One of my most developed *cough* “bike skills” is smashing the rear wheel of my hardtail into stuff, usually just enough to ding the rim but not destroy the wheel. A few weeks ago, Chipps handed me a 26 inch Procore set; here’s how I’ve been getting on with it.
For those of you who’ve been hiding under a rock rather than making unwise, ambitious line choices over them, Procore is a system developed by Syntace and Schwalbe, designed to prevent pinch flats and burps in tubeless tyre setups. We first saw tales of it last year. An inner chamber sits on the rim at 65 – 85PSI, locking the tyre beads in place and protecting the rim from impacts. In turn, that lets you run silly low tyre pressures, down to 11.6PSI if you so desire.
Because it involved a tube, an airguide, an inner tyre, the actual tyre, and then sealant, installation sounded a faff. If anything though, I found Procore made tubeless setup easier: Many tyres are a tight fit on the rims I run, but the inner chamber gave the beads an extra push outward. One went up without even having to soap it. The kit is well designed and comes with straightforward instructions, along with little stickers to put around your valves. I’m not sure if those are for showing off, or just in case someone else is going to work on your bike. Perhaps they’re for forgetful riders who’d otherwise plunge a big anchovy-laden spike through the lot while repairing a tubeless tyre.
As soon as it was installed, I pumped the inner chambers up to 85PSI, let my tyres down to 14, and set off for the cruellest local rock gardens and waterbars I could find. That first ride was a 55km loop taking in a lot of the downhill runs around Todmorden and Hebden Bridge. It took a while to get used to the sensation of the back tyre bottoming out against the inner one, but after feeling it against a rock at speed and realising the tyre wasn’t going down, I got more confident and took bigger risks with each descent.
From the second descent on, I was deliberately letting the back wheel hit stuff in ways that have destroyed tubes, tyres and rims for me before. Hairy line choices were suddenly rendered sensible. More than once I expected to drop off a high line, but the bike just kept tracking along edges. I laughed like a maniac all the way down Pecket Well, feeling glued down to whatever line I chose. The only thing I’ve ridden with as much grip is a fatbike, and Procore is more fun.
Eventually, after much trying, I did flat. It took two days and 70km of deliberately clumsy riding, and even then I rolled home on a soft tyre rather than it completely going down. The inner chamber seemed to have lost some pressure over time, so in hitting something hard I’d managed to put a tiny snakebite in it, at the same time nicking a sidewall badly enough that it took a few minutes to seal properly. Since the inner chamber of Procore seems to basically be a road tube with a special valve, the repair was simple and I’ve been careful to check my pressures before each ride since. I switched back to riding with some care and slightly higher pressures; there have been no more flats, and no significant air loss over time either.
So there we go. It’s not indestructible, but riding it so far has been a lot of fun. I’ve adjusted my tyres to a better all round feeling 18PSI, because anything lower created an unpleasant pogo effect on climbs. If I were doing uplift, I’d happily go back down further though, because the grip is phenomenal. Low tyre pressures can have some other beneficial effects too: more grip climbing and braking, and noticeably smoothing out a little trail chatter on the hardtail too.
I’ll be testing this long term to see how it holds up, though so far it’s been superb. Nothing is indestructible, but on the first ride I pushed this way beyond anything I’d do to a normally set up pair of wheels. Tyre pressures are always a compromise between grip and other factors, but by giving some protection against flats, I’ve found Procore certainly expands the range of pressures I can choose to run without worrying.
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