HOT: Active* forum members generally gain 5% discount at starbike.com store!
Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Articles FAQ Contact About




Post new topic Reply to topic  [ 34 posts ] 
Go to page Previous  1, 2, 3  Next
Author Message
PostPosted: Sun Aug 19, 2012 5:10 pm 
Offline

Joined: Tue Sep 20, 2011 8:15 pm
Posts: 177
This is stupid and pointless. No one here ACTUALLY has the means to check scientifically how stiff their frame is, let alone even really tell a difference between frame X and frame Y which is stiffer. Something as small as a slightly higher tire PSI will be mistaken for a bike seeming stiffer because it rides harder. There are just too many other variable to just guess like this.

Anyway... nearly all oversized, overbuilt modern carbon frames are plenty stiff for you. If you need stiffer, go custom.


Top
 Profile  
 
PostPosted: Sun Aug 19, 2012 5:26 pm 
Offline
in the industry
User avatar

Joined: Sun Dec 16, 2007 9:33 pm
Posts: 713
Location: Luxembourg / Sweden
The stiffest bb measured by Zedler/tour has been the Specialized Tarmac at 72Nmm. Then there are quite a few bikes measured at 71Nmm. The Cannondale mentioned is actually quite compliant in the bb area but very stiff around the headtube where the S/W ratio is calculated.
I said has been.
A few days ago Zedler Institute measured a carbon bike at 91Nmm bb stiffness.

_________________
Technical Artisans


Top
 Profile  
 
Posted: Sun Aug 19, 2012 5:26 pm 


Top
  
 
PostPosted: Sun Aug 19, 2012 5:34 pm 
Offline

Joined: Sat Aug 27, 2011 3:26 am
Posts: 388
Location: Sydney, Australia
sounds promising...


Top
 Profile  
 
PostPosted: Sun Aug 19, 2012 5:43 pm 
Offline

Joined: Fri Oct 07, 2011 2:08 pm
Posts: 1365
I like to have some flex . I think the bike reacts a bit more to your movement and reacts with you. If a bike is to stiff it feels like you are fighting it.


Top
 Profile  
 
PostPosted: Sun Aug 19, 2012 5:50 pm 
Offline
in the industry
User avatar

Joined: Sun Dec 16, 2007 9:33 pm
Posts: 713
Location: Luxembourg / Sweden
The right flex is indeed highly personal and dependent on weight, power output, riding style, properties prioritized in a frame, personal preferences in 'feel' etc, etc.. Quite a few pros demand ultra stiff frames however.

_________________
Technical Artisans


Top
 Profile  
 
PostPosted: Sun Aug 19, 2012 9:34 pm 
Offline

Joined: Thu Mar 08, 2012 11:43 pm
Posts: 515
DartanianX wrote:
Stiffest bike in it's entirety would have to be the Ridley Noah.


Why?


Top
 Profile  
 
PostPosted: Sun Aug 19, 2012 10:00 pm 
Offline

Joined: Mon Jan 24, 2011 8:09 pm
Posts: 714
DartanianX wrote:
Stiffest bike in it's entirety would have to be the Ridley Noah.


Nope. Scott Foil and Venge are stiffer than that bike.


Top
 Profile  
 
PostPosted: Mon Aug 20, 2012 12:05 am 
Offline

Joined: Mon May 24, 2010 4:18 am
Posts: 366
Location: Australia
Litespeed Ghisallo would have to be up there too. Probably not top of the list, but certainly near the top.

:thumbup:


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 1:35 am 
Offline
User avatar

Joined: Sun Sep 03, 2006 1:55 pm
Posts: 1838
Location: Western Australia
Ah, trolls be trolling.


In all honesty it doesn't really matter as long as it is stiff enough to not ghost shift (so don't buy a Merida Scultura).

Get a frame that fits well. Test ride a few. See which ones you like. The bike that rides the best may not be the 'stiffest' bike.

Also, if you're trying to save weight, pick a light frame. Otherwise, ignore the weight, since frames are all 'light' at the top end these days and since it makes the heart of the bike, save weight elsewhere.

_________________
Cyclist turned music producer

Visiting South West Australia? Visit Crank n' Cycles!


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 5:50 am 
Offline
User avatar

Joined: Tue Nov 20, 2007 7:18 pm
Posts: 588
Location: Lyon
andy2 wrote:
The stiffest bb measured by Zedler/tour has been the Specialized Tarmac at 72Nmm. Then there are quite a few bikes measured at 71Nmm. The Cannondale mentioned is actually quite compliant in the bb area but very stiff around the headtube where the S/W ratio is calculated.
I said has been.
A few days ago Zedler Institute measured a carbon bike at 91Nmm bb stiffness.


Image

Results from RoadBike.de results from some time ago, pretty different testing methodologies if the 72N/mm is the highest value achieved

I don't agree about you comment about preferences in BB stiffness. The main problem is that with traditional double diamond frames you are coupling BB stiffness with rear end compliance, the parameter that many riders use to define frame comfort. In my book, a stiffer BB is always positive

_________________
BIKE DESIGN AND +

http://cds-0.blogspot.com/


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 6:03 am 
Offline

Joined: Sat Jun 02, 2007 1:10 am
Posts: 1843
Location: Melbourne, Australia
who are red bull buying bikes form these days? last I saw they were buying the rights to other ppls frames - not open mold as such, just buying the rights to use some ones else's very good frames.

_________________
http://www.blingmybike.com.au - Shiny light weight bike parts


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 6:58 am 
Offline
in the industry
User avatar

Joined: Sun Dec 16, 2007 9:33 pm
Posts: 713
Location: Luxembourg / Sweden
We use the Zedler no:s because they are widely accepted industry standards. They have also tested hundreds of bikes using the same protocol for years making for a huge base if data. We don't agree on the absolute relevance on how he calculates the bb stiffness, but it is the current apples to apples test.

Comfort is indeed a different spec mainly defined by flex on the seattube / post.
But as as you know bb stiffness is not about the bb flexing but rather the down tube and chainstays bending torsionally. Also the infamous vertical compliance in the main triangle is factored in the Zedler bb flex figure. Torsional flex in the downtube may also give some bump absorbing properties (comfortableTi frames).

Best

/a

_________________
Technical Artisans


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 7:37 am 
Offline
User avatar

Joined: Tue Nov 20, 2007 7:18 pm
Posts: 588
Location: Lyon
Comfort can come from two approaches, isolating the bike (vertical compliance of the rear end) or isolating the rider (seat tube flex)

andy2 wrote:
But as as you know bb stiffness is not about the bb flexing but rather the down tube and chainstays bending torsionally. Also the infamous vertical compliance in the main triangle is factored in the Zedler bb flex figure.


It's the first time that I hear about vertical compliance of the main triangle. Can you comment in detail how they factor this figure?

_________________
BIKE DESIGN AND +

http://cds-0.blogspot.com/


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 7:50 am 
Offline
in the industry
User avatar

Joined: Sun Dec 16, 2007 9:33 pm
Posts: 713
Location: Luxembourg / Sweden
If you pm me we can go into detail about this.
Zedler factors the vertical component along with the sideway component (pendulum movement) of the bb. The top tube will flex some under vertical load, yes.

_________________
Technical Artisans


Top
 Profile  
 
PostPosted: Tue Aug 21, 2012 4:51 pm 
Offline
User avatar

Joined: Thu Feb 02, 2006 10:26 pm
Posts: 540
Location: NoVA
HammerTime2 wrote:
Ramjm_2000, are you confusing stiffness with stiffness to weight ratio?


Nope. Highest score ever given...period.


Top
 Profile  
 
Posted: Tue Aug 21, 2012 4:51 pm 


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 34 posts ] 
Go to page Previous  1, 2, 3  Next


Who is online

Users browsing this forum: Bing [Bot], clarkson, Exabot [Bot], farva, Google Adsense [Bot], NiFTY, pmclamb, RedRacer and 41 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:  

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. 2014 Carbon Bike w/ Ultegra Di2 Choices?

in Road

ajwu11

12

1765

Mon Mar 24, 2014 6:49 pm

johnnyscans View the latest post

There are no new unread posts for this topic. Frame failure Carbon Road Bike

[ Go to page: 1, 2 ]

in Road

Tucker13

24

2249

Sun Aug 17, 2014 7:27 pm

mattr View the latest post

There are no new unread posts for this topic. Light bike or stiff bike?

[ Go to page: 1, 2, 3 ]

in Road

Kermithimself

32

2479

Mon Sep 22, 2014 7:19 pm

06SpiceRed View the latest post

There are no new unread posts for this topic. Why you need to inspect carbon. ( Carbon failure)

[ Go to page: 1, 2 ]

in Road

Juanmoretime

18

3561

Thu Aug 07, 2014 1:45 am

Juanmoretime View the latest post

There are no new unread posts for this topic. My next bike. SL3 or SL4?

in Road

Iamspecialized

13

873

Sat May 17, 2014 6:34 am

mpulsiv View the latest post


It is currently Thu Oct 02, 2014 4:57 am

All times are UTC + 1 hour




Advertising   –  FAQ   –  Contact   –  Convert   –  About

© Weight Weenies 2000-2013
hosted by starbike.com


How to get rid of these ads? Just register!


Powered by phpBB