Gravel tire rolling resistance tested

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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Singular
Posts: 423
Joined: Mon Jul 27, 2020 8:59 am

by Singular

fa63 wrote:
Thu Jan 06, 2022 12:29 am
It is anecdotal, but I was down to one bike (my gravel bike) for several months and group rides where I am normally one of the strongest (we usually average around 32 kph on moderately hilly terrain), I struggled to keep up with and even got dropped twice while on Panaracer GK 38mm tires (the slick ones; ones that test as one of the fastest by BRR). I don't ride with power anymore so I don't know about difference in power.
...but there is a ton of factors playing into that (and I expect the tyres per se to be one of the minor).
Marin wrote:
Tue Jan 04, 2022 1:23 pm


PS 6 bar is insane for the Bon Jovi, but it won't be much slower at 4 in the real world
That much pressure is truly Living on a prayer.

by Weenie


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warthog101
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by warthog101

fa63 wrote:It is anecdotal, but I was down to one bike (my gravel bike) for several months and group rides where I am normally one of the strongest (we usually average around 32 kph on moderately hilly terrain), I struggled to keep up with and even got dropped twice while on Panaracer GK 38mm tires (the slick ones; ones that test as one of the fastest by BRR). I don't ride with power anymore so I don't know about difference in power.
I am finding my gravel bike significantly slower than the roadie also.
Yep I am putting a significant portion of that down to the tyres too.

eins4eins
Posts: 332
Joined: Wed Sep 28, 2016 11:49 am

by eins4eins

In the offseason, i'm doing all my outdoor riding on the CX bike with 40mm Tufo Thundero tires and im always suprised about the speed when i come home. Did some longer base rides the last few weeks on the weekend: Flat terrain, little wind, ~220W avg power and average speed is still between 31-32kph.
But my cx bike position is very close to my road position, so quite aero and that matters more than a few watts from tires.

req110
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Location: Prague, Czechia

by req110

These tufos have very high TPI. I have them, but i usually try to ride as much gravel as possible on gravel bike.

How much pressure are you pumping them?

If i ride tarmac on gravel bike and these tires on 2.8 bar, i am usually 2 km/h below road avg.
S-Works SL7 Dusty Blue 56cm @ Sram RED AXS Quarq & ZIPP 404 Firecrest (7.2kg)
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Singular
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Joined: Mon Jul 27, 2020 8:59 am

by Singular

req110 wrote:
Thu Jan 06, 2022 4:34 pm
These tufos have very high TPI. I have them, but i usually try to ride as much gravel as possible on gravel bike.

How much pressure are you pumping them?

If i ride tarmac on gravel bike and these tires on 2.8 bar, i am usually 2 km/h below road avg.
As said, comparing two different bikes is really tricky as there is a lot of things that influence it - position, drivetrain, wheels (especially wheels in relation to tires) and much more.

On the other hand - at normal crusing speed (30ish km/h) a 2km/h delta is something around 30w. That is surely not unheard of in tyres alone if picking a GP5000 as a reference compared to a not-very-fast gravel tyre.

req110
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Location: Prague, Czechia

by req110

Understood.

Just to mention, my fit on road and gravel was similar, and wheels both 45mm profile.

Tufo gravel thundero 40mm
vs.
GP5000 28 clincher with tubolito

factor ls
vs.
supersix 2021

cockpit both farsports f1
S-Works SL7 Dusty Blue 56cm @ Sram RED AXS Quarq & ZIPP 404 Firecrest (7.2kg)
S-Works Epic 2022 Gloss Fluid L @ Sram XX1 AXS Quarq & Berg Ratheberg (9.4kg)

Singular
Posts: 423
Joined: Mon Jul 27, 2020 8:59 am

by Singular

req110 wrote:
Thu Jan 06, 2022 5:03 pm
Understood.

Just to mention, my fit on road and gravel was similar, and wheels both 45mm profile.

Tufo gravel thundero 40mm
vs.
GP5000 28 clincher with tubolito

factor ls
vs.
supersix 2021

cockpit both farsports f1
Yep, but the width of the wheels (in relation to the tyres) make for a large influence. I'm not saying that Hambini is right or wrong (and I do most certainly not support his style and rethorics), but the findings in width regarding wheels and tyres below is quite interesting (and is supported for example by Josh Poertner's findings): https://www.hambini.com/testing-to-find ... le-wheels/

What often contributes to gravel bikes being slower is that power gets lost in the drivetrain (due to single/smaller chainrings).

FlatlandClimber
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by FlatlandClimber

Singular wrote:
Thu Jan 06, 2022 5:19 pm
What often contributes to gravel bikes being slower is that power gets lost in the drivetrain (due to single/smaller chainrings).
Like how many watts do you think the smaller chainrings make up? 3W at 300W? Hard to imagine it's more than that.
It's not like Gravel bike chainrings are that tiny compared to a climbing set up on an RB (46/30 or 48/31 vs 50/34 or in SRAM 43/30 vs 46/33).

For 1X the difference is probably even less. You have smaller Chainrings, but larger sprockets.

There are many reasons why a gravel bike is slower (geometry, tires, weight, usually no focus on aero), but I don't think chainring size is a noticeable factor really.
Specialized SW Æthos (2021) 6.1kg
Specialized SW Crux (2022) 7.9kg
Specialized SW Tarmac (2022)
Cervelo P5 Disc (2021) 9.1kg

*all weights are race ready bikes, large frame size.
Sold: Venge, S5 Disc, Roubaix Team, Open WI.DE, Émonda, Shiv TT Disc

Singular
Posts: 423
Joined: Mon Jul 27, 2020 8:59 am

by Singular

FlatlandClimber wrote:
Thu Jan 06, 2022 7:53 pm
Singular wrote:
Thu Jan 06, 2022 5:19 pm
What often contributes to gravel bikes being slower is that power gets lost in the drivetrain (due to single/smaller chainrings).
Like how many watts do you think the smaller chainrings make up? 3W at 300W? Hard to imagine it's more than that.
It's not like Gravel bike chainrings are that tiny compared to a climbing set up on an RB (46/30 or 48/31 vs 50/34 or in SRAM 43/30 vs 46/33).

For 1X the difference is probably even less. You have smaller Chainrings, but larger sprockets.

There are many reasons why a gravel bike is slower (geometry, tires, weight, usually no focus on aero), but I don't think chainring size is a noticeable factor really.
Like mentioned, it is one of the marginal drains;

Image

The crux of smaller/single chainrings is that you have to use smaller sprockets too for the same gearing.

Marin
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Location: Vienna Austria

by Marin

Another anecdote, did a longer ride on 35mm Bon Jovies here https://www.strava.com/activities/5851833913

I'm happy with the avg speed taking into account the amount of climbing on the route (302km 2275m 28.8kph)

Image

warthog101
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by warthog101

Anyone used the schwalbe g one r.

https://off.road.cc/content/review/tyre ... eview-8153

They are expensive but are they fast?

henau212
Posts: 102
Joined: Sun Dec 09, 2018 12:27 pm

by henau212

warthog101 wrote:
Fri Jan 07, 2022 6:12 am
Anyone used the schwalbe g one r.

https://off.road.cc/content/review/tyre ... eview-8153

They are expensive but are they fast?
My favorite atm. Was riding Gravel H and Conti TS before that. Got more grip than both, is way more durable than the TS and is as fast. Rode them for about 1,5k now. They look almost as new and no punctures. I am running those tubeless.

warthog101
Posts: 442
Joined: Wed Sep 25, 2013 10:05 am

by warthog101


henau212 wrote:
My favorite atm. Was riding Gravel H and Conti TS before that. Got more grip than both, is way more durable than the TS and is as fast. Rode them for about 1,5k now. They look almost as new and no punctures. I am running those tubeless.
Thanks might give em a go. :)


Edit;
Had a look on BRR.
The terra speed tests comfortably better for both rolling resistance and puncture protection.

https://www.bicyclerollingresistance.co ... be-g-one-r

I like Conti's road tyres and they are cheaper. May try them first.

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nickf
Posts: 1193
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by nickf

In the real world which is faster? Anyone have experience with both?

Gravelking SS 38c
VS
Conti Terra speed 40c

With the gravelking you will save 100+grams but it comes with a 2 watt penalty. I know I won't notice 2 watts. A race with 2-3k meters of climbing I'll take that 100g savings with the SS. I have done many races on the SS, no issues with grip even on loose dry gravel. Would those small blocks on the terra speed provide any noticable improvement in grip?

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Singular
Posts: 423
Joined: Mon Jul 27, 2020 8:59 am

by Singular

Keep in mind - sensations are not really a great indicator of speed.

You might not feel 2W, but it is surely there nibbling away a percent of your effort, especially on long and slow days...

100 grams of tyre is noticeable but only a tenth or two of a percent of your system weight and is only slowing you down accordingly on the (steepest of) hills.

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