Kudos to OPQS and Zipp/Specialized (esp. Rolf Aldag who was a major driver) for their bold move with tires and pressures yesterday, especially the move to 30mm rear tires. Tire pressures have never been so low with any success, we’re talking 4.0-4.2 bar for a ~160lb rider (and yes, this requires some pretty special pumps/gauges to minimize risk). The first year we had wheels win at Roubaix, the riders were on 27’s and ran 6-6.5 depending on rider weight and front/rear and THAT felt like a scary low pressure…phenomenal to see the combination of layup, rim shape, new materials, tire specific tire well geometries, tire construction techniques and about a dozen other factors being massaged to the point that something even those of us right in the middle of it would have said was just not possible 4 years ago, was successfully used by an entire team.
Kudos for breaking with tradition. It seems like road racing is often afraid to innovate or try anything different, even when it’s common in other disciplines and there’s overwhelming data to support it. I sometimes think road racers believe the world is still flat. With 30mm, why was this so risky with a light rider and bike? Were these clinchers or tubulars? That’s still 58-60psi. I’ve run 38mm tires at 3.0bar on my cyclocross bike and that’s within the published range. Factoring in that I’ve ridden it that way at 175lbs in winter gear and the bike weighs about 24lbs. I’ve ridden it on MTB trails that way as well. If tubular s the risk of punch flats mostly goes away. Plus its’ my understanding the the cobbles are not usually sharp hits like midwestern potholes. They are more rounded, so more like constant washboard.
What special pumps did you need? I could see needing a larger gauge, or using a digital gauge on the pump for higher resolution. A shorter stroke pump would also make it easier, but you could also just bleed off the pressure with a good gauge. Though with 30mm, it probably takes 2x the number of strokes to inflate than a 23mm.
I bet much of the time most pro riders are still running over 100psi in their tires, when based on their weight and newer wider rims, they should be as low as 90/95.