Quite Possibly the most influential product since the dropper post.
A few years ago, you may recall a brief 'teaser' blurb from an Interbike booth, or a race pit in Val De Sol -- where Schwalbe had a funky system, with two valves, and required drilling an additional hole in the rim. But the biggest thing of all? It was a dual-chamber, sure-fire way to prevent with 100% confidence that your tubeless tire will remain seated on your rim through the roughest of terrain. The best part of all? No pinch flats!
That prototype left a lot to be desired by many consumers... who really wanted to drill a second valve hole in their rim on a product they were uncertain of? I sure would have, but I'm nuts. Most sane people wouldn't want anything to do with that; plus, it voids your warranty. D'oh!
A year, or two... or maybe it was three years go by with hardly a peep from Schwalbe on this innovative new product, then one day: *ping*, an email alert from our distributor saying ProCore 27.5" is in stock. And after a year of dented rims, pinch-flatted tires, and endless holes blown in tires, I (Alex) was more than enthusiastic to get my hands on this nifty new technology. At the time it was released, there were no internet reviews, very few images, and not a tremendous amount of information on how everything worked.
So what is it?
Schwalbe's ProCore is a dual-chamber tire inflation system, designed around using a high-pressure tire and tube, sandwiching your tire's bead between an ultralight inner tire at 45-65psi, and the rim's sidewall.
Because pinch flats.
And burped tires.
You may only care about one of those, they may all matter to you. For me, I had jabbed a pointy rock through enough of my tires in an effort to have the traction I wanted from low tire pressure. High tire pressure was not an option, as control and traction went away in an effort to prevent flat tires.
Weighing in at a whopping 223g for one wheel's worth of ProCore (29" version). This includes the tube, ultralight inner tire, and air guide (little red thing). When you're battling pinch flats and snake-bitten tires left and right, and start to consider Double Down or DH-casing tires; the additional half-pound and the ability to ride a more supple single-ply tires, the choice is clear. ProCore allows you to run the tire pressure you want, without running the risk of a pinch flat, or a burped tire.
Compatible with inner rim widths from 23mm up to 35mm, and tires from 2.2" up to 3.25", ProCore opens up a whole new world of possibilities in the realm of traction. Have you ever wondered what it would be like to run 13psi on your 2.3" Maxxis DHR? Well, it's amazing. How about fearlessly venturing into the nether-regions of ultra-low pressures on your 27.5+ or 29+ setup? Don't even sweat it. Have carbon wheels, but don't want to risk smashing your carbon rims into oblivion? Problem solved.
There is one catch... We have found that the deepest rim that ProCore is compatible with is limited to a maximum of about 25mm. We've successfully installed it on Nox Farlow, but have found that deeper rims just don't quite work without some funky modifications (think drill bit, aluminum billet, and some fun-time on a lathe).
After over a year of riding ProCore on my Nomad, I am extremely happy to say this is my favorite addition to my bike. Eddie, Jordyn, and Dan have all added ProCore to their various bikes, and we all agree -- it. rocks. your. socks. off. Or something like that. Jordyn and I choose to rock it on the rear tire only to protect our most dented and flatted rim / tire, while Eddie and Dan choose to run it front and rear.
Pressure? What pressure?
On average, between the four of us, we typically keep the ProCore tube set to anywhere between 50-60psi; I've somehow settled on 60psi as my sweet spot pressure for the ProCore; for no good reason, really.
However, the "outer tire", your actual tire... My rear tire pressure is typically lower than that of my front. I range from 17.5-19psi on the back for trail riding, and 19-21psi for super chunky rides or bike park riding. The traction and trail-damping characteristics that you are allowed from these low pressures is amazing, and without the fear of your tire unseating or denting your rim, shred forth and ride fearlessly into the sunset!