The Cannondale Slice Hi-Mod is one of the newer time trial shapes in the ProTour, having first seen action in competition less than two years ago at the 2007 Giro d'Italia. Though late to the all-carbon TT bike game (the previous Six13 Slice used a mix of aluminium and carbon tubes), Cannondale at least enjoyed the benefit of already knowing what would work and what wouldn't.
Proven aero technology on Basso's Slice Hi-Mod includes the deep 'Speed Shadow' rear wheel cutout, a more compact rear triangle for reduced frontal area, a slender horizontal top tube, and an aero fork whose crown integrates relatively tightly with the slightly dropped down tube. Of course, aero-profile tubing is used wherever applicable and the included deep-section carbon seatpost sports two offset positions to accommodate both time trial and triathlon events.
For the 2009 season, Cannondale upped the ante further with a new Hi-Mod version that uses a stiffer blend of carbon fibres. According to Cannondale marketing manager Bill Rudell, the new version is stiffer than before and also lighter. Frame weights now hover at just over 1100g - awfully respectable for a carbon road frame and exceptionally light for an aero time trial machine.
But the complete bike of returning Italian star Ivan Basso (Liquigas) isn't quite so svelte - total weight was a portly 8.92kg (19.67lb) when we caught up with it prior to this year's Tour of California. That said, Cannondale's own Slice Hi-Mod Ultimate production version reportedly weighs as little as 6.44kg (14.2lb) without pedals.
Why the huge discrepancy?
Like an increasing number of pro riders, Basso chooses to both race and train with a power meter and though SRM offer a model based on Cannondale's own ultralight Hollowgram crankset design, its 175mm maximum arm length falls short of Basso's preferred 177.5mm dimension for time trials.
As such, he has to resort to SRM's solid aluminium version plus its accompanying Shimano Ultegra Octalink bottom bracket and threaded BB30 frame adapter and pays a 500g (1.1lb) weight penalty in the process - or roughly 700g heavier than the standard Hollowgram SL unit.
Basso's SRM setup is valuable for collecting data, but he pays a weight penalty
Other major weight additions include a Vision Trimax semi-integrated aluminium aero bar with an additional brake lever (about 980g with brake levers as compared to the stock 699g USE Tula), the Mavic Io five-spoke carbon front wheel (750g vs. 568g for the stock Zipp ZEDTech 4) and the matching Mavic Comete rear disc (1150g vs. 780g for the stock Zipp ZEDTech 8).
Factor in a pair of stainless steel-axled Speedplay Zero pedals (206g per pair), last year's Campagnolo Record 10-speed componentry (the stock bike uses SRAM Red), and the large 58cm frame size and the 8.92kg suddenly begins to make a little more sense.
Basso's Slice is at least meant to be comfortable, though, thanks to Cannondale's Slice Aero Vibration Elimination (SAVE) stay shaping. According to Cannondale, slightly flattened sections on the chain stays and carefully designed bends on the slender seat stays yield a modest leaf spring effect as Basso rolls down the road.
Basso's perch is a modified fi'zi:k Arione CX
Basso has not always been known for his prowess in time trials but the returning Italian rider is hoping to shed that reputation in 2009. Prior to his doping suspension in the summer of 2007, Basso's performances against the clock had begun to improve thanks in part to wind tunnel work with then-team CSC. He had also been scheduled for another session after the Tour of California before a knee injury sidelined the appointment.
With stated targets to include the upcoming Giro d'Italia, it seems that Basso may still have some more work to do though. Basso posted a mid-pack 66th in the opening Tour of California prologue and more recently, a reasonable 19th place finish during stage 5 of Tirreno-Adriatico - 1'14 down on stage winner Andreas Klöden (Astana).
But the surprisingly long and hilly time trial on stage 12 of the Giro may prove to be interesting with its long 61.5km route and two climbs: the Passo del Bracco (600m of climbing) and the Passo del Termine (500m). Basso has yet to decide whether he will use a time trial bike or a standard road machine for what is likely to be a decisive stage, but rumours suggest Cannondale may uncork something special for Basso just for that day.
An even lighter Slice perhaps or maybe even an aero-tubed road frame? Check back with us in May.
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