Eurobike speed demons: Zipp, BB30, SRAM, THM
By Ben Atkins and Warren Rossiter | Saturday, September 13, 2008 8.00am
The Zipp VumaChrono chainset is claimed to be the fastest TT crankset there is. Ben Atkins
Zipp adds a time trial version of its VumaQuad chainset for 2009 called the VumaChrono.
According to Zipp, the VumaChrono is nine seconds faster over 40km than the leading competitor, thus apparently making it the fastest chainset in the world. Zipp also claims it’s the stiffest chainset in terms of chainring deflection thanks to the spider-less design and unique method of chainring attachment.
Instead of the usual four or five points of contact, the outer ring (which is basically just a hollow circle of teeth) is affixed to the outside of the carbon face with nine small bolts. A separate set of bolts allows for an inner ring, too, implying that it is suitable for track use. Like Zipp’s existing VumaQuad, the VumaChrono has a 30mm-diameter bottom bracket spindle. It is specifically designed for use with Zipp’s own external thread-in cups, but we anticipate a proper BB30 version as well.
Wheels are the things that Zipp is most associated with and several small improvements have been made to much of its range. The new 188 hubs use larger 17mm-diameter alloy axles and the bearings now have adjustable preload. Naturally, Zipp claims the 188 hubs to be the fastest in the world.
The spoke flange has been increased in size, particularly on the rear, and driveside spokes have been moved outwards slightly to lessen the dish, and thus stiffen and strengthen the rear wheel.
The 808 and 404 rims have benefited from technology originally developed for the 1080, both now having lower-drag toroidal cross sections which are said to save between 2 and 7 watts at 30mph for the 808. The braking surface is now also slightly wider to form a more seamless joint with the tyre, presenting a more even profile to the wind.
All new for 2009 is Zipp’s SLSpeed stem. As an all-carbon stem, the SLSpeed has no embedded metal parts and so Zipp was forced to come up with a completely new way of moulding. The faceplate is made from forged titanium, and like Oval Concepts’ stems, is held in place by reverse bolts. The single steerer clamp bolt is attached to a floating nut to ensure better alignment when tightened. Claimed weight is 100g for a 100mm stem.
Zipp has also increased its handlebar range with the new Contour SL bar, available in Zipp’s short and shallow as well as the increasingly resurgent traditional bend. With a flattened top section, the Contour SL is designed for more all-day comfort and aerodynamics.
Full Speed Ahead for BB30
FSA is continuing to push the BB30 standard across its range with no fewer than seven different chainsets available throughout the range, including one under its Gravity subsidiary.
Sitting at the top of the BB30 road range is the K-Force Light, similar in most respects to the standard MegaExo version but for a few noticeable differences. Firstly, the BB30 version is lighter - even with the bigger spindle - when the bottom bracket cups and bearings are all included. More importantly though, the BB30 system is stiffer – due to its increased diameter – and also more durable thanks to its larger bearings.
While pedal stance width between both versions is identical, the width at the spindle – what FSA calls the U-factor – is noticeably narrower for greater ankle clearance since the bearings (in this case ceramic) are internally housed in a 68mm-wide bottom bracket shell.
SRAM introduces road wheels
As expected, SRAM has leveraged its recent ownership of Indianapolis carbon specialist Zipp to launch its own range of wheels based on the latter’s lower budget Flash-Point line. The carbon-and-aluminium rims feature Zipp’s trademark toroidal cross section but not the dimpled finish associated with the more expensive models.
The cartridge bearing alloy hubs feature alloy freehub bodies as well and stainless steel straight-pull spokes are used all around. The new SRAM wheels come with 40mm, 60mm or 80mm-deep sections and are dubbed S40, S60 and S80, respectively. All are available for clincher tyres only.
SRAM has also launched its own BB30-compatible crankset, in this case an offshoot of its top-end Red groupset. Like the FSA versions, the BB30 Red crank is lighter, stiffer and more durable than its standard sibling while also providing more heel clearance. With the lighter weight crank, total weight of a complete Red package now falls even lighter than before to sub-1900g.
Ultralight German carbon from THM Carbones
German carbon ultralight specialist THM Carbones unveiled two brake related prototypes as follow-ups on its Scapula road fork (the lightest all carbon road fork available at a claimed 235g) and Clavicula crankset (again one of the lightest chainsets available; can you see a theme here?).
The Fibula brakeset has a claimed weight of 100g per pair (without pads) and although similar in appearance to the Orion from competitor AX Lightness, THM Carbone’s stoppers have a built-in linkage to mimic the power of a dual pivot brake while retaining single-pivot weight.
THM Carbones also directly integrated the new Fibula into a special prototype Scapula fork, thus producing what is quite likely the lightest combination out there. Hiding the Fibula brake system inside the fork crown might also yield some aerodynamic advantages with the cleaner overall profile and reduced frontal area. It’s probably a mechanic’s nightmare though, as pad adjustments look to require removing the brake from the fork (there were no access holes on the prototype).
You can follow BikeRadar on Twitter at twitter.com/bikeradar and on
Facebook at facebook.com/BikeRadar.
can also improve your fitness and train with us on training.bikeradar.com.