Pinch flats have plagued our sport ever since modified beach cruisers found their way into the mountains and riders began lowering tire pressures to increase traction. Despite all the advancements in modern mountain biking, finding the right tire pressure continues to be a constant balancing act between optimizing traction and handling, while avoiding the risk of flats. But what if you could separate this risk from the equation? What if you could set the pressure in the happy place without worrying about destroying your tire and smashing your rim?
When Mavic introduced the tubeless system to mountain bikes in 1999, it was an enormous step in the right direction. But it wasn't the end of snake bites that it promised to be. Just like inner tubes, tires pinch flat, too. A tubeless setup can be less prone to flats, but the balancing act is still there, and you can still smash your rim to smithereens. Schwalbe's Procore system lets you set your pressure wherever you want without factoring pinch-flat probability into the equation. It doesn't mean the end of flat tires. In fact, within five minutes of setting up Procore, I had gotten one.
When my tire's sidewall sustained a quarter-inch slice, I was not pleased. It wasn't Procore's fault that my tire was cut–not directly anyway. Schwalbe claims that you can run a less reinforced tire with Procore, netting zero weight gain of adding the 400-gram kit. That method didn't work out too well for me. Procore reduces the risk of pinch flats, not punctures–you still need a robust tire for that part.
Since the Procore chamber was still holding air, I was able to ride halfway down the Whistler Mountain Bike Park without bottoming out on the rim. Pretty awesome, I thought. The blue thing you see is essentially a road-tire casing without any rubber on it. Inside that is an ordinary road tube with a special valve that can direct air into either the Procore chamber or the tire. The bead of the rubberless road casing sandwiches the bead of the tire between itself and the rim, creating a mechanical bead lock. It's possible to run pressures as low as you want without the risk of burping.
But the $230 Procore system isn't all peaches and cream. It adds a pound to the most weight-sensitive part of your bike–that is, if you can get the kit installed in the first place. The process may risk your (or your mechanic's) sanity. Since you're essentially mounting two tires on one rim, things get really tight. The tire levers that come with the kit do help, but it can still be frustrating. Also, the special valve needs to be lined up just right, and when mine shifted somehow during my ride, it cut off the air pathway and required a complete breakdown and re-install. If you do attempt the installation yourself, make sure to watch the instructional video on Schwalbe's website. It definitely helps.
With the proper tires, Procore's armor can make your bike feel indestructible. For the first time in my 20-year riding career, I could obliterate rock gardens while running scary-low tire pressure, without even thinking about wrecking my rim. If that's not progress, I don't know what is.