I recently had the chance to test the new range of Vittoria
graphene tires. I would like to thank David Polveroni for sending me a preview of these models (David having had a year-round partnership with
the Italian manufacturer). For explanations and technical arguments! Matos vélo has made
a very good summary here . David sent me the top-of-the-range Corsa Speed in 23 mm (weighing 215g)! the Corsa 25 mm (weighing
250 g) and the all-terrain Rubino 25 mm (weighing 245 g).
The Corsa 25 mm rear / Speed 23 mm front set gives
the bike a retro look and makes you think you buy phone number list have tubular tires fitted. In terms of comfort with the
Panaracer R’air inner tubes it’s quite impressive because the result is really good. Rarely have the roughness
of the tarmac been so little felt on the Aéroad.
With 7 bars! the comfort is
really excellent. The many days of gusty winds did not allow me to test these Vittoria Graphene tires in the field! and to be able
to compare them with the best on the market (Continental GPTT and S). I therefore had to carry out the tests on
rollers with a protocol to be finalized. My first tests had revealed that it was absolutely necessary to control the
temperature of the room and keep it constant to within 1 degree. The table
below shows the evolution of the Crr (rolling coefficient) as a function of
temperature.
Crr/temp linear regression line
The higher the temperature! the better the rolling.
Another point
concerned the test area on the roller. As shown in the
photos below! it is essential to stay in line towards the middle this video will show of the roller to avoid Vittoria Graphene distorting the performance. Once the rollers are hot!
there can be a difference of 4 to 5 degrees between the middle and the edge.
also the heating of the tire and its running-in that must be taken into account. Indeed
! it already takes 6 to 7 minutes for the tire and the inner tube
to reach temperature and for the performance to stabilize. At the same time! a
running-in phenomenon occurs. The tire tread! under be numbers pressure on the 2 rollers! is polished and its performance improves by a few watts. Lastly! the various tests have shown that it is easier to
maintain a cadence than to maintain the speed or the power! the latter fluctuating more quickly on
the display of the meters. These are Vittoria Graphene already some points to know to make a
repeatable comparison.