Jan Heine "Busts" Another Tire/Wheel Myth...
#51
Senior Member
Join Date: Apr 2012
Location: Nor Cal
Posts: 6,016
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1814 Post(s)
Likes: 0
Liked 923 Times
in
569 Posts
I noticed in the article linked by the OP on tire size, it was said that they found insignificant aerodynamic differences between 25mm and 32mm tires,
but also cited a study:
"The German magazine TOUR built a sophisticated setup with a motorized dummy rider and found that a 28 mm-wide tire had the same wind resistance as a 25 mm tire when the wind was coming from straight ahead. With a crosswind, the wider tire was very slightly less aerodynamic. Even then, the wider tires required only 5 watt more..."
Wind speed is not mentioned, but if this was at moderate speed, and the test was scaled up to larger tires at fast road speeds, the aero penalty would hardly be insignificant.
but also cited a study:
"The German magazine TOUR built a sophisticated setup with a motorized dummy rider and found that a 28 mm-wide tire had the same wind resistance as a 25 mm tire when the wind was coming from straight ahead. With a crosswind, the wider tire was very slightly less aerodynamic. Even then, the wider tires required only 5 watt more..."
Wind speed is not mentioned, but if this was at moderate speed, and the test was scaled up to larger tires at fast road speeds, the aero penalty would hardly be insignificant.
Likes For woodcraft:
#52
Cheerfully low end
Join Date: Jun 2020
Posts: 1,978
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 646 Post(s)
Liked 1,044 Times
in
667 Posts
I rode a set of RTPs on my 26er MTB until I had worn the rear tire to the point of having frequent flats. The other RTP is still on a front wheel and on my bike at present. That front tire has never flatted. They are really delightful on roads and crushed stone or gravel (until things get wet and soft).
I’m trying out a Contact Speed 26x2.0 for the rear now which is probably a couple of watts more than the RTP but hopefully a bit better protected against puncture. There aren’t many options for a wide roadish 26” tire that actually rate with a low rolling resistance.
Otto
#53
Newbie
To be fair, testing tires under real-world conditions is an exceedingly complex undertaking in controlling for all the possible variables, including subjective ones, and he does point this out in his articles. I believe Heine has done as good a job at this as anyone has attempted.
N.B. I also seem to recall that Heine has an advanced degree (post-graduate, not sure if MS or PhD) in geology, so he likely has a decent grasp of the scientific method.
N.B. I also seem to recall that Heine has an advanced degree (post-graduate, not sure if MS or PhD) in geology, so he likely has a decent grasp of the scientific method.
#54
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,272
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4257 Post(s)
Liked 1,355 Times
in
941 Posts
I'm saying that it's obvious that it can't (so he can't be doing that).
#55
Senior Member
Best in an universal sense is interesting also in the context of cornering. Wider tires on smaller rims don't necessarily corner as well in the loose as their thinner larger rimmed counterparts. It's a bit counter intuitive because of course the wider tire has more surface are and thus more grip. But in fact the wider tire has also more float meaning that it can float off the loose stuff while the thinner tire digs in the gravel and holds its course. This in turn means that to corner as well the wider tire may need studs whereas the thinner tire can be more slick.
It all depends on riding conditions, but I've found this to be the case on fine gravel roads when comparing 650x47 and 700x40 slickish tires.
It all depends on riding conditions, but I've found this to be the case on fine gravel roads when comparing 650x47 and 700x40 slickish tires.
#57
Senior Member
Join Date: Sep 2017
Posts: 7,879
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 6963 Post(s)
Liked 10,963 Times
in
4,688 Posts
Of course. But no one is saying it's supposed to take your preferences into account (since it's obvious that it can't).
You seem to think that his goal is to determine the "best in a universal sense".
I'm saying that it's obvious that it can't (so he can't be doing that).
You seem to think that his goal is to determine the "best in a universal sense".
I'm saying that it's obvious that it can't (so he can't be doing that).
#58
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,272
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4257 Post(s)
Liked 1,355 Times
in
941 Posts
No one is really claiming that it does.
Last edited by njkayaker; 07-23-20 at 03:45 PM.
#59
Banned
Not just wider but high thread-count thin , light tread 'supple ' casings.. @ $80 or so each..
#60
Senior Member
Join Date: Sep 2017
Posts: 7,879
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 6963 Post(s)
Liked 10,963 Times
in
4,688 Posts
Except you, in post #26 .
#61
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,272
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4257 Post(s)
Liked 1,355 Times
in
941 Posts
Except you, in post #26 .
The scientific method is for testing hypotheses, which might include questions about the effect of tire size (or width) on rolling resistance, smoothness/comfort, speed, etc. But since those are sometimes competing goals, it cannot tell us what is "best." In other words, "best" is a subjective judgment which reflects preferences or priorities.
The point is to understand the properties so that it can inform a choice.
No one is saying the purpose is to determine a singular "best" tire for all uses.
1) Agreed.
2) Scientific testing might prove that a wider tire gives a smoother ride, but only you (your preferences) can determine whether that is "better," since a wider tire brings other tradeoffs. This gets to your first point: that the tests can only inform your choice, not determine what is "best" in any universal sense.
3) Agreed.
2) Scientific testing might prove that a wider tire gives a smoother ride, but only you (your preferences) can determine whether that is "better," since a wider tire brings other tradeoffs. This gets to your first point: that the tests can only inform your choice, not determine what is "best" in any universal sense.
3) Agreed.
Then, you veered back into the weeds by arguing against a point no one really claimed. You are weirdly stuck on the "best" stuff.
Last edited by njkayaker; 07-23-20 at 04:39 PM.
#62
Senior Member
Join Date: Oct 2015
Location: San Diego, California
Posts: 4,077
Bikes: Velo Orange Piolet
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 2228 Post(s)
Liked 2,011 Times
in
972 Posts
Jan Heine's science is pretty good. I know a person that sells tires should be suspect when he tests tires, but he does a good job. I'm always looking for someone that has personal interest in "x" and makes "scientific" claims about "x" - one of my hobbies - and Jan Heine has been a pretty solid player in that area. I think he makes a good faith effort to be a straight shooter.
Likes For tyrion:
#63
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,272
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4257 Post(s)
Liked 1,355 Times
in
941 Posts
Jan Heine's science is pretty good. I know a person that sells tires should be suspect when he tests tires, but he does a good job. I'm always looking for someone that has personal interest in "x" and makes "scientific" claims about "x" - one of my hobbies - and Jan Heine has been a pretty solid player in that area. I think he makes a good faith effort to be a straight shooter.
He's showing the data he generates as part of this process. The sort of data which companies often keep a secret.
Ideally, some other independent concern would test tires (in a competent way) to produce "unbiased" results.
Nobody is stopping anybody from doing that.
Likes For njkayaker:
#64
Newbie racer
Join Date: Feb 2018
Posts: 3,406
Bikes: Propel, red is faster
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 1575 Post(s)
Liked 1,569 Times
in
974 Posts
Drum testing (like bicyclerollingresistance.com does) doesn't always reflect real world performance.
https://blog.silca.cc/asymmetric-eff...e-optimization
https://blog.silca.cc/asymmetric-eff...e-optimization
You can’t do it.
A test like the drum provides a consistent set of parameters so that you can compare data taken in those consistent conditions. It isnt going to tell you what pressure to run (which showing the truer pressure curve was the point of that article). It will give a lot larger data set than endless low controlled outdoor testing.
If someone cares so much anyway, you’ll pick the top contenders in a standardized data set then do your own real world conditions test.
Real world you can buy a few sets among teammates and use Chung VE testing by holding aero constant instead of CRR and see the delta in CRR for your personal setup. Not actual CRR, but delta.
I do this. I did a test showing a 19mm track tub to have lower CRR than another normal TT tire in 23mm (if you want to risk not finishing the race by using a track tire).
Point being, there are people who talk crap and post articles, then there are folks who actually use the data sets to apply them in the real world to themselves. Then go race.
I’m a hobbyist TT rider. Not very strong. No money for tunnel testing or a $10k bike. I’m all-in on all TT kit I own under $1500. Despite paltry power and a low budget, I’m pretty freaking quick.
How am I that quick on low power and budget? Hopes and dreams and fairy dust? No, some of us do know WTF we’re talking about.
#65
Senior Member
Join Date: Jul 2009
Posts: 5,949
Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3951 Post(s)
Liked 7,296 Times
in
2,946 Posts
By that logic, tires by every manufacturer should rank high in their own tests, since they're all trying to figure out how to make better tires.
#66
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,272
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4257 Post(s)
Liked 1,355 Times
in
941 Posts
If they don't show their data, we don't know.
That the company's tires rank higher doesn't necessarily mean they are cheating either (it's possible).
Last edited by njkayaker; 07-23-20 at 04:58 PM.
Likes For tyrion:
#68
Senior Member
Join Date: Jul 2009
Posts: 5,949
Bikes: Colnago, Van Dessel, Factor, Cervelo, Ritchey
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 3951 Post(s)
Liked 7,296 Times
in
2,946 Posts
#69
Senior Member
Join Date: Sep 2007
Location: Far beyond the pale horizon.
Posts: 14,272
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 4257 Post(s)
Liked 1,355 Times
in
941 Posts
Are all of these likely to rank exactly the same?
It's possible that people are cherry-picking the tires being compared but it might not be just Heine doing that.
One issue is that these companies might be optimizing narrower tires. It seems that wider tires tended be more focused on durability than performance.
I said it was reasonable to be skeptical.
At this point, you really need to run your own unbiased test. I'll wait.
Last edited by njkayaker; 07-23-20 at 07:11 PM.
#70
Senior Member
Join Date: Jun 2014
Location: Ontario, Canada
Posts: 4,624
Bikes: iele Latina, Miele Suprema, Miele Uno LS, Miele Miele Beta, MMTB, Bianchi Model Unknown, Fiori Venezia, Fiori Napoli, VeloSport Adamas AX
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1324 Post(s)
Liked 927 Times
in
640 Posts
Use what you just posted to try to explain why I should run a GP5000 clincher latex instead of a CS TL in a time trial.
You can’t do it.
A test like the drum provides a consistent set of parameters so that you can compare data taken in those consistent conditions. It isnt going to tell you what pressure to run (which showing the truer pressure curve was the point of that article). It will give a lot larger data set than endless low controlled outdoor testing.
If someone cares so much anyway, you’ll pick the top contenders in a standardized data set then do your own real world conditions test.
Real world you can buy a few sets among teammates and use Chung VE testing by holding aero constant instead of CRR and see the delta in CRR for your personal setup. Not actual CRR, but delta.
I do this. I did a test showing a 19mm track tub to have lower CRR than another normal TT tire in 23mm (if you want to risk not finishing the race by using a track tire).
Point being, there are people who talk crap and post articles, then there are folks who actually use the data sets to apply them in the real world to themselves. Then go race.
I’m a hobbyist TT rider. Not very strong. No money for tunnel testing or a $10k bike. I’m all-in on all TT kit I own under $1500. Despite paltry power and a low budget, I’m pretty freaking quick.
How am I that quick on low power and budget? Hopes and dreams and fairy dust? No, some of us do know WTF we’re talking about.
You can’t do it.
A test like the drum provides a consistent set of parameters so that you can compare data taken in those consistent conditions. It isnt going to tell you what pressure to run (which showing the truer pressure curve was the point of that article). It will give a lot larger data set than endless low controlled outdoor testing.
If someone cares so much anyway, you’ll pick the top contenders in a standardized data set then do your own real world conditions test.
Real world you can buy a few sets among teammates and use Chung VE testing by holding aero constant instead of CRR and see the delta in CRR for your personal setup. Not actual CRR, but delta.
I do this. I did a test showing a 19mm track tub to have lower CRR than another normal TT tire in 23mm (if you want to risk not finishing the race by using a track tire).
Point being, there are people who talk crap and post articles, then there are folks who actually use the data sets to apply them in the real world to themselves. Then go race.
I’m a hobbyist TT rider. Not very strong. No money for tunnel testing or a $10k bike. I’m all-in on all TT kit I own under $1500. Despite paltry power and a low budget, I’m pretty freaking quick.
How am I that quick on low power and budget? Hopes and dreams and fairy dust? No, some of us do know WTF we’re talking about.
Cheers
Likes For Miele Man:
#71
Advanced Slacker
Join Date: Feb 2017
Posts: 6,210
Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2762 Post(s)
Liked 2,537 Times
in
1,433 Posts
Real world testing yields messy, less-than consistent and somewhat subjective data, but it is describing the EXACT thing we are most interested in.
Roller Drum tests yield precise, quantifiable, reproducible, and consistent data.... but.... its relationship to what we really care about is unclear..
The former is an example of measuring what you value.
The latter is an example of valuing what you can measure.
Unfortunately people are too often seduced by the latter. They are essentially mistaking precision for accuracy.
Roller Drum tests yield precise, quantifiable, reproducible, and consistent data.... but.... its relationship to what we really care about is unclear..
The former is an example of measuring what you value.
The latter is an example of valuing what you can measure.
Unfortunately people are too often seduced by the latter. They are essentially mistaking precision for accuracy.
#72
Senior Member
Join Date: Aug 2017
Location: Northern Virginia
Posts: 727
Bikes: Current: 2016 Bianchi Volpe; 1973 Peugeot UO-8. Past: 1974 Fuji S-10-S with custom black Imron paint by Stinsman Racing of PA.
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 215 Post(s)
Liked 204 Times
in
142 Posts
A few years ago Jan Heine dispelled the generally held belief that narrower tires are always faster than wider tires of the same size. There are some particular and specific parameters, but it really shook up the industry. (https://www.renehersecycles.com/12-m...es-are-slower/)
Well, last week he challenged the notion that 700 wheels roll appreciably faster than 650/26" wheels (and smaller). Again, there are specific parameters (the wheels must have pneumatic tires on them).
https://www.renehersecycles.com/why-...t-roll-faster/
As before, how a tire/wheel combination FEELS can be different from how it PERFORMS.
Well, last week he challenged the notion that 700 wheels roll appreciably faster than 650/26" wheels (and smaller). Again, there are specific parameters (the wheels must have pneumatic tires on them).
https://www.renehersecycles.com/why-...t-roll-faster/
As before, how a tire/wheel combination FEELS can be different from how it PERFORMS.
When I bought my current bike, it came with Vittoria Randenneur 28mm tires. A dreadful, heavy, sluggish, but very durable tire many like for touring or commuting. Switching to Continental GP4000SII 28mm tires (wonderful) and then to the Rene Herse (Compass) 28mm tires (even more wonderful with tan sidewalls) and then to Rene Herse 32s, I was hooked on the feel like I remembered feeling with Clement Seta tubulars and Clement hand made cotton clinchers. They were responsive and rolled very well, and good in damp, especially the GP4000SII. (Damp means damp as is a wet, but not raining road.)
I have yet to have a flat with any of those tires.
So to paraphrase what they said in the '60s, if it feels good, I will use it.
Likes For Bill in VA:
#73
Senior Member
Join Date: Feb 2015
Location: Mission Viejo
Posts: 5,806
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: 1944 Post(s)
Liked 2,164 Times
in
1,323 Posts
I would think every tire mfg can make an equally flexible paper thin tire that will ace rolling resistance tests no matter where they are performed.
I didn’t care enough to read the article close enough to find out if he was running his Extralights for the tests. If he was then I would believe they roll fast. I’m not sure they are truly any faster in repairing a flat.
People talk real world, well real world is buying a tire that rolls fast enough with the least headaches. After the fighting over testing criteria is done, they go buy Gatorskins.
John
I didn’t care enough to read the article close enough to find out if he was running his Extralights for the tests. If he was then I would believe they roll fast. I’m not sure they are truly any faster in repairing a flat.
People talk real world, well real world is buying a tire that rolls fast enough with the least headaches. After the fighting over testing criteria is done, they go buy Gatorskins.
John
#74
Senior Member
Join Date: Oct 2014
Location: Portland, OR
Posts: 12,905
Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder
Mentioned: 129 Post(s)
Tagged: 0 Thread(s)
Quoted: 4806 Post(s)
Liked 3,928 Times
in
2,553 Posts
In the heyday of bicycles (when the really bright people were designing bikes, not computers, software, aerospace ... someone did a study of wheel diameter vs road surface. (This was back when the worst roads were, by our standards, really bad and good pavement was a new concept.) He found that the rougher the surface, the bigger the optimum wheel diameter. Interestingly, he found that on smooth pavement, 29" 27" was optimum. (27" being nearly exactly the outside diameter of a 700c road tire.)
Racers have settled on that diameter. Now, there have been race bikes built around much smaller wheels. In criteriums those bikes are fully competitive because what they give away in rolling resistance they gain in radically lower inertia; paying real dividends every corner.
The place where we moderns missed the boat is on poor surfaces. Mountain bikes. 45 years ago, the 26" wheel was adopted. Not because it had any advantages but because kid's bikes were available and cheap. Yes smaller wheels do better in tight places and fit smaller people better, but the disadvantages on rough surfaces were so limiting that you had to be seriously hard core (and slightly crazy) or willing to spend money, research, technology, etc, etc, to get enough suspension to make those bikes rideable. Much later, the 29s came along. Just what that guy told us 120 years ago!
Ben
Racers have settled on that diameter. Now, there have been race bikes built around much smaller wheels. In criteriums those bikes are fully competitive because what they give away in rolling resistance they gain in radically lower inertia; paying real dividends every corner.
The place where we moderns missed the boat is on poor surfaces. Mountain bikes. 45 years ago, the 26" wheel was adopted. Not because it had any advantages but because kid's bikes were available and cheap. Yes smaller wheels do better in tight places and fit smaller people better, but the disadvantages on rough surfaces were so limiting that you had to be seriously hard core (and slightly crazy) or willing to spend money, research, technology, etc, etc, to get enough suspension to make those bikes rideable. Much later, the 29s came along. Just what that guy told us 120 years ago!
Ben
#75
Occam's Rotor
Join Date: Jul 2013
Posts: 7,248
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 2,331 Times
in
1,164 Posts
Yes, there is not universal agreement - that's why there have been sooo many books and intellectual debates about it. I can recall reading a ton of that stuff in grad school, since I had some profs who were into it.
In the case of Heine's experiments, I've always found that - while he may be doing as well as possible for "real world" tests - his methods don't allow him to adequately control for the variables other than those in which he is interested. (You know, the whole ceteris paribus thing.) Additionally (and this is not entirely disqualifying, but still), it is clear that he is a less-than-dispassionate analyst.
In the case of Heine's experiments, I've always found that - while he may be doing as well as possible for "real world" tests - his methods don't allow him to adequately control for the variables other than those in which he is interested. (You know, the whole ceteris paribus thing.) Additionally (and this is not entirely disqualifying, but still), it is clear that he is a less-than-dispassionate analyst.