This is a translation of the Spada Stiletto article kindly provided by Delpi.
Please see http://weightweenies.starbike.com/forum/viewtopic.php?t=550&postdays=0&postorder=asc&start=90
for the original thread on lightweight clincher wheels.
SPADA STILETTO, “Ciclismo”, October 2003
Article provided by: Delpi
Translation provided by: cadence90
Climbing is easier if one owns a light bicycle, in addition to being in great physical shape. The tests of the new Stiletto wheels by Corrado Spada and Hutchinson Carbon Comp Air Light tires has allowed us to judge, using a simple heart monitor and the same climb, these advantages.
Text and Photos by Alessandro Turci
How much can one gain, in terms of time, using a light or superlight bicycle or components? Why are professional cyclists, especially in recent years, tending to equip their bicycles with special equipment, often of their personal choice and not of the team sponsor? The answer to these questions is rather simple, and quantifiable. If one is lighter, in addition obviously to being in great physical form, it is possible to significantly better one’s performance especially in climbing; that is, when it becomes fundamental to beat gravity in order to move at the highest possible speed. Inspired by the latest Grands Tours, where the riders have unveiled real “secret weapons” during the most difficult and important stages, we decided to try a set of special wheels, produced by the master from Tirano (Sondrio, Italy), Corrado Spada, equipped with a pair of Hutchinson Carbon Comp Air Light tires and the latex tubes made and advised for these tires.
The Stiletto wheels are the natural evolution of the first model, now used profusely by some of the sports best amateur climbers such as Attilio Romani, for example, who also this year won the “Re Stelvio”, a race which finishes at the Stelvio pass, reached via the road from Bormio. On the scale, these wheels weigh 1080 grams (without skewers), a phenonemal weight when one considers that these are designed for clinchers, and not for tubulars as is the norm for the majority of special event wheels. Compared to the first edition of the Stiletto, which weighed 1292 grams, the Lombard craftsman [Spada] has succeeded in saving 212 grams, over both wheels, working primarily on the rims, which has become “bigger” [“chunkier”] and a bit on the hubs, which already in the first version were characterized by very light weight. The hubs utilize flanges in anodized Ergal with a body of multi-directional carbon fiber, independently machined and then joined with structural glue. The front hub utilizes 24 holes (12 per flange), with drilling that allows for radial lacing of the spokes. The spokes are made from stainless steel, in a profile of 2/1.2/2mm. The rear hub, obviously, is different, and utilizes a traditional flange, for radial lacing, on the non-drive side, and on the drive-side a very particular flange, designed and machined by Corrado Spada, in the shape of a rose with ample milling in order to reduce weight, with the spokes laced 1x. The rims are 21.5 mm wide and 23 mm deep, therefore deeper than the first version, with a machined braking surface.
HUTCHINSON CARBON COMP AIR LIGHT
These are very light tires, utilized by the US Postal team of Lance Armstrong, and characterized by a structure that allows a weight of 187 grams for the 700x23 version (which we used on our road test) down to 177 grams for the narrower 700x20 version.
The compostion of the tread comprises a mixture of silica and carbon in order to deliver smoothness and lightness, but above all resistence to puncture as well as durability. This concept represents how far, technologically speaking, Hutchinson has been able to push their know-how and experience in the production of road racing tires. Optimizing smoothness, with the particular tread composition and the possibility of an inflation pressure of 8.7 bar, the data provided by the French company speak of a 20% improvement in acceleration speed. Not a small thing, especially if one thinks of the reduced speeds typical in climbing. The design of the tread has been conceived to optimize speed, by means of the smooth middle section, and grip, thanks to the knurled outside faces. Particular attention has been given to the tube, which is the Hutchinson Latex model, obviously in latex, and which weighs 55 grams.
The total bicycle weight is completely respectable: 7 kg exactly, practically 500 grams less than the weight of the bicycle with Mavic Ksyrium SL wheels, a noted model which we intended to use as the basis for comparison since they are widely used also in the amateur ranks. The most interesting aspect is that the weight has been saved in the rotating areas, which in climbing are most important in determining ease and speed. The method we used to gather road test data was heart rate (but we also could have used a power meter), since heart rate is verifiable and comparative via the use of a simple monitor, and a climb we always use to test all kinds of equipment. We paid particular attention to the gearing, using an FSA Carbon Pro Elite Compact crankset with 50x34 chainrings. These ratios allowed us to ride the “easy” part of the climb with a 50x21 and the rest of the course with a 34x19. The climb we scaled is the Roncola, in the area of Bergamo, 7 km with a gradient of 7% average and 10% maximum. A fairly difficult climb, then, especially at the end, which is part of the “Giro di Lombardia” and also was the climbing time trial stage of last year’s “Settimana Lombarda” won by the Mexican rider for Panaria, Alberto Perez Cuapio. At the conclusion of the test, we had ridden the 530 meters of vertical in 25’01”, which is an improvement of circa 4% in that the previous record time was 26’06” (+65”). The average heart rate reached during the test with the Stiletto was 159 bpm, while with the Ksyrium the average was 158 bpm. The tests were conducted in a short time period with equal weather and physical conditions, utilizing a consistent cadence and power. The results, significant in terms of time gained relative to equal force exerted, cause us to think how important it is, if one has the money, to lighten one’s bicycle and especially the wheels. Above all, to improve in this manner is legal, completely without damaging side effects: certainly the improvement is not macroscopic, but at least it is all “flour from the same sack”.
Climb: Roncola (BG)
Length: 7 km
Vertical: 531 m
Average gradient: 7%
Maximum gradient: 10%
Average heart rate: 159 bpm
Maximum heart rate: 170 bpm
Average speed: 16.5 km/hr
Maximum speed: 26.3 km/hr
Average cadence: 71
Maximum cadence: 94
Calories consumed: 429 Kcal
Model: Spada Stiletto
Hubs: Ergal/Carbon fiber
Front spokes: 24
Rear spokes: 28
Width: 21.5 mm
Depth: 23 mm
Weight front wheel: 474 g
Weight rear wheel: 606 g
Price: Euro 850 (MSRP)
Builder: Corrado Spada
Via Benefattori, 12
tel: 39 (0342) 705 033