TYRES: speed v p******* resistance

gbs

What is known about the tradeoff between lightness and speed v reliability?

I am guessing that for example Schwalbe Ultremo will give a 1kph, possibly 2kph benefit over Durano.

rolf_f

gbs wrote:

What is known about the tradeoff between lightness and speed v reliability?

I am guessing that for example Schwalbe Ultremo will give a 1kph, possibly 2kph benefit over Durano.

The Ultremo will help to give the bike a sprightlier acceleration and it might enable faster cornering but other variables are so much more significant that I doubt you'd be able to do two rides to compare the two and actually determine that any difference in speed between the rides was down to the tyres*.

If you start making your life a misery by buying Schwalbe tyres with a 'plus' in the name, then you'll probably start to see a difference. But they tend to weigh a fair bit more and have much less compliant sidewalls.

*unless of course the lighter construction of the Ultremo results in a puncture in which case the Durano will be noticeably faster in overall journey time!

gbs

"Plus = misery". Why? Difficult to fit?

I am not expecting to measure the differences on the road but I would expect there to be lab test data. I have enquired at Schwalbe (currently my preferred brand).

ugo.santalucia

1-2 Kph is very very optimistic. The best rolling resitance Vs a very bog standard 5 tyre will probably give you 2-3 Watt and 2-3 Watt will not translate in 1-2 Kph under any circumstance.
When you spend money, you get better grip, you get a tyre which handles better in corners and keeps a better momentum over a rough terrain.
IME when it comes to speed and averages, the difference is negligible, until you start comparing slick Vs Knobbly

rolf_f

gbs wrote:

"Plus = misery". Why? Difficult to fit?

I am not expecting to measure the differences on the road but I would expect there to be lab test data. I have enquired at Schwalbe (currently my preferred brand).

To be fair, my experience is based on a few rides on a mates bike that I renovated for him - the shop convinced him to go for Marathon Plus. They made the bike a total drudge to ride. I'd rather have the occasional puncture. They are tricky to fit but nothing too bad - it's not as though you need to take them off much/ever!

Irrc, the standard Durano still has a high proportion of the puncture resistance of the Durano Plus but a lot less weight and I suspect a far nicer ride. I mostly use the Durano S (all year round) which are lighter and probably the optimum Schwalbe choice if you are dithering between Ultremo and Durano.

chanjy

I'm guessing that the entire aggregated time you save with 'faster' tyres will be lost fixing your puncture.

But nicer tyres to corner better.

drlodge

"Fast" tyres will cut up more easily so are suitable only for dry summer roads. GP4000S and Michelin Pro4 Service Course are tyres that give a good balance between being "fast" and "durable" IMHO. Currently using the latter and liking them.

BenderRodriguez

ugo.santalucia wrote:

1-2 Kph is very very optimistic. The best rolling resitance Vs a very bog standard 5 tyre will probably give you 2-3 Watt and 2-3 Watt will not translate in 1-2 Kph under any circumstance.

Plenty of tyre tests have shown that a supple tubular with a thin latex tube, such as a Vittoria SC, will save 5 watts over a 'fast' clincher such as a GP4000s fitted with a butyl tube, and that is on a test rig using a smooth roller. On a real road with a typically rough road surface the differences will up to twice this as the supple tyre will dissipate much less energy as it flexes, assuming appropriate tyre pressures. So, for a pair of wheels you are looking at as much as 10 - 20 watts, depending on the road surface, more than enough to be noticeable, and the difference between a good tub and a heavy duty touring tyre will be greater still.

I ride on a board track in the winter was was running Conti Sprinter tubulars, but due to their poor grip over the painted advertisements changed to Vittoria Pista Evos, which are one of the fastest tubs around. I don't have a power meter but my times on the track suggest these tyres are worth a good 1 km/hr over the Sprinters at 40 - 45 km/hr.

ugo.santalucia

BenderRodriguez wrote:

Plenty of tyre tests have shown that a supple tubular with a thin latex tube, such as a Vittoria SC, will save 5 watts over a 'fast' clincher such as a GP4000s fitted with a butyl tube, and that is on a test rig using a smooth roller. On a real road with a typically rough road surface the differences will up to twice this as the supple tyre will dissipate much less energy as it flexes, assuming appropriate tyre pressures. So, for a pair of wheels you are looking at as much as 10 - 20 watts, depending on the road surface, more than enough to be noticeable, and the difference between a good tub and a heavy duty touring tyre will be greater still.

There are all sorts of tests around and some suggest a lot less, if anything. My experience is that I don't notice any significant speed improvement on a timed course going from a pair of Panaracer Pasela, to Randonneur PRO, to Gatorskin and finally to Vittoria CX. The difference in "feel" and handling is huge though and I could probably name each of them on a blindfolded test. (Gatorskin is the poorest of them all... )

BenderRodriguez

ugo.santalucia wrote:

There are all sorts of tests around and some suggest a lot less, if anything.

Yes, all using a rig with a smooth roller and the tyre pumped up rock hard so the differences arising from losses as the carcass of the tyre flexes over irregularities are not apparent!

ugo.santalucia wrote:

My experience is that I don't notice any significant speed improvement on a timed course going from a pair of Panaracer Pasela, to Randonneur PRO, to Gatorskin and finally to Vittoria CX.

All pressures fitted with a butyl tube? If so, perhaps there is no wonder that the differences are smaller than, for example, between a Vittoria SC tub and a Conti GP4000s pressure.

To my mind, if there was no real advantage to be had from running a really supple tubular, especially over rough road surfaces, then the majority of the pro teams wouldn't be saying 'Sponsor's tyre contract be damned', lets buy a crate load of FMBs!

Anyhow, back to the original question. I would say that the GP4000s provides a good compromise between puncture resistance, durability and rolling resistance. Avoid riding a pair of decent tubs, so you never know what you are missing, and you will probably be happy ever after!

ugo.santalucia

BenderRodriguez wrote:

To my mind, if there was no real advantage to be had from running a really supple tubular, especially over rough road surfaces, then the majority of the pro teams wouldn't be saying 'Sponsor's tyre contract be damned', lets buy a crate load of FMBs!

Interestingly Paris Roubaix is the only race where tyres do matter. There is a huge difference in behaviour between a soft tub that flexes at the high frequency required and a harder one. FMB are the softest tubs out there and they are also very easy to damage, so they do win P-R, but they might not actually get to the end of P-R. A friend of mine ripped one open 20 miles in his first ride over a section of rough tarmac.

As for my experience, that includes clinchers, tubulars and clinchers run tubeless... I really want to see a difference, but there isn't any in speed, annoyingly (as we all want to believe that those 100 quid in tyres made a difference)

BenderRodriguez

ugo.santalucia wrote:

Interestingly Paris Roubaix is the only race where tyres do matter. There is a huge difference in behaviour between a soft tub that flexes at the high frequency required and a harder one.

But FMB are the first choice of tyre for many more races other than Paris-Roubaix. I would agree, though, that the worse the surface, the greater the gains to be had from a supple tyre.

ugo.santalucia wrote:

As for my experience, that includes clinchers, tubulars and clinchers run tubeless... I really want to see a difference, but there isn't any in speed, annoyingly (as we all want to believe that those 100 quid in tyres made a difference)

Perhaps you ride smoother roads than I do! On the winter damaged Alpine back roads I frequent there certainly is an advantage to be had from riding a supple tubular at an appropriate pressure as opposed to my usual GP4000s wheels. I have tried playing around with the pressures in my Contis but they can't come close, either bumping all over the place over the irregularities when hard or dragging like an MTB tyre if I soften them up. Grant you, the difference is probably only 0.5 km/hr or so, but during an 8 hour Alpine sportive that still adds up.

As you said earlier, whatever the speed difference, for many the riding qualities of a supple tyre are enough reason in themselves to make the choice. I would also think that the increased comfort will help to stave off fatigue to some small degree, so aiding speed that way as well.

ugo.santalucia

BenderRodriguez wrote:

As you said earlier, whatever the speed difference, for many the riding qualities of a supple tyre are enough reason in themselves to make the choice. I would also think that the increased comfort will help to stave off fatigue to some small degree, so aiding speed that way as well.

That's for sure

darkhairedlord

^ the most sensible thing said on tyres for a long time. It's not all about rolling resistance, all those little jolts and jars or vibrations (energy) need absorbing somewhere and rather in the tyre than by my hands, feet and arse.

drlodge

Comfort is the biggest performance boost IMHO.

jordan_217

drlodge wrote:

Comfort is the biggest performance boost IMHO.

drlodge in fabric softner doping shocker :shock:

BenderRodriguez

darkhairedlord wrote:

It's not all about rolling resistance, all those little jolts and jars or vibrations (energy) need absorbing somewhere and rather in the tyre than by my hands, feet and ars*.

Another way to look at is that those jolts and vibrations are themselves the most significant contributors to rolling resistance, as the energy that it takes to bump the weight of the bike and rider upwards is energy that would otherwise be propelling you forward. Consequently, it is by making the ride 'smoother' that a pneumatic tyre reduces rolling resistance in the first place. This is also why tyre pressures need to be matched to the smoothness of the surface, not just pumped to the max.

The potential downside is that casing and tube flex also absorb energy, which is why a supple tub with a thin latex tube will be faster than a pressure, especially one with a butyl tube. The shape of a tub also helps as the whole tyre can deform, whilst with a pressure the flex is more or less restricted to the sidewalls above the bead of the rim.

drlodge

jordan_217 wrote:

drlodge wrote:

Comfort is the biggest performance boost IMHO.

drlodge in fabric softner doping shocker :shock:

Remember to take it at the end of the cycle.

It makes a great recovery drink