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

Triple monocoque = 3 monocoques ? (Specialzied Tarmac)

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

Triple monocoque = 3 monocoques ? (Specialzied Tarmac)

Old 06-06-10, 01:53 PM
  #1  
mustang1
Senior Member
Thread Starter
 
mustang1's Avatar
 
Join Date: Jul 2006
Location: London, UK
Posts: 2,719

Bikes: 2006 road bike, 2012 cx bike, 2012 carbon rb, 2014 hardtail

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked 0 Times in 0 Posts
Triple monocoque = 3 monocoques ? (Specialzied Tarmac)

On Specialized's website, it describes Tarmac frame as:
"Specialized FACT 6r carbon triple monocoque frame"

What does that mean? I thought the whole point of monocoque means singular (mono = one unit) so when they write triple monocoque, what is that?
mustang1 is offline  
Old 06-06-10, 02:21 PM
  #2  
993guy
free-basing user
 
993guy's Avatar
 
Join Date: Dec 2006
Location: Exton, PA
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I thought it was because they use three molds to make the frame?
993guy is offline  
Old 06-06-10, 02:54 PM
  #3  
SwingBlade
Here to Learn
 
SwingBlade's Avatar
 
Join Date: Apr 2010
Location: SoCal, USA
Posts: 220

Bikes: 2008 Specialized S-works Tarmac SL & Specialized Hybrid

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Explanation of "Triple Monocoque" by Specialized

The Roubaix design uses a monocoque (one-piece) structure for the entire
front triangle. The chainstays and seatstays are each individual monocoque structures.
The chainstays and seatstays are bonded to the front triangle and then over-wrapped
with carbon (a tow) where the sections come together, to form strong and secure joints.
Note: we call this construction method a triple monocoque, since three monocoque
subsections are molded into a single piece. Note: This is a far more secure construction
than the simple bonded joints many of our com petitors use. If designed properly, this
method adds no weight and creates a more secure structure. Given this painstaking
process, only ten Roubaix frames can be made per day from each tool (size).

A Digression: Why Is A Monocoque Better? By making a single lay-up for the entire
front triangle, bonding of lugs and tubes is eliminated. This has a number of advantages:
· Stress concentration at the end of the lug is eliminated with monocoque.
· There is no chance for bonding problems, poor glue fill and uneven glue thickness
around the bond (depends on accuracy of bonding fixturing)
· Less chance that the frame will be out of alignment (since it’s less dependent on
fixturing than a bonded frame)
· No redundant overlapping structures putting unneeded material (weight) material in
the wrong places. Bottom line: more strength/stiffness, less weight (note the charts
that follow to see for yourself)
· Since there are no bonds, the paint won’t crack down the road. (Bonded joints are
famous for paint cracking problems. )
· Carbon lugs are difficult to make really good and light (but easy to make heavy
and/or poorly).

Tarmac (Carbon). The new all-carbon Tarmac is made in the same triple monocoque
construction method as our Roubaix frames, but from a completely different layup
schedule, which, in addition to its tighter wheelbase and more upright steering geometry,
gives the Tarmac a completely different ride and road feel.

Note 2: Technically, a monocoque is any structure where loads are carried on the skin of the structure, i.e., there are no internal supporting members. By this definition all standard bicycle frames are monocoques. However, in composites, the term is more generally used to mean “single-piece”.

Last edited by SwingBlade; 06-06-10 at 06:51 PM.
SwingBlade is offline  
Old 06-06-10, 03:29 PM
  #4  
993guy
free-basing user
 
993guy's Avatar
 
Join Date: Dec 2006
Location: Exton, PA
Posts: 105
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
DAMN!

Looks like someone slept at a Holiday Inn Express last night!
993guy is offline  
Old 06-06-10, 03:36 PM
  #5  
kindablue
Fly on the wall
 
Join Date: Jun 2009
Location: Colorado Springs
Posts: 981

Bikes: a few

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by SwingBlade View Post
The Roubaix design uses a monocoque (one-piece) structure for the entire
front triangle. The chainstays and seatstays are each individual monocoque structures.
The chainstays and seatstays are bonded to the front triangle and then over-wrapped
with carbon (a tow) where the sections come together, to form strong and secure joints.
Note: we call this construction method a triple monocoque, since three monocoque
subsections are molded into a single piece. Note: This is a far more secure construction
than the simple bonded joints many of our com petitors use. If designed properly, this
method adds no weight and creates a more secure structure. Given this painstaking
process, only ten Roubaix frames can be made per day from each tool (size).

A Digression: Why Is A Monocoque Better? By making a single lay-up for the entire
front triangle, bonding of lugs and tubes is eliminated. This has a number of advantages:
· Stress concentration at the end of the lug is eliminated with monocoque.
· There is no chance for bonding problems, poor glue fill and uneven glue thickness
around the bond (depends on accuracy of bonding fixturing)
· Less chance that the frame will be out of alignment (since it’s less dependent on
fixturing than a bonded frame)
· No redundant overlapping structures putting unneeded material (weight) material in
the wrong places. Bottom line: more strength/stiffness, less weight (note the charts
that follow to see for yourself)
· Since there are no bonds, the paint won’t crack down the road. (Bonded joints are
famous for paint cracking problems. )
· Carbon lugs are difficult to make really good and light (but easy to make heavy
and/or poorly).

Tarmac (Carbon). The new all-carbon Tarmac is made in the same triple monocoque
construction method as our Roubaix frames, but from a completely different layup
schedule, which, in addition to its tighter wheelbase and more upright steering geometry,
gives the Tarmac a completely different ride and road feel.

Note 2: Technically, a monocoque is any structure where loads are carried on the skin of the structure, i.e., there are no internal
supporting members. By this definition all standard bicycle frames are monocoques. However, in composites, the term is
more generally used to mean “single-piece”.
Is this why specialized hasn't jumped on the whole internal cable routing fad?
kindablue is offline  
Old 06-06-10, 03:59 PM
  #6  
SwingBlade
Here to Learn
 
SwingBlade's Avatar
 
Join Date: Apr 2010
Location: SoCal, USA
Posts: 220

Bikes: 2008 Specialized S-works Tarmac SL & Specialized Hybrid

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Makes sense to me. In aviation, monocoque refers to stressed metal skin which absorbs most or all of the stresses to which the frame/body is subjected in flight. It means the stressed skin (monocoque fuselage) is performing much of the same functions as might otherwise be performed by heavier and more dense structural frame members. To what extent the term monocoque has the same meaning in bicycle framework is beyond my pay grade.
SwingBlade is offline  
Old 06-06-10, 04:02 PM
  #7  
Sourpuss Magee
Senior Member
 
Sourpuss Magee's Avatar
 
Join Date: Jul 2009
Location: Middlesex
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
My mind is going to explode.
Sourpuss Magee is offline  
Old 06-06-10, 06:39 PM
  #8  
johnny99
Senior Member
 
Join Date: Apr 2005
Location: Northern California
Posts: 10,867
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 101 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
I think all monocoque carbon frames are made by molding the triangles separately, then bonding them together. No idea why Specialized has started calling this technique "triple monocoque".
johnny99 is offline  
Old 06-06-10, 06:48 PM
  #9  
SwingBlade
Here to Learn
 
SwingBlade's Avatar
 
Join Date: Apr 2010
Location: SoCal, USA
Posts: 220

Bikes: 2008 Specialized S-works Tarmac SL & Specialized Hybrid

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by johnny99 View Post
I think all monocoque carbon frames are made by molding the triangles separately, then bonding them together. No idea why Specialized has started calling this technique "triple monocoque".
If you read the first paragraph of their layman's explanation above, I think you will get a basic understanding of what they do beyond simple molding and bonding.
SwingBlade is offline  
Old 06-06-10, 08:04 PM
  #10  
nitropowered
Senior Member
 
Join Date: Dec 2004
Location: Athens, Ohio
Posts: 5,104

Bikes: Custom Custom Custom

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Who doesn't make their front triangle, then stays separately these days.

Its just a bunch of marketing BS.

Just buy the bike that fits you the best and you can get the best deal on
nitropowered is offline  
Old 06-06-10, 08:44 PM
  #11  
pigmode
works for truffles
 
pigmode's Avatar
 
Join Date: Jun 2002
Posts: 2,038
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by SwingBlade View Post
To what extent the term monocoque has the same meaning in bicycle framework is beyond my pay grade.


Its pretty obvious that here the three tubes and tube joints in the fore-triangle, are formed as a singular integrated structural component. Still this marketing wordspeak with the term "triple", borders on a nauseating example of commercial pandering on a product that doesn't need hype.
pigmode is offline  
Old 06-06-10, 08:48 PM
  #12  
mike868y
avatar by Sean Powers
 
mike868y's Avatar
 
Join Date: Jul 2008
Location: charm city
Posts: 9,284

Bikes: 2009 Specialized Tarmac Pro

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 248 Post(s)
Liked 0 Times in 0 Posts
Does it really matter?
mike868y is offline  
Old 06-07-10, 12:52 AM
  #13  
SwingBlade
Here to Learn
 
SwingBlade's Avatar
 
Join Date: Apr 2010
Location: SoCal, USA
Posts: 220

Bikes: 2008 Specialized S-works Tarmac SL & Specialized Hybrid

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Whether you are talking golf club shafts or bicycle frames, yes, it does really matter. Each of the major companies is developing a variety of carbon techniques and objectives to offer a unique product. The differences are huge. Small differences matter. I'm not saying which makes are superior or even which one is on the top tier, but carbon technology is neither as uniform nor as simplistic as some seem to believe.
SwingBlade is offline  
Old 06-07-10, 02:01 AM
  #14  
jermso
Senior Member
 
Join Date: May 2010
Posts: 130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by SwingBlade View Post
Whether you are talking golf club shafts or bicycle frames, yes, it does really matter. Each of the major companies is developing a variety of carbon techniques and objectives to offer a unique product. The differences are huge. Small differences matter. I'm not saying which makes are superior or even which one is on the top tier, but carbon technology is neither as uniform nor as simplistic as some seem to believe.
x 2
jermso is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
stillcovalent
Bicycle Mechanics
5
05-28-14 03:21 PM
Degran
Road Cycling
1
08-19-10 09:13 PM
waterrockets
"The 33"-Road Bike Racing
38
05-29-08 09:39 AM
leftthread
Classic & Vintage
8
06-03-07 09:41 AM
vrkelley
Commuting
1
03-31-05 07:11 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.