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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
(Click for larger image)

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
(Click for larger image)

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
(Click for larger image)

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
(Click for larger image)

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.


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Images by James Huang/Cyclingnews.com

Images by Mavic

Images by BlackBottoms Cycle Wear