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PostPosted: Sun Mar 07, 2004 6:40 am 
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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.
Happy reading :D

SPADA STILETTO, “Ciclismo”, October 2003
Article provided by: Delpi
Translation provided by: cadence90

LIGHTER, STRONGER

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.

SPADA STILETTO
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.

TESTING
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”.

TEST DATA:
Climb: Roncola (BG)
Length: 7 km
Vertical: 531 m
Average gradient: 7%
Maximum gradient: 10%
Time: 25’01”
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

TECHNICAL DATA:
Model: Spada Stiletto
Hubs: Ergal/Carbon fiber
Front spokes: 24
Rear spokes: 28
Rims: Aluminum
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
Tirano (So)
tel: 39 (0342) 705 033
web: http://www.spadabike.com
e-mail: corradospada@tiscali.it


Attachments:
spada stiletto_04_front hub.jpg
spada stiletto_04_front hub.jpg [ 33.91 KiB | Viewed 2126 times ]
spada stiletto_03_rear hub.jpg
spada stiletto_03_rear hub.jpg [ 46.61 KiB | Viewed 2130 times ]
spada stiletto_02_rim.jpg
spada stiletto_02_rim.jpg [ 23.02 KiB | Viewed 2136 times ]
spada stiletto_01_wheels.jpg
spada stiletto_01_wheels.jpg [ 99.13 KiB | Viewed 2135 times ]

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Posted: Sun Mar 07, 2004 6:40 am 


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PostPosted: Sun Mar 07, 2004 7:35 am 
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THANK YOU :D


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 Post subject: Nonsense......
PostPosted: Sun Mar 07, 2004 11:02 am 
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Does this author really say the that the Spada’s 500 grams weight advantage makes him 65 seconds faster on a 531 metres climb? Sorry, but that is just big bullshit! I made a very simple model in MS Excel for roughly calculating the effects of weight loss on climbing speed.

The results from that model: (note, it neglects air resistance, but for climbing that’s not such a big problem)

Input Parameters:
Rider weight: 65 kg’s (just an assuption, the article doesn’t mention it)
Power output: 245 Watts (assumption: all the power goes to overcoming gravity)
Level difference: 531 metres.


Results:

Climbing time with a 7,5 kg bike: 25:41
Climbing time with a 7,0 kg bike: 25:31

Just a 10 seconds difference!



Okay, maybe the Spada’s are more aero…. How much of a difference would that make…..
At 49 km/h a standard 32 spoke wheel has 2,27 Newton drag, a disc wheel only 1,13 N (Source: ‘The Racing Bike Book,’ Steve Thomas, Ben Searle and Dave Smith, 1997)
At 16 km/h these values will be about 0,64 N for the 32-spoke wheel (2,27 / (49/16)^2) and 0,32 N for the disc wheel (1,13 / (49/16)^2)

Now let’s assume the difference in aerodynamics between Spada and Ksyrium is as big as the difference between a disc wheel and a classic 32-spoke wheel. (which is big nonsense of course)

Than the Spada’s have 2 * (0,64 – 0,32) = 0,64 N less drag than the Ksyriums, that makes 0,64 * (16 km/h /3,6) = 2,84 Watt less drag.

So we assume that when using te Spada’s the power available to overcome gravity is 2,84 Watt higher than when using the Ksyriums…

Well then the model says:

Climbing time with 7,5 kg bike and 245 Watts: 25:41
Climbing time with 7,0 kg bike and 247,84 Watts: 25:13

Difference: still only 28 seconds.

Okey, I know I used some totally unrealistic assumptions in this calculation, but I just intended to show that it’s absolutely impossible that 500 grams lighter wheels make such a big difference.
By the way, if you are interested in that model, just email me I’ll send it to you.

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 Post subject: Re: Nonsense......
PostPosted: Sun Mar 07, 2004 11:27 am 
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asphaltdude wrote:
Does this author really say the that the Spada’s 500 grams weight advantage makes him 65 seconds faster on a 531 metres climb? Sorry, but that is just big poo!

Yes, really. Sorry, but have you ridden to verify?

asphaltdude wrote:
I made a very simple model in MS Excel for roughly calculating the effects of weight loss on climbing speed.
*****
Okey, I know I used some totally unrealistic assumptions in this calculation, but I just intended to show that it’s absolutely impossible that 500 grams lighter wheels make such a big difference.

Your model is a mathematical abstraction, no?
Does it account for less cumulative fatigue?
Does it take into account the effect of 500 grams less rotating weight over 7 km of real road conditions?
We constantly ask for the ideal of "objective" real world testing on this site (read the Cat brakes threads), with same rider, same conditions, same equipment: someone provides one which seems very clearly comparative, and the response is an Excel spreadsheet :!:
As a rider, I'll take the test as a more realistic source of information. :wink:
Delpi can provide you with a 110 second improvement with a different frame/wheels over his same route. If you Excelled his data (no pun intended) you probably would end up with less theoretical improvement. But, he rode it...in real life.

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 Post subject: Re: Nonsense......
PostPosted: Sun Mar 07, 2004 12:15 pm 
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cadence90 wrote:
Does it account for less cumulative fatigue?
Does it take into account the effect of 500 grams less rotating weight over 7 km of real road conditions?


I still don't believe the smaller inertia of the lighter wheels make such a big difference. I made another model: When accelerating from 5 to 10 m/s on a flat road with a total weight of 72 kilograms and a constant power output, a 500 grams lighter wheelset (where all the weight advantage comes from a lighter rim) wil make a difference of 0,25 seconds (this model takes into account air drag, rolling resistance etc etc etc)

And hey.... if you stop pedaling a heavier wheelset will keep its speed longer.

Such a test ride is influenced by sooooo many factors, such as temperature, air pressure, good/bad day fore the rider, psychological factors etc. So in my opinion it can't be used to determine the tiny advantage of a slightly lighter wheelset.

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 Post subject: Re: Nonsense......
PostPosted: Sun Mar 07, 2004 12:38 pm 
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http://www.analyticcycling.com/ForcesLe ... _Page.html
I used this model to calculate the difference of 500g weight and it's 10s, maybe it's more when it's on the wheels.
But the head is also important :lol:


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 Post subject: Re: Nonsense......
PostPosted: Sun Mar 07, 2004 1:12 pm 
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Joel wrote:
http://www.analyticcycling.com/ForcesLessWeight_Page.html
I used this model to calculate the difference of 500g weight and it's 10s, maybe it's more when it's on the wheels.
But the head is also important :lol:


That's true.... if you believe a particular wheelset will make you faster it actually WILL!

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 Post subject: Re: Nonsense......
PostPosted: Sun Mar 07, 2004 1:30 pm 
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Joel wrote:
http://www.analyticcycling.com/ForcesLessWeight_Page.html
I used this model to calculate the difference of 500g weight and it's 10s, maybe it's more when it's on the wheels.
But the head is also important :lol:


The author is wrong. It's 10seconds.
It is true that saving weight on rotating things is more important than on 'dead' parts. But that is for acceleration.


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PostPosted: Sun Mar 07, 2004 1:36 pm 
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i hate to be a doubter, but the weights listed for this wheelset seem to be a little optimistic at best. last we heard, spada was using magnesium rims, and according to the listing, they're now alloy, and still weigh around 1080 grams for the pair. hmmm. someone could be telling porkies i think...

i dare say those rims pictured in those grainy photos are alloy, as magnesium rims have a completely different look to them. maybe someone on the forum will put a set of these wheels onto a scale for us and post the pics? that would help to silence the critics.


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PostPosted: Sun Mar 07, 2004 3:54 pm 
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jim wrote:
i hate to be a doubter, but the weights listed for this wheelset seem to be a little optimistic at best. last we heard, spada was using magnesium rims, and according to the listing, they're now alloy, and still weigh around 1080 grams for the pair. hmmm. someone could be telling porkies i think...

i dare say those rims pictured in those grainy photos are alloy, as magnesium rims have a completely different look to them. maybe someone on the forum will put a set of these wheels onto a scale for us and post the pics? that would help to silence the critics.


They are Magnesium, not Al according to Corrado Spada.

The weights in the article are from weights the writer measured himself, they are real independant weights, still not good enough for you Jim? These are the wheels you suggested were vapour ware when I mentioned them in another thread, here is a (translation of) peer reviewed and publicly published article, which according to scientific norms is what is necessary to prove something is in existance or correct in that community.

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PostPosted: Sun Mar 07, 2004 5:45 pm 
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The rim is a 280g magnesium-aluminium alloy. But the 280g (MGR4)series is at the moment not durable enough.
I hope, i can get the 320g aerorims (MGR2) soon -they´re strong enough :)


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PostPosted: Sun Mar 07, 2004 6:58 pm 
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I'll concur with Ye Olde, I would believe the listed weights. "Ciclismo" is not some back-corner rag of a magazine, and I would think these issues interest them as well. They state they weighed the wheels themselves, and the type.
Now, since we don't believe everything we read, the "modellers" may be right or wrong regarding the time gained on the test result. It seemed to me that the article had no particular agenda in promoting Spada over Ksyrium, compared the 2 equally, same bicycle, similar conditions, same time, same "head", etc., etc. and in this particular instance the Spada-equipped ride demonstrated an improvement in time.
If the "modellers" show an improvement of between 10-28 seconds, and the article states 65, I don't know how to account for that difference. It would be interesting to see another real test I suppose.....

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PostPosted: Sun Mar 07, 2004 8:22 pm 
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1 min on 25 is not that much. When you ride a climb one two times, you'll be faster the second time with the same condition, just because you know what follows,etc.


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PostPosted: Sun Mar 07, 2004 10:57 pm 
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someone gets a little touchy everytime i say anything negative about spada...

it would be interesting to see how well these wheels hold up under someone weighing 180lbs... 24 / 28 with those thin little spokes wouldn't bode too well i think. revolution spokes, being of a heavier gauge do not hold well under someone of this weight, particularly when used with a rim of this profile.

anyone can produce a wheelset this light, but as for it's functionality, reliability, longevity, etc, that is a whole other aspect. in hindsight, i probably should have said this in my original posting.

also ye olde bald guy, i have seen some eastern european magnesium rims first hand, that look very similar to the ones spada are using?, and they are bad quality to say the least. longevity on the braking track (no surface treatment), spoke holes, etc, is very questionable.

your thoughts ye olde bald guy?


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Posted: Sun Mar 07, 2004 10:57 pm 


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PostPosted: Mon Mar 08, 2004 1:31 am 
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Joel wrote:
1 min on 25 is not that much. When you ride a climb one two times, you'll be faster the second time with the same condition, just because you know what follows,etc.

This is the climb they use for all their testing, it says so in the article.
Also, the article mentions the force exerted was kept consistent, 159bpm on the Spadas, 158bpm on the Ksyriums, in order to provide a clear basis for comparison. It's not like they didn't know know the climb with the other products and therefore by the time they got to Spada familiarity bred betterment.
It's more like Ferrari testing at Maranello: everything except the one variable being observed is kept consistent. Seems valid to me.

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