When you buy your tyres are you swayed at all by the rolling resistance of them? I tend to go for something pretty puncture resistant over a faster rolling tyre.
How much difference would a race tyre make on a journey compared to a training tyre?
Rolling resistance?
Re: Rolling resistance?
If you get a puncture a lot!
I think that rolling resistance is too far down the list of slowing forces relative to wind resistance for me to care. And I hate punctures
I think that rolling resistance is too far down the list of slowing forces relative to wind resistance for me to care. And I hate punctures
"Marriage is a wonderful invention; but then again so is the bicycle puncture repair kit." - Billy Connolly
very good.Re: Rolling resistance?
Hi,
When buying tyres I look very hard for discounted tyres of the type I want.
Generally the more expensive roll better, and I try to get them cheap.
But I don't compromise on what I want, like puncture protection.
rgds, sreten.
FWIW due to the ongoing thinner tyres roll better, when they really
don't on typical roads, there are some real bargains to be had, if
you buy into fitting fatter tyres on your bike.
When buying tyres I look very hard for discounted tyres of the type I want.
Generally the more expensive roll better, and I try to get them cheap.
But I don't compromise on what I want, like puncture protection.
rgds, sreten.
FWIW due to the ongoing thinner tyres roll better, when they really
don't on typical roads, there are some real bargains to be had, if
you buy into fitting fatter tyres on your bike.
Re: Rolling resistance?
I am conscious that fat tyres roll better. I much prefer 25 over 23 on my road bike, and use nothing less than 2" on my 26" utility bike.
I should coco.
Re: Rolling resistance?
After a set of new Marathon Duremes felt slow. I swapped them for a pair of Vittoria Randoneur Hypers and compared them on a roll down test on a local hill with times in the 40s area and terminal speeds in the high 20s. The Vittorias were 10% faster despite the runs being fast enough that wind resistance was a factor. The Vittorias are more comfortable as well having more flexible construction.
As yet no punctures though no big miles yet. But I'm convinced they are about 10% faster in real use than the Duremes. Why wouldn't you use a faster tyre with no downsides? The only ones I can see is possibly shorter life.
Looks like the Hyper has almost the lowest RR in these tests
https://www.fietsersbond.nl/sites/defau ... hwalbe.pdf
As yet no punctures though no big miles yet. But I'm convinced they are about 10% faster in real use than the Duremes. Why wouldn't you use a faster tyre with no downsides? The only ones I can see is possibly shorter life.
Looks like the Hyper has almost the lowest RR in these tests
https://www.fietsersbond.nl/sites/defau ... hwalbe.pdf
Re: Rolling resistance?
Hi
Some test data for the Conti GP4 Seasons (the 28mm has been my commuting tyre of choice for 3 years) and some others http://www.conti-tyres.co.uk/conticycle/download_files/TyreTests/RoadBike_winter_test_02_11.pdf
My best bike has 25mm Conti 4000S although I've never run a comparison on times
Regards
tim-b
Some test data for the Conti GP4 Seasons (the 28mm has been my commuting tyre of choice for 3 years) and some others http://www.conti-tyres.co.uk/conticycle/download_files/TyreTests/RoadBike_winter_test_02_11.pdf
My best bike has 25mm Conti 4000S although I've never run a comparison on times
Regards
tim-b
~~~~¯\(ツ)/¯~~~~
Re: Rolling resistance?
I find that race tyres don't have the puncture resistance that I want, especially for commuting. The gain over a good touring or training tyre is small, and for me, at least all but unnoticeable unless I am training for speed or time trialling, or something.
Like tim-b, I prefer Continental GP 4 seasons tyres. And even when I've tried other tyres that should be similar (like the Conti GP 4000S), I haven't liked them as well.
Like tim-b, I prefer Continental GP 4 seasons tyres. And even when I've tried other tyres that should be similar (like the Conti GP 4000S), I haven't liked them as well.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom
― Nelson Mandela, Long Walk to Freedom
Re: Rolling resistance?
Rolling drag is indeed relatively unimportant for those cyclists who work their socks off to go as fast as possible, because for them aerodynamic drag is indeed hugely greater. But paradoxically, if you're a slow cyclist intent upon (or only capable of) expending a minimal amount of energy, rolling drag matters a great deal, because for you it is likely to be the largest single factor making you even slower - and the only one you can easily do something about.
Because cycling is dominated by the sporty types however, the needs of the rest of us are belittled and neglected. It is presumed that if you are not trying to go fast, you cannot care about how slow you go and it does not matter if your laziness is punished by inefficient equipment. So it's very hard to find useful information about rolling drag of sensible models of tyres.
The good news is that wider tyres don’t necessarily have more rolling drag. In fact, all else equal, a wider tyre has a shorter contact patch, so its casing distorts less on entry and exit from that patch, hence it actually rolls easier. All else, of course, is seldom equal, and the main reason narrow tyres usually roll easier than wide ones is because (all else equal again) a narrower pipe can hold a higher pressure. Of course that only holds true if the narrow tyre actually has a much higher pressure in it, even higher than its relative reduction in width. And if the user worries that his narrow tyres will be more puncture prone, so fits a model with loads of protective belting etc., the rolling advantage is totally negated.
I’ll tell you a story. When the Panaracer Category-1s that came on my Audax bike wore out, I put on some Schwalbe Stelvios I’d been sent for review. The bike didn’t seem to go so well. People I used to out-freewheel downhill were going past me now. Even my slightly taller but in those days no heavier son, on a touring bike, went past me, saying “your fast bike is a bit pants downhill dad”! I had to agree.
So I salvaged the Panaracers from the okay-for-emergencies pile and did some roll-down tests. The bike rolled several metres further. Then out of curiosity, to see how much slower it was, I got out the tourer. All conventional wisdom said it shouldn’t go so well, due to more wind drag from wider mudguards and other stuff like lamps, as well as broader, thicker-tread tyres. And its good old 32mm Conti Top Tourings were only at 85psi, rather than the 110 I’d put in the Audax bike’s 25mm tyres. So I was very surprised to find that it nevertheless rolled just as well as the Audax on Panaracers! That’s what prompted me to learn a bit more about where rolling drag actually comes from. It isn’t as simple as most people think.
So now I happily commute and tour on really good quality 37mm touring tyres, pumped up hard, and though I weigh a far from heavy 66kg, there aren’t many who can outroll me downhill! My favourites from Schwalbe are Marathon so-called Racer and Supreme, Continental Top Contact, Vittoria Randonneur Pro. There may be other really easy tyres I haven't tried yet.
Even the racers, so I hear, are moving up from 23 to 25mm and sometimes even 28! So I don’t think there’s any good reason for anyone else to use such narrow tyres as 23mm, especially given this country’s dilapidated road surfaces. Only the bad reason, that one has unwisely bought a bike that denies one the option of fitting anything wider.
Mike Burrows has some surprising roll-down results from Marathon Plus, which seems to be the exception to the rule that puncture prevention makes a tyre 'slow', or as I would put it: 'draggy'. I speculate that the high-hysteresis (hence grippy but lossy) tread rubber buckles into that thick wodge of super-low hysteresis rubber laid underneath it to repel sharp things, rather than stretching or squashing, thus absorbing less energy than if it were to be stretched or squeezed by bending of the tyre casing as it passes in and out of the road contact patch. I nevertheless do not fit these tyres personally, on account of their sheer weight and because personally I don't have a problem with punctures (except for some rim tape trouble on one bike a year ago).
Because cycling is dominated by the sporty types however, the needs of the rest of us are belittled and neglected. It is presumed that if you are not trying to go fast, you cannot care about how slow you go and it does not matter if your laziness is punished by inefficient equipment. So it's very hard to find useful information about rolling drag of sensible models of tyres.
The good news is that wider tyres don’t necessarily have more rolling drag. In fact, all else equal, a wider tyre has a shorter contact patch, so its casing distorts less on entry and exit from that patch, hence it actually rolls easier. All else, of course, is seldom equal, and the main reason narrow tyres usually roll easier than wide ones is because (all else equal again) a narrower pipe can hold a higher pressure. Of course that only holds true if the narrow tyre actually has a much higher pressure in it, even higher than its relative reduction in width. And if the user worries that his narrow tyres will be more puncture prone, so fits a model with loads of protective belting etc., the rolling advantage is totally negated.
I’ll tell you a story. When the Panaracer Category-1s that came on my Audax bike wore out, I put on some Schwalbe Stelvios I’d been sent for review. The bike didn’t seem to go so well. People I used to out-freewheel downhill were going past me now. Even my slightly taller but in those days no heavier son, on a touring bike, went past me, saying “your fast bike is a bit pants downhill dad”! I had to agree.
So I salvaged the Panaracers from the okay-for-emergencies pile and did some roll-down tests. The bike rolled several metres further. Then out of curiosity, to see how much slower it was, I got out the tourer. All conventional wisdom said it shouldn’t go so well, due to more wind drag from wider mudguards and other stuff like lamps, as well as broader, thicker-tread tyres. And its good old 32mm Conti Top Tourings were only at 85psi, rather than the 110 I’d put in the Audax bike’s 25mm tyres. So I was very surprised to find that it nevertheless rolled just as well as the Audax on Panaracers! That’s what prompted me to learn a bit more about where rolling drag actually comes from. It isn’t as simple as most people think.
So now I happily commute and tour on really good quality 37mm touring tyres, pumped up hard, and though I weigh a far from heavy 66kg, there aren’t many who can outroll me downhill! My favourites from Schwalbe are Marathon so-called Racer and Supreme, Continental Top Contact, Vittoria Randonneur Pro. There may be other really easy tyres I haven't tried yet.
Even the racers, so I hear, are moving up from 23 to 25mm and sometimes even 28! So I don’t think there’s any good reason for anyone else to use such narrow tyres as 23mm, especially given this country’s dilapidated road surfaces. Only the bad reason, that one has unwisely bought a bike that denies one the option of fitting anything wider.
Mike Burrows has some surprising roll-down results from Marathon Plus, which seems to be the exception to the rule that puncture prevention makes a tyre 'slow', or as I would put it: 'draggy'. I speculate that the high-hysteresis (hence grippy but lossy) tread rubber buckles into that thick wodge of super-low hysteresis rubber laid underneath it to repel sharp things, rather than stretching or squashing, thus absorbing less energy than if it were to be stretched or squeezed by bending of the tyre casing as it passes in and out of the road contact patch. I nevertheless do not fit these tyres personally, on account of their sheer weight and because personally I don't have a problem with punctures (except for some rim tape trouble on one bike a year ago).
Chris Juden
One lady owner, never raced or jumped.
One lady owner, never raced or jumped.
Re: Rolling resistance?
i can't say that i've really noticed that much difference in various tyres with 'rolling resistance' when i'm up to speed. air resistance on me yes, but not really 'rolling' resistance on the tyres. what sort of % is this? i.e if i were to stop pedalling at 20mph on a flat road with tyre A against B i would come to a stop about how much more quickly down to the resistance of the tyres alone?
what i do notice is just sheer weight of different tyres when accelerating initially most likely made more significant by the wider rims i use with heavier tyres. the change back to such as an open pro rim with lightish weight 23c tyre in spring is marked after a winter on continental winter grip type tyres and A117 rims.
what i do notice is just sheer weight of different tyres when accelerating initially most likely made more significant by the wider rims i use with heavier tyres. the change back to such as an open pro rim with lightish weight 23c tyre in spring is marked after a winter on continental winter grip type tyres and A117 rims.
Re: Rolling resistance?
mig wrote:i can't say that i've really noticed that much difference in various tyres with 'rolling resistance' when i'm up to speed. air resistance on me yes, but not really 'rolling' resistance on the tyres. what sort of % is this? i.e if i were to stop pedalling at 20mph on a flat road with tyre A against B i would come to a stop about how much more quickly down to the resistance of the tyres alone?
Depends what your 'up to speed' speed is. If it is indeed 20mph, then air resistance will be more important. If you tour at 10mph, I would expect rolling resistance to be more important.
Re: Rolling resistance?
I notice that the Bike Quarterly used roll down tests to show that fatter tyres were lower rolling resistance. Then again that is being used here.
I always find that the big heavy tyres and the big heavy bikes roll down hills faster and go a bit further up the next one. This is surely due to all the extra PE in their mass and in the case of the tyres the extra rotational momentum that they are storing.
I feel that any results of a roll down test are more due to the mass of the tyre than its rolling resistance and fatter tyres are normally heavier and with the C0G slightly further out.
So, yes, fatter/heavier tyres go further down hills but you have to get them up there first.
I always find that the big heavy tyres and the big heavy bikes roll down hills faster and go a bit further up the next one. This is surely due to all the extra PE in their mass and in the case of the tyres the extra rotational momentum that they are storing.
I feel that any results of a roll down test are more due to the mass of the tyre than its rolling resistance and fatter tyres are normally heavier and with the C0G slightly further out.
So, yes, fatter/heavier tyres go further down hills but you have to get them up there first.
Re: Rolling resistance?
Interesting replies. So it would appear that faster rolling tyres would benefit a touring cyclist at moderate to slow speeds more than an outright racer perhaps? I'd not thought of it that way before. Why don't racing cyclists fit wider tyres - because they want those very high pressures a smaller tire gives?
I must admit the wider tyre/less rolling resistance completely threw me when I first read about it but I'm beginning to understand the theory behind it more.
I have noticed that brand new tyres which hold there intended shape always feel faster than older ones of the same make that have begun to square off with wear.
I must admit the wider tyre/less rolling resistance completely threw me when I first read about it but I'm beginning to understand the theory behind it more.
I have noticed that brand new tyres which hold there intended shape always feel faster than older ones of the same make that have begun to square off with wear.
Last edited by Dave W on 5 Aug 2014, 6:30pm, edited 1 time in total.
Re: Rolling resistance?
Dave W wrote:Why don't racing cyclists fit wider tiyes - because they want those very high pressures a smaller tire gives?
Interestingly, recent science shows that a fatter tyre is typically more aerodynamic than a thinner one - within reason - hence the move away from 22/23 on road bikes to a more portly 25c. But aerodynamics really only comes into play at higher speeds.
I should coco.
Re: Rolling resistance?
I've changed from 25mm to 23mm and always thought they felt faster. However without any proof they could in fact be slower I suppose.