Index Categories: 
    Carbon Construction – Impact strength of carbon rims
    Carbon Construction – Woven vs. unidirectional

From:
tri_gear  Apr 18, 2006, 9:36 AM

Question:
 What does Carbon Fiber look like?
 I have an Argon 18, Mercury. Parts of it are carbon fiber. I was riding with my friend on the weekend and he told me that how the bike is painted is not really what carbon fiber looks like… you know… that criss cross look?? He told me that it's just "painted' that way to give it that certain look? Is this right?

Josh:
 The woven fiber you see on many parts and frames is not really just a cosmetic layer in most cases. That material is in fact real carbon and it is generally more expensive than unidirectional fiber as it has to be woven together. The woven fiber is not as strong or as stiff as unidirectional, but has one key property: toughness. With plain unidirectional material, the fibers are stronger and stiffer because they are not bent at the fiber intersections of the weave, but if you crack this material, there is nothing to stop that crack from propagating within a ply as the crack can run along the resin lines between fibers. 90% of the time the unidirectional fiber is all you need, but if you are drilling any holes or have any areas of likely crack formation or impact, woven materials are really ideal.

If you look at one of our rims you see that there is woven material at the spoke bed and tire bed to eliminate crack formation and propagation from those holes, and also on top of the rim at the impact zone of the rim as woven materials generally have higher elongation before crack properties as well as keeping cracks from growing. If we were to use unidirectional materials in these zones, the rims could be made just as strong and impact resistant, but at a weight penalty. Also in parts like handlebars the woven can serve to hold the unidirectional onto the part, as a part that is subject to high deformations like a handlebar, can have individual strands of carbon peel away from the part if the part is deflected substantially.

A few years ago I was in china visiting a factory and a company was working on a light carbon downhill mtn bike bar and they were trying to do it entirely in unidirectional, and the bar was sitting on a test machine with a massive nest of carbon strands peeled up and wrapped around the stem, where the free ends of the unidirectional fiber peeled away during the impact testing and subsequent loading allowed the fibers to continue peeling away. It looked like a really nasty bird's nest! By the time that product got to market they had put a thin ply of woven fiber over top of the unidirectional so that the part looked didn't gain much weight, but wouldn't have this problem.

For a more detailed description from our tech section click here:
What Are Composites? 
http://www.zipp.com/Technology/CompositeTechnologies/WhatAreComposites/tabid/98/Default.aspx

Woven Carbon vs. Unidirectional
http://www.zipp.com/Technology/CompositeTechnologies/WovenCarbonvsUnidirectional/tabid/99/Default.aspx


Index Categories: 
    Other – Valve extender issues

From:
Bone Idol Mar 14, 2006, 7:13 PM

Question:
Zipp 808 valve extender question/ problem

 I've just bought a new set of Zipp 808s, and they come with specially designed, extra long, Zipp valve extenders. The odd thing is, the valve extenders aren't just long, they are fat, and they don't fit through the valve holes of the 808s. What am I supposed to do? Attack my $2000 carbon wheels with a hand drill? I'm thinking maybe not.

Josh:
This is a problem we are aware of. Our vendor had a machine tool insert break during manufacture of these parts and about 1000 oversized extensions ended up in a box of like 5000 extensions. Since they come to us prepackaged we have been trying to sort them out by measuring through the plastic wrapping until the batch of replacements arrives. If you call 800.472.3972 they will make sure to get replacements in the mail to you ASAP.
 
Index Categories: 
    Carbon Construction – Storing carbon wheels when not in use

From:
aerojunkie2  Mar 21, 2006, 5:07 AM 

Question:
How to Correctly Store Zipps?

How do you do it? Is it safe to hang them? I just got a set of 404's and am to scared to have them out of my eyesight. Would there be any damage to the rim if I hung them on a metal rack? Thanks.

Josh:
After getting this question all the time we developed a wheel bag for storage and travel. We found that people were using their Mavic and Campagnolo bags for travel, but these bags are just thin nylon meant to protect from dust and provide a handle to hang the wheels from. If you are doing any travel, or will be stuffing your race wheels into your trunk at any time, check out our wheelbag: 

http://www.zipp.com/OnlineStore/Accessories/tabid/58/CategoryID/4/List/1/Level/1/ProductID/67/Default.aspx?SortField=ISBN%2cISBN

Our bag is nicely padded with an offset design so that the hubs can't damage the other wheel, plus it uses reinforced plastic hub 'baskets' sewn into the bag to protect the hubs and spokes (the most common shipping damage is one hub bending or breaking a spoke in the adjacent wheel). Bill Vance worked with the vendor for like 5 months on this bag and it really shows… internal pockets for skewers as well as external pockets for small parts or other stuff. The bag isn't cheap, but neither are the wheels.

Index Categories: 
    Other – Coke in the TDF?
    Tires – Effects of Tire width on aerodynamics

From:
flman   Jul 13, 2006, 5:57 AM

Question:
Using Coke in TDF?

I noticed yesterday T-Mobile was drinking 8oz cans of Coke during their ride. This was the first time I noticed that in the tour. Is this common and what value does it provide a rider? Obviously they can drink whatever they want and would know what works best (usually, minus sponsor money) so there must be some benefit. Anyone out there doing this?

Josh:
 I first saw this when I was racing in Europe in the early 90's. Coming from a country that has 1000 energy drinks and worshiping at the altar of Cytomax I was horrified, but realized a couple of things. One, they historically were not as progressive with that sort of stuff as we had been in the states, and second, cycling is a working class sport, so kids get used to using coke as a cheap energy drink as juniors and it really works well for them. Along with sugar and caffeine, coke also has a decent bit of salt, so it really is a decent little fluid replacement drink and some people like the carbonation on their stomachs.

There are no special low-fizz cokes, and having been in the car handing these out at the Dauphine and other races I can tell you that the soigneurs go to the Aldi or LEclerq or whatever and just buy these ahead of time, or during the transition between stages. They can also be had in the morning in the rider hang-out area along with coffee and pastries. What they do is very lightly begin to open the can until you hear gas starting to escape, then after a few hours of riding in the cooler in the team car, the cans have gassed out much of their carbonation, but don't really leak or spill.

I find that our bastardized Coke made with corn syrup and other corn derivatives since the early 1980's is much harsher on the stomach and can cause heartburn due to it's higher acidity when compared to the Euro coke made with real sugar and other generally higher quality ingredients, but that I guess is true with much of what we eat, where the Euro's like to 'keep it real' and we like to just make it cheap to consume in large quantities, but that is another thread altogether.