Rolling resistance?

[sreten]

Also, that perhaps some "less wide" tyres roll better than some wider tyres.
All this is very subjective.

Hi,

The opposite argument is very much the case in this thread.
No one has subjectively backed trying fatter tyres and going
back to skinny tyres, the skinny types just insist they are better.
(Without ever trying fatter, so its just dogmatic opinion.)
Its pretty obvious who have their "heads in the sand".
Like the pretension of the above, just claim the opposite.

rgds, sreten.

[reohn2]

Also, that perhaps some "less wide" tyres roll better than some wider tyres.
All this is very subjective.

Hi,

The opposite argument is very much the case in this thread.
No one has subjectively backed trying fatter tyres and going
back to skinny tyres, the skinny types just insist they are better.

Not quite,Meic has,though hasn't,as yet stated which type of wider tyre he's compared his narrow HP Rubino's with.

(Without ever trying fatter, so its just dogmatic opinion.)
Its pretty obvious who have their "heads in the sand".
Like the pretension of the above, just claim the opposite.

rgds, sreten.

FWIW and IME the only thing wide 32mm> supple quality tyres(slicks or near slick) have against them is weight and unless they are made paper thin and impractical,will always be so,a quality 23 to 28mm(actualsize)supple slick comes in at around 235 to 295g,compared to a 35mm(actual)similar quality tyre @395g ie;Hypers(there are a couple of Grand Bois tyres lighter),which is a whopping 100g .
The air chamber(read suspension)is huge by comparison and the bigger tyres,because of that,are able to be ridden at a lot lower pressure(IME up to 30%+ lower) without loss of rolling resistance.
The heavier tyre will take a little more energy to wind up to speed but at the kind of speeds most of us ride at(I'm suspecting mid 'teens averges with about 12mph for touring with a load) the extra energy consumption is negligible.
The real plus is comfort,especially on long rides,which shows toward the day's end and if a rider feels 'beat up' toward the end of a ride it is cumulative on back to back multi day riding,especially for us weak and feeble old 'uns
My(practical) 2d's worth

[MartinC]

..........................The opposite argument is very much the case in this thread.
No one has subjectively backed trying fatter tyres and going
back to skinny tyres, the skinny types just insist they are better..........................

Like many, many people I've bikes with tyres that range from 23mm to 1.5" in width. I repeatedly change from skinny to wide and vice versa depending on how, where, when and who with I want to ride.

Clue. For some uses of a bicycle the notional advantages of a wider tyre are outweighed by the compromises in frame geometry and rotational inertia you need to make to be able to use them.

[reohn2]

Today into a 13to15mph headwind a tractor a big 4x4 one with a full width grass cutter on the rear came past.
I was struggling to get over 15mph but managed to 'catch the draft' and sat in for almost a 11/2miles @22 to 25mph with very little energy being expended at all.
It's a while since I've been so fortunate .
BTW I was on 35mm Hypers @ 45f and 65r psi.
To quote the Man 'The answer my friend is blowing in the wind,the answer is blowing in the wind'................

[MartinC]

Today into a 13to15mph headwind a tractor a big 4x4 one with a full width grass cutter on the rear came past.
I was struggling to get over 15mph but managed to 'catch the draft' and sat in for almost a 11/2miles @22 to 25mph with very little energy being expended at all.
It's a while since I've been so fortunate .
BTW I was on 35mm Hypers @ 45f and 65r psi.
To quote the Man 'The answer my friend is blowing in the wind,the answer is blowing in the wind'................

............................rather than the blowing in your tyres.

[reohn2]

Today into a 13to15mph headwind a tractor a big 4x4 one with a full width grass cutter on the rear came past.
I was struggling to get over 15mph but managed to 'catch the draft' and sat in for almost a 11/2miles @22 to 25mph with very little energy being expended at all.
It's a while since I've been so fortunate .
BTW I was on 35mm Hypers @ 45f and 65r psi.
To quote the Man 'The answer my friend is blowing in the wind,the answer is blowing in the wind'................

............................rather than the blowing in your tyres.

Apparently

[garry71]

I recently swapped my 23mm Gatorskins for some 32mm Continental City Rides. It's a much nicer ride, but they've really slowed the bike down a lot. They're at 55psi at the moment, but next time I'll pump them to the maximum of 60 psi to see if there's much difference.

Cheers
Garry

[reohn2]

I recently swapped my 23mm Gatorskins for some 32mm Continental City Rides. It's a much nicer ride, but they've really slowed the bike down a lot. They're at 55psi at the moment, but next time I'll pump them to the maximum of 60 psi to see if there's much difference.

Cheers
Garry

You've over doubled the weight of your tyres 560g compared to 220g,added block tread,and gone down the quality standing.
Conti don't seem to give TPI carcass numbers but I'd say it'll be low and the carcass will be stiff.
TBH,It doesn't look good for rolling resistance

[Scunnered]

I recently swapped my 23mm Gatorskins for some 32mm Continental City Rides. It's a much nicer ride, but they've really slowed the bike down a lot.

Not all wide tyres roll well. Check this table: https://www.fietsersbond.nl/sites/default/files/test_schwalbe.pdf

[MartinC]

Interesting posts. My view is that there are many other factors at work which can easily overwhelm any simple consideration of width.

The view from the Panaracer guy in the last BQ is relevant too. Suppleness isn't a simple consideration of tpi. High tpi carcasses may be more supple because the threads are thinner but the density of the weave has a large effect too - lots of threads densely woven isn't supple so just equating high tpi with suppleness isn't true.

[Brucey]

yes but because there are at least two plies, the tyre sidewall is of finite thickness. You can't flex the sidewall without there being some shearing between the plies, and the thicker the sidewall the more the net shearing action is going to be, because there is a bigger difference between the internal and external radii. It is my view that a good deal of the hysteresis in tyre carcasses arises because of this effect in the sidewall.

Obviously if you have a low tpi count each cord is thicker and so is each ply, too. There may be shearing in 3D around each cord in a low tpi carcass too, rather than a 'sheet over sheet' deformation as you might get in a high tpi carcass where the cords are much closer together.

Similar arguments apply within each cord also; these are spun and contain individual fibres that slide over one another whenever the cord is flexed, again with hysteresis. Such effects are out of proportion with the simple diameter of the cord, or sidewall thickness, in the same way as the bending stiffness of beams goes with the cube of the depth.

In both cases there is a suggestion that the hysteresis will increase roughly in inverse proportion to the tpi count, for a sidewall of a given nominal static strength (cord area), if everything else is kept equal. Which it probably won't be...

cheers

[CJ]

I recently swapped my 23mm Gatorskins for some 32mm Continental City Rides. It's a much nicer ride, but they've really slowed the bike down a lot.

Not all wide tyres roll well. Check this table: https://www.fietsersbond.nl/sites/default/files/test_schwalbe.pdf

Very useful table, thanks.

Swap a narrow tyre of thin construction for a wide tyre of thick construction and it shouldn't surprise anyone that the bike goes slower!

And have you ever noticed, when you put some new tyres on, that worn tyres roll better? I'm finding it hard to pension off my old (must be at least 14 years given the name!) Conti Top-Touring 2000 tyres, that I like to put on for actual tours. Now they're nearly worn out there's less rubber to bend and they roll even better than when they were new! But they're getting to look awful cracked and crazed, so although they still have no really dangerous cuts and a shallow vestige of tread yet remains, I've put on a pair of new Top Contacts (same size: 37-622).

And frankly, I'm disappointed. The promise of "handmade in Germany" and "same high-tech materials as our racing tyres" (I paraphrase) does not make them roll as easily as those old 2000s - or the original Top-Tourings (I still have one pair left of the dozens I bought cheap when they discontinued my favourite ever touring tyre). Since then it seems like Conti have become insistent upon the insertion of extra casing layers, to resist the punctures I don't get enough of to worry about, and separate tread blocks which shuffle like the all-joined-up Top-Touring tread couldn't. That Fietsersbond/Schwalbe data bears out my feeling that the Top Contact isn't quite the bees knees, so I've ordered some Vittoria Hyper/Randonneur Pros (not sure exactly which I'll get from Wiggle/CTCshop's slightly confused ordering page!): a tyre I've enjoyed riding before and which scores a significantly lower Crr than anything Conti.

[geocycle]

And have you ever noticed, when you put some new tyres on, that worn tyres roll better? I'm finding it hard to pension off my old (must be at least 14 years given the name!) Conti Top-Touring 2000 tyres, that I like to put on for actual tours. Now they're nearly worn out there's less rubber to bend and they roll even better than when they were new! But they're getting to look awful cracked and crazed, so although they still have no really dangerous cuts and a shallow vestige of tread yet remains, I've put on a pair of new Top Contacts (same size: 37-622).

I know what you mean about worn, but not worn-out tyres. I was discussing this with a friend as I swapped my part worn rear marathon supreme to the front to even wear across the pair. His argument was that you should always have the best tyre on the front which I also agree with, but how to say which is the best???! Not only do they seem to roll better they also seem to harden with age (both unscientific observations on my behalf).

[reohn2]

I know what you mean about worn, but not worn-out tyres. I was discussing this with a friend as I swapped my part worn rear marathon supreme to the front to even wear across the pair. His argument was that you should always have the best tyre on the front which I also agree with, but how to say which is the best???!......

(man opens can of worms again )
IMO the tyre that's seen the least amount of abuse should be on the front.
If a tyre has been on the rear it's seen most of the weight,it's taken most of the hits coz if you hit something it's usually with the rear tyre,rear tyres get most of the punctures too,because of this.
That's why I prefer not to rotate cycle tyres,preferring to use best upfront system,moving front tyre to rear and fitting new on the front.
Disclaimer; Others may have other opinions .

[Brucey]

I'm a tyre rotator, except on things like dutch bikes, where the rear tyre (which is often something altogether different to the front one anyway) can stay put until it dies.

cheers