycke]

I've used the Pro One Tubeless pretty extensively since it came out, in both 23mm and 25mm variants. They're great when the weather is dry, but, for me, I found they didn't handle as well as other top-end tires when it's wet out.

[Mark McM]

This test is also being discussed on the SlowTwitch forums:

http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/I_thought_high_tire_pressure_was_bad__P6238886/

One point noted in the Slowtwitch discussion is that all test protocols will have some built in biases (either intentional or unintentional). In this case, the Wheel Energy test reported by BikeRadar has a bias toward tubeless tires, because of using (high-loss) butyl inner tubes in the standard clinchers instead of (low-loss) latex tubes. Tests of different inner tube types have shown that latex tubes can give a rolling resistance reduction of 3 - 4 Watts per pair of tires (http://www.bicyclerollingresistance.com/specials/schwalbe-one-tubeless-clincher), which would put the standard clinchers in this test on par with the tubeless tires.

[YesNdeed]

I haven't yet looked thoroughly into the wideness and size differences, but it looks I'll not only stick with the year round tires I use and love, Schwalbe Pro One Tubeless, but I won't switch to a 23 for race day.

[sparky33]

How wide does a 28 Schwalbe Pro One tubeless actually measure on a wide rim...something with a 20-21 internal width?

Also, I would have liked to see how the Compass (Cayuse Pass) 26mm tire compared in the tire test. I doubt any test would change my fondness for narrow Compass tires, but I am curious how the data would shake out.

[tv_vt]

Do you always have to use sealant with tubeless tires?

[jamiec]

It would be great to see another test where he tests some everyday tires. I am not sure how many people can get away running a lot of those tires on every ride.

[KSCycling]

I'd like to see research on grip, for the purposes of Criterium racing. Also, what about wind tunnel testing and crossing the research between the drum test and the wind tunnel. My wide designed carbon wheel recommends a size 23mm tire for aerodynamics vs a 25mm.


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[Mark McM]

Do you always have to use sealant with tubeless tires?

For true tubeless compatible rims and tires, you technically don't need to use sealant; for "tubeless ready" tires and/or rims, it generally is a requirement. In addition, you can use sealant inside an inner tube.

[sparky33]

Do you always have to use sealant with tubeless tires?
Technically you don't always have to but it makes a lot of sense to always use sealant with tubeless tires.
While many tubeless tires will hold air without sealant, having sealant in there makes punctures self-sealing... that convenience is one of the main benefits of running tubeless.

[Mark McM]

I'd like to see research on grip, for the purposes of Criterium racing. Also, what about wind tunnel testing and crossing the research between the drum test and the wind tunnel. My wide designed carbon wheel recommends a size 23mm tire for aerodynamics vs a 25mm.

Tire traction testing is actually a bit more problematic than rolling resistance testing, or even aero testing. To measure the traction limit on a given surface, you have to take the tire all that way up the point where it slips out - in other words, the point at which the bicycle falls. Automobiles do this on a skid pad, but automobiles don't fall over like bikes do when the tires skid out.

I am aware of two organizations that test the limits of tire traction - Michelin (tire manufacturer) and Tour (a German cycling magazine) - and these are done with special bicycles and riders wearing padded safety gear. Michelin keeps their test results private, but Tour periodically publishes tire test results.

(Note: Tire traction testing usually tests on wet pavement, because most high performance tires have more than adequate dry traction.)

Tire shape can have a larger affect on wheel aerodynamics, so for lowest aero drag, the tire should be matched to the wheel. However, the most aero tire isn't necessarily the one with the lowest rolling resistance, and it is the combined resistance (aero + rolling) that matters in the end. Unfortunately, it is costly and time consuming to try to test all possible combinations of wheels and tires. However Flo Cycling recently did a study to find the best tire for one of their aero wheels, taking into account both aero drag and rolling resistance:

http://flocycling.blogspot.com/2016/06/flo-cycling-a2-wind-tunnel-tire-study.html

[Bwana]

It would be great to see another test where he tests some everyday tires. I am not sure how many people can get away running a lot of those tires on every ride.

I ran GP4ks2's all last year without a single flat and now I'm on Corsa G+'s.

Granted, there's not a "real" winter down here, but still.

[bfd]

To measure the traction limit on a given surface, you have to take the tire all that way up the point where it slips out - in other words, the point at which the bicycle falls. Automobiles do this on a skid pad, but automobiles don't fall over like bikes do when the tires skid out.



You mean something like this? My all-time favorite cornering photo:

http://www.trentobike.org/Countries/Europe/Tour_Reports/Tour_of_the_Alps/Gallery/tiretest.jpg

Jobst Brandt was the man! Good Luck!

[Ken Robb]

Then there are the tests that have shown that the specific tire/pressure combo that was best on a smooth drum was not best on a textured surface like a typical paved road so this test won't influence my choice of tires. Heck, I'm old and slow no matter what tires I use so comfort and puncture resistance mean a lot to me.

[Mark McM]

Then there are the tests that have shown that the specific tire/pressure combo that was best on a smooth drum was not best on a textured surface like a typical paved road so this test won't influence my choice of tires. Heck, I'm old and slow no matter what tires I use so comfort and puncture resistance mean a lot to me.

Tire drum rolling resistance information (smooth or otherwise) can still be very useful for tire selection - even for real world tire selection.

Modern ideas on tire rolling resistance break down losses into two categories: Tire hysteresis losses, and system vibration losses (which Jan Heine calls "suspension losses" and Josh Poertner calls "impedance"). Drum testing can determine hysteresis losses, although not system vibration losses. See Josh Poertner's post on this subject:

https://silca.cc/blogs/journal/part-4b-rolling-resistance-and-impedance

The results of drum and real world testing have repeatedly shown that the relative order of rolling resistances between tires is maintained on different surfaces, even if the absolute magnitude of rolling resistance changes. In other words, if tire A has lower rolling resistance on a smooth drum than tire B, than tire A will also have lower rolling resistance on a rough road than tire B, even if the rough road resistance is higher for both.

So yes, even if you don't actually ride on smooth drums, smooth drum tests data will still show you which tire will have the lowest rolling resistance on your bumpy roads.

[Gummee]

I'd like to see research on grip, for the purposes of Criterium racing. Also, what about wind tunnel testing and crossing the research between the drum test and the wind tunnel. My wide designed carbon wheel recommends a size 23mm tire for aerodynamics vs a 25mm.


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this

There's lots of older wheel designs out there that were designed around 23c tires...

I'm curious who's 'the best' all-round.

M

[KSCycling]

http://flocycling.blogspot.com/2016/06/flo-cycling-a2-wind-tunnel-tire-study.html



Great info!

[stephenmarklay]

Fun to read. However, it seems like the bicycle rolling resistance guy has more comprehensive data. He however does not use a rough drum. It does appear that most of the results are pretty similar.

http://www.bicyclerollingresistance.com

[oldpotatoe]

Fun to read. However, it seems like the bicycle rolling resistance guy has more comprehensive data. He however does not use a rough drum. It does appear that most of the results are pretty similar.

http://www.bicyclerollingresistance.com

I find this type of info 'interesting' but note that the differences between the 'fastest' and 'slowest' is teeny. Like a lot of things bike, unless the tires are just sluggish dogs(like a Conti Contact, IMHO), reliability is more important, IMHO.

[Rusty Luggs]

I find it interesting that most of these articles do not seem to support the notion that lower pressure = lower rolling resistance, except on exceptionally rough road surfaces

[Pastashop]

I find it interesting that most of these articles do not seem to support the notion that lower pressure = lower rolling resistance, except on exceptionally rough road surfaces



Jobst Brandt had argued that lower pressure is slower, period. Part of Jan Heine's hypothesis was that vibrations propagated into the rider are ultimately dissipative (that is, a source of energy loss), not to mention contributing to fatigue. I've not seen definitive measurements done that are sufficiently free of confounding factors to convince me either way. And I'm too cheap and time crunched to invest in a power meter and do my own experiments.

[ColonelJLloyd]

I find this type of info 'interesting' but note that the differences between the 'fastest' and 'slowest' is teeny. Like a lot of things bike, unless the tires are just sluggish dogs(like a Conti Contact, IMHO), reliability is more important, IMHO.

Comfort or "feel" is another significant criteria. The difference between a 28mm high end Vittoria and a Gatorskin is significant to me.

[monarchguy]

With regard to smooth vs. rough drum tests, the Conti GP4Ks had a significant rank change compared to others. That's interesting, especially since I'm currently running it. Very curious as to how this reflects in the real world.
-- Dan

[cachagua]

Jobst Brandt was the man...

The man, and a well-dressed man, too.

[shovelhd]

http://i331.photobucket.com/albums/l453/shovelfl/2011%20racing/_JDP7810_zps4acb8c19.jpg

I also like the Pro One's in 28's. Has anyone ever run them with latex tubes? I'm thinking of converting them for the travel bike.

[Mark McM]

I find it interesting that most of these articles do not seem to support the notion that lower pressure = lower rolling resistance, except on exceptionally rough road surfaces

There are two primary source of rolling resistance - hysteresis losses in the tire, and vibrational losses in rest of the system. Hysteresis losses in the tire always decreases with pressure; however these losses decreases asymptotically, so there is little extra gain at very high pressures. On the other hand, vibrational losses increase with pressure, almost proportional with pressure. Therefore, there exists a point where the decreases in hysteresis losses are more than offset by increases in vibrational losses, so the total losses will only increase with pressure. The pressure at which this inflection occurs is sometimes called the Breakpoint Pressure. The existence of the Breakpoint pressure is discussed in this article on Slowtwitch:

http://www.slowtwitch.com/Tech/What_s_in_a_tube__1034.html

The Breakpoint Pressure will vary with the tire and the surface roughness, and will be lower on rough surfaces and higher on smooth surfaces.

In regard to the applicability of drum testing to the real world: Drum testing only tries to measure hysteresis losses in the tire itself, not the vibration losses in the rest of the system, which is why drum rolling resistance only decreases with pressure. However, it has been confirmed multiple times that although the magnitudes of rolling losses varies with surface roughness, the relative ranking of tire rolling resistance stays the same. In other words, if tire A has lower resistance than tire B on a smooth surface, then tire A will still have a lower resistance than tire B on a rough surface (even when adding in the vibrational losses). Therefore drum testing is useful for comparison purposes between tires.