Notices
General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

Tire question?

Old 01-24-21, 02:23 PM
  #1  
Scubaquarius
Senior Member
Thread Starter
 
Join Date: Jul 2020
Posts: 149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 34 Post(s)
Likes: 0
Liked 12 Times in 11 Posts
Tire question?

Intuitively, it would seem that wider, lower pressure tires would present more resistance to peddling. Whereas, the opposite would - intuitively -
also seem to be true - that narrower, high pressure tires should provide less resistance to peddling. For now let's just disregard the tire groove
configuration.
Does this sound correct? I only ask because I am currently shopping for a hybrid type bike. Some of them have wider, lower pressure tires.
And I'm only interested in pavement, concrete trail riding.

Thanks for any comments,
Scubaquarius
Scubaquarius is offline  
Old 01-24-21, 02:42 PM
  #2  
rm -rf
don't try this at home.
 
rm -rf's Avatar
 
Join Date: Jan 2006
Location: N. KY
Posts: 5,918
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 964 Post(s)
Liked 496 Times in 343 Posts
Wider tires have been tested to have lower rolling resistance than skinnier versions of the same tire. It's related to rolling over the rough surface of a road. If the roads were glass smooth, like indoor tracks are, then the tires would likely be quite similar.

Lower rolling resistance at the same pressure. Equivalent rolling resistance at much lower pressures than the narrow tire. So wider is more comfortable on rough roads, but not slower.

However, it does depend on the tire construction. Thin, flexibile tread, like the smaller road bike tires, can efficiently flex over bumps. Extra thick, stiff tires that are extremely puncture resistant are a lot slower. And knobs can be very slow as they squirm when contacting the road.

Hybrids would tend toward the stiffer, puncture resistant end of the range. Those tires would be cheaper, have longer mileage, and fewer punctures. Good for casual riders.

Last edited by rm -rf; 01-24-21 at 02:46 PM.
rm -rf is offline  
Likes For rm -rf:
Old 01-24-21, 02:43 PM
  #3  
veganbikes
Clark W. Griswold
 
Join Date: Mar 2014
Location: ,location, location
Posts: 13,280

Bikes: Foundry Chilkoot Ti W/Ultegra Di2, Salsa Timberjack Ti, Cinelli Mash Work RandoCross Fun Time Machine, 1x9 XT Parts Hybrid, Co-Motion Cascadia, Specialized Langster, Phil Wood Apple VeloXS Frame (w/DA 7400), R+M Supercharger2 Rohloff, Habanero Ti 26

Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 4253 Post(s)
Liked 3,866 Times in 2,579 Posts
Jan Heine at René Herse Cycles has done a ton of research on tires and has fairly well concluded that wider tires are not slower. I won't go deep into his thoughts as he can tell them better and has on his blog/journal but essentially for me lower pressure wider tires more easily rolls over anything instead of having to deflect and lose speed and with more comfort and confidence on the road I can go faster. However a lot of factors go into tires like tread, sidewall, rubber compounds...and that will all contribute or take away from your ride.

If you are looking for a better ride a nice tire with a supple sidewall and some extra width will certainly be a boon. The wider lower pressure tire will also help with flats as I eluded too above. A skinny tire is potentially faster on a smooth surface like say an indoor velodrome but in the real world the wider tire is going to perform better. Very few people after riding wider tires say "I want something a lot narrower" the only time I go narrow is when I cannot fit anything more in the bike which has happened a few times.

For me the perfect tire for road is in the 28-42mm range and ideally would be a nice soft and supple sidewall with a good rubber on top ideally with graphene probably in a nice chevron pattern or something non-obtrusive.
veganbikes is offline  
Likes For veganbikes:
Old 01-24-21, 02:48 PM
  #4  
Scubaquarius
Senior Member
Thread Starter
 
Join Date: Jul 2020
Posts: 149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 34 Post(s)
Likes: 0
Liked 12 Times in 11 Posts
Originally Posted by rm -rf
Wider tires have been tested to have lower rolling resistance than skinnier versions of the same tire. It's related to rolling over the rough surface of a road. If the roads were glass smooth, like indoor tracks are, then the tires would likely be quite similar.

Lower rolling resistance at the same pressure. Equivalent rolling resistance at much lower pressures than the narrow tire. So wider is more comfortable on rough roads, but not slower.

However, it does depend on the tire construction. Thin, flexibile tread, like the smaller road bike tires, can efficiently flex over bumps. Extra thick, stiff tires that are extremely puncture resistant are a lot slower. And knobs can be very slow as they squirm when contacting the road.

Hybrids would tend toward the stiffer, puncture resistant end of the range. Those tires would be cheaper, have longer mileage, and fewer punctures. Good for casual riders.
Very interesting, I guess that explains why I'm not an engineer .

Thanks, Scubaquarius
Scubaquarius is offline  
Old 01-24-21, 02:50 PM
  #5  
Scubaquarius
Senior Member
Thread Starter
 
Join Date: Jul 2020
Posts: 149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 34 Post(s)
Likes: 0
Liked 12 Times in 11 Posts
Originally Posted by veganbikes
Jan Heine at René Herse Cycles has done a ton of research on tires and has fairly well concluded that wider tires are not slower. I won't go deep into his thoughts as he can tell them better and has on his blog/journal but essentially for me lower pressure wider tires more easily rolls over anything instead of having to deflect and lose speed and with more comfort and confidence on the road I can go faster. However a lot of factors go into tires like tread, sidewall, rubber compounds...and that will all contribute or take away from your ride.

If you are looking for a better ride a nice tire with a supple sidewall and some extra width will certainly be a boon. The wider lower pressure tire will also help with flats as I eluded too above. A skinny tire is potentially faster on a smooth surface like say an indoor velodrome but in the real world the wider tire is going to perform better. Very few people after riding wider tires say "I want something a lot narrower" the only time I go narrow is when I cannot fit anything more in the bike which has happened a few times.

For me the perfect tire for road is in the 28-42mm range and ideally would be a nice soft and supple sidewall with a good rubber on top ideally with graphene probably in a nice chevron pattern or something non-obtrusive.
Thanks for the response and info.
Scubaquarius
Scubaquarius is offline  
Likes For Scubaquarius:
Old 01-24-21, 03:15 PM
  #6  
cxwrench
Senior Member
 
cxwrench's Avatar
 
Join Date: Jul 2013
Location: Nor-Cal
Posts: 3,767

Bikes: lots

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1958 Post(s)
Liked 2,932 Times in 1,489 Posts
Pedaling.
cxwrench is offline  
Old 01-24-21, 04:19 PM
  #7  
chaadster
Thread Killer
 
Join Date: Aug 2008
Location: Ann Arbor, MI
Posts: 12,373

Bikes: 15 Kinesis Racelight 4S, 76 Motebecane Gran Jubilée, 17 Dedacciai Gladiatore2, 12 Breezer Venturi, 09 Dahon Mariner, 12 Mercier Nano, 95 DeKerf Team SL, 19 Tern Rally, 21 Breezer Doppler Cafe+, 19 T-Lab X3, 91 Serotta CII

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 3078 Post(s)
Liked 1,631 Times in 1,005 Posts
Alluded to
chaadster is offline  
Likes For chaadster:
Old 01-24-21, 04:57 PM
  #8  
70sSanO
Senior Member
 
70sSanO's Avatar
 
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,772

Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1935 Post(s)
Liked 2,150 Times in 1,313 Posts
My opinion, which means little, is rolling resistance has little bearing on a hybrid with an upright riding position. The worst rolling resistance tire on a drop bar road bike will probably outperform the best on a hybrid.

That said, get a lightweight higher thread count quality folding tire and base the width on what you have now for the same or more comfort.

John
70sSanO is offline  
Likes For 70sSanO:
Old 01-25-21, 12:24 AM
  #9  
chaadster
Thread Killer
 
Join Date: Aug 2008
Location: Ann Arbor, MI
Posts: 12,373

Bikes: 15 Kinesis Racelight 4S, 76 Motebecane Gran Jubilée, 17 Dedacciai Gladiatore2, 12 Breezer Venturi, 09 Dahon Mariner, 12 Mercier Nano, 95 DeKerf Team SL, 19 Tern Rally, 21 Breezer Doppler Cafe+, 19 T-Lab X3, 91 Serotta CII

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 3078 Post(s)
Liked 1,631 Times in 1,005 Posts
Originally Posted by 70sSanO
My opinion, which means little, is rolling resistance has little bearing on a hybrid with an upright riding position. The worst rolling resistance tire on a drop bar road bike will probably outperform the best on a hybrid.

That said, get a lightweight higher thread count quality folding tire and base the width on what you have now for the same or more comfort.

John
Not following your rationale here...lower rolling resistance always means less energy is needed to keep it rolling, so the benefits accrue regardless of bike type. As for outperforming, what do you mean by that? Tire rolling resistance performance has to do with the construction of the tire, not the bicycle it’s mounted to, so a tire with, say, a Crr of .0041 has that same Crr regardless of the bike type it’s rolling on (system weight and pressure being equal).
chaadster is offline  
Likes For chaadster:
Old 01-25-21, 12:37 AM
  #10  
Rolla
Guest
 
Join Date: Sep 2020
Posts: 2,888
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1346 Post(s)
Liked 3,269 Times in 1,439 Posts
For casual riding, I'd choose comfort over efficiency, regardless of terrain. Higher volume = more comfort. A typical hybrid bike will probably feel and ride great with 35 - 42mm width tires. Stay within the manufacturer's psi recommendations, but experiment a little; five pounds of pressure more or less can have a noticeable effect.
Rolla is offline  
Likes For Rolla:
Old 01-25-21, 07:00 AM
  #11  
Herzlos
Senior Member
 
Join Date: Sep 2020
Location: Scotland
Posts: 501

Bikes: Way too many

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 827 Post(s)
Liked 584 Times in 345 Posts
Originally Posted by 70sSanO
My opinion, which means little, is rolling resistance has little bearing on a hybrid with an upright riding position. The worst rolling resistance tire on a drop bar road bike will probably outperform the best on a hybrid.

That said, get a lightweight higher thread count quality folding tire and base the width on what you have now for the same or more comfort.

John
I'm not sure I see that in reality, but then I'm a casual rider so most likely power constrained. With some testing I found very similar speeds between a 700x28c slick tyre on a drop bar road bike, to a 26x1.95" hybrid tyre on a flat bar hybrid bike (the road bike was about 5 seconds slower over a 2 mile lap). I certainly found the hybrid easier to ride with less concern about road surface.

I also found I could go faster on 700x40c than 700x28c because the road surface wasn't as problematic (there are some awful roads here that are bone shaking on 28mm tyres @ 100psi but not bad on 40mm tyres @ 60psi).

For hybrid commuters I'd probably go for comfort and durability.
Herzlos is offline  
Old 01-25-21, 07:38 AM
  #12  
ofajen
Cheerfully low end
 
ofajen's Avatar
 
Join Date: Jun 2020
Posts: 1,965
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Liked 1,040 Times in 663 Posts
There will be good tire choices for any width. For a hybrid, I would tend to go for wider tires. There won’t be much difference in efficiency for a good tire of any width, but the wider tire can be run at a lower pressure on rougher ground or a higher pressure (if you want) on smooth surfaces.

Also bear in mind that a bike’s geometry is designed around a particular wheel and tire size and the handling will change (at least a little) from that intended design if you change the tire size.

Otto

Last edited by ofajen; 01-25-21 at 11:42 AM.
ofajen is offline  
Old 01-25-21, 08:15 AM
  #13  
pdlamb
Senior Member
 
Join Date: Dec 2010
Location: northern Deep South
Posts: 8,847

Bikes: Fuji Touring, Novara Randonee

Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 2578 Post(s)
Liked 1,901 Times in 1,193 Posts
Originally Posted by rm -rf
However, it does depend on the tire construction. Thin, flexibile tread, like the smaller road bike tires, can efficiently flex over bumps. Extra thick, stiff tires that are extremely puncture resistant are a lot slower. And knobs can be very slow as they squirm when contacting the road.

Hybrids would tend toward the stiffer, puncture resistant end of the range. Those tires would be cheaper, have longer mileage, and fewer punctures. Good for casual riders.
Tire construction is doubtless one key. For years the default was larger tires correlated with heavier, stiffer tires. That's a big reason we thought for years that wider tires were less energy efficient. I'll give Heine credit for getting some wider (started around 42 mm, IIRC), thinner, more flexible tires made and testing them. For completeness' sake, when Compass (now Rene Herse) tires hit the market at $70 each, I was happily riding $20 tires.

Another key is the surface you're riding on. There are a half dozen streets in my town I'd rather walk than ride because the etched concrete is so bad. Other than those abominations, 28-32 width tires are fine for me on paved roads. If you're going to ride dirt or gravel roads, the bigger the rocks, the wider the tire you'll want.
pdlamb is offline  
Old 01-25-21, 09:07 AM
  #14  
70sSanO
Senior Member
 
70sSanO's Avatar
 
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,772

Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1935 Post(s)
Liked 2,150 Times in 1,313 Posts
Originally Posted by chaadster
Not following your rationale here...lower rolling resistance always means less energy is needed to keep it rolling, so the benefits accrue regardless of bike type. As for outperforming, what do you mean by that? Tire rolling resistance performance has to do with the construction of the tire, not the bicycle it’s mounted to, so a tire with, say, a Crr of .0041 has that same Crr regardless of the bike type it’s rolling on (system weight and pressure being equal).
My point was wind resistance. If you are sitting upright with flat bars and another person with equal ability is in the drops, how much do you think your lower rolling resistance will help.

People agonize over the little things and ignore the major factor that will offset any gains.

John
70sSanO is offline  
Old 01-25-21, 09:38 AM
  #15  
BobbyG
Senior Member
 
BobbyG's Avatar
 
Join Date: Jan 2009
Location: Colorado Springs, CO
Posts: 5,962

Bikes: 2015 Charge Plug, 2007 Dahon Boardwalk, 1997 Nishiki Blazer, 1984 Nishiki International, 2006 Felt F65, 1989 Dahon Getaway V

Mentioned: 54 Post(s)
Tagged: 0 Thread(s)
Quoted: 1359 Post(s)
Liked 1,658 Times in 822 Posts
TL/DR:
I have found that my bigger, cushier street tires are as fast or faster than narrower, higher-pressure tires they replaced...they just don't feel as fast.

Jan Heine talks about how the increased chatter between high pressure tires and the road feels like speed.

https://www.bikeforums.net/commuting...ig-bouncy.html
https://www.bikeforums.net/commuting...-part-two.html
BobbyG is offline  
Old 01-25-21, 10:03 AM
  #16  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 642 Times in 363 Posts
The more that I learn about tiers, the more I find that I don't know. There are lots of factors and they all work together.

Rolling resistance: What is it really? Look at a tire on any loaded vehicle. There will always be a flat spot at the bottom. That flat spot moves around the tire as the vehicle rolls down the road. Now take a naked tire and try to push a flat spot into one part of the tread. That will require some amount of energy. On a bicycle that energy ultimately has to come from the rider. If everything else is equal, a tire with a thin supple sidewall will have lower rolling resistance than a tire that has stiff sidewalls. A tire that has a thick anti-puncture layer will have greater resistance than one that has a thin tread layer.

Now look at the shape of the flat spot on the bottom of the tire. The size of the flat spot will be approximately equal to the load divided by the tire's internal air pressure. A wider tire will have a short contact patch. A skinny tire at the same air pressure will have a long narrow tire patch. Remember the energy required to form a flat spot in the tire? If everything else is equal, at equal air pressure a wider tire will have lower rolling resistance than a narrow one. That means you can run a wider tire at lower, more comfortable, air pressure and enjoy the same rolling resistance or you can pump up a narrow tire harder to achieve the same rolling resistance.

All roads aren't silky smooth. Most people realize that a hard, high pressure tire will bounce more over every tiny little bump than a soft, lower pressure tire. That means that you are actually lifting the bike and rider upward over bumps that a softer tire would encapsulate. Guess where that energy comes from? On a bicycle, it ultimately has to come from the rider. That skittish feeling may feel faster subjectively, but it really takes more energy.

So why do racers use such skinny little tires? Rolling resistance isn't everything. At roughly 15 miles per hour on a flat road, air resistance surpasses all of the other factors that are holding you back combined. As you r speed increases beyond 15 MPH, the importance of air resistance becomes progressively more and more significant. Skinny little tires have less frontal area and consequently less air resistance than wide ones.

I assume there is a rubber compounding factor to rolling resistance but the only thing I know for sure about that is that carbon makes tires both black and wear longer. Look at little kids bikes - boy's bike tires, which are black, wear at least 3 times as long as little girl's bikes that have white tires.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.
Retro Grouch is offline  
Old 01-25-21, 11:17 AM
  #17  
ofajen
Cheerfully low end
 
ofajen's Avatar
 
Join Date: Jun 2020
Posts: 1,965
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Liked 1,040 Times in 663 Posts
Originally Posted by 70sSanO
My point was wind resistance. If you are sitting upright with flat bars and another person with equal ability is in the drops, how much do you think your lower rolling resistance will help.

People agonize over the little things and ignore the major factor that will offset any gains.

John
Don’t forget that there are hills. Aerodynamics is scarcely a factor on steeper grades, so it’s hard work against gravity plus rolling friction. The difference of two slow tires could be as much 30 watts. I typically do 300-325 watts up our hills, and I would much rather put as much of that as possible into speed up a hill than dissipate it in slow tires. As an example, my 26x2.2 Race Kings are rated about 20W per tire, while there are MTB tires at more like 35W per tire.

Otto
ofajen is offline  
Old 01-25-21, 11:21 AM
  #18  
chaadster
Thread Killer
 
Join Date: Aug 2008
Location: Ann Arbor, MI
Posts: 12,373

Bikes: 15 Kinesis Racelight 4S, 76 Motebecane Gran Jubilée, 17 Dedacciai Gladiatore2, 12 Breezer Venturi, 09 Dahon Mariner, 12 Mercier Nano, 95 DeKerf Team SL, 19 Tern Rally, 21 Breezer Doppler Cafe+, 19 T-Lab X3, 91 Serotta CII

Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 3078 Post(s)
Liked 1,631 Times in 1,005 Posts
Originally Posted by Retro Grouch
So why do racers use such skinny little tires? Rolling resistance isn't everything. At roughly 15 miles per hour on a flat road, air resistance surpasses all of the other factors that are holding you back combined. As you r speed increases beyond 15 MPH, the importance of air resistance becomes progressively more and more significant. Skinny little tires have less frontal area and consequently less air resistance than wide ones.
It's not so simple as that. Air resistance is not just a function of frontal area, as turblence across the tire/rim interface and trailing edge of the rim can create a ton of drag. Being able to make light, wide, aero profile rims has changed the paradigm, and I'd bet the ranch that a 25c tire on a 22mm internal width rim with a 45mm deep profile has less drag than a 23c tire on a classic, 15mm internal width rim with a sub-20mm rim depth (e.g. the old Mavic Open Pro).

World Tour pro race teams usually run 25c these days (and wider on rough/cobbled segments), so they've come up in the past handful of years from 23s, but they're balancing weight and aero very carefully, so who knows if we'll see them on 30c in the future; I suppose it would depend on tire weight and rim weight for the width and depth needed to carry a 30c tire efficiently. Notably, Alaphilippe won TdF stage 2 last year on 26c S-Works Turbo rubber...on tubed, 33mm deep, 21mm internal clinchers at that, so yeah, width does not tell the whole story about aero.
chaadster is offline  
Old 01-25-21, 12:18 PM
  #19  
70sSanO
Senior Member
 
70sSanO's Avatar
 
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,772

Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1935 Post(s)
Liked 2,150 Times in 1,313 Posts
Originally Posted by ofajen
Don’t forget that there are hills. Aerodynamics is scarcely a factor on steeper grades, so it’s hard work against gravity plus rolling friction. The difference of two slow tires could be as much 30 watts. I typically do 300-325 watts up our hills, and I would much rather put as much of that as possible into speed up a hill than dissipate it in slow tires. As an example, my 26x2.2 Race Kings are rated about 20W per tire, while there are MTB tires at more like 35W per tire.

Otto
Not to argue, but sooner or later you will be going downhill. And that upright position is a real killer.

MTB’s are a totally different animal as rolling resistance can be good or bad depending on the terrain. I’m sure there are those here who don’t want lower rolling resistance over wet slick surfaces.

My point is the rider position is a bigger detriment than a marginal tire gain. As I said a good quality, high thread count, lightweight folding tire is a good choice than splitting hairs on this or that particular tire “for a hybrid”.

John
70sSanO is offline  
Old 01-25-21, 12:23 PM
  #20  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 4,514
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1028 Post(s)
Liked 447 Times in 263 Posts
Originally Posted by Retro Grouch
Rolling resistance: What is it really? Look at a tire on any loaded vehicle. There will always be a flat spot at the bottom. That flat spot moves around the tire as the vehicle rolls down the road. Now take a naked tire and try to push a flat spot into one part of the tread. That will require some amount of energy. On a bicycle that energy ultimately has to come from the rider. If everything else is equal, a tire with a thin supple sidewall will have lower rolling resistance than a tire that has stiff sidewalls. A tire that has a thick anti-puncture layer will have greater resistance than one that has a thin tread layer.

Now look at the shape of the flat spot on the bottom of the tire. The size of the flat spot will be approximately equal to the load divided by the tire's internal air pressure. A wider tire will have a short contact patch. A skinny tire at the same air pressure will have a long narrow tire patch. Remember the energy required to form a flat spot in the tire? If everything else is equal, at equal air pressure a wider tire will have lower rolling resistance than a narrow one. That means you can run a wider tire at lower, more comfortable, air pressure and enjoy the same rolling resistance or you can pump up a narrow tire harder to achieve the same rolling resistance.
Many people with training in science or engineering have studied rolling resistance. It is quite well understood. I suggest you seek out some of their explanations. The explanation you propose is mostly incorrect and only occasionally bumps up against what's true.
asgelle is offline  
Old 01-25-21, 02:02 PM
  #21  
Moisture
Drip, Drip.
 
Moisture's Avatar
 
Join Date: Oct 2020
Location: Southern Ontario
Posts: 1,575

Bikes: Trek Verve E bike, Felt Doctrine 4 XC, Opus Horizon Apex 1

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 1034 Post(s)
Liked 193 Times in 163 Posts
Keep in mind that a wider tire will have the exact same contact patch depending on which PSI you use.

So it mainly depends on the tread of the tire and how it works with your typical terrain conditions.
Moisture is offline  
Old 01-26-21, 12:22 PM
  #22  
ClydeClydeson
Senior Member
 
Join Date: Mar 2019
Posts: 1,606
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 581 Post(s)
Liked 921 Times in 518 Posts
I generally use wide-ish tires for road riding, 32 or 35mm. On rougher surfaces and at slower speeds they are superior to narrow tires IMO.

Above a certain speed (someone above said 15mph) the aerodynamic resistance of the tires outweighs any difference in rolling resistance. When looking at the whole bike+rider+wheels system, at higher speeds, rolling resistance is a very small part of the energy equation.
ClydeClydeson is offline  
Old 01-26-21, 12:40 PM
  #23  
Hiro11
Senior Member
 
Join Date: Jun 2010
Posts: 2,608

Bikes: 2022 Specialized Allez Sprint custom build, 2019 Giant Defy Advanced Pro 0, 2018 Seven Mudhoney Pro custom build, 2017 Raleigh Stuntman, various others

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 782 Post(s)
Liked 475 Times in 238 Posts
Originally Posted by ClydeClydeson
Above a certain speed (someone above said 15mph) the aerodynamic resistance of the tires outweighs any difference in rolling resistance. When looking at the whole bike+rider+wheels system, at higher speeds, rolling resistance is a very small part of the energy equation.
This is the real point here. Aerodynamic drag accounts for the vast majority of cycling effort. Rolling resistance is rounding error in comparison. Within a given range of widths, pressures and tread patterns, some tires "feel fast" or "feel slow" but the actual difference in terms of watts expended to go a certain speed is pretty small.
Hiro11 is offline  
Old 01-26-21, 01:09 PM
  #24  
asgelle
Senior Member
 
Join Date: Apr 2006
Location: Albuquerque, NM
Posts: 4,514
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1028 Post(s)
Liked 447 Times in 263 Posts
Originally Posted by Hiro11
... pretty small.
I have no idea what "pretty small" means, but I do know that the difference in rolling resistance between tires can be 10 W or more (and of course, that's totally independent of what may be going on aerodynamically). I also know how hard I have to work to improve my power by 10 W.
asgelle is offline  
Likes For asgelle:
Old 01-26-21, 03:23 PM
  #25  
HTupolev
Senior Member
 
Join Date: Apr 2015
Location: Seattle
Posts: 4,261
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 1971 Post(s)
Liked 1,297 Times in 629 Posts
Originally Posted by ClydeClydeson
Above a certain speed (someone above said 15mph) the aerodynamic resistance of the tires outweighs any difference in rolling resistance. When looking at the whole bike+rider+wheels system, at higher speeds, rolling resistance is a very small part of the energy equation.
What matters for tire selection isn't the rolling resistance of the tire versus the aerodynamic drag of the whole system. It's the rolling resistance of the tire versus the difference in aerodynamic drag caused by the tire selection. If you change to a tire that's 10W-faster-rolling but 5W-higher-aero-drag at 20mph, you're going to save 5W at 20mph regardless of whether the rider's body is in a tuck that's producing 100W of aero drag or an upright posture that's producing 170W of aero drag.
HTupolev is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.