chucky

I thought it was tire aerodynamics which was being pointed out: that as speed increases tire aerodynamics have more of an impact vs tire rolling resistance, hence, the preference for skinnier tires. Skinnier tires also have an advantage at the opposite end of the spectrum: lower weight when for accelerating (ie from a stop).

But, yeah, I agree that control and traction are usually more important...although wider lower pressure tires also improve control and traction without compromising rolling resistance (but at the expense of aerodynamics and weight).

tsl

Which would fall under the category of "none that they're willing to share".

Steely Dan

i'm merely countering your opinion with my own. is that not allowed anymore? if the exchange of opinion is now forbidden, then perhaps the entire forum should be shut down.




and i contend that the very notion that there is a "reasonable OBJECTIVE best" tire choice is patently absurd when you consider the multitudes of variables that go into the equation - different riders, different styles of riding, different strengths of riders, different levels of handling proficiency of riders, different styles of bikes, different riding surface conditions, different meteorological conditions, different topographical conditions, different wind conditions, etc. etc. etc. each individual rider, through research and often with a bit of trial and error, will hopefully find the tires that best meet the needs and wants of the type of riding that they do. a ""reasonable OBJECTIVE best" overall tire? a one-size-fits-all answer to a question with thousands of individual answers? give me a break.






well, all i can tell you is that in over 4,000 miles of daily commuting with them, i have yet to encounter a single moment where i wanted for more grip.





it's impossible for you to know that with the information about me that you have.





first off, having looked at them, i find the testing methods of the tire testing labs to be highly dubious when compared against real world riding conditions. second, i don't ride crits. if crit riders want to ride crossers with 40mm tires because the labs tell them it's faster, well they're free to do so, however i've never seen anyone riding crits on 40mm tires.





i simply don't believe that is true. when i commuted on big apples @ 70psi on my old bike, i could barely keep the thing over 20 mph if i killed myself. now, when i'm not battling some fierce headwind off the lake, i can cruise 20+ with ease, and frequently fly north of 25. to do that on a bike with 40mm tires @ 70 psi would require far more wattage.





perhaps, but my bike has never let me down in those regards, so i can only imagine there's a point of diminishing returns for braking and handling on the type of smooth pavement that i ride on.





my bike handles so well (very short wheel-base, super twitchy), i can swerve around any pothole. i have yet to hit one.





with 4,000 miles on my rubino pro 23s, no punctures so far. how can i have less than zero punctures?





you have not demonstrated that is so, merely pontificated and bloviated.






for what purpose? commuting? why are you assuming that all commuting is the same? refer back to my second response in this post. different riders and different riding situations will inform different tire decisions. one-size-fits-all when it comes to tires for commuting is NONSENSE.





uhhhhh, no sh1t. at no point did i ever try to pass off my preference for high pressure tires as some immutable law of the universe that dictates they alone are the only "reasonable OBJECTIVE best" tire in existence and that all other tires have no conceivable purposes or advantages.





Lesson in basic reading comprehension: don't confuse "i think that different riders and different riding situations will inform different tire decisions" with whatever nonsense you've invented in your own mind that you think i might have said. you're the only one talking about "best", i have made absolutely zero claims that any tire is "best", because i find the notion that such an ideal even exists to be absurd.





then why do manufactures make other types of tires in multitides of different widths? if 40s are objectively superior to 23s, then why do amateur and professional road racers alike all compete on narrow high-psi tires? why are they not all on crossers with 80psi 40s?

Burton

Think you might have misread somethig Chucky - or maybe I did because I was ranking priorities. Anyway here are the numbers as I understand them:

At low speeds (below 10kmph and excluding wind influences) the major energy requirements come from the need to overcome rolling resistance from tires and bearings. Thats definately commutor territory.

From 10kph to 20kph things are about split between energy needed to overcome rolling resistance and energy needed to overcome air resistance. Thats still largely commutor territory.

Wind resistance increases with the square of the velocity and by 40kph overcoming air resistance sucks up about 90% of a riders energy. But if both rider and bike are both optimized for aerodynamics - 66% of the drag is still from the rider and only 33% from the bike.

Aerodynamic drag from an optimized bike would be split about 50/50 between the frame and wheelset, and the most aerodynamic wheelset short of a disk would be a high profile low spoke count rim with a tire with a narrower profile than the rim. Unfortunately I don`t want to commute on a $2,000 wheelset and 18mm tires.

And since I`m already willing to compromise in an area that might contribute to 15% of 90% and probably wouldnl`t have the chance to roll at speeds like that in 30km zones anyway - my emphesis would be less on aerodynamics in general and more on practical things. Like the fact that the new flat protection in those Marathon Supreme`s gives better flat protection and still let them shed a pound from each tire.

Unfortunately the 28 x 2in size isn`t readily available in Canada and I may have to import - if there`s any left. Suppliers have to place orders 6 monthes in advance and when they`re gone - well ....

Retro Grouch 

That's too bad because I know the answer to the second one - at least if you ride with a group.

If you ride a lot with a group of people, check out what tires they are using and buy the same thing. Here's why - eventually you are going to have a flat because, sooner or later, everybody has flats. If you're using the same tires as everybody else, you aren't going to have to endure a "stupid tire choice" lecture while you are repairing your flat.

furballi

I did an informal 23C vs. 32C last year. Under normal riding condition on smoothly paved roads (cruising speed between 15 and 20mph), the 23C has an edge of no more than 0.3mph. Even with a 50% experimental error, the maximum advantage of 23C is limited to 0.5mph max. I try to slowly build up speed after coming to a stop to give the lighter/smaller 23C tire a test advantage (heavier tires takes a little longer to come up to speed).

Didn't even attempt to run on poorly paved roads. 23C @ 110 psi cannot provide adequate traction to keep up with 32C. The bike was bouncing all over, making very difficult to speed up or maintain cruising speed.

meanwhile

That advantage is meaninglessly small. Rider mass dominates low speed acceln, then RR.

meanwhile

Assuming that you all have a compatible rim size...

meanwhile

This is a stupid question*!

Firstly, NOT ALL TYRES ARE DESIGNED FOR COMMUTING! A 23 is an optimal TT tyre, a 25 an optimal crit tyre, a 28-32 an optimal Rouabix tyre (for "normal" rider weights.)

Secondly, NOT ALL BIKES WILL TAKE 40s!

Thirdly, TYRE MAKERS ARE IN BUSINESS TO SELL TYRES. Not to enforce optimal tyre selection!

Then you should have been polite enough not to use the word "foolish".

This has nothing to do with what you actually posted. I can understand why you wish you had posted this instead of what you did, but so what?

What utter rubbish! Of course I know that much about you. Just as I know that you can't hold your breath for half an hour - you do NOT make your daily commute at the speed that a decent rider trains to peak at in a TT! Even a good TT rider doesn't ride at that speed in a commute! In fact, you don't even ride at the speed of a crit racer. Now stop being silly, hmm?

*It's exactly as stupid as if I told you that insulated boots were the ideal wear for Antarctic exploration and you responded by asking me why dress pumps and running shoes exist. Really, whether I'm right or wrong, this is a ridiculous argument for you to make!

Six jours

WRT the original poster, as far as I am aware all tire companies that do testing rely on steel drums. This is probably pointless, unless you do your riding on steel drums, so I wouldn't bother listening to anything the manufacturers have to say about rolling resistance.

Sixty Fiver

Running your tyres at too high or low a pressure will degrade their performance... the sidewall markings usually indicate a safe operating range but the highest psi rating is not always the fastest.

Tyre pressure and the pressure you run is a function of the bike and rider weight and if your tyres do not deflect just a little when you are oni the bike they will ride harshly and not absorb road shocks which can lead to a loss of control and accidents... this becomes especially critical in hard turns where you want your tyre to grip and absorb enough shock to not skip off small objects.

I am pretty light and the 700:23's on my fg road bike are rated to 120 psi but if I ran them this high I would knock my fillings out but at 100 psi the ride feels like I am rolling on much plusher tyres.

My road bike runs 630:20 racing tyres that ride beautifully at 120 psi.

Booger1

Here's some stuff about thread casings and rolling resistance:
https://www.vittoria.com/tech/what_makes_a_good_tyre/

Steely Dan

you do not know any of that, merely assuming once again. being correct is easy when you allow yourself to invent your own reality, but that's not the way the real world works.

i think it is silly to believe that there is an "objective best tire" because there are too many variables that go into the equation that inform a tire decision for a given rider of given ability for different conditions, purposes, and preferences. you think the opposite is true. at this point we will simply have to agree to disagree, as it seems neither of us will persuade the other to our respective position.

if you should ever find yourself bike commuting in chicago, i'll be sure to give a nod to you as i blow past at 25+mph on my hard-as-steel 23s while you struggle to stay over 20mph on your spongy, energy-sucking 40s.

I_like_cereal

Should Rolling resistance topics be placed in the P and R forum?

We have a lot of good information and lot of good opinion. Some people prefer the 23c at the highest PSI and others seem to prefer a softer tire. Different strokes different folks.

Personally I just want a good tire that wont slow me down and gives me good puncture resistance. 'Dillos are nice, but tank like. I am looking for some more in the APC range. In other words bullet proof, but still subject to "IEDs" If that tire is a 23 at 200psi fine, if it is a 25 at 100 psi fine.

I understand the math a little better re what makes a tire slower/faster.

meanwhile

[QUOTE=Steely Dan;12456347]

Dan - I have no problem getting 40mm tyres to 25. What you have failed to understand is that

1. That speed is a (low?) AVERAGE for a TT, whereas for you it's a peak speed.

2. If you increased your air resistance by 2% by putting, say, 28mm tyres on - which might give you double the contact patch - then your speed would be reduced by much less than 2% - in fact it would be reduced by about 0.007%. (Air resistance is a cube law, hmm?) In a TT this might make a serious difference in your placing; in a commute it turns a 30 minute commute into a 30 minute and TWELVE SECOND ONE. Going to a 40mm tyre might add 5% to your total aero (that's probably way too much, given the drag generated by spokes) and, again, the cube law will turn this into something that only an imbecile would care about outside of a race. Even if tyres added 10% to aero, you'd still only take a 3% hit on journey time. That's fifty four seconds, Dan.

If you had been smart enough to understand the maths that other people explained in this thread, this wouldn't have come as a surprise to you. This is why, objectively, 40mm tyres made of low hysteresis rubber are the best tyres for a commute - even if you're moving much faster than Dan really, is if you're moving much faster than he claims too, then the aero penalty in speed is minute. But the increase in contact patch (and hence braking and turning) and in ability to handle potholes (23mm tyres have to be babied even on smooth tarmac, whereas 40mm is pretty decent offroad rubber.)

That's not to say that Dan should switch from 23s if he enjoys pretending to be Lance Armstrong while he commutes. But from an objective engineering point of view, a drop bar bike that will take a fast 40mm tyre *is* a better commuter and a better tourer. (And better again if if it will take disc brakes.) People who spend a lot of money on racing bikes like to believe that they are super bikes. In fact they're anything but. They're machines that have made huge concessions in a whole range of handling characteristics - braking, stability over road "noise", sustained turning ability, comfort - to get ***tiny*** advantages in straight line speed and the "twitch" handling you need when fighting for position in a peloton.

Steely Dan

i still don't know why you have such a hard time accepting that different people have different types and styles of commuting, but i suppose it's moot and futile at this point. as i said before, we're both firmly entrenched in our positions and have absolutely no hope of persuading the other to our respective view point, thus the only adult thing to do is to agree to disagree and ride on. i ride faster now with skinny high-PSI tires than i did with fat low-PSI tires, and because i find speed exhilarating, i will continue to love the crap out of riding my race bike (weather permitting) to work every morning and you can have your fun commuting on your touring bike outfitted with 40s.

meanwhile

I don't. I'm pointing that that ***objectively*** 23mm tyres trade the ability to take a pot hole without crashing, and to turn and brake fast, for less than a minute's advantage in speed in a half hour sprint.* Outside of a race, where a minute is a huge advantage, this is pretty dumb from an engineering pov.

I'm sure that you do. However, you haven't been smart enough to understand what I'm saying: which is that your slow fat tyres were slow for reasons that you don't understand, not because they were fat. Which isn't surprising, as you don't strike me as the sort of person who would bother reading the tech docs at a tyre maker's site or a book on bicycle design. As a general rule, people who aren't very smart like obvious explanations - and "Fat tyre make me go slow!" is pretty obvious. It's not terribly true, but there you go. "High hysteresis energy tyres slow me down" is quite a cognitive lump to digest - you're probably not up to it, so you cling to the simpler (but untrue) explanation. That way you don't feel like an idiot.

To help illustrate your lack of understanding, the OP got something like a 25% speed increase on his uphill commute by switching tyres - but both sets were high pressure 23s. You're simply ignorant of what determines tyre performance.

* Yes, I know the fat tyres you replaced with thin ones weren't that fast. But partly that was because they were on a less aero bike and partly because they were made of relatively thick high hysteresis energy rubber. Try to keep up, hm? If you want to understand the effects of tyre widths you have to keep bike type and rubber compound constant. Which I would have thought was obvious, but there you go...

Steely Dan

don't you also have to keep tire pressure constant as well? i don't know of any 40s that will safely take 135 PSI (i'm not saying they don't exist, i just don't know of any), so how does one make a direct comparison in rolling resistance of a 40 with 85 PSI max vs. a 23 with 145 PSI max?

if there were a 40 out there made of the high quality rubber you're talking about and could take 135 PSI, i'd certainly give it a whirl. tire pressure is everything to me, when i ride on a 75 PSI tire, i can feel the "spongieness" of the tire sucking away my forward momentum. i hate soft tires. i hate the way they feel. i hate the way they ride. i like the feeling of a being a locomotive with a steel wheel on a steel rail.

Six jours

Due to some physical law I don't understand, a wide tire doesn't need as much pressure as a narrow one to feel as hard. And FWIW, there's a guy in Seattle who's setting a bunch of brevet records using 42 mm tires - usually pumped to 60 psi or so. He has mentioned that narrow high-pressure tires feel faster to him because they give higher-frequency vibrations. But testing demonstrated to his own satisfaction that under real-world conditions, narrow high-pressure tires rarely match the rolling resistance of more moderately sized tires at moderate pressure.

furballi

A very hard narrow tire will bounce/hop on normal roads (loss of traction). When this happens, the rider will notice that it takes less effort to pedal the bike. Noobs tend to associate less effort=faster speed. Rougher roads translate to more loss of traction.

iforgotmename

I recently got some Schwalbe Marathon Dureme in 26x2.0 for my LHT and they fit this bill. They aren't much slower than my 1.6 Marathon Supremes but can go off road a little better. I will still run the supremes when the weather is a little nicer but these tires are great for spring and it's grit strewn roads.

Burton

Some people might be lucky enough to have paved surfaces the whole way and few traffic lights and roads in good repair.

My own commute takes me accross 4 sets of train tracks, some generally poorly maintained roads and at this time of year - a minefield of potholes.

So although I have a series of bikes with 700 x 25c and 700 x 33c and 26 x 1.75 tires - the latest machine is a carbon frame mtb with a DT Swiss XMC 130 fork, Shimano Deore XT wheelset and Geax BMX tires.

And those tires measure 26 x 2.3 or 58 x 559 and each weighs 590 grams. And rolling resistance isn`t an issue - in fact they`ve cut down my commute time. Maybe in part because I don`t have to slow down for anything except traffic lights at this point.

I have managed to run out of gear in several stretches with a 44T x 11T drive combo so I`ll probably have to up the triple to a 46T or 48T large chainring. And although a commute may not be a competition there are always lots of other riders in the street - I have yet to have anyone pass me - on skinny tires or anything else. I`ll see about posting a few photos later tonight.

Burton

The tires are actually BMX and have an extremely round profile that makes them exceptionally agile for maneuvering in the city and dodging stuff at speed.

And they're great in the street and on gravel and unpaved parking lots - not to mention train tracks and have definitely cut down my commute time.

But I have to be careful on trails like this because the combination of low tread profile that makes for great street performance doesn't work when mud and rocks are combined on trails like this. But dry they're less of an issue.


And I did cut down the bars down better maneuverability in the city but that probably doesn't affect rolling resistance anyway.


What I'm finding surprising is how stable this rig is at speed - as in in excess of 50kph. Have to get some taller gearing!

garage sale GT

No, the energy lifting the bike comes from your pedaling.

That's why narrower tires are good, incidentally. They can be run at a higher PSI without bouncing or shaking. This factor is not testable by the steel drum tests in the picture on the first page of this thread.

I_like_cereal

My experience after running 25c Vittorio Rubinos and then running 23c Armadillos I can say that the 23cs push more vibration into my handle bars than the 25s. I am running an old Look Carbon Fork with a steel 1" threaded headset to a quill stem with Bontrager Race Bars. I noticed immediately that the road buzz was more in the 23s than the 25s. I also noticed that the 23s tend to shoot road debris from under the tire whereas the 25s rolled over it.

YMMV and I am sure it depends on the tire/tube combination.