Gravel tire rolling resistance tested

[gwerziou]

Here's an interesting new article along these lines: https://www.renehersecycles.com/bq-tire-test-results/

[Point]

Have the Challenge Getaways been tested yet?

I've been riding them for several months now and they feel great and fast but I have absolutely no real figure bearing on how they're performing compared to my old Gravel King SK's.

I used my BRR Pro review request to get them added for testing, but they are still pretty far down in votes to get them reviewed. I agree they seemed to ride really fast for a non-slick, but it was such an effort to get them on either pair of my Enves that I have given up on them for now.

Great work!

Well hopefully they'll get tested soon enough, it'll be good to get a proper idea from data.
Mine are mounted on Hunt 4 Season Alu wheels and besides being a little tight, I managed to get them on with not much effort. Though I appreciate mounting tight tyres to carbon rims isn't as fun.

[tanhalt]

Here's an interesting new article along these lines: https://www.renehersecycles.com/bq-tire-test-results/

....ummm, I think I'd call those more like "test non-results", rather than "test results". A closer look at the methodology reveals they aren't able to reliably distinguish between the Crr of the tires being tested. The number of repeats, even with low variation, doesn't change that fact. Even in the low speed tests, >50% of what they're measuring is the effects of aerodynamic drag. This has been true for all of their tire field "tests", I'm afraid to say...I know what they did took a lot of work.

To be clear, I'm not saying they don't make nice tires. They do. I've used them AND recommended them to others at times. It's just that their "testing" often leaves much to be desired, and incorrect conclusions often drawn from them (such as, a non-statistically signficiant difference means there's "no difference"...that really just means you can't reliably SAY there's a difference. There may actually be a difference, but the data taken doesn't support that...and that could be because your test isn't sensitive enough to the thing you're trying to measure)

[bobrayner]

To be clear, I'm not saying they don't make nice tires. They do. I've used them AND recommended them to others at times. It's just that their "testing" often leaves much to be desired, and incorrect conclusions often drawn from them (such as, a non-statistically signficiant difference means there's "no difference"...that really just means you can't reliably SAY there's a difference. There may actually be a difference, but the data taken doesn't support that...and that could be because your test isn't sensitive enough to the thing you're trying to measure)

To be fair, even mentioning "statistical significance" puts them ahead of a lot of other industry research.

I bought lots of different things from other vendors which all promised to save 5-10 watts, according to "research". Why can't I get a free ride? If all those vendor promises were true, I should be riding at 60km/h now.

[tanhalt]

To be clear, I'm not saying they don't make nice tires. They do. I've used them AND recommended them to others at times. It's just that their "testing" often leaves much to be desired, and incorrect conclusions often drawn from them (such as, a non-statistically signficiant difference means there's "no difference"...that really just means you can't reliably SAY there's a difference. There may actually be a difference, but the data taken doesn't support that...and that could be because your test isn't sensitive enough to the thing you're trying to measure)

To be fair, even mentioning "statistical significance" puts them ahead of a lot of other industry research.

I bought lots of different things from other vendors which all promised to save 5-10 watts, according to "research". Why can't I get a free ride? If all those vendor promises were true, I should be riding at 60km/h now.

Right, but mis-applying it in the context doesn't help much. It lends an air of "science" and preciseness where it may not be appropriate. Tests of significance are great if the majority of errors are random. If the possible errors are systematic, or variables not even accounted for, then they aren't as useful.

A physical measurement analogy of the same relative magnitudes (this is the math for their 30pkh tests, where aero drag accounts for ~75% of the time measurement they took) for what they're trying to accomplish is: It's like trying to measure the thickness differences between a .23" shim and a .25" thick shim, by placing each separately against a .75" thick block and then measuring across both the block and shim with a ruler that has 1/32" (.031") gradations...by eye. Many repetitions isn't going to get a more accurate measure of either shim.

[zmjones]

To be clear, I'm not saying they don't make nice tires. They do. I've used them AND recommended them to others at times. It's just that their "testing" often leaves much to be desired, and incorrect conclusions often drawn from them (such as, a non-statistically signficiant difference means there's "no difference"...that really just means you can't reliably SAY there's a difference. There may actually be a difference, but the data taken doesn't support that...and that could be because your test isn't sensitive enough to the thing you're trying to measure)

To be fair, even mentioning "statistical significance" puts them ahead of a lot of other industry research.

I bought lots of different things from other vendors which all promised to save 5-10 watts, according to "research". Why can't I get a free ride? If all those vendor promises were true, I should be riding at 60km/h now.

Right, but mis-applying it in the context doesn't help much. It lends an air of "science" and preciseness where it may not be appropriate. Tests of significance are great if the majority of errors are random. If the possible errors are systematic, or variables not even accounted for, then they aren't as useful.

A physical measurement analogy of the same relative magnitudes (this is the math for their 30pkh tests, where aero drag accounts for ~75% of the time measurement they took) for what they're trying to accomplish is: It's like trying to measure the thickness differences between a .23" shim and a .25" thick shim, by placing each separately against a .75" thick block and then measuring across both the block and shim with a ruler that has 1/32" (.031") gradatations...by eye. Many repetitions isn't going to get a more accurate measure of either shim.

yea he i think is shady in this regard. they periodically mention that they have phds but never what in. lots of scientism throughout.

[req110]

I have installed panaracer gravelking SS 38c... semi-slick and i have to admit that tires are pretty fast (2.6bar front 2.9 bar rear for my 76kg). Their abilities in dry gravel are good. But when it's wet, not much luck.

[fourfa]

Hello WW. I recently bought a pair of Pirelli Cinturato Gravel H [EDIT: 650 x 50] as a low rolling resistance hard surface tire and found (a page or two back on this thread) that while the specs say the weight is 540g, the pair I received weigh 640.0 and 643.2g. I sent email to Pirelli to complain a little, no response. [Link: https://velo.pirelli.com/en/uk/product/ ... 00x35c/red]

Well I bought a Gravel M 650x50 to use as a front tire on an spare front wheel. (I find it works to put a knobbier front tire on here to occasionally go with the more moderate-tread rear, for more trail/less pavement oriented days). Reviews on the Gravel M looked even better than the Gravel H, like a good all-arounder with a lot more side bite but still a slick-rolling center band. And I expected a similar size as the 650x50 Gravel Hs, which max out the tire clearance on my gravel frame and fork. Spec weight is 550g [https://velo.pirelli.com/en/uk/product/ ... 0b/classic] - mine weighs 695.3g.

I'm not planning to return them or anything, the Gravel H really does seem to roll as well as the RennRad test a while ago indicates (where Pirelli was tops in rolling resistance, you can find it earlier in this thread), Gravel M looks to be similar. But all reviews have been for the 700c versions and weights seemed to match there. So there's something up with their 650B figures. If I had the correct weights I might not not have bought, who knows. Weight surely isn't everything, neither is CRR, but it sure as hell ain't nothing either.

Anyway this being WW I figured it was worth a first-hand report

[scoobydrew]

Interesting weight discrepancy on the Gravel H that you have. That's quite a drastic difference from the listed specs.

I have the Gravel H in 700x40. It's listed at 480g each, but mine weighed in at 492g and 496g.

[Marin]

I built a bike with 700x40 Gravel H and they were only "industry standard" overweight, but not excessively.

[shiiiison]

I currently am riding the 700x40 Gravel H and it's a very very nice tire. That said I have a set of the Zipp Tangente G40's that I want to test. Has anyone seen any numbers for the Zipp Tangente's yet?

[jfranci3]

They should roll mid pack at best. They look like a Conti Trail, Maxxis Rambler, Hutchinson Toureg, etc and they all roll about the same. Zipp tires are usually made Vittoria (as are/were Bontrager), so it's usually just a matter of them using the good rubber, casing, and didn't put too much rubber around the tire (indicated by weight). Vittoria Dry tire is said to weigh 446gr and these weigh "480gr" which would indicate Zipp just added the file tread.

[shiiiison]

They should roll mid pack at best. They look like a Conti Trail, Maxxis Rambler, Hutchinson Toureg, etc and they all roll about the same. Zipp tires are usually made Vittoria (as are/were Bontrager), so it's usually just a matter of them using the good rubber, casing, and didn't put too much rubber around the tire (indicated by weight). Vittoria Dry tire is said to weigh 446gr and these weigh "480gr" which would indicate Zipp just added the file tread.

Thanks for that. I really appriciate the extra history into where they likely come from.

Best.

[kervelo]

According to some review (cxmagazine?) the G40 tyres are made in France. The bead-to-bead protection and 127TPI are quite similar to the Touareg, but I have not seen any comment about the manufacturer.

The tyre has just been rebranded as Zipp G40 XPLR.

[jfranci3]

Having said all that... you're right... The sidewall looks just like the Pirelli and the they are both made in France.... so Hutchinson/Mavic/Pirelli - my bad.
https://www.cxmagazine.com/zipp-rolls-i ... e-g40-tire