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Tech News – August 28, 2007

Edited by James Huang

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Carbon Drive Systems: the next big thing?

Aggressive ports allow for mud evacuation.
Photo ©: James Huang
(Click for larger image)

If you could have a drivetrain that was lighter, smoother, longer lasting, totally silent, more responsive, and required no lubrication, would you buy it? The folks at start-up company Carbon Drive Systems certainly hope so, and they claim its new system not only offers all of the above but a free cup of frozen custard, too (okay, we're lying about the last part, but that does sound good right now. Mmm... custard).

The system is built around a 52g toothed 'polychain' comprised of multiple strands of stretch-resistant carbon fiber embedded in flexible polyurethane. The matching proprietary chain ring and cog are made from CNC-machined aluminum, and the whole shebang weighs just 180g (yes, we said "180g," and no, it's not a typo. Read it again if you must).

The embedded carbon fibers are also said to transfer tension faster than conventional roller pin chains for more immediate response to pedal inputs, and CDS even claims belt lives up to 10,000 miles for its 'endurance' model (a smoother running 'performance' system supposedly offers only marginally shorter lifespans). Gaping ports in the troughs of the cog and chain ring teeth also appear rather capable of evacuating even the nastiest goop, and after eight iterations of design refinement, CDS is confident in the final product.

So what's the catch, you ask? The system will almost certainly be forever limited to fixed-gear or singlespeed applications, and the belt currently cannot be separated and respliced so you probably won't be able to use it on your current rig very easily. However, CDS is working with singlespeed maverick Spot Brand to bring the system to market on a wide range of bikes thanks to a clever 'keystone' dropout that allows users to easily split the drive side chain stay and seat stay with virtually zero visual indication that it's anything out of the ordinary. The dropout is only made in steel for now but CDS says titanium and aluminium ones are imminent.

The non-separating belt
Photo ©: James Huang
(Click for larger image)

Spot will offer five CDS-equipped bikes next year, including the Longboard singlespeed 29er, a singlespeed cyclo-cross bike, the Sprawl urban fixie, the internal hub- and fender-equipped Highline commuter, and Spot's standard 26" singlespeed MTB model. Keystone dropouts will be standard equipment across the board, although conventional one-piece dropouts will still be available by special request. CDS also reports that two other companies have signed on for 2009.

Notably absent from the lineup, however, is a full-suspension model. As with any singlespeed drivetrain that doesn't rely on a tensioner, the CDS design is rather intolerant of changes in effective chain stay length as the rear end moves through its travel. While this doesn't necessarily completely eliminate the possibility of a full-suspension rig altogether, it does severely limit the types of systems on which it will work in its current form (dropout issues notwithstanding). Nevertheless, CDS says it has already begun a collaborative project with another well-known builder for a full-suspension model so we'll see where that leads soon enough.

One question left currently unanswered, though, is that of drivetrain efficiency. Conventional roller pin chains are also among the most efficient drive systems on earth, and it's difficult to imagine that a polyurethane belt and its seemingly obvious hysteresis effects can improve on that. CDS is optimistic nonetheless, however, and is currently undergoing third party tests to confirm (or refute) its claims.

Regardless of those findings, CDS reports that Quality Bicycle Products has already signed on to distribute the system and its individual components. A 'framebuilder kit' will also be available that will include a belt, chain ring, rear cog, and dropouts, and CDS is also open to enquiries from other OEM manufacturers who wish to use the drivetrain.

Currently, chainrings are only available in 32/34/42/44T (effective) sizes and Shimano spline-compatible cogs in 16/18/20/22T sizes. Chainrings are only offered in four-bolt 104mm BCD patterns for now but CDS says more chain ring and cog sizes and patterns are on their way. Retail prices for the chainrings and cogs range from US$38-45, and belts will cost approximately US$60. Further information is available on the Carbon Drive Systems web site.

New Rock Shox SID just around the corner?

The Rock Shox SID carries on for another season…
Photo ©: James Huang
(Click for larger image)

Rock Shox's original SID debuted way back in 1997 and revolutionized the world of cross-country race forks overnight with its enticing combination of light weight and tuneability. Now a full ten years into its running, the SID hasn't changed all that much in its fundamental appearance or chassis layout (in fact, many parts are interchangeable).

The current World Cup model uses a one-piece crown-and-steerer assembly, the lower legs received an overhaul just a handful of seasons ago and, thankfully, the internals have been thoroughly updated, but the most basic dimension of its 28mm-diameter stanchions have carried on year after year. Nevertheless, it still remains one of the most popular front ends on the XC circuit.

In honour of SID's tenth anniversary, Rock Shox has revived the original graphics scheme for its sponsored racers including the original 'SID' logo and that distinctive blue hue. This isn't all that significant in and of itself but Rock Shox has clearly taken a page out of the automotive marketing textbook by displaying this commemorative model on what is certainly the eve of its replacement.

Recently surfacing spy photos suggest the new SID will finally wear an oversized chassis (probably with 32mm stanchions) and the top model looks to be filled with the company's latest Motion Control damper and Dual Air spring design. Rock Shox has also launched its own teaser site but it's frustratingly devoid of any real information. It's been a good run, SID, but your time has come. Stay tuned.

Truvativ founder debuts new line of accessories

Lezyne aims to deliver premium design
Photo ©: James Huang
(Click for larger image)

Truvativ now falls under the corporate umbrella SRAM but original owner and founder Micki Kozuschek never quite got the bug out of his system after selling his successful drivetrain company. Kozuschek returns to the bicycle industry with a new line of accessories and a new brand called Lezyne.

Kozuschek says he and '#2' Dillon Clapp (also formerly of Truvativ) were motivated to create "a brand from nothing; a brand that combines the experience of battling Shimano for years and a brand that appreciates good design." The initial range of offerings includes multi-tools, tyre repair kits, mini-pumps, saddle bags, and hydration packs, most of which will fall in the mid-to-high-end of the cost spectrum but supposedly will deliver "unmatched value at a given price point."

That edict is reflected in a number of areas of Lezyne's lineup. All of the tool bits feature stronger solid bases forged and machined from either stainless or chrome vanadium steel, and sandwiched between carbon fiber or aluminium side plates. Pumps utilize CNC machined barrels and internals, along with concealed hoses on some models, and saddle packs include well-thought-out shapes, straps and internal organization.

We'll see how things ultimately shake out for Lezyne, but Kozuschek is certain of at least a few things no matter what. "In retrospect of the last five months of my life I would have to say that we used all our knowledge to hopefully build a better, great looking product, that I never spent that many hours in 3D, [and] that we never created anything that cool."

Tools will range in cost from US$14.99 to US$99.99, saddle bags from US$14.99 to US$24.99, pumps from US$18.99 to US$33.99, and hydration packs from US$44.99 to US$99.99.

Rotor continues to expand range of Q-Rings

Rotor will expand its range of Q-Ring offerings
Photo ©: Rotor
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Rotor has updated and expanded its already successful range of elliptical Q-Rings, which the company claims to deliver increased power while simultaneously decreasing perceived effort and lactic acid production. New sizes include a 23/33/44T MTB set in both standards 104/64mm BCD (US$235) and XTR M970-specific patterns (US$250), and 36/52T and 36/50T compact road for 110mm BCD (US$217).

All of the new sets supposedly offer improved shift quality courtesy of revised tooth shaping across the board; compact road rings will also feature new pin and ramp locations as well as two additional pins.

Further down the road in September, Rotor also plans to release sets to fit Campy's newest compact road crank arms and a special 50T compact 110BCD outer ring for Shimano, Time AXS, Stronglight Pulsion, THM Clavicula, or any other model that will not accept the existing Q-Ring due to contact with the backside of the arm.


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Images by James Huang/Cyclingnews.com

Images by Rotor