Tech News June 20, 2007
Edited by James Huang
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Mavic introduces 'Tracomp' concept with new R-SYS road wheelset
R-SYS uses carbon spokes laced
radially on the non-driveside
Photo ©: James Huang
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With very few exceptions (anyone remember the Black Hole?), modern spoked
bicycle wheel design has always involved a rim connected to a hub using
tensioned spokes… that is, until now. The new R-SYS wheels from French
wheel giant Mavic symbolizes "the third generation of wheel design" by
virtue of an intriguing new Tracomp (Traction Compression) technology.
Using its extensive in-house testing facility, Mavic determined that
the fundamental flaw of a traditional wheel is that lateral loads tend
to cause some spokes to lose tension (or become detensioned completely).
More specifically, typical wire spokes are apparently too easy to stretch
and offer little to no structural support when placed in compression.
In seeking that elusive "third generation", Mavic designers and engineers
identified spoke stiffness and flange spacing as the biggest contributors
to a wheel's lateral rigidity, while rim stiffness, spoke length, hub
flange diameter, and spoke lacing patterns all are said to offer little
significant influence. More surprisingly, Mavic also claims that spoke
tension has a negligible influence, and increasing the spoke tension actually
reduces overall lateral rigidity (although it does delay the onset
of complete spoke detensioning).
One of Mavic's giant wheel testing
machines
Photo ©: James Huang
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Mavic's new Tracomp technology is built upon a 4mm-diameter hollow tubular
carbon fiber spoke that is substantially stiffer than other spoke materials
in tension, but more importantly, can also operate in compression ('tension'
is also referred to as 'traction', hence the nomenclature). Citron-anodized
(it's back!) aluminum ends are permanently bonded to either end of the
spoke, which is radially anchored at the rim thanks to the direct threading
of Mavic's FORE system, and at the hub courtesy of a new Tracomp ring
that is pressed into the end of the hub shell.
The new R-SYS road wheelset is the first product to integrate the Tracomp
concept: radially-laced carbon spokes are used throughout the front wheel
and on the non-driveside of the rear wheel, and the non-driveside spoke
flange has been pushed out by 4mm (thinner bladed Zicral spokes in a two-cross
pattern are used on the driveside instead of the fatter carbon spokes
in order to keep that flange as close to the cassette as possible).
Aluminum is used for the 22mm-deep front and 25mm-deep rear rims for
durability, reliability, and predictable braking. Contrary to Mavic's
prior stance on the subject, the rear rim is also asymmetrically drilled
to help even out the spoke tension. The hubs incorporate Mavic technologies
introduced last year. Thankfully, the use of fairly standard construction
and components means that the R-SYS will remain as user-serviceable as
the current Ksyrium line.
Gilberto Simoni inspecting a new
R-SYS wheel.
Photo ©: Mavic
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Mavic says the new R-SYS wheel is both 10% lighter and 30% stiffer
than the current Ksyrium ES. The carbon spokes and their aluminum ends
weigh only 5g apiece (Mavic's Zicral spoke and nipple are about 7g each),
and since the entire wheel is built with lower tension, the hub and rim
can use less material without compromising durability (an R-SYS clincher
rim is said to be under 400g). Claimed weight for a complete clincher
pair is just 1355g (570g front, 785g rear, without skewers); the tubular
version shaves another 25g a set.
We sampled the new R-SYS on a brief ride around Lake Annecy, France near
Mavic's main headquarters. Although initially skeptical, our brief 60km
(40mi) of rolling terrain left us with excellent initial impressions on
the new wheel's ambitious rigidity claims. The R-SYS is noticeably more
responsive than the Ksyrium ES, especially when climbing out of the saddle
and sprinting. Moreover, the increased wheel rigidity also had a surprising
effect on our test bike's handling characteristics, turning our normally
fairly docile LeMond Tęte de Course into an almost twitchy machine.
Mavic says the new R-SYS is also substantially more vertically compliant
than the Ksyrium ES. On the contrary, we actually thought it felt more
rigid, although the carbon spokes seem to lend some damping effects. We
can, however, vouch firsthand for Mavic's weight claims: our clincher
test set was 560g for the front wheel and 810g for the rear, or just 15g
heavier than advertised overall (we'll take that any day). Suggested retail
for the pair is US$1400, including skewers and wheel bags.
Mavic offered up little information on future products that would incorporate
Tracomp technology, but suggested that it was looking into other applications.
It did say, however, that the Ksyrium ES will be replaced for 2008 with
the Ksyrium SL Premium, which will be functionally identical but dressed
in a more subdued black-and-grey color scheme. More significantly, though,
both it and the standard Ksyrium SL will also incorporate the new offset
rear rim.
Pegoretti retailer allows public to send a 'Note to Dario'
We reported recently on the unfortunate
condition of renowned Italian framebuilder Dario Pegoretti, and the
sizeable response from well-wishers has prompted one of Pegoretti's largest
dealers to offer a formal outlet to send messages.
Competitive Cyclist, North America's largest online Pegoretti retailer,
has built a "Note to Dario" web page after receiving multiple requests
for the builder's contact information. "Note to Dario" users can send
messages to Dario Pegoretti through the site (up to 1000 characters),
in addition to images of themselves with "any brand of bike".
"This isn't just for Pegoretti owners," says Competitive Cyclist CEO
Brendan Quirk. "Dario's warmth has touched countless people in the bike
industry, regardless of the company they represent. It's meant for all
of us who care about him -- those who ride Pegoretti bicycles and those
who don't."
Entries from four countries were received in only the page's first day
after going live, and submissions have filled seven pages after just a
week. Those wishing to send their own message to Dario Pegoretti can do
so at the Competitive
Cyclist web site.
Hunter Allen to offer Power Training and CyclingPeaks WKO+ 'webinar'
Hunter Allen, owner of Peaks Coaching Group, Inc., co-developer of CyclingPeaks
WKO+ training analysis software, and author of Training and Racing
with a Power Meter, will present an on-line seminar on June 27th beginning
at 6pm EST.
Allen is a world-renowned coach that has specialized in incorporating
the use of power meters to develop an athlete's potential and claims to
have analyzed over 3000 power meter files. Coaches, athletes, and all
'webinar' attendees alike will have access to this experience and information
during the interactive 75-minute session. Allen will also provide instruction
on using the WKO+ software and directly address individual concerns during
a Q&A session.
Topics covered will include, but are not limited to, the following:
- Determining threshold power by analyzing user's power files
- Learning how to count number of 'matches' burned during a particular
workout or event
- Personalizing the WKO+ athlete home page for particular needs
- Locating hidden useful details in workout files
- Identifying power zones to target in future workouts
- How to maximize the usefulness of your power meter and CyclingPeaks
WKO+ software
This webinar is recommended for beginner-to-intermediate level users,
and attendees must already possess CyclingPeaks WKO+ software on their
desktop. Attendees are also encouraged to first read the
most recent articles by Hunter Allen and Dr. Andrew Coggan related
to creating and understanding the Performance Manager Chart aspects of
the software.
The cost of the webinar is US$69.95, and interested parties can sign
up at the Peaks
Coaching Group web site.
Saunier Duval-Prodir reports zero punctures at Giro d'Italia
The Saunier Duval-Prodir team enjoyed numerous successes at this year's
Giro d'Italia, including stage wins by Gilberto Simoni, Leonardo Piepoli,
Riccardo Ricco, and new signing Iban Mayo. However, one of the team's
biggest achievements of the race will never see the light of an official
record book: according to team tire sponsor Hutchinson, all of the Saunier
Duval-Prodir riders arrived in Milan without having suffered a single
puncture after traversing the entire 3442km (2139 miles) parcours.
When accounting for all nine finishing Saunier Duval-Prodir riders, the
team's Hutchinson tires went 30,978km (19,249mi) flat-free. Whether by
luck or other fate of circumstance, that figure is impressive nonetheless.
New shorts from BlackBottoms Cycle Wear enhance nighttime safety
BlackBottoms Cycle Wear introduces
the new Argento short
Photo ©: BlackBottoms Cycle Wear
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BlackBottoms Cycle Wear has launched a new short that integrates reflective
side panels for greater visibility in low-light conditions. The Italian-made
four-way stretch panels incorporate a thin, colored layer of microscopic
glass beads bonded on to its surface. According to BlackBottoms, light
reflected off of a 10x10cm (4x4") panel is visible at nearly 120m (400ft).
"I've been hearing more and more about cyclists being hit by cars, even
when they are riding far to the side of the road," said Jay Elggren, BlackBottoms'
owner and operator. "I found the reflective fabric last year and felt
I could integrate it into a pair of cycling shorts. I ordered some fabric,
stitched up some sample shorts and did a few simple tests. The pumping
action of a rider's legs in conjunction with the reflective light can
make riders more visible on early morning and late evening rides. The
panels even have some reflective properties in bright daylight."
For now, the new Argento shorts are only available in a women's model,
complete with a low-rise waist, shorter 5- to 6-inch inseam, flat-lock
stitching, and an "anatomical four-way stretch Italian chamois." The new
shorts will retail for approximately US$84; men's versions are currently
in development.
Photography
For a thumbnail gallery of these images, click here
Images by
James Huang/Cyclingnews.com
Images by
Mavic
Images by
BlackBottoms Cycle Wear
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