SCHWALBE Procore dual chamber system – (interim) verdict: by c_g
I have been on the SCHWALBE Procore double chamber system since May this year and have ridden it in any conceivable situation and did almost anything to it that I could think of as a tester. In its essence Procore is not much more than a tire within a tire – the inner tire with high pressures (4 to 6 bar /50 to 90 PSI) for snake bite protection and to hold the outer tire safely on the rim; the outer tire to be run with only 0.9 to 1.5 bar (13 to 18 PSI) for seemingly endless traction and comfort.
Sounds familiar? From Plus tires? Yes indeed. Although the means to get there are different at first glance, the riding characteristics of tires equipped with Procore and Plus sized tires are rather similar. But more on that later …
… first let’s talk about SCHWALBE’s Procore itself:
ASSEMBLY / TUBELESS properties: I have had the system mounted on various wheels ranging from 23-35 mm internal width and, with very few exceptions, the process was very simple (listed in more detail already here) and inflation of the tubeless-ready outer tire was almost always done quite easily with a small hand pump. I even tried it on a dented rim, which by itself is no longer capable of being ridden tubeless and it worked – thanks to the inner tires actively pressing the outer tire’s bead outward and onto the rim.
The simple fact of knowing that the tires always sit securely on the rim and any chance of burping being eliminated, helps me to attack harder and feel more relaxed and confident.
However, I should also mention that there was one case where the Procore inner tire fit so tight on the rim that I would have needed metal tire levers in order to install the system – an absolute no-go for carbon rims. Those were the DT-SWISS XMC 1200 rims as ridden on the PIVOT Mach 429 Trail. I had brought a Procore kit specifically for this bike on a trip to the USA and was really bummed not to be able to use it.
-> If you are among those hesitant to go tubeless for its (potential) hassle and mess, SCHWALBE’s Procore is the best upgrade you can ever do to your bike. The system makes the task in 95% of the time dead simple. It is also very positive that Procore fits a wide range of rim widths but it is important to note that there may well be some rims that Procore won’t work with.
Riding impressions (traction, safety & Co.):
If you haven’t read the earlier posts on that topic, let me sum it up for you: A double chamber system like Procore will bring any bike suspension and tire to the next level! The simple fact that a tire can be ridden safely at pressures from 0.9 to 1.25 bar creates such a suppleness that small bumps are virtually swallowed and the tire conforms to the ground soooo much better. Also gravel or loose over hard pack can be ridden in a much more relaxed and confident way. Especially on long and steep forest road ascends, where it’s sometimes hard to keep the tire from spinning out, it generates such a level of grip, that I am not hesitant to call it even more “more efficient” despite its higher rolling resistance and weight. On slippery terrain it increases the traction and trail manners of any tire exponentially. One can suddenly ride lines that had previously been considered “on the limit”. The other way around, a faster and lesser profiled tires becomes safer and more universally capable.
The only weak pointI have experienced in terms of performance, is in situations with very high lateral forces (hard landings or bermed corners). In such circumstances the tire can easily feel a bit flexy and undefined.
What is really good: Despite my best efforts I had never been able to induce any defects or unwanted air loss to the system.
With regards to the rolling resistance, there is no denying that one needs to do more and work harder on asphalt and hard surfaces with a tire at such low pressures. Once the ground becomes slightly uneven (by my feeling, already the case on common forest roads) the advantages outweigh the higher rolling resistance in that the tires swallow most irregularities which otherwise would be transmitted to the suspension and ultimately the rider. In addition, it is important to note once more that the system provides an exceptional vibration damping, much more comparable to Plus or fatbike tires. This and the incredibly confident ride allowed me to stay much more relaxed during rides, which in turn saves more energy. Of course, these effects can also be used to simply go faster and more aggressively ;-).
-> If you are out riding your tire with such low pressures for the first time and with Procore as your back up), you are certain to come back deeply impressed if not ecstatic about the feeling it gave you. Such a level of comfort and traction was previously known only from Fatbikes and more recently on Plus-bikes – only that in both cases these advantages are coupled with compatibility issues and often a very limited selection of tires. A dual-chamber system as Procore can produce a very similar riding performance, but with your own bike and tires. If you are the kind of rider always searching for more comfort, more traction and more confidence on rough trails, I would consider Procore and Co. currently to be the most noticeable and effective measure one can take.
MORE WEIGHT: There is no doubt – Procore adds some serious weight to your bike, and what’s even worse, it is being added where it can be felt the most. Those 250 g more per tire therefore are the most severe argument to not even try it. Definitely nothing for the weight weenie XC racer type. In my personal riding experience and with a bias towards technical trails and single trail riding, I feel this is far less problematic than expected, but it is an argument nonetheless.
With tires in the range of 700 to 800 g, the total weight ultimately reaches that of a full featured enduro tire (without Procore), but IMO with a better overall performance. Only recently when riding an already aggressive Enduro tire – the CONTI “The Baron 2.4 project”, which already weighs about 1000g the combination with Procore seemed to be “too much of a good thing”. Here, for the first time the weight really felt bothersome (with a simultaneous excess in traction that I likely will never need). For all other tires I noticed the extra weight of Procore, but it never bothered me.
The sometimes heard argument that with Procore one can rely on lighter tires is only partly true. It is true that one can very well ride a lesser knobbed tire (like me changing from the Schwalbe Nobby Nic 2.35 to a Rock Razor 2:35 on the rear) and thus save a few grams, but it is not true that one can go to a fundamentally smaller tires, like a 2.1″ instead of 2.35“. This is due to the fairly large air chamber of Procore, which when ridden with a 2.1 “wide tires means you are very often riding on the internal chamber rather than the outer tire as intended. Even SCHWALBE states that Procore works best with tires of 2.2“ and larger.
-> There is no doubt – with about 500 grams extra weight on the tires, you can feel the presence of Procore. For the classic XC racer the current system is hardly suitable. But if, like me, you are not counting lap times or seconds of a ride, the additional traction and the incredible comfort simply rate higher and you will quickly be falling love with Procore.
Also, keep in mind the current SCHWALBE Procore is the first generation of such a system. I’m sure that there is weight savings potential here to be realized in the future.
Wheel & rim manufacturers’ approval – “A mere formality? Much mistaken!”: This brings us to a presently quite bitter pill one has to swallow when interested in SCHWALBE’s Procore. When I had made inquiries to SCHWALBE on this subject over a year ago, I heard that the rim and wheel manufacturers were already evaluating the system and it would be only a matter of time before the approvals would came in. Today, a year later, there are still only one manufacturer (SYNTACE, who also has been involved of the development from the start) who has given an official OK for use of Procore on their rims / wheels. Others speak of “still too little evidence of its effect on durability”. Still others mention “significant reduction in the wheel’s spoke tension” and “potential problems on the wheel’s strength” and still others say openly that they have not even received testing samples to evaluate the impact of the system on their products at all …
For my part I can say that I have noticed no real anomalies in the previous 5 months of continuous and intensive use on my AMERICAN CLASSIC Wide Lightning wheels. And because the Wide Lightning as one of the lightest aluminum wheels existing, I take the issue rather calmly. In addition, the smart special valve solution does not require any changes to the rims which further reduces the work involved to mount the system and the potential weakening of the rim.
-> As unfortunate as it may be, but if you currently want to mount Procore on your bike, you are voiding your wheel manufacturer’s warranty. Some are willing to overlook this fact because of the obvious benefits – for others, however this is an important hurdle and it certainly doesn’t help Procore in establishing itself in the market.
Overall conclusions: The Procore double chamber system in its basic concept resembles a quantum leap in terms of riding performance. I am almost tempted to name it alongside innovations such as the clipless pedals, disc brakes or suspension forks – so great is the positive net effect for the bikers. It promotes all the positive characteristics of a tire – increases the puncture resistance, makes tubeless finally an easy thing, adds traction, increases confidence and comfort – making it an effective measure to have more fun out on the trail.
However, in its current version, it also brings a substantial extra weight to the bike and is for now officially approved by none of the major manufacturers. Two major problems that make the purchase decision quite a bit more difficult. The price of Euro 195.- is another obstacle though I am convinced the others far outweigh that – simply because the system is so modular and can be easily transferred to another bike.
Like all innovations, it would be naive to think that something so new can be perfect from the outset. I myself very much hope to see more and more manufacturers approving Procore on their rims and count on the weight to come down with the next generation. If these two things fall into place I predict a golden future for Procore and other dual-chamber systems – if not … well ;-).
OUTLOOK: This indeed concludes the real test of SCHWALBE’s double chamber system Procore, but as mentioned earlier, there are other questions related – for example: “How does it do in a direct comparison with the distinguished Plus format?” Maybe we will look into another aspect: “If I already am willing to ride a tire system in the weight range of 1000 g (consisting of a 700-800g tire plus Procore) how then does that compare to a modern enduro tires which comes out around the same weight class?” Both are absolutely legitimate questions which we will follow up in the coming months … as soon as the appropriate test material arrives.