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Road Tires: Width vs Speed Penalties?



 
 
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  #21  
Old December 16th 17, 11:53 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 5,697
Default Road Tires: Width vs Speed Penalties?

On Sat, 16 Dec 2017 00:24:22 -0600, Tim McNamara
wrote:

On Fri, 15 Dec 2017 16:07:29 -0800 (PST), HaloTupolev
wrote:
but don't say anything about width-vs-speed penalties.


Compass generally claims that width itself doesn't cause significant
differences in net performance.

I can't remember which issue it was (43 maybe?), but one of the
editions of Bicycle Quarterly included testing on the apron of
Marymoor Velodrome where the entire range of Compass tire widths
performed identically, within the precision of their measurement
methodology.


I haven't read that one, but their earlier ones involved roll-down
testing and (from one of the photos in the article) timing with a
wris****ch. I put little credence into that article because if the
likelihood of noise in the data.

They later did some interesting testing using a power meter, which
struck me as a better way to assess performance.

That said, I think that Compass is correct in that given identical
construction (casing, tread thickness, rubber compound) the effects of
width as a variable would be small. The more traditional drum tests
suggested (e.g. the ones done for Avocet). For as long as I can
remember, most wider tires also feature heavier casings and much thicker
rubber- wide high performance tires were rare. Compass has pushed in
that direction quite aggressively and good for them.

Compass's assertion that inflation pressure has little impact on
performance is out of keeping with that testing, although when
real-world road textures/roughness are included there may be relatively
little adverse impact from lower pressures. Jim Papadopoulos wrote
about that in this forum many years ago under the rubric of suspension
losses, and his thinking had a direct impact on Compass's tire design
philosophy.

My bike with 26 x 1.8 Compass tires seems as fast as my bikes with 700 x
25 or 700 x 28 Paselas. At least based on average speeds on my cycle
computer and similar subjective effort. That is of course far from a
scientific approach!


On the other hand if you go out and ride your 50 km loop with the wide
26" tires and then go out the next day and ride the same loop with
your 700c x 28 tires in the same time, can science tell you any more
:-)
--
Cheers,

John B.

Ads
  #22  
Old December 16th 17, 05:13 PM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 5,870
Default Road Tires: Width vs Speed Penalties?

On Saturday, December 16, 2017 at 2:53:06 AM UTC-8, John B. wrote:
On Sat, 16 Dec 2017 00:24:22 -0600, Tim McNamara
wrote:

On Fri, 15 Dec 2017 16:07:29 -0800 (PST), HaloTupolev
wrote:
but don't say anything about width-vs-speed penalties.

Compass generally claims that width itself doesn't cause significant
differences in net performance.

I can't remember which issue it was (43 maybe?), but one of the
editions of Bicycle Quarterly included testing on the apron of
Marymoor Velodrome where the entire range of Compass tire widths
performed identically, within the precision of their measurement
methodology.


I haven't read that one, but their earlier ones involved roll-down
testing and (from one of the photos in the article) timing with a
wris****ch. I put little credence into that article because if the
likelihood of noise in the data.

They later did some interesting testing using a power meter, which
struck me as a better way to assess performance.

That said, I think that Compass is correct in that given identical
construction (casing, tread thickness, rubber compound) the effects of
width as a variable would be small. The more traditional drum tests
suggested (e.g. the ones done for Avocet). For as long as I can
remember, most wider tires also feature heavier casings and much thicker
rubber- wide high performance tires were rare. Compass has pushed in
that direction quite aggressively and good for them.

Compass's assertion that inflation pressure has little impact on
performance is out of keeping with that testing, although when
real-world road textures/roughness are included there may be relatively
little adverse impact from lower pressures. Jim Papadopoulos wrote
about that in this forum many years ago under the rubric of suspension
losses, and his thinking had a direct impact on Compass's tire design
philosophy.

My bike with 26 x 1.8 Compass tires seems as fast as my bikes with 700 x
25 or 700 x 28 Paselas. At least based on average speeds on my cycle
computer and similar subjective effort. That is of course far from a
scientific approach!


On the other hand if you go out and ride your 50 km loop with the wide
26" tires and then go out the next day and ride the same loop with
your 700c x 28 tires in the same time, can science tell you any more
:-)


Science would tell you that your 700C X 28mm bike sucks or that you live in a place with absolutely no elevation gain.

Most of the uber-fat tire stories start with "I need fat tires because narrow tires beat me up." To me, that is a tire casing and quality issue and not so much about super-fat tires. I've ridden some Clement silk 22.5mm tubulars that were far more cushy than the el cheap-o 32mm Vittoria tires on my commuter. On dirt and gravel, you need more float and some tread pattern -- which produces a somewhat swampy road feel, which is a reasonable trade off. I also can see going fat to get a larger contact patch for rain or snow riding, but I don't see a need to go super fat on smooth dry road. YMMV.

What I love are the stories about fat tires being as "fast" as 25mm on a full-on race bike. The deal is that a 26" bike is typically a whole other type of bike with long stays, more trail and generally less stiff. A Compass mega-fat tire weighs twice as much as a reasonable 25mm tire. If your full-on racing bike is not producing better times on a 50km loop with varied terrain, then there is a problem with your race bike -- or you're having a bad day.

-- Jay Beattie.


  #23  
Old December 16th 17, 07:45 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Road Tires: Width vs Speed Penalties?

On 2017-12-14 18:01, Tim McNamara wrote:
On Thu, 14 Dec 2017 07:14:50 -0800 (PST), jbeattie
wrote:

I found the Paselas were prone to sidewall damage. I also had a
problems mounting Gatorskins on a CR18s because of the shallow rim
well, so choosing a tire that fits that rim is important.


I have had several Paselas fail due to casing separation where the ends
of the carcass overlap (also every Ritchey Tom Slick I ever used had a
casing failure). Most of them have just worn out. I've neved
specifically had sidewall damage with the Paselas. Generally I run
tires at the maximum rated pressure, unlike Jan Heine. I've just too
heavy for lower pressures at 230 lbs. The Compass tires are rated to 75
PSI, though, and I find 50-55 works very well so they are the exception
so far. I think lower pressures increase the risk of sidewall damage.


Similar experience here, less the Compass tires because I would never
plunk down that much money for a bicycle tire unless it lasts at least
3x of the usual.


I'm still amazed at the $90 on price tag. What about all the Schwalbe
tires?


Bike component makers have figured out that we will pay stupid amounts
of money for products that wear out and have to be replaced relatively
often- $200 chains, $150 cassettes, $100 tires, etc. Repeat customers
are where the cash is...


Then there are the customers like me who don't and in consequence walk
away. To online sources overseas.


My complaints about tires typically involve tires that are sluggish.


The Compass tires feel less sluggish than the Paselas, althouogh as
noted that is most noticeable at slow speeds and climbing. When rolling
along on flat ground, wind drag overwhelms the signal from the tires
pretty quickly. At the same pressures I would say the two sets of tires
are similar in comfort.

All that being said, I know a couple of people who have switched to
Compass tires and sing their praises loudly and enthusiastically. I am
reasonably satisfied with them but am a bit more muted about it.


Must be rich guys :-)

--
Regards, Joerg

http://www.analogconsultants.com/
  #24  
Old December 16th 17, 08:34 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Road Tires: Width vs Speed Penalties?

On 12/16/2017 11:13 AM, jbeattie wrote:

What I love are the stories about fat tires being as "fast" as 25mm on a full-on race bike. The deal is that a 26" bike is typically a whole other type of bike with long stays, more trail and generally less stiff. A Compass mega-fat tire weighs twice as much as a reasonable 25mm tire. If your full-on racing bike is not producing better times on a 50km loop with varied terrain, then there is a problem with your race bike -- or you're having a bad day.


I think coasting downhill next to another rider gives at least some
information. I say this because I have 28mm Paselas on my touring bike,
which is the bike I use for most non-tandem club rides. Most people I
ride with have bikes tending more toward racing, and almost all use
narrower tires (mostly 25s). Yet I consistently out-coast most of them.

It could be excess weight on my part, but at 180 lb. I'm not unusually
heavy for this club. It could be aerodynamics, but my touring bike
always carries a handlebar bag and usually a Carrimor saddlebag, plus
fenders. There's also a bottle dynamo and a headlight hanging out in the
wind.

I'm not claiming 28mm Paselas are magic, low-resistance tires. But I
don't see evidence that they're slowing me much, if at all.

--
- Frank Krygowski
  #25  
Old December 17th 17, 01:13 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 5,870
Default Road Tires: Width vs Speed Penalties?

On Saturday, December 16, 2017 at 11:34:27 AM UTC-8, Frank Krygowski wrote:
On 12/16/2017 11:13 AM, jbeattie wrote:

What I love are the stories about fat tires being as "fast" as 25mm on a full-on race bike. The deal is that a 26" bike is typically a whole other type of bike with long stays, more trail and generally less stiff. A Compass mega-fat tire weighs twice as much as a reasonable 25mm tire. If your full-on racing bike is not producing better times on a 50km loop with varied terrain, then there is a problem with your race bike -- or you're having a bad day.


I think coasting downhill next to another rider gives at least some
information. I say this because I have 28mm Paselas on my touring bike,
which is the bike I use for most non-tandem club rides. Most people I
ride with have bikes tending more toward racing, and almost all use
narrower tires (mostly 25s). Yet I consistently out-coast most of them.

It could be excess weight on my part, but at 180 lb. I'm not unusually
heavy for this club. It could be aerodynamics, but my touring bike
always carries a handlebar bag and usually a Carrimor saddlebag, plus
fenders. There's also a bottle dynamo and a headlight hanging out in the
wind.

I'm not claiming 28mm Paselas are magic, low-resistance tires. But I
don't see evidence that they're slowing me much, if at all.


28mm is svelte compared to the Compass tires under discussion -- like the 26" 54mm rat trap pass. Also, I think a fat tire takes more time to get up to speed on a downhill, but slick versus slick with a few mm difference (25 versus 28mm or even 32mm) probably makes little difference, particularly if the fatter tire is more positive in corners. Throw in some aggressive tread, and the calculus changes -- and stop, turn around and go up -- then it can make a lot of difference. Also, bikes make a difference. My gravel bike is a hoot, but its a slug up hill compared to my race bike. The Jan Heine "surfing" paradigm doesn't really cut it when you're slugging up hill trying to keep up with your cohorts.

-- Jay Beattie.
  #26  
Old December 17th 17, 02:58 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 5,697
Default Road Tires: Width vs Speed Penalties?

On Sat, 16 Dec 2017 08:13:42 -0800 (PST), jbeattie
wrote:

On Saturday, December 16, 2017 at 2:53:06 AM UTC-8, John B. wrote:
On Sat, 16 Dec 2017 00:24:22 -0600, Tim McNamara
wrote:

On Fri, 15 Dec 2017 16:07:29 -0800 (PST), HaloTupolev
wrote:
but don't say anything about width-vs-speed penalties.

Compass generally claims that width itself doesn't cause significant
differences in net performance.

I can't remember which issue it was (43 maybe?), but one of the
editions of Bicycle Quarterly included testing on the apron of
Marymoor Velodrome where the entire range of Compass tire widths
performed identically, within the precision of their measurement
methodology.

I haven't read that one, but their earlier ones involved roll-down
testing and (from one of the photos in the article) timing with a
wris****ch. I put little credence into that article because if the
likelihood of noise in the data.

They later did some interesting testing using a power meter, which
struck me as a better way to assess performance.

That said, I think that Compass is correct in that given identical
construction (casing, tread thickness, rubber compound) the effects of
width as a variable would be small. The more traditional drum tests
suggested (e.g. the ones done for Avocet). For as long as I can
remember, most wider tires also feature heavier casings and much thicker
rubber- wide high performance tires were rare. Compass has pushed in
that direction quite aggressively and good for them.

Compass's assertion that inflation pressure has little impact on
performance is out of keeping with that testing, although when
real-world road textures/roughness are included there may be relatively
little adverse impact from lower pressures. Jim Papadopoulos wrote
about that in this forum many years ago under the rubric of suspension
losses, and his thinking had a direct impact on Compass's tire design
philosophy.

My bike with 26 x 1.8 Compass tires seems as fast as my bikes with 700 x
25 or 700 x 28 Paselas. At least based on average speeds on my cycle
computer and similar subjective effort. That is of course far from a
scientific approach!


On the other hand if you go out and ride your 50 km loop with the wide
26" tires and then go out the next day and ride the same loop with
your 700c x 28 tires in the same time, can science tell you any more
:-)


Science would tell you that your 700C X 28mm bike sucks or that you live in a place with absolutely no elevation gain.


While I wasn't specifically thinking of hills and such but the fact
remains that if you ride your 50 km loop at the same speed with the
two bikes and you are happy with the ride... what else is there?

If one wants to get scientific, my guess is that the average guy
posting has well over 10% body weight as fat, in fact I read that the
*average* Usian is 23 lbs over his "ideal body weight" (which totally
ignores tissue make up).

(Note: I an excepting James from this as I believe that he is still
maintaining his lean body mass near optimum).

So, to be scientific, lets say, "You'd be far, far better off getting
rid of 15 - 20 lbs of that stuff hanging over your belt, before you
start buying new tires.... its cheaper too :-)



Most of the uber-fat tire stories start with "I need fat tires because narrow tires beat me up." To me, that is a tire casing and quality issue and not so much about super-fat tires. I've ridden some Clement silk 22.5mm tubulars that were far more cushy than the el cheap-o 32mm Vittoria tires on my commuter. On dirt and gravel, you need more float and some tread pattern -- which produces a somewhat swampy road feel, which is a reasonable trade off. I also can see going fat to get a larger contact patch for rain or snow riding, but I don't see a need to go super fat on smooth dry road. YMMV.

What I love are the stories about fat tires being as "fast" as 25mm on a full-on race bike. The deal is that a 26" bike is typically a whole other type of bike with long stays, more trail and generally less stiff. A Compass mega-fat tire weighs twice as much as a reasonable 25mm tire. If your full-on racing bike is not producing better times on a 50km loop with varied terrain, then there is a problem with your race bike -- or you're having a bad day.

-- Jay Beattie.

--
Cheers,

John B.

  #27  
Old December 17th 17, 03:10 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 5,697
Default Road Tires: Width vs Speed Penalties?

On Sat, 16 Dec 2017 14:34:21 -0500, Frank Krygowski
wrote:

On 12/16/2017 11:13 AM, jbeattie wrote:

What I love are the stories about fat tires being as "fast" as 25mm on a full-on race bike. The deal is that a 26" bike is typically a whole other type of bike with long stays, more trail and generally less stiff. A Compass mega-fat tire weighs twice as much as a reasonable 25mm tire. If your full-on racing bike is not producing better times on a 50km loop with varied terrain, then there is a problem with your race bike -- or you're having a bad day.


I think coasting downhill next to another rider gives at least some
information. I say this because I have 28mm Paselas on my touring bike,
which is the bike I use for most non-tandem club rides. Most people I
ride with have bikes tending more toward racing, and almost all use
narrower tires (mostly 25s). Yet I consistently out-coast most of them.

It could be excess weight on my part, but at 180 lb. I'm not unusually
heavy for this club. It could be aerodynamics, but my touring bike
always carries a handlebar bag and usually a Carrimor saddlebag, plus
fenders. There's also a bottle dynamo and a headlight hanging out in the
wind.

I'm not claiming 28mm Paselas are magic, low-resistance tires. But I
don't see evidence that they're slowing me much, if at all.


The (probably) overriding factor in bicycle speed is wind resistance
so perhaps you are more streamlined :-)

--
Cheers,

John B.

  #28  
Old December 17th 17, 04:31 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Road Tires: Width vs Speed Penalties?

On 12/16/2017 8:58 PM, John B. wrote:


If one wants to get scientific, my guess is that the average guy
posting has well over 10% body weight as fat, in fact I read that the
*average* Usian is 23 lbs over his "ideal body weight" (which totally
ignores tissue make up).

(Note: I an excepting James from this as I believe that he is still
maintaining his lean body mass near optimum).

So, to be scientific, lets say, "You'd be far, far better off getting
rid of 15 - 20 lbs of that stuff hanging over your belt, before you
start buying new tires.... its cheaper too :-)


I think the difference is: For most of us here, buying new tires is
possible. In fact, it's easy.

Losing 20 pounds, on the other hand...

--
- Frank Krygowski
  #29  
Old December 17th 17, 05:19 AM posted to rec.bicycles.tech
Tim McNamara
external usenet poster
 
Posts: 6,945
Default Road Tires: Width vs Speed Penalties?

On Sun, 17 Dec 2017 08:58:35 +0700, John B wrote:

While I wasn't specifically thinking of hills and such but the fact
remains that if you ride your 50 km loop at the same speed with the
two bikes and you are happy with the ride... what else is there?


I raced from 1992-2000 and then stopped as I realized I was no longer
having fun riding a bike. 2003-2008 I did brevets and then stopped
because I realized I just wanna ride my bike, not follow a bunch of
organizational rules. So now I am more concerned with smiles per hor
than miles per hour. On the down side, I now resemble the following:

If one wants to get scientific, my guess is that the average guy
posting has well over 10% body weight as fat, in fact I read that the
*average* Usian is 23 lbs over his "ideal body weight" (which totally
ignores tissue make up).


Ayup. Saw bicycling photos of me tonight, I look like a **** brickhouse
on wheels. Time to lose some weight, yeek.
  #30  
Old December 17th 17, 06:18 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 5,870
Default Road Tires: Width vs Speed Penalties?

On Saturday, December 16, 2017 at 5:58:40 PM UTC-8, John B. wrote:
On Sat, 16 Dec 2017 08:13:42 -0800 (PST), jbeattie
wrote:

On Saturday, December 16, 2017 at 2:53:06 AM UTC-8, John B. wrote:
On Sat, 16 Dec 2017 00:24:22 -0600, Tim McNamara
wrote:

On Fri, 15 Dec 2017 16:07:29 -0800 (PST), HaloTupolev
wrote:
but don't say anything about width-vs-speed penalties.

Compass generally claims that width itself doesn't cause significant
differences in net performance.

I can't remember which issue it was (43 maybe?), but one of the
editions of Bicycle Quarterly included testing on the apron of
Marymoor Velodrome where the entire range of Compass tire widths
performed identically, within the precision of their measurement
methodology.

I haven't read that one, but their earlier ones involved roll-down
testing and (from one of the photos in the article) timing with a
wris****ch. I put little credence into that article because if the
likelihood of noise in the data.

They later did some interesting testing using a power meter, which
struck me as a better way to assess performance.

That said, I think that Compass is correct in that given identical
construction (casing, tread thickness, rubber compound) the effects of
width as a variable would be small. The more traditional drum tests
suggested (e.g. the ones done for Avocet). For as long as I can
remember, most wider tires also feature heavier casings and much thicker
rubber- wide high performance tires were rare. Compass has pushed in
that direction quite aggressively and good for them.

Compass's assertion that inflation pressure has little impact on
performance is out of keeping with that testing, although when
real-world road textures/roughness are included there may be relatively
little adverse impact from lower pressures. Jim Papadopoulos wrote
about that in this forum many years ago under the rubric of suspension
losses, and his thinking had a direct impact on Compass's tire design
philosophy.

My bike with 26 x 1.8 Compass tires seems as fast as my bikes with 700 x
25 or 700 x 28 Paselas. At least based on average speeds on my cycle
computer and similar subjective effort. That is of course far from a
scientific approach!

On the other hand if you go out and ride your 50 km loop with the wide
26" tires and then go out the next day and ride the same loop with
your 700c x 28 tires in the same time, can science tell you any more
:-)


Science would tell you that your 700C X 28mm bike sucks or that you live in a place with absolutely no elevation gain.


While I wasn't specifically thinking of hills and such but the fact
remains that if you ride your 50 km loop at the same speed with the
two bikes and you are happy with the ride... what else is there?

If one wants to get scientific, my guess is that the average guy
posting has well over 10% body weight as fat, in fact I read that the
*average* Usian is 23 lbs over his "ideal body weight" (which totally
ignores tissue make up).

(Note: I an excepting James from this as I believe that he is still
maintaining his lean body mass near optimum).

So, to be scientific, lets say, "You'd be far, far better off getting
rid of 15 - 20 lbs of that stuff hanging over your belt, before you
start buying new tires.... its cheaper too :-)


If I lost 20lbs, I'd look like a death camp survivor. Ten would be O.K. Anyway, even when I'm carrying a few extra pounds, I can feel the difference in effort needed to move different bikes and tires. I just switched out some OE Schwalbe Luganos for some Pro4 Endurance -- both 28mm. https://www.bicyclerollingresistance...be-lugano-2015 I can feel the difference between the two, even though I was just slugging along today through the hills. I ride 6-7 days a week and ride three different bikes with regularity. They're all different. Tomorrow will be a group ride with guys I've been riding with weekly for years or decades -- racers and former racers, and although it won't be a death race this time of year . . . two guys a ride, three guys a race and more guys more race. I don't want to be flogging some touring bike with balloon tires up a hill when everyone else is on a racing bike.

-- Jay Beattie.
 




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