Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Blog NEW Galleries NEW FAQ Contact About Impressum
It is currently Sat Dec 03, 2016 2:48 pm
Recently the board software has been updated and there are some known bugs/failures:
- Avatars are currently not being displayed ✔ FIXED
- Tapatalk connection is currently broken ✔ FIXED
- Avatars cannot be uploaded ✔ FIXED

Please note that we will soon do some changes in WW board template design in case to get a fully mobile/desktop responsiveness board!
If you find more errors please post it here: http://weightweenies.starbike.com/forum/viewtopic.php?f=7&t=139062


All times are UTC+01:00





Post new topic  Reply to topic  [ 24 posts ]  Go to page 1 2 Next
Author Message
PostPosted: Mon Dec 10, 2012 5:01 pm 
Offline

Joined: Mon Nov 07, 2011 5:46 am
Posts: 225
I have no idea how good these tires are in the extra legere version, but the weight is pretty spectacular. 181 grams for the 23 mm tires and 232 grams for the 32 mm version.

I've used the regular versions of both the 23 and 32 and they are really nice tires. Hopefully the extra light versions will be just as good.

_________________
Riding the Catskills


Top
   
PostPosted: Mon Dec 10, 2012 6:12 pm 
Offline

Joined: Tue Jun 23, 2009 10:47 pm
Posts: 227
The same place that sells those tires has some good information on rolling resistance:

http://janheine.wordpress.com/2012/06/1 ... -of-tires/


Top
   
Posted: Mon Dec 10, 2012 6:12 pm 


Top
   
 
PostPosted: Mon Dec 10, 2012 9:21 pm 
Offline
User avatar

Joined: Wed Sep 26, 2007 1:57 pm
Posts: 7917
Location: San Francisco, CA
I regret they're not available in 26 mm. I'm sold on 26 versus 23. The regular Grand Bois are really good tires: supple and decent puncture resistance until the tread wears too thin, then they become puncture prone. But I've gotten good life out of the ones I've gotten.

_________________
http://djconnel.blogspot.com/
Fuji SL/1


Top
   
PostPosted: Mon Dec 10, 2012 10:48 pm 
Offline

Joined: Mon Nov 07, 2011 5:46 am
Posts: 225
Agree. 26 mm extra legere would be nice. If it helps any, though, the regular Col de la Madelaine 23 mm tires actually measure 24.5 mm on Enve 3.4s freshly mounted, and the Grand Bois tires have a tendency to expand a mm or two over time. Haven't measured them recently because I moved and can't find my caliper!

John

_________________
Riding the Catskills


Top
   
PostPosted: Tue Dec 11, 2012 12:44 am 
Offline
Tubbie Guru

Joined: Tue May 03, 2005 2:20 am
Posts: 5850
Location: Belgium
Hi,

Estelja wrote:
The same place that sells those tires has some good information on rolling resistance:

http://janheine.wordpress.com/2012/06/1 ... -of-tires/" onclick="window.open(this.href);return false;


They seem to have convinced themselves allright...... :?

A mild case of not seeing the trees for the forest if you'd ask me.

Ciao, ;)

_________________
Being a snob is an expensive hobby.


Top
   
PostPosted: Tue Dec 11, 2012 1:40 am 
Offline

Joined: Mon May 30, 2005 7:13 am
Posts: 1536
I don't know exactly what fdegrove is saying, but I will say this; I wouldn't automatically throw width out the window as the article seems to, if you are interested in fast paced riding. The difference between say a 23mm tire and a 27mm tire on the FC Zipp 303s can even be pretty huge, like 10 watts at 10-15 degrees of yaw, which at least from data I've seen is typically larger than the rolling resistance differences between a same brand and design 23 and 27mm tire.


Top
   
PostPosted: Tue Dec 11, 2012 2:53 am 
Offline
Tubbie Guru

Joined: Tue May 03, 2005 2:20 am
Posts: 5850
Location: Belgium
Hi,

That's just one aspect, one which you'll need to take into account once you're reaching a certain level of wind resistance.
I would not be surprised to learn that the difference in wind resistance as seen by say, a 23mm compared to the 27mm version of the same tyre is far bigger than 10 to 15 Watt at higher speeds in a wind free environment already.
Either way, let's just assume that windresistance was not the target of the test.

If you want to measure rolling resistance than the protocol should be the same for every tyre within the apples to apples and oranges to oranges range. Carrying out such tests is far more easy to do and far more precise in a controlled environment.
From that prespective the lab tests as carried out by Tour magazine are scientifically far more valid than any such test carried out on a road.

Whether or not the tyre sees a fixed load (brick of lead fror instance) or a rider + a road as load isn't relevant at all for measuring rolling resistance either for as long as the load is the same for all devices under test. Something you can't be sure of when testing outdoors on a strip of road.
Point is that the relative order of difference between the test participants should and will be absolutely the same in both tests. The absolute figures may differ yet the differences should remain.

In short, there are a number of remarks and conclusions in that article that just goes to show that there's nothing new under the sun; setting up tests is one thing, drawing the right conclusions is quite another....

Plus ca change.....

Ciao, ;)

_________________
Being a snob is an expensive hobby.


Top
   
PostPosted: Tue Dec 11, 2012 3:16 am 
Offline
User avatar

Joined: Wed Oct 31, 2007 10:32 pm
Posts: 8349
Location: Los Feliz, Los Angeles, California
Just someone tell me what the ultimate tire and wheel combo to buy for all conditions at all times and under all riders.

Image

_________________
Exp001 || Other projects in the works.


Top
   
PostPosted: Tue Dec 11, 2012 3:41 pm 
Offline

Joined: Sun Nov 25, 2012 5:45 am
Posts: 25
Anyone planning on getting the 23s? Curious how they would compare to say Conti 4000s's


Top
   
PostPosted: Tue Dec 11, 2012 4:19 pm 
Offline
User avatar

Joined: Tue Aug 08, 2006 1:41 pm
Posts: 853
Location: The Netherlands
I agree with fdegrove. This kind of testing is pretty silly.

_________________
My Renovo R1 wooden bike project and the reason for my passion for all that is wood.

Check it out: the most amazing vintage Colnago, Merckx and Pinarello collection


Top
   
PostPosted: Tue Dec 11, 2012 4:34 pm 
Offline

Joined: Tue Apr 12, 2011 8:08 am
Posts: 2292
Location: Pedal Square
From a bird's eye perspective, the testing protocol doesn't seem less in touch with reality than rolling on a steel drum. What do you not agree with specifically, SWijland?

_________________
Bikes: Raw Ti, 650b flatbar CX


Top
   
PostPosted: Tue Dec 11, 2012 6:10 pm 
Offline

Joined: Mon Nov 07, 2011 5:46 am
Posts: 225
Agree. Testing on a steel drum may be more accurate and reproducible, but it has little, if any, relationship to real world use.

You can poke holes in Jan's methodology, but how else are you going to perform the experiment under conditions approximating actual roads? Although they didn't specify their methods, one of the testers is a statistician and ran a presumably valid statistical analysis on the results. The differences were significant. This is a powerful argument that the results that they are seeing are highly likely to be real.

I haven't seen the Tour steel drum test (and I can't read German, anyway) but I'm betting that their experimental methods were shakier than Jan's, and I'm also willing to bet that they did not do a statistical analysis of their results.

I'd suggest that you read the actual papers before passing judgement. Although I disagree with a significant amount of what I read in Bicycle Quarterly, Jan and his fellow testers deserve to be commended for actually attempting to do an analysis that approximates actual riding conditions.

_________________
Riding the Catskills


Top
   
PostPosted: Tue Dec 11, 2012 6:16 pm 
Offline

Joined: Mon May 30, 2005 7:13 am
Posts: 1536
xrs2 wrote:
Agree. Testing on a steel drum may be more accurate and reproducible, but it has little, if any, relationship to real world use.


That's funny because people have found high correlation between Al Morrison's extensive roller data and use in field testing...


Top
   
PostPosted: Tue Dec 11, 2012 6:29 pm 
Offline
in the industry
User avatar

Joined: Sun Jul 29, 2012 2:59 pm
Posts: 855
Location: Ruidoso, NM
fdegrove wrote:
Carrying out such tests is far more easy to do and far more precise in a controlled environment.
From that prespective the lab tests as carried out by Tour magazine are scientifically far more valid than any such test carried out on a road.


That "road" test simply has too many confounding variables... wind being a huge one, plus body position, different wheels, etc. These are easily great enough to swamp any Crr numbers.

_________________
formerly rruff...


Top
   
Posted: Tue Dec 11, 2012 6:29 pm 


Top
   
 
PostPosted: Tue Dec 11, 2012 6:41 pm 
Offline

Joined: Mon Nov 07, 2011 5:46 am
Posts: 225
NGMN wrote:
xrs2 wrote:
Agree. Testing on a steel drum may be more accurate and reproducible, but it has little, if any, relationship to real world use.


That's funny because people have found high correlation between Al Morrison's extensive roller data and use in field testing...


Could you please point out the study where they correlated roller data and use in field testing. I'd love to see the methodology because I haven't seen these data.

_________________
Riding the Catskills


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 24 posts ]  Go to page 1 2 Next

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Giving up extra gears for Di2

in Road

photocycler

8

830

Mon May 23, 2016 4:54 am

mattyNor View the latest post

There are no new unread posts for this topic. Switching from Speedplay to SPD-SL: Extra Leg Fatigue

in Road

KS59

10

824

Wed May 04, 2016 8:31 pm

Rick View the latest post

There are no new unread posts for this topic. EVOC bike bag - extra wheel set?

in Road

Donic

6

472

Fri Sep 30, 2016 4:47 pm

mattr View the latest post

There are no new unread posts for this topic. 23 mm tires on a C17 (25 mm) rim

in Road

speedyvelo1

7

651

Fri Jul 08, 2016 12:37 pm

dj97223 View the latest post

There are no new unread posts for this topic. Help with tires

in Road

isarug

2

327

Mon Aug 08, 2016 10:34 pm

isarug View the latest post


All times are UTC+01:00


Who is online

Users browsing this forum: alistaird, Bing [Bot], catpoison, CLEAR, Fluoro7, MSNbot Media and 29 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited