Wide vs Less Wide Tires, Another View
09-11-17, 01:17 PM
#101
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I'm not playing scientist. I'm interested in what setup takes the least time to go between two points. Most of the factors I'm aware of are not discovered so easily by having a lab test either. I'm fine guessing and generally guess pretty well from handlebar tape to shaving arms.
I have loaned wheels and received the expected responses.
Another example that I like is the helmet. Certain long TT helmets test better in the wind tunnel. KASK with their Bambino suggesting that riders don't really ride like that. That they look down to get a water bottle, or look to the side.
So which helmet is faster?
The one the rider goes faster with.
09-11-17, 01:18 PM
#102
Senior Member
That when I see real rides of riders going very fast, even out and back to minimize hill issues, wind issues etc, that they do way better than calculators. Or it takes much less power to go fast.
That 32.2mph run above was closer to 300W not 610W. If I put the parameters into a bike calculator I get high W for speeds that are done all the time.
I have found through testing, my riding and talking to other riders that there are energy/fatigue cost from equipment. It is pretty well accepted that higher profile wheels are not good on gusty days.
If they were faster I'd think they'd be used - sometimes anyway. But they are known to be slower. Exactly why they are slower, I don't know. But I do see increase in HR. And a 15mph gusts will spit packs. Is it because the rider can't handle the beast and they are scared, or is it because for some reason it takes more energy to handle them - or both. I just know they turn out to be slower in some conditions. Would I be afraid of using the same the track, no. I don't know how wind tunnels have tested that. But riders know that. I've at least seen something in HR.
The similar approach is applied to tire pressure, drive train, weight etc. In the end seems the calculators are generally beat by an mph or so.
That 32.2mph run above was closer to 300W not 610W. If I put the parameters into a bike calculator I get high W for speeds that are done all the time.
I have found through testing, my riding and talking to other riders that there are energy/fatigue cost from equipment. It is pretty well accepted that higher profile wheels are not good on gusty days.
If they were faster I'd think they'd be used - sometimes anyway. But they are known to be slower. Exactly why they are slower, I don't know. But I do see increase in HR. And a 15mph gusts will spit packs. Is it because the rider can't handle the beast and they are scared, or is it because for some reason it takes more energy to handle them - or both. I just know they turn out to be slower in some conditions. Would I be afraid of using the same the track, no. I don't know how wind tunnels have tested that. But riders know that. I've at least seen something in HR.
The similar approach is applied to tire pressure, drive train, weight etc. In the end seems the calculators are generally beat by an mph or so.
That doesn't mean a thing. You guys have spend thousands of $$$s to achieve a better than average aerodynamic drag on the bike. The fact your son is able to adopt an aero position and get more slippery than a bike calculators assumptions doesn't change the fact that 5 seconds over 30 minutes equates to about 3 watts. All you're actually saying is that because of the aerodynamics of your son...the actual difference in watts might be closer to 1.5 watts than 3 watts.
Last edited by Abe_Froman; 09-11-17 at 01:21 PM.
09-11-17, 01:21 PM
#103
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That doesn't mean a thing. The fact your son is able to adopt an aero position and get more slippery than a bike calculators assumptions doesn't change the fact that 5 seconds over 30 minutes equates to about 3 watts. All you're actually saying is that because of the aerodynamics of your son...the actual difference in watts might be closer to 1.5 watts than 3 watts.
Like my last post - on the helmet, there are things you can't really tell so much in the wind tunnel.
09-11-17, 01:23 PM
#105
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I don't believe for a second you can tell more on the bike than scientists can tell in a lab.
09-11-17, 01:27 PM
#106
Senior Member
Some helmets are also haunted. One of my helmets is the Trek Factory Racing Ballista helmet, and it speaks to me in unintelligible words if I look to the side while riding fast or into wind. The unsettling vibes might counteract some of the aerodynamic benefits.
09-11-17, 01:27 PM
#107
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For me, though? No question it would be 28mm tires at lower pressure. I don't believe that any drawbacks, if they even exist in the first place, would overcome the benfits of my happiness and comfort on the bike. I know for a fact I work harder when I'm not getting bounced around. More importantly, I want to ride more often, and farther. No opinion on fancy large profile wheels...never had an opportunity to ride them.
09-11-17, 01:39 PM
#108
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...
For me, though? No question it would be 28mm tires at lower pressure. I don't believe that any drawbacks, if they even exist in the first place, would overcome the benfits of my happiness and comfort on the bike. I know for a fact I work harder when I'm not getting bounced around. ...
For me, though? No question it would be 28mm tires at lower pressure. I don't believe that any drawbacks, if they even exist in the first place, would overcome the benfits of my happiness and comfort on the bike. I know for a fact I work harder when I'm not getting bounced around. ...
I understood way back the OP said "faster". I think there is zero debate on what is more comfortable.
You answered the faster question for you it would be 28.
With the way the market loves to convince us to get new stuff, would you agree that there is no market resistance to getting the fastest riders in the world on 28s?
So why are the fastest on 25s or small, what does that tell you?
Anyway I have to work now.
09-11-17, 01:42 PM
#109
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That when I see real rides of riders going very fast, even out and back to minimize hill issues, wind issues etc, that they do way better than calculators. Or it takes much less power to go fast.
That 32.2mph run above was closer to 300W not 610W. If I put the parameters into a bike calculator I get high W for speeds that are done all the time.
I have found through testing, my riding and talking to other riders that there are energy/fatigue cost from equipment. It is pretty well accepted that higher profile wheels are not good on gusty days.
If they were faster I'd think they'd be used - sometimes anyway. But they are known to be slower. Exactly why they are slower, I don't know. But I do see increase in HR. And a 15mph gusts will spit packs. Is it because the rider can't handle the beast and they are scared, or is it because for some reason it takes more energy to handle them - or both. I just know they turn out to be slower in some conditions. Would I be afraid of using the same the track, no. I don't know how wind tunnels have tested that. But riders know that. I've at least seen something in HR.
The similar approach is applied to tire pressure, drive train, weight etc. In the end seems the calculators are generally beat by an mph or so.
That 32.2mph run above was closer to 300W not 610W. If I put the parameters into a bike calculator I get high W for speeds that are done all the time.
I have found through testing, my riding and talking to other riders that there are energy/fatigue cost from equipment. It is pretty well accepted that higher profile wheels are not good on gusty days.
If they were faster I'd think they'd be used - sometimes anyway. But they are known to be slower. Exactly why they are slower, I don't know. But I do see increase in HR. And a 15mph gusts will spit packs. Is it because the rider can't handle the beast and they are scared, or is it because for some reason it takes more energy to handle them - or both. I just know they turn out to be slower in some conditions. Would I be afraid of using the same the track, no. I don't know how wind tunnels have tested that. But riders know that. I've at least seen something in HR.
The similar approach is applied to tire pressure, drive train, weight etc. In the end seems the calculators are generally beat by an mph or so.
09-11-17, 01:48 PM
#110
Senior Member
Then I kinda lost the discussion point. I asked along the lines of the fastest. Not you (or me). You pump to ideal PSI and that is not what this thread was about. Wide/less wide tires is.
I understood way back the OP said "faster". I think there is zero debate on what is more comfortable.
You answered the faster question for you it would be 28.
With the way the market loves to convince us to get new stuff, would you agree that there is no market resistance to getting the fastest riders in the world on 28s?
So why are the fastest on 25s or small, what does that tell you?
Anyway I have to work now.
I understood way back the OP said "faster". I think there is zero debate on what is more comfortable.
You answered the faster question for you it would be 28.
With the way the market loves to convince us to get new stuff, would you agree that there is no market resistance to getting the fastest riders in the world on 28s?
So why are the fastest on 25s or small, what does that tell you?
Anyway I have to work now.
In the peleton or a fast group ride, incorporating drafting? I daresay the wider tire will be consistently faster; or rather, require less power to maintain speed.
Market resistance to it? No. But that doesn't mean the choice of pros to ride on slightly smaller tires means it is the correct one. I think it has been well documented that there is quite a bit of inertia when it comes to pros adopting new ideas. And you can't really blame them...why mess with what works? That doesn't mean that is the BEST way though, only that it is tried and shown to be effective.
09-11-17, 02:23 PM
#111
Senior Member
That when I see real rides of riders going very fast, even out and back to minimize hill issues, wind issues etc, that they do way better than calculators. Or it takes much less power to go fast.
That 32.2mph run above was closer to 300W not 610W. If I put the parameters into a bike calculator I get high W for speeds that are done all the time.
That 32.2mph run above was closer to 300W not 610W. If I put the parameters into a bike calculator I get high W for speeds that are done all the time.
09-11-17, 02:26 PM
#112
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28mm tires as the fastest choice seems pretty arbitrary.
Wouldn't it be important to consider tire weight and suppleness?
Also, why 28? Why not 32 or 35?
As you know we've got a thread over in the gravel subforum about how fast 60mm tires are, why not 60mm? The ones we're looking at show lower rolling resistance than 25mm tires.
You posted this in that thread:
How were you able to tell? Are you a scientist in a lab? All the stuff you posted earlier and you're going to claim you can somehow feel the difference in 4-8 watts of rolling resistance? 
Here's the Hyper data: https://www.bicyclerollingresistance...ger-hyper-2016
Rolling Resistance 60 psi / 4 Bar 17.7 Watts
Rolling Resistance 45 psi / 3 Bar 21.1 Watts
Here's the GPS 4000II data: https://www.bicyclerollingresistance...-4000s-ii-2014
Rolling Resistance 100 PSI / 6.9 Bar 12.9 Watts
Rolling Resistance 80 PSI / 5.5 Bar 13.7 Watts
Wouldn't it be important to consider tire weight and suppleness?
Also, why 28? Why not 32 or 35?
As you know we've got a thread over in the gravel subforum about how fast 60mm tires are, why not 60mm? The ones we're looking at show lower rolling resistance than 25mm tires.
You posted this in that thread:
Here's the Hyper data: https://www.bicyclerollingresistance...ger-hyper-2016
Rolling Resistance 60 psi / 4 Bar 17.7 Watts
Rolling Resistance 45 psi / 3 Bar 21.1 Watts
Here's the GPS 4000II data: https://www.bicyclerollingresistance...-4000s-ii-2014
Rolling Resistance 100 PSI / 6.9 Bar 12.9 Watts
Rolling Resistance 80 PSI / 5.5 Bar 13.7 Watts
Last edited by Spoonrobot; 09-11-17 at 02:29 PM.
09-11-17, 02:28 PM
#113
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09-11-17, 02:36 PM
#114
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28mm tires as the fastest choice seems pretty arbitrary.
Wouldn't it be important to consider tire weight and suppleness?
Also, why 28? Why not 32 or 35?
As you know we've got a thread over in the gravel subforum about how fast 60mm tires are, why not 60mm? The ones we're looking at show lower rolling resistance than 25mm tires.
You posted this in that thread:
How were you able to tell? Are you a scientist in a lab? All the stuff you posted earlier and you're going to claim you can somehow feel the difference in 4-8 watts of rolling resistance?
Here's the Hyper data: https://www.bicyclerollingresistance...ger-hyper-2016
Rolling Resistance 60 psi / 4 Bar 17.7 Watts
Rolling Resistance 45 psi / 3 Bar 21.1 Watts
Here's the GPS 4000II data: https://www.bicyclerollingresistance...-4000s-ii-2014
Rolling Resistance 100 PSI / 6.9 Bar 12.9 Watts
Rolling Resistance 80 PSI / 5.5 Bar 13.7 Watts
Wouldn't it be important to consider tire weight and suppleness?
Also, why 28? Why not 32 or 35?
As you know we've got a thread over in the gravel subforum about how fast 60mm tires are, why not 60mm? The ones we're looking at show lower rolling resistance than 25mm tires.
You posted this in that thread:
How were you able to tell? Are you a scientist in a lab? All the stuff you posted earlier and you're going to claim you can somehow feel the difference in 4-8 watts of rolling resistance?
Here's the Hyper data: https://www.bicyclerollingresistance...ger-hyper-2016
Rolling Resistance 60 psi / 4 Bar 17.7 Watts
Rolling Resistance 45 psi / 3 Bar 21.1 Watts
Here's the GPS 4000II data: https://www.bicyclerollingresistance...-4000s-ii-2014
Rolling Resistance 100 PSI / 6.9 Bar 12.9 Watts
Rolling Resistance 80 PSI / 5.5 Bar 13.7 Watts
Regarding why not go 30mm+? For myself, obviously I DON'T have an issue with it. I've got 40mm tires back on my bike right now, and as noted, I feel they're plenty fast. Of course....I'm not doing any 30mph solo 60minute time trials...so I don't experience the same aerodynamic drawbacks. I'm sure if someone had enough time and equipment, they could create a graph showing the ideal tire width relative to speed from 1mph to 50mph. For most riders...I think the ideal is somewhere between 23-28mm. For me, who really doesn't go much over 20mph, and if I am I'm probably drafting someone (thereby negating most aero benefits), I'm perfectly happy sacrificing a small bit of speed for vastly more comfort, and the impossibility of pinch flats. That said....when I wear out these tires, I'll probably go back to GP4000s, just because of their measured speed, and the difference in cornering is noticeable. I'll get 28's though (obviously
).
Last edited by Abe_Froman; 09-11-17 at 02:45 PM.
09-11-17, 02:43 PM
#115
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Likely not. 13 min 135lb rider. That was solo, still wind weather using a TT technique/equipment.
Here is a 2" taller (6'1), 20 lb heavier (155) rider on a 1% grade out and back.
Most calculators are off enough there is no point in using them.
Capture.JPG
My point is the calculators aren't really designed with parameters that take into account real high speed stuff. One I saw had more drag for hands on hood than hands on drops. None had forearms on tops.
Here is a 2" taller (6'1), 20 lb heavier (155) rider on a 1% grade out and back.
Most calculators are off enough there is no point in using them.
Capture.JPG
My point is the calculators aren't really designed with parameters that take into account real high speed stuff. One I saw had more drag for hands on hood than hands on drops. None had forearms on tops.
09-11-17, 02:48 PM
#116
Senior Member
********** Analyticcycling.com lets you put in whatever parameters you want. (and when you say real high speed stuff, I don't know what you mean. Reynolds number changes less than an order of magnitude over the range of normal cycling)
09-11-17, 02:53 PM
#117
Senior Member
Likely not. 13 min 135lb rider. That was solo, still wind weather using a TT technique/equipment.
Here is a 2" taller (6'1), 20 lb heavier (155) rider on a 1% grade out and back.
Most calculators are off enough there is no point in using them.
Attachment 580110
My point is the calculators aren't really designed with parameters that take into account real high speed stuff. One I saw had more drag for hands on hood than hands on drops. None had forearms on tops.
Here is a 2" taller (6'1), 20 lb heavier (155) rider on a 1% grade out and back.
Most calculators are off enough there is no point in using them.
Attachment 580110
My point is the calculators aren't really designed with parameters that take into account real high speed stuff. One I saw had more drag for hands on hood than hands on drops. None had forearms on tops.
09-11-17, 03:00 PM
#119
Senior Member
analyticcycling.com implements the Martin model, so the limits from whatever you think might not be included have been quantified and shown not to limit its applicability.
09-11-17, 03:00 PM
#120
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I still think the issue is not the calculators are off, per se, but they're designed with an average rider in mind. I don't have a power meter....but I've got a pretty rough idea of my power output from a couple cycle machines, which lines up pretty well with both the calculators online, and strava estimates, which yes, I know, is not the most accurate in the world. But I don't believe for a second I'm seeing numbers that are off hundreds of watts. And the calculators I've seen match up pretty identically with my speeds on the bike.
09-11-17, 03:07 PM
#121
Senior Member
What someone is testing, depends on what they're measuring and how the data is used.
09-11-17, 03:08 PM
#122
Senior Member
You are exactly right. But when you want to test the fastest stuff - what are you testing? Labs are not doing wind tunnel testing at 20mph (generally) they are testing the non-average rider at 30+. At those speeds, as I posted and showed by posting speeds are getting a lot higher with much less than the calculated watts. Guys can do good math, there is stuff now they may not have considered then. The list is pretty big.
09-11-17, 03:09 PM
#123
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09-11-17, 03:10 PM
#124
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I don't have a link. I'd like one and can check how they match real numbers I have. With Strava, there are a lot of real numbers out there.
09-11-17, 03:11 PM
#125
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