Go Back  Bike Forums > Bike Forums > General Cycling Discussion
Reload this Page >

will slicker tires make a notable difference?

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!

will slicker tires make a notable difference?

Old 01-15-21, 11:20 AM
  #76  
Kapusta
Cyclochondriac
 
Join Date: Feb 2017
Posts: 4,085
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1753 Post(s)
Liked 1,017 Times in 612 Posts
Originally Posted by RChung View Post
Yikes.
Since you have been quoted here, I was going to reach out to you to get some clarification:

How wide a range of tires did you find the roller data to match up consistently with the real world data (at least in terms of ranking)? Does this include touring and gravel tires? Different surfaces?

I'm also happy just to follow a link if you point me in the right direction.

Please know I am not questioning what you are doing or your results, just trying to understand what is being covered.

This is exactly the info I've been hoping to find for several years now.

Thanks in advance.

Last edited by Kapusta; 01-15-21 at 11:48 AM.
Kapusta is offline  
Old 01-15-21, 11:54 AM
  #77  
Brett A
Word.
 
Brett A's Avatar
 
Join Date: Jul 2008
Location: Rural New England
Posts: 166

Bikes: Surly Disc Trucker, Specialized Roubaix, Felt fat bike (5" studded), DB Sortie Black 29er trail bike, many, many others out in the barn.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Liked 48 Times in 26 Posts
I can offer a side note in saying that when I went from a patterned Marathon Mondial to a smooth Conti Travel Contact, I appreciated the latter's silence. The Mondails hum on the road which, of course, is energy lost as sound and heat. I didn't care so much about that, but the silence of a smooth tire sure is nice.

Last edited by Brett A; 02-01-21 at 10:29 AM.
Brett A is offline  
Old 01-15-21, 12:32 PM
  #78  
RChung
Senior Member
 
Join Date: Sep 2009
Posts: 1,672
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 419 Post(s)
Liked 294 Times in 117 Posts
Originally Posted by Kapusta View Post
Since you have been quoted here, I was going to reach out to you to get some clarification:

How wide a range of tires did you find the roller data to match up consistently with the real world data? Does this include touring and gravel tires?

This is exactly the info I've been hoping to find out for a long time.

Thanks in advance.
So, first a bit of historical background. Neither Tom Anhalt, nor Al Morrison, nor Andy Coggan, nor Jens Heycke, nor I work in the bicycle or the tire industry. We all started out because we raced and wanted to find the best tires for our own use. Since none of us worked in the industry and we weren't selling anything, we didn't need to keep anything secret -- but it also meant that we didn't need to produce papers for publication. I'm a professor in a completely unrelated academic field; papers on bicycles or bike racing or how to measure rolling or aerodynamic drag for a bike don't add to my day job and, to the extent they take away time from it, are actually a distraction. So, back then, we were *exactly* occupied with this question of the agreement or disagreement between roller and field tests. We were 100% concerned that roller tests were not realistic, and we were hoping to use field tests to prove that roller tests were inadequate. Most of this stuff was just presented and discussed and analyzed and shared on the Slowtwitch Forum. Here's the part you're not gonna like, and I don't really like it either: if you go to Slowtwitch and search the forum for posts by any of us with subject headings like "roller Crr" or "roller vs. field test" or variants of that, you'll see the discussions. So, you can look up the discussions -- they're still there, including the descriptions of what we found and discussion and arguments, but you'll have to read through a bunch of scattered posts to find where we concluded that *we were wrong* and the rank ordering of roller and field tests is almost always preserved. Look in the time frame around 2008 or 2009 or so.

Second, more to your purposes, we were racing, so almost all of our tests (except for a couple of tests of training tires) were for racing tires, and those were tires that we either personally owned or were sent to us for testing -- remember, I said none of us work in the industry. So, altogether, there were maybe a a dozen of these joint tests until we got tired (!) of doing them -- field testing is a lot more time intensive than roller testing and none of us were getting paid for it (cuz we're not in the industry) so once we saw that relative rankings hardly ever changed, we stopped that unless there was a really good reason. I was happy and relieved for that.

Third, one of the really good reasons to continue field tests, even though they're time-consuming, was because of what is presently called "impedance." Once again, if you go onto Slowtwitch and search for it, you'll find in what was then real-time, this puzzle that although the roller and field test rank orderings didn't change, we were interested in finding out why the raw Crr estimates differed. (If you listen to Josh's recent podcast on Models and Modeling, you'll see that we were still trying to understand the tire resistance model). So we were trying a bunch of things, including different temperature tests, adding texture to rollers, seeking out freshly paved vs. older asphalt vs. chipseal vs. cobbled pave' (I was living in Europe and had cobblestones outside my door), and changing tire pressure. It was during this phase of testing that Tom observed what we now call a "breakpoint" inflection with tire pressure. This was unexpected. So at first we (we including Tom) thought his experiments were in error. So he repeated them, and we were shooting emails back-and-forth trying to diagnose what he'd done wrong. Once again, the main point is that we were trying to disprove what we were seeing, not prove something we hypothesized the existence of.

Fourth, what I didn't know at the time was that people in the bike and tire industry were following what we were doing. Among those people was Josh (but there are others). It wasn't until years later that Josh started talking publicly about the tire and inflation testing they were doing for Paris-Roubaix. Tom still does gravel racing so he's been expanding his tests to gravel tires, but I'm still riding on the road so I only care about road tires.

This is a long way of saying that the evidence is really there, but not collected in a single paper, or a single post. We don't make any money off this so we don't have an incentive to collect the data into a paper. The people who do get money from this have an incentive not to give away their research. You have to paw through a hundred posts spread out over 3 or 4 years to get the full picture -- but it's there.
RChung is offline  
Likes For RChung:
Old 01-20-21, 03:18 AM
  #79  
Danhedonia
Senior Member
 
Join Date: Jul 2018
Posts: 356
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 209 Post(s)
Liked 154 Times in 84 Posts
Geez, didn't you want to keep bleating "I'm waiting" like a 2nd grade teacher ... until an authority shows up? Then your manner changes.

Honestly, I couldn't care less about roller tests, but this forum devolves into MAMIL posturing matches with depressing frequency.
Danhedonia is offline  
Old 01-20-21, 06:13 AM
  #80  
Kapusta
Cyclochondriac
 
Join Date: Feb 2017
Posts: 4,085
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1753 Post(s)
Liked 1,017 Times in 612 Posts
Originally Posted by Danhedonia View Post
Geez, didn't you want to keep bleating "I'm waiting" like a 2nd grade teacher ... until an authority shows up? Then your manner changes.
No, because I am not waiting anymore. I got what I was looking for: a knowledgeable explanation (Thanks, Rchung)

That discussion ended 5 days ago. Do you really want to drag this up again and keep it going?
Kapusta is offline  
Old 01-20-21, 06:18 PM
  #81  
Danhedonia
Senior Member
 
Join Date: Jul 2018
Posts: 356
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 209 Post(s)
Liked 154 Times in 84 Posts
Five days is the blink of an eye for threads on this forum. Unless, I guess, you spend your days snapping at people that you're waiting on their posts?

I think it would have gone down easier if you simply manned up and said you got your ass handed to you.
Danhedonia is offline  
Old 01-20-21, 09:10 PM
  #82  
Kapusta
Cyclochondriac
 
Join Date: Feb 2017
Posts: 4,085
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 1753 Post(s)
Liked 1,017 Times in 612 Posts
Originally Posted by Danhedonia View Post
Five days is the blink of an eye for threads on this forum. Unless, I guess, you spend your days snapping at people that you're waiting on their posts?

I think it would have gone down easier if you simply manned up and said you got your ass handed to you.
Wow, you really DO want to keep this going

You actually want to have an argument about an argument..... that you were not even part of.

Yeah, BF at its finest, here.

Last edited by Kapusta; 01-20-21 at 09:56 PM.
Kapusta is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.