"MikeyOz" <[email hidden]> wrote in message
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Quoted message said:
have you ridden Pro Race 2's..... how do they compare if so ?
--
MikeyOz
There was a thread in r.b.t (Tour 10/2005 23mm clincher test) about rolling
friction coefficients from a German magazine test that has details for the
ProRace2 and the older GP3000, here's some of the info:
-------------------
Antti Salonen:
Yes, the tyres were tested on what looks like a steel drum. The wheel
and inner tube were the same for all tyres and the pressure always 7.0
bar. The equipment was actually Continental's so the result probably
didn't come as a surprise to them.
Of course their (Continental's) tyres also had strong points like excellent
puncture
resistance and a combination of low weight and good mileage. They just
aren't very fast. I don't know if it's an exaggeration to say that they
are not suitable for competition.
The rolling friction coefficients in your post were a bit off, but here
are all coefficients from the mag, lowest first. All tyres were
foldable 23-mm clinchers.
<snipped repeated coeffs>
The test also included a calculation that on a flat 40 km time trial, a
rider with a 300 W power output would finish 2 minutes and 18 seconds
faster with the Deda Tre tyres than with Hutchinson Top Speed.
-------------------
Ron Ruff:
Crr= Prr/(W*V) = Prr/ (85kg*9.81m*30km/hr*.2778) = Prr*.0001233
Here is the speed and differentials for all of the tires:
Tire Crr Speed* Delta
Deda Tre Giro d'Italia 0.0038 23.08
Vittoria Open Corsa Evo CX 0.0039 23.05 0.03
Michelin Pro 2 Race 0.0042 22.96 0.12
Vittoria Diamante Pro Rain 0.0044 22.90 0.18
Michelin Megamium 2 0.0047 22.81 0.27
Pariba Revolution 0.0048 22.78 0.30
Michelin Carbon 0.0050 22.72 0.36
Panaracer Stradius Pro 0.0051 22.69 0.39
Schwalbe Stelvio Plus 0.0052 22.66 0.42
Schwalbe Stelvio Evolution Front 0.0056 22.54 0.54
Continental GP Force (rear) 0.0057 22.51 0.57
Hutchinson Fusion 0.0057 22.51 0.57
Schwalbe Stelvio Evolution Rear 0.0057 22.51 0.57
Continental Ultra GatorSkin 0.0058 22.48 0.60
Ritchey Pro Race Slick WCS 0.0058 22.48 0.60
Schwalbe Stelvio 0.0059 22.45 0.63
Specialized S-Works Mondo 0.0061 22.39 0.69
Continental GP 3000 0.0067 22.21 0.87
Hutchinson Top Speed 0.0069 22.15 0.93
Continental GP Attack (front) 0.0073 22.04 1.04
* = in MPH
185lb rider + bike
250W rider output
CdA = .32m^2 (racing crouch, normal road bike)
Transmission efficiency = 96%
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