Gravel tire rolling resistance tested

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PatchuaPatcherson
Posts: 8
Joined: Tue Nov 22, 2022 9:19 am

by PatchuaPatcherson

Had my eyes on thunderos for some time due to tread pattern- rolling resistance review sealed the deal. have put in about 500km now over long road rides, city riding, sand, mud, gravel and singletrack.

-36c tanwall measuring out to 38 on moderate 21mm internal rims. Running tubeless.

-Main comparison tubeless tyres- gravelking slick 38c and schwalbe g one 35c (pre-all round version)

- I found the gravelkings to be overly sensitive to air pressure. To get a decent feel on the road they needed to be very high psi otherwise they would wallow in corners and under power. On trails they similarly were either too soft and unsteady or too hard and pinging and bouncing all over the place. Tubeless performance and air holding pretty poor over the life of the tyre

- g ones were a much more damped carcass and the smaller size helped to support the tyre and reduce wallowing. Much better feel on road at a wide range of pressures esp climbing though definitely slower. pushing into the same gk psi territory to get that low rolling resistance led to a supremely plasticky and dead feeling tyre. Trail performance much less fussy with solid feel over a decent range of pressures and excellent performance over rocky stuff and larger hits. The increased braking and acceleration aggression of the tread was welcome. Cornering on roads was great. I felt i wanted more aggression on the side knobs as well as a fuller, longer lasting centre tread. Tubeless performance was exceptional though air holding reduced over the final months of the tyres life.

-Thunderos so far seem to be a great midpoint in terms of casing. A little more supple than g ones so as to be more comfortable at high road pressures without being too soft. Still very tough feeling on trails and holding shape well. Notably faster feeling on rougher surfaces. Hard to split tread performance between g one and thundero from current off road experience. Thundero has a big advantage in mud and sand. Grabs and paddles a bit more and sheds mud easily. On road the gappier side tread feels a touch more sketchy than the g one but no actual issues yet- potentially need to develop confidence with it. So far very close to a best of both worlds tyre with very little given up

DouglasDDX
Posts: 30
Joined: Tue May 24, 2022 10:08 am

by DouglasDDX

I have a lot of heavy and kind of muddy roads here in the winter where in a straight line the tires diggs down roughly 10mm and its just super heavy. On some of these routes grip isn't an issue really. What do you guys think is the type of tire with least rolling resistance in these kind of conditions?
A narrow 35mm or a wide 50mm? Slick pattern or more of a grippy pattern?

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PatchuaPatcherson
Posts: 8
Joined: Tue Nov 22, 2022 9:19 am

by PatchuaPatcherson

Some wider pirelli Ms id say. They roll quite well but also shed mud with a readiness not seen on comparative gravel tyres.

RDY
Posts: 2354
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

Anyone tried Ultradynamico Cava Race 42s?

FlatlandClimber
Posts: 2491
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

BRR has finally updated their protocol of Gravel tire testing, that were formally tested with a 160g Conti Butyl tube, and are now tested with tubeless sealant. Both data sets are available now on the pages of individual tires. Interestingly, from what I can grasp, most data sets are fairly consistent (all tires are faster with sealant than with an inner tube, but the gaps are very similar).
https://www.bicyclerollingresistance.co ... e-protocol

Pretty frustrating though, that only 30ml of sealant were used, even in the 50ml Terra Hardpack. Don't think anyone would use these sub 60ml, rather 100ml+
Cervelo P5 Disc (2021) 9.1kg
Factor Ostro Gravel (2023) 8.0kg
S-Works SL8 (2023) 6.3kg

*weights are race ready, size 58/L.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT, Crux, Aethos, SL7

RDY
Posts: 2354
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

It seems almost completely uniform the difference. Between the Strada Bianca Pro HTLR, Getaway Pro HTLR, all have 3.8W lower at low pressure, and 5W lower at extra low. I don't think more sealant would make a huge difference. It makes more difference to rotational weight than RR.

Edit: this can't be legit ... it's exactly the same on GP5000 S TR 32 and Snoqualmie Pass. All 3.8 / 5W. Wildly different sizes, construction and compounds, surely they'd react slightly differently?

FlatlandClimber
Posts: 2491
Joined: Tue Mar 31, 2020 3:37 pm

by FlatlandClimber

Amount of sealant does impact RR: https://www.aero-coach.co.uk/tubeless-s ... resistance

You are right about the differences. Seems fishy...
Although, wouldnt it make sense that you basically only measure the difference between 20ml of sealant and a 160g butyl tube? Down to the .1 appears highly unlikely, but approximately it should be the case.

Edit: yeah, they are just recalculated to make them comparable, stated in the test of the Terra Hardpack. I misread that.
Cervelo P5 Disc (2021) 9.1kg
Factor Ostro Gravel (2023) 8.0kg
S-Works SL8 (2023) 6.3kg

*weights are race ready, size 58/L.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT, Crux, Aethos, SL7

RDY
Posts: 2354
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

FlatlandClimber wrote:
Thu Jan 26, 2023 3:09 pm
Amount of sealant does impact RR: https://www.aero-coach.co.uk/tubeless-s ... resistance

You are right about the differences. Seems fishy...
Although, wouldnt it make sense that you basically only measure the difference between 20ml of sealant and a 160g butyl tube? Down to the .1 appears highly unlikely, but approximately it should be the case.

Edit: yeah, they are just recalculated to make them comparable, stated in the test of the Terra Hardpack. I misread that.
That's a very low volume 25mm tire though, and still the difference is quite small. Bigger ones it's going to be pretty minimal.

That makes sense then ... no way would tested data be that uniform. I suspect there will be some significant divergence though, so the Conti 50mm is probably the only one with really accurate TL data.

stevesbike
Posts: 324
Joined: Thu Oct 24, 2019 5:33 pm

by stevesbike

I've never understood the use of a simulated road surface for testing gravel tires. The resulting wattage differences typically are trivial for real-world performance - a rambler, riddler, Cinturato Gravel M are within a few watts of each other yet they give the rambler a low rating due to lack of speed (despite being one of the most popular race tires for mixed conditions) and their grip testing doesn't reflect actual grip performance for tires like these where grip is determined not just by rubber compound but tread pattern. Comparison charts with slick tread vs knobbies also is problematic. It all seems like a misapplication of road tire testing to gravel.

CampagYOLO
Posts: 705
Joined: Thu May 06, 2021 3:58 pm

by CampagYOLO

stevesbike wrote:
Thu Jan 26, 2023 5:27 pm
I've never understood the use of a simulated road surface for testing gravel tires. The resulting wattage differences typically are trivial for real-world performance - a rambler, riddler, Cinturato Gravel M are within a few watts of each other yet they give the rambler a low rating due to lack of speed (despite being one of the most popular race tires for mixed conditions) and their grip testing doesn't reflect actual grip performance for tires like these where grip is determined not just by rubber compound but tread pattern. Comparison charts with slick tread vs knobbies also is problematic. It all seems like a misapplication of road tire testing to gravel.
BRR do give a disclaimer in the grip section basically stating what you just have when it comes to their grip test with Gravel/CX tyres.
It's critical to understand our static wet grip test works with a hard surface. This means the grip data is only directly useful for comparing tires on hard surfaces where the rubber compound creates the grip. Understanding the test results gets more difficult when grip is created by the knobs digging into the surface.


On soft surfaces (loose sand, grass, etc), almost all grip will be created by the knobs digging into the surface, and our test results will be of little use.


There will also be many surfaces where the total grip will be a combination of the tread compound grip and the grip provided by the knobs. Under these circumstances, the hard surface grip can still be a deciding factor.


Given these shortcomings, we feel our grip test, combined with the knob height measurements, will still be valuable information when comparing tires.


For more about our grip test, and how the knobby tread pattern affects the test results, we have more information here.
The Rambler tested poorly but having used it I've found it a very grippy gravel tyre in dry/damp conditions, that may be why it's so popular in gravel races.

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F45
Posts: 1077
Joined: Wed Jun 08, 2011 6:08 am

by F45

I'm liking that Michelin Power Gravel 35. Only 21W of resistance and good knobs.

HBike
Posts: 190
Joined: Sun Aug 14, 2022 8:22 pm

by HBike

Woland wrote:
Tue Oct 25, 2022 4:35 pm
Nohands83 wrote:
Fri Oct 21, 2022 7:32 am
It’s winter tyres time in the UK, considering trying out Tufo Swampero, Pirelli S or Hutchinson Tundra this year - any user experience with these?
+500km on Swampero 700x40, previously on Terra Speed 700x40. The Swampero is more grippy and supple that the Terrra Speed, but does feel a little slower on asphalt and hardpack gravel. I switched mainly for more cornering grip = fun and the Swampero has delivered.

I've heard that the Tufo's (Speedero/Thundero/Swampero) are more prone to punctures than the Contis, but that hasn't been my experience so far.
I put Speedero on my gravel/commuter bike and had quite a few punctures. Frustrated I switched back to S-Works Pathfinders. Higher RR but no issues with punctures in lots of riding. Additionally, the Speederos mounted difficult, which is a pain when using a TPU tube on the commute.
When whether is nice I use the Panaracer GravelKing TLC 40, which I like, too.
Next tire will be Schwalbe G-One RS.

robeambro
Posts: 1829
Joined: Sat Jul 07, 2018 6:21 pm

by robeambro

A couple questions..

I am waiting on a new gravel race bike, which in theory has official clearance for 45mm tyres. Due to SRAM porky FD battery, I suspect real clearance will be somewhere in the region of 37-40mm WAM.
I currently have a set of Terra Speeds (old gen, I think, as I got them for 50% off or so) 40's which I'd like to mount to my road rims which are slightly narrow (21IW, 28 wide).

My questions are:
- how wide could I expect these Terra Speeds to balloon up to?
- if these ended up being too wide (likely), what's my best bet for a fast rolling tyre that can also do a bit of mud (gravel in the UK is hardly ever fully dry..)?
- considering that aerodynamics are compromised anyway, would it be silly to run a chonky front tyre to make full use of clearance and maximise grip, and a skinnier rear tyre (not as a choice - just cause I've got limited clearance), or would it have some unwanted side effects? e.g. 42/35mm F/R.

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Nohands83
Posts: 259
Joined: Tue Feb 13, 2018 7:41 am
Location: Leeds, UK

by Nohands83

Mixing different threads and size is pretty commonplace on MTBs. I've done it with a pair of Pirelli M (front) and H (rear), 45 on the 40 on the rear. It worked OK, but it does change the geo of the bike slightly as it raises up the front end, effectively changing the head angle and slowing down the steering. If you are going to do it you might want to try and keep the size differences a bit closer.

In terms of a UK mud/gravel tyre I've been riding Vittoria Mezcals since Christmas and I'm really impressed, feel like they roll well and deal with 1cm of mud well. Anything deeper and you need Terreno wets - which are a different level in mud to every other gravel tyre I've ridden. The Mezcals I've been using are 44mm and come up around 43.5mm on 25mm internal rim so probably too big for your rear but they do also make them in 35mm.

The Pirelli M are ok but the almost solid centre-line is slippery AF in mud. The Tufo Swampero in 40mm might be worth a look if you can squeeze them.

What bike are they going on btw?

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robeambro
Posts: 1829
Joined: Sat Jul 07, 2018 6:21 pm

by robeambro

Nohands83 wrote:
Mon Feb 06, 2023 5:48 pm
Mixing different threads and size is pretty commonplace on MTBs. I've done it with a pair of Pirelli M (front) and H (rear), 45 on the 40 on the rear. It worked OK, but it does change the geo of the bike slightly as it raises up the front end, effectively changing the head angle and slowing down the steering. If you are going to do it you might want to try and keep the size differences a bit closer.

In terms of a UK mud/gravel tyre I've been riding Vittoria Mezcals since Christmas and I'm really impressed, feel like they roll well and deal with 1cm of mud well. Anything deeper and you need Terreno wets - which are a different level in mud to every other gravel tyre I've ridden. The Mezcals I've been using are 44mm and come up around 43.5mm on 25mm internal rim so probably too big for your rear but they do also make them in 35mm.

The Pirelli M are ok but the almost solid centre-line is slippery AF in mud. The Tufo Swampero in 40mm might be worth a look if you can squeeze them.

What bike are they going on btw?
If all goes well they'll go on an Ostro Gravel - it's been impossible to find an Addict Gravel 2022 frame, and the 2023 colours are vomit-inducing, so I went for the expensive option.

Issue is, I don't ride cross and I I'm not sure I want to pick a tyre for muddy conditions (the tread on the Mezcal and Swampero seems to suggest they are) which is then going to punish me on faster sections - on the other hand as you said I don't know whether I trust a slick centre-line for when it's less grippy. I've only done the Dirty Reiver last year and the weather and gravel were gloriously dry, dusty even. But I would be a fool to expect the same come this April..

So yeah, maybe I don't even know myself what I truly want and need. :lol:

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