Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

A (Non-Scientific) Tires/Wheels Experiment

Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

A (Non-Scientific) Tires/Wheels Experiment

Old 05-17-15, 08:16 AM
  #1  
DaveLeeNC
Senior Member
Thread Starter
 
Join Date: Jan 2011
Location: Pinehurst, NC, US
Posts: 1,191

Bikes: 90's Vintage EL-OS Steel Bianchi-2014 Campy Chorus Upgrade

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked 11 Times in 10 Posts
A (Non-Scientific) Tires/Wheels Experiment

I own/ride a nice (in its day) mid 90's Bianchi frame road bike (EL-OS Nivacrom steel) that is 'original' except for some serious upgrades in 2014 (Campy Chorus 11sp, 50/34 chainring, seat/seatpost, and new wheels). The original wheels (Mavic rims, 32sp, Campy hub) on the front and new hub and 11sp freewheel on the rear now have 25mm Gatorskin tires and butyl tubes. I use those when I ride this bike doing 'local errands' (I'm in the middle of a 'one car experiment'). This set has a Chorus 12/25 cassette.


My 'real wheels' are Bontrager RXL (not carbon, BTW) with 23mm Bontrager AW3 hardcase Lite tires and latex tubes (although the RXL's are tubeless ready). FWIW, this set has an 11/27 cassette - yeah, I'm not sure that the 11t cog is that useful, but then I'm not sure that adding a 16t cog is that big a deal either. Pic attached just for grins. And if you strip it down as a new bike would be marketed (no pedals, cages, gauges, etc) it weighs in at BARELY under 18 pounds, so I can claim this as a '17 pound bike' .

Yesterday's "plan" was an easy or off day. So I decided to do an A/B test as follows. I picked a 8-9 mile local route with no stops (and breezes were VERY light yesterday). I started with the older Mavic set of wheels and tried to ride this route as a 'easy but steady ride'. Like everything around here it is all lightly rolling terrain (hardly ever flat for any distance but a 1 min. climb is long). I have Garmin Vector S pedals and a Garmin 800 computer.

Then I swapped out the wheels and tried my best to exactly repeat the ride. I would like to think that I came relatively close as the average power came out exactly the same (to the nearest watt anyway).

Here is a summary of the results.

1) The Mavic/Gatorskin combo (with skewers and cassette) weighs almost exactly 1 pound more than the Bontrager stuff. And it is mostly all rotating (at the rim) weight.

2) The times were 29:34 on the old Mavic/Gatorskin stuff vs. 28:38 with the Bontrager stuff (note - same average power)

3) There is a noticeable difference between riding the two sets of wheels/tires/tubes. "Responsiveness" felt obviously (and instantaneously) better with the Bontrager stuff. And note that I am NOT a sophisticated and experienced roadie. It must be rotating weight as it was more than just the equivalent of an extra (full) water bottle (around a pound). It just felt different (and better).

4) The ride comfort difference was not hugely obvious until I got to Chicken Plant Rd. That was close to intolerable in places on the Gatorskins (note - this road is in good repair but IMHO you have to do extra work to make chipseal stuff this rough). It was 'only' very unpleasant on the Bontrager stuff. BTW, both sets of tires were pumped to 90 pounds so there was probably a tad of rideability available from the slightly larger Gatorskins with a bit less pressure.

FWIW.

dave
Attached Images
File Type: jpg
AfterSide2.jpg (53.1 KB, 21 views)
DaveLeeNC is offline  
Old 05-17-15, 08:23 AM
  #2  
gregf83 
Senior Member
 
Join Date: Jun 2008
Location: Vancouver, BC
Posts: 8,752
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 896 Post(s)
Liked 22 Times in 16 Posts
Doesn't sound surprising. Lower rolling resistance tires are faster. Difference would have been a little closer if you'd run the 25s at a lower pressure. Lower weight would have made a negligible difference.
gregf83 is offline  
Old 05-17-15, 08:28 AM
  #3  
chaadster
Thread Killer
 
Join Date: Aug 2008
Location: Ann Arbor, MI
Posts: 9,321

Bikes: '15 Kinesis Racelight 4S, '76 Motebecane Gran Jubilée, '17 Dedacciai Gladiatore2, '12 Breezer Venturi, '09 Dahon Mariner, '05 Novara Big Buzz, '12 Mercier Nano, '95 DeKerf Team

Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 1026 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
What was comparative power and time over the Chicken Plant segment for each wheelset? Just curious if, despite the Contis being less comfy, the width let you roll faster.
chaadster is offline  
Old 05-17-15, 09:41 AM
  #4  
DaveLeeNC
Senior Member
Thread Starter
 
Join Date: Jan 2011
Location: Pinehurst, NC, US
Posts: 1,191

Bikes: 90's Vintage EL-OS Steel Bianchi-2014 Campy Chorus Upgrade

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked 11 Times in 10 Posts
Originally Posted by chaadster View Post
What was comparative power and time over the Chicken Plant segment for each wheelset? Just curious if, despite the Contis being less comfy, the width let you roll faster.
Interesting question. For that segment the Gatorskin tires 'saw' 1W more than the Bontrager's 'saw' (call it a wash). I went 3.4% faster on the Bontrager's where for the whole ride, while I rode virtually the same speed on the Bontrager's on the chipseal. And FWIW this is easily the steepest (both up and down) and least flat portion of the route. It is 1.64 miles long.

So on a relative basis I would judge that the Gatorskins' relative performance (if you can stand it) was a tad better on rough surfaces.

dave
DaveLeeNC is offline  
Old 05-17-15, 10:25 AM
  #5  
Fiery
Senior Member
 
Fiery's Avatar
 
Join Date: Oct 2010
Posts: 1,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 218 Post(s)
Liked 0 Times in 0 Posts
Originally Posted by DaveLeeNC View Post
It must be rotating weight as it was more than just the equivalent of an extra (full) water bottle (around a pound).
Not necessarily. I recently had the chance to test ride a couple of Williers - Zero7 and Cento1 Air - back to back. Same frame size, very similar positon, same tyres. The Zero7 is a lighter frame and it had lighter wheels with most of the difference being in the rims. The Cento1 still felt lighter and quicker. In this case the slight differences in frame stiffnes and geometry played a part for sure, but I think a lot of it was wheel (or maybe just rim) stiffness as well.
Fiery is offline  
Old 05-17-15, 10:57 AM
  #6  
wphamilton
Senior Member
 
wphamilton's Avatar
 
Join Date: Apr 2011
Location: Alpharetta, GA
Posts: 14,541

Bikes: Nashbar Road

Mentioned: 65 Post(s)
Tagged: 0 Thread(s)
Quoted: 2509 Post(s)
Liked 56 Times in 34 Posts
I think that you should repeat the A/B test, but using the same bike for both runs to determine whether factors other than the bike may be involved. For example, you may have been more warmed up after the first 8-9 miles. You may be more efficient later in the day. Or other factors.
wphamilton is offline  
Old 05-17-15, 01:53 PM
  #7  
DaveLeeNC
Senior Member
Thread Starter
 
Join Date: Jan 2011
Location: Pinehurst, NC, US
Posts: 1,191

Bikes: 90's Vintage EL-OS Steel Bianchi-2014 Campy Chorus Upgrade

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked 11 Times in 10 Posts
Originally Posted by wphamilton View Post
I think that you should repeat the A/B test, but using the same bike for both runs to determine whether factors other than the bike may be involved. For example, you may have been more warmed up after the first 8-9 miles. You may be more efficient later in the day. Or other factors.
A number of things could be done to create a 'better controlled' experiment. HOWEVER, one of them WILL NOT be another ride on Chicken Plant Road and those Gatorskin tires/wheels

But measured power is measured power - I'm not sure what being warmed up or not would have to do with that. A different power profile (that created the same avg power) - maybe.

dave
DaveLeeNC is offline  
Old 05-17-15, 07:35 PM
  #8  
wphamilton
Senior Member
 
wphamilton's Avatar
 
Join Date: Apr 2011
Location: Alpharetta, GA
Posts: 14,541

Bikes: Nashbar Road

Mentioned: 65 Post(s)
Tagged: 0 Thread(s)
Quoted: 2509 Post(s)
Liked 56 Times in 34 Posts
Originally Posted by DaveLeeNC View Post
A number of things could be done to create a 'better controlled' experiment. HOWEVER, one of them WILL NOT be another ride on Chicken Plant Road and those Gatorskin tires/wheels

But measured power is measured power - I'm not sure what being warmed up or not would have to do with that. A different power profile (that created the same avg power) - maybe.

dave
That's true, I didn't notice that "Vector S" pedals are power meters.

But certainly the difference would be in where the power is expended if the total power was the same, and I could see that varying from your physical state as easily, or more easily, than from a pound or two extra.

Last edited by wphamilton; 05-17-15 at 07:45 PM.
wphamilton is offline  
Old 05-17-15, 07:42 PM
  #9  
RChung
Senior Member
 
Join Date: Sep 2009
Posts: 1,493
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 291 Post(s)
Liked 26 Times in 18 Posts
Originally Posted by wphamilton View Post
That's true, but since you didn't really measure power and went by perceived effort (or did you use a power meter, that isn't clear?), being warmed up probably has a lot to do with it.
He said in his post that he has the Vector S.

That means he's already got the data he needs to do a reasonable analysis, if he wanted to.
RChung is offline  
Old 05-17-15, 07:44 PM
  #10  
DaveLeeNC
Senior Member
Thread Starter
 
Join Date: Jan 2011
Location: Pinehurst, NC, US
Posts: 1,191

Bikes: 90's Vintage EL-OS Steel Bianchi-2014 Campy Chorus Upgrade

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 178 Post(s)
Liked 11 Times in 10 Posts
Originally Posted by wphamilton View Post
That's true, but since you didn't really measure power and went by perceived effort (or did you use a power meter, that isn't clear?), being warmed up probably has a lot to do with it.
Maybe I should have been more explicit, but when I said that "the average power came out exactly the same (to the nearest watt, anyway)", that was from a power meter.

dave
DaveLeeNC is offline  
Old 05-17-15, 07:49 PM
  #11  
wphamilton
Senior Member
 
wphamilton's Avatar
 
Join Date: Apr 2011
Location: Alpharetta, GA
Posts: 14,541

Bikes: Nashbar Road

Mentioned: 65 Post(s)
Tagged: 0 Thread(s)
Quoted: 2509 Post(s)
Liked 56 Times in 34 Posts
Originally Posted by RChung View Post
He said in his post that he has the Vector S.

That means he's already got the data he needs to do a reasonable analysis, if he wanted to.
Yes I went back and double-checked after I posted that, and corrected it.
wphamilton is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bloodfont
General Cycling Discussion
14
05-18-17 10:12 AM
ruirui
Forum Suggestions & User Assistance
0
08-10-04 04:15 PM
Gustaf
Road Cycling
2
11-24-03 09:12 PM

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

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.