When Schwalbe introduced its tire-inside-a-tire Procore system this year, most people believed that it was developed primarily to prevent pinch flats from scuttling a downhiller's race run. Surely, pinch-flat protection was one of the motivations for Procore, but the inception of the design actually came about as a means to solve a far more important problem - one that bicycle suspension designers have been wrestling with for fifteen years. Procore tire technology was the brainchild of two German think tanks: the engineers at Schwalbe, and the people at Syntace. The information about this synergistic relationship was revealed at the Dornier Aviation Museum across the Zeppelin port from the Eurobike Expo in Friedrichshafen, where Schwalbe officially launched its 2015 range.
Sam Hill lights the Maribel World Cup DH course on fire. Hill was third fastest in the top splits, and easily made up the time on the blazing fast flat and off-camber corners in the lower section of the course for the win. Did he have a hidden advantage?
At the museum, I had the opportunity to speak with Syntace founder Jo Klieber, one of the industry's most progressive and creative thinkers, and the man who began the development process which ultimately led to the Procore system. Kleiber said that he was experimenting with the rolling efficiency of the three wheel diameters versus the effectiveness of large-volume tires. Klieber rented an expensive high-speed camera so he could watch how the tires deflected and the suspension reacted to bumps of various shapes and sizes in slow motion. Klieber said that while viewing the slo-mo recordings, he was surprised to discover that the tires would deflect almost to the rim - sometimes actually contacting the rim flanges – before the rear suspension or fork would begin to move.
Using telemetry to track the way that the tire and suspension interacted after an impact revealed that the spring rate of the tire was very linear and that it ramped up too gradually to overcome the suspension's static friction. When the suspension did begin to move, the hand-off between the spring rate of the tire and that of the suspension created a distinct spike in the compression rate at the very moment when the suspension should have been progressing smoothly through its stroke. The result was a lack of compliance for soaking up small to medium-sized bumps. Up until now, suspension tuners have wrestled with compromises to eliminate the spike. The most common solution has been to over-inflate the tire, which stiffens its overall spring rate and thus activates the suspension at an earlier moment - but that fix also reduces traction and small-bump sensitivity.
Schwalbe's Procore dual-tire system allows DH racers to safely run tubeless without burping air, and to optimize their tire pressures for the race course without risking pinch flats. Procore's less obvious secret, however, is that when the two tires meet, they interact with the suspension to create a seamless compression event.
Klieber reasoned that if he added a second, highly pressurized casing inside the tire, the spring rate of the tire would ramp up faster when the two began to compress in unison and thus would activate the suspension in a more seamless and gradual manner. If successful, the tire-inside-of-a-tire system would allow the rider to use lower pressures and at the same time, force the suspension and tire to react as a single unit to small bumps. Klieber predicted that both actions would dramatically enhance traction, along with the potential benefit of reducing pinch flats. Syntace, however, could not move forward on the project without securing a partner willing to produce the inner tire, which was a non-standard diameter. They contacted their friends at Schwalbe tires, who were excited about the project, but unable to respond with prototypes at that time. Klieber and company would have to wait.
Finally, Syntace engineer Oliver Zuther took matters, literally into his own hands and crafted some tubular tires in his basement that could be glued into the wells of Syntace's rims. Klieber says that testing immediately showed that the hybrid wheels performed as they imagined, and armed with the results, Syntace again approached Schwalbe for assistance to get the concept to market. This time, Schwalbe was already working on a similar concept that was intended to eliminate pinch flats for gravity racers. The two companies decided to join forces and produce one design that could address Klieber's vision of mating the tire's performance with the bike's suspension and Schwalbe's desire to end the dreaded pinch flats that so often sideline gravity racers.
The beads of the Procore system's internal high-pressure treadless casing force-seal the beads of the main tire against the rim flanges. In the case of a puncture, the tire cannot leave the rim and remains partially supported by the high-pressure inner casing. As a result, a competitor can finish his ot her race run and possibly salvage points from what would have normally been a writeoff performance. That story has taken place at least once this year.
In the end, Procore delivered more than expected. Schwalbe's insistence that the inner tire be a clincher type instead of a tubuler had the effect of pinning the beads of the tubeless outer tire to the rim's flanges, so if the main tire flatted, it would remain on the rim and still be rideable for the entire race run. Pinch flats were almost completely eliminated, and the tires could be run at 1.5 bar (22psi) with complete confidence. Schwalbe's sponsored riders began competing on the system at World Cups, midway through the 2014 season with excellent results. Reportedly, one of the most prominent users is Mister Samuel Hill. Schwalbe and Syntace say that the additional sensitivity afforded by the ability to run lower tire pressures, and the enhanced sidewall stability created by the inner tire being able to support the tire casing above the rim flanges give the rider a huge cornering advantage.
While it would be a stretch to claim that Schwalbe's Procore tire system is largely responsible for Hill's recent domination of the World Cup DH, there can be no doubt that the Australian has owned every off-camber section and slippery corner in the second half of the 2014 season. Hill always keeps his cards close to his chest, but I suspect that the world's fastest man on flats has a secret weapon. It could be a can of old fashioned Whoop-Ass, or it could be Schwalbe's Procore tire system.
I also can't wait to try it out! But maybe with a ghetto thing with a road tire and stuff.
From a german forum:
fthumb1.mtb-news.de/cache/950/auto/1/1/fstatic1.mtb-news.de/f3/16/1652/1652209-p0pc4co556ka-rrsr2-large.jpg
fthumb1.mtb-news.de/cache/950/auto/1/1/fstatic0.mtb-news.de/f3/16/1652/1652208-tdsfmr1ppr5b-rrsr1-large.jpg
vimeo.com/74188832
forums.mtbr.com/wheels-tires/ghetto-home-made-procore-dual-chamber-diy-928600-post11421192.html#post11421192
You may end up with about 300g (100g more than the original). Comparing to a Maxxis heavy duty DH tube (490g) is better, Schwalbe durano 28-559 (260g) is also another good and cheap possibility (it has more volume). A road tube weigths about 60-100g
This definitely sounds (!) interesting but to say Hill won because of the system is a bit over the top.
Sam won because he's Sam, and back to shape. He's unequivocally one of the top 5 greatest DH'ers in the sport because of his skill.
Still waiting for tubular DH tires with a bead lock style rims......... hehe
Also, it's 'a lot'. Is alot some sort of an animal?
1 - advantage is nominal : seeing as you haven't tested it I find this strange. Now if we are to believe the first reviews of the system and what schwalbe has said having more traction is NOT nominal it is a big deal independently if you are a racer or not
2 - Sam is still running reasonable pressures - I don't know what tire pressure he is currently using and tire deflection is irrelevant if it won't roll off and if it gives you more traction
3 - because once you start hauling ass, you need to increase pressures to avoid excessive squirming and destroying the set up - true with a standard setup but not necessarily true with this system seeing as the tire compression isn't linear.
1: This is based on shawalbes press release, and interviews. They clearly state the 'advantage' is being able to perform a run, and it's help with preventing burping, which I listed as the real 'advantage'. There is no 'traction' advantage to be had from an inner bladder. The advantage is less flats at a desired low psi that downhill racers have run for over a *decade* (low to high 20s, depending on rider).
2: As per interview, and several other interviews, he's running mid 20s. that's reasonable, and not in the teens like some would have you believe. Tire deflection is very relevant, but you'd need to read a few books to understand that.
3: as above, it's still possible to flat, and with increase in speeds comes increase in forces applied.
Again, zero assumptions. All based on information from interviews, my education and understanding of forces and basic physics, and the interwebs.
If you want to play this game, might want to brush up on your 'science' so you can actually bring something to the table, because as it stands all my information is correct and you aren't stating anything other than antagonizing with zero credibility.
@pancakeflathead that was the impression I got from it. Totally insulting.
In this article alone (let alone other interviews) "Pinch flats were almost completely eliminated, and the tires could be run at 1.5 bar (22psi) with complete confidence"
Guys rarely went that low before for risk of flatting. In the 10s is a joke. This isnt' trials riding. You think rock crawling trucks run the same psi settings as pre runners or Dakar racing trucks?
Also, I didn't 'discredit' shit. Stop making stuff up. It's clear I stated the advantages and stated that they did little, if anything' to help Sam win, which was clearly mentioned in the article, and which others took issue with as well. As someone who's been racing since 2001 I had my fair share of things to experiment with
I think it's a factor of speed, riding style, rim/tire set up. I don't think we jumped to any assumptions, but rather jumped on the silly assumption that Hill had an 'advantage' by using these.
These are all just benefits that are inherent to this type of system whether moto or MTB, just marketed from a slightly different angle to make it sound like less of a replica of the well established moto versions.
That being said if it gives good grip, less tyre rolling/burping and better traction it'll be all good. Except it will be an absolute bastard to fit.
All I know is that Syntace told me to run lower pressures on wide rims and after first two descents I took it back up as I had it on barrow ones, to feel the benefit. I also know that I am not the only one feeling the same about this. I smell awesome flat protection, but not much more unless they totaly redesign tread patterns.
Edit: ignore me, it literally says that on the diagram. I am an idiot.
Does anyone else read that as
Schwalbe - "oh yeah that idea of yours we said we couldn't do, we're working on our own version now"
Syntace - "er right dude um LAWSUIT?"
Schwalbe - "hmm good point let's see your design again..."?
"sorry we can't help you right now"
"oh look, we've been working on the same thing, what were the odds!"
The eliminator rim I think??
It had potential though..
esmtb.com/wp-content/uploads/2014/08/100_samhill.jpg
Regardless of how tight the beads are held on by the inner tire, how would the outer tire not be squirmy as hell between 10-20psi? Can anyone explain that? @RichardCunningham?
I know that being over 220lbs fully geared up with a pack, I can't really run less than 25psi without feeling my tires moving all over the place underneath me in corners... I shudder to think about 10psi!
Another thing that occurred to me: you're Schwalbe slave for life with Procore
BTW: I don't think that pressure as low as 1,5 bar make sens in anything other then DH racing.
Problem with top riders not riding for Schwalbe?
Can other tyre manufacturers find an other solution?
I have an other different idea if other tyre manufacturers are looking in HELLO Maxxis ect. GET THINKING!!!!!!!!!!1 or get in touch !!!!
That being said I'm sure this technology is great and will be very useful to people in the future.
Also means i can steal my dads enduro spec dirty dans and run them safely instead of replacing my own twin wall ones.
That might make me sound like a kid but i'm 32. Whoops
And yes, he's a true bike visionary!
Didn't Stevie had that back in 2012 in Hafjell?
www.vitalmtb.com/photos/features/Bike-Check-Stevie-Smiths-World-Cup-Winning-Devinci-Wilson-Carbon,4520/Slideshow,0/bturman,109
Picture n°8
Well between "can't possibly get" because it's not available or "can't possibly get" because I don't have the money...
Same thing to me
A: costing almost as much as this does
B: significant weight penalty vs procore.
before you scoff at the weight penalty, keep in mind we're talking about unsprung perimeter rotational weight: there's literally no place else on a bike that weight is more of a penalty than at the edges of the wheels.