Flat tires. They happen to everyone, despite tire technologies progressing over the years, and there are ways to help prevent them and keep them at bay in many situations. Tubeless tire set-ups with your choice of sealant the most common set-up and preventative measure but in the last couple of years, tire liners such as CushCore, Flat Tire Defender, and Huck Norris, among others have become increasingly popular in adding an extra level of protection against flats.
There are a number of systems available now, each claiming their own benefits over the other, but they're similar conceptually. The foam liners further protect the wheel and tire from damaging impacts. They also allow the rider to run a lower air pressure without as great of a chance of rolling the tire off the rim and also giving some extra cushion against rim and tire damaging impacts that may occur. There are a number of other benefits people will claim ranging from increased vibration damping properties to being able to ride out a flat, but, that's the main idea.
Whether these foam liners actually provide that much more protection and make a difference that's worth the frustration of installation and the associated weight penalty is heavily debated among riders—not to mention their price. I'd wager that there's a pretty mixed spread of people who do and don't use them. It does, however, seem that foam liners have progressed beyond the point of being considered a gimmick and there are some real benefits they can offer in a number of situations.
What are your thoughts on tire inserts? Do you use them? Want to? Have no desire to? Tried them and hate them? Couldn't even get them set up? Let's hear it.
Not saying I have a better solution (besides, you know, running proper tires for your EWS race), but I am saying that inserts sure seem silly to me... even if they do work.
But I am pretty lightweight..
I feel rock/rim clashes way too often at the the pressures I'd like to run so have to compromise and run more. An insert seems like a reasonable solution to the constant fight between pressure, grip and protection.
With a proper tubeless rim and tubeless tire, my failures where more cut sidewalls(looking at you scwhalbe) than actual flats. I only run tubeless now at 33-35PSI and maxxis tires and can say I haven't had a flat in over 1.5 years.
I'd need to try running Cush Core before commenting on if adding damping to the tire is good for ride quality or not.
@mikelevy - you are 100% correct, inserts and more flats -
those are connected, that is because companies making inserts say that you can run lower pressures or thinner tyres which is BS.
Having said that I am totally sold on Procore. Single ply + procore for downcountry and Double down + procore for Enduro. All things park, just get a fkng DH tyre...
Running procore now and while you can run lower pressures without issues, the coolest part for me is being able to run 25 psi in my back tire without burping. It really locks the bead on with 60psi of force. Tokens for your tires. On an xc bike that likes to go uphill fast better off with fast skinny super light tires and 40+ psi with no inserts.
Still want to try cuschcore, simply because my ocd hates dents in rims. That and spiderweb looking creases in rims scare me on my dh bike. They destroy the necessary gear confidence for me.
Cyclists obsession with weight is likely the reason for a majority of tyre issues.
If you believe they work
Converting to carbon was enough for me. I used to be hard on aluminum rims.
It’s just carbon rimmed folks who can’t use procore.
£2.50.
By using some engineering equations (I'll spare everyone by not going into in detail), I was able to get a graph that relates tire pressure on impact to initial air volume. As the initial air volume of the tire is decreased (such as with a foam insert), the tire pressure on impact increases drastically. Essentially, this means that with a tire insert, the tire pressure will be higher on impact than what you would see without an insert. A tire without an insert doesn't have a large pressure spike for normal impacts but tires with an insert can, depending on geometry and other factors. Overall, this could be a reason for some of the failures we have been seeing recently as the tire pressure could be too high on impacts for the system to handle.
There are several ways I can think of to combat this effect. First, you could start at a lower tire pressure so the pressure on impact isn't too high. Second, you can use a lower profile insert so that the initial air volume isn't reduced as much from a standard tire. I suspect that less failures have been seen with the Huck Norris, as many have mentioned below, because it is relatively low profile and is not changing the tire system as drastically as CushCore, for example. Finally, you could have an insert that can deform without a rock actually striking it, such as ProCore with a lower pressure insert...
Hopefully my ramblings make sense to you. I think I'm just gonna stick with tubeless tires for now.
I’m sure they aren’t the only brand that’s 0FG on Procore/Ghetto-Procore.
@WAKIdesigns:
However (and obviously), closed cell is used so that the product doesn't soak up sealant and render it useless.
Going down that path... are we at a point yet where we don't need sealant to run a tubeless system? Are the rim and tire tolerances good enough yet that we can achieve a good seal without the sealant. And just use plugs for punctures? Similar to car tires?
And you end up running less pressure with Cushcore so the end pressure on impact is not super high.
Also, the statement Mike made " it sure seems like we're seeing more exploding rear wheels since these inserts have caught on" may or may not be true. So the whole theory that foam inserts have something to do with exploding rear wheels might be bunk.
So it's staying for now. Not decided whether to do the HB160 when it eventually gets delivered.
huck Norris is like a basic insurance.
It needs to be the right rider and terrain to justify it though. I'm an aggressive, 200lbs rider who chops through rock gardens like a fit kid through a ice cream cone. Before Cushcore I was denting rims running 33+ PSI. Our trails in Colorado can be very tough on bikes and wheels so the added weight penalty is worth it. If I rode on trails that were more smooth or actually cared how fast I climbed, I'd be singing a different tune.
I'd like to also add that I cut my EXO tire open on a rock and rode on Cushcore down a series of rocky sections for about a mile. It didn't cause any damage to my rim (which is carbon) or the insert.
The Syntace guy (name escapes me at the moment), so the story goes, wanted the fork/shock to start moving earlier during an impact. He ended up working with Schwalbe and they released the end product.
If you had a solid tyre then all the movement would be in the suspension.
Those pressure peaks should be lower than modelled if you allow for suspension motion.
The forces exerted on the wheel warped/bent/untrued the wheel drastically. The wheel isnt ment to resist forces in those directions.
I would imagine a similare result when you pop the high pressure tube in the procore.
Ftd has a new design, i just got them, cake to install, but my wheels and tires are easy to seat.
Raceface turbine and maxxis wt tires
As for tires...I feel like Maxxis is the only company to market towards wider rims. WTB and Schwalbe 2.5/2.6 tires have a nice slightly rounded profile and good sidewall support on 35mm rims.
The cushcore is simply mindblowing.
I seriously cant believe theres this much fickle nonsense about it. Embrace change and enjoy it. Modern mtn bikes are simply amazing.
This place is just bizarre ,sometimes
Its awesome in every way
Id quit if i had to go back to running 33/35 psi.
I wish I could get away with that but my rims are beat up enough
If wheels are exploding from a massive impact with a large contact patch (like a big flat landing or g-out) then I could see how you can create a larger change in volume and larger increase in pressure with an insert
I think Enve are onto something with their rim strip that is base on a split tube setup.
I also agree that we just might be imagining this correlation between inserts and exploding tires. Sometimes it is easy to notice a phenomenon when we don't think it should be happening as much, as with the tire inserts.
I agree that the tire inserts increase the tire stiffness so the suspension does more work. That is one benefit of the system. I guess you might want to re-tune your suspension after installing an insert then!
I still want to try cushcore very badly.
I drool over Santa Cruz Reserves though, I wouldn’t complain about that change in my setup.
We were wondering if the smaller volume created by an insert neccesitates a higher air pressure to get the same performance? Kind of like a 2.5 tire compared to a 3.0 tire.
We thought about this because I tried Pro Core at lower psi than I usually run in a DH set up and I was rolling the tire and getting rim strikes.
I’m running Cush Core on my trail bike now and while it has hasn’t allowed me to drop pressures it has allowed me to run EXO casing again with out flatting every other week. I have tried lower pressures and while the bead doesn’t come off the tire feels to squirmy in turns and on jump faces.
1. I didn't want to go through the trouble of seating a tubeless tire, using compressors or pressurized containers, tire levers or whatever else I'm reading over here. With Procore I can use whatever tiny handpump I can get my hands on and install the tire.
2. I don't want to be able to run low pressures without the risk of burping air or damaging tire or rim through hard impacts.
If you're running rims that are designed for tubeless use (like Stans) you should check with them whether they're up to the 6bar max pressure the tube is designed to accept. My rims were designed with Procore in mind so I don't expect any issues.
Would love to see a carcass between a bontrager SE and conti Baron.
Even a 20% increase in air pressure (say from 5psi to 30psi) isn't going to result in a meaningful stress on the wheel.
Run a DH course at sub-50kgF tension and you'll see wheel failures.
I do admit tubes really are easy to work with. Apparently some idiots who ditch their punctured tubes in nature may have given it a bad name. But I've stuck with tubes until quite recently and I was quite happy with them actually. I was running latex tubes which may constantly lose air (over the course of days) but they're light, easy to patch and don't puncture easily. I have to admit I tried butyl tubes recently and these are nowhere as nice. No idea why these are more common and popular than latex. I was running them at (about) 1.5 bar in the rear and 1.25 bar in the front. It is just that because my new wheels came with a label "procore ready" that I took the plunge. Mainly because installing a tire is as easy as with a tube and the procore system protects my rim. So far I haven't found any downsides with procore. It may add to the cost but as I don't see how it could possibly wear I expect it to be a one-time investment.
I reckon I would appreciate the impact protection of procore - my old alloy rims were dinged to buggery by the time I'd moved to the carbon hoops. I essentially run slightly higher pressures to ward of dings now.
250g of insert in a light weight tyre
Or
250g extra built in to a stronger tyre?
agreed. there's a lot to be said for simplicity.
One of the 1st times I’ve thought you have talked sense rather than shit.
All great points lads, an yeah I 'd really like to see a test as, it seems modern lower pressures are an lighter tyres are causing the blow outs on blow offs that require the need tyre inserts.
As a heavier (fat) rider myself, I've never liked the squirmy feeling of super low psi. That means my fine line of grip vs squirm has a higher psi. Meaning I can get away with good stout DH tyres. I get the puncture resistance from that, less to no dings from that. So, believe it or not..... I'm still running medium weight tubes on good heavy tyres.... But yeah, lighter riders with lower psi are gonna get away lighter tyres so.... More punctures an the need for tubeless so more blow offs an dings so the need for inserts...
I guess there's a balance somewhere but would that sell £$€¥50-150 tyre inserts? So nah, probably no tests on PB any time soon
And, tubes. So no worries about leaky dinged rims
If I do badly damage a rim, no worries
However, a pool noodle isn't effecting the suppleness of the casing (read: traction and comfort). Beefing the casing up is going to cause a loss in those two areas.
No interest in heavy, hard to install systems here. Especially if u slash a sidewall out in the backcountry. I hear it's murder to try to get the bead off the rim, then where the fk do u put the insert when you throw a tube in the tire? For sure could make sense for racing tho.
Huck Norris in my standard casing 950-1000g tires cuz it's easy as sh*t and lightweight and staves off the occasional rock ping against my carbon rims. A very easy way to add a level of insurance. Negligible weight. No it won't save me if i lazily plow thru a boulderfield at mach turkey with 15psi, but i think it's a good solution for some riders.
For alot of riders definitely worth considering something equiv to a DD casing on the rear, tho.
you still need a good DH tire to prevent flats.
I got myself the flat tire defenders after investing enough money into great carbon rims. Rim width 32mm (inner) Reartire Maxxis WT, Front Magic Mary SG.
But: for all those thinking about getting insert for the first time: at least the flat tire defenders: mounting tires is easy. But unmounting at least for me only works with a tire mounting machine. Also refilling or changing milk only work through the valves. No way to lever the tire from the rim with a tire lever, since the insert presses the tire onto the rimwall permanently.
Try to dismount your crushcore in the wild and dirty trails. Even the procore is bad but it is manageable. Try to stuff your crushcore back into your backpack. I talk about the whole package, what is the lightest derailleur good for if it fails that much on trails. What are tire Inserts good for if you get a flat but are unable to pull them out to get home fast with a tube.
*Destroys wheels/tyres whilst not getting full travel from shock
*Adds a volume reducer to tyre
*Profit?
Maxxis DD and Conti Trail King Protection, before that I had at least 4-5 punctions with DH tires.
It works pretty well for less weight, for me.
@mammal: I’m around 155 lb. I am pretty light on the bike and don’t really make a habit of smashing through stuff.
I just run it in rear though.
3 months ago I swapped Huck for Cushcore....and now I would have a hard time not riding without CC. Yes, CC is heavy. Yes, initial installation is a bear. But the ride quality is unreal. I don't know if it's the claimed "damping" effect, but I have lowered by psi to 18/19. Traction, including drive, braking and cornering, are simply better. I can plow through rock gardens without thinking about damaging the rims or worrying about pinching.
There is also a dramatic improvement in cornering precision. The sidewalls are indeed stiffer and I find myself holding lines much tighter than before. It's like I eliminated an understeering problem that I didn't know existed. And, after 3 months riding through sharp rocks, I've had zero sidewall tears.
Having said that, I'm dreading the day I get tear on trail, since doing a trailside repair that a tire plug can't fix, is essentially out of the question with CC
Quote:
Another option is to carry a lightweight inner tube with a long (48mm) valve stem. In the event of a flat, force the valve stem through the foam so CushCore can remain inside the tire.
But the guys who were running inserts, were able to run lower pressures since the inserts also stiffen the sidewalls and as such gain traction and speed.
Not that it affected my placing... I'm just out there for fun, but it's interesting talking to the guys and chatting about various set-ups.
It will always be a battle between grip vs. squirming/folding vs. flat/rim protection. trying to find the sweet spot is tough.
Poll is a bit odd though. I do run tubes, doesn't make it no.
well... nevermind if inside and outside are communicated by a puncture, you just can't flat lol
Science's never been my thing.
The more you know...
Last season installed cush core and went to double down casings and only killed one rim.
5 FR 570's= $325
Cushcore = $150
Im sold.
Rims destroyed equally. Flared from impacts and big s-bends.
Cushcore I thought would give more protection, and doubling up rock gardens proved to be too much (180# rider, sb5.5, avy tuned shock).
Im just accepting a race will cost a rear rim. Giving up on inserts.
The sidewall support and massive grip you get is well worth it. It also acts to slow the rebound/bucking you get when running higher PSI.
I dont think any of the other inserts really mimic what cushcore does. You can literally ride home on a flat and not worry about carrying a spare tube and CO2.
180lb rider on rocky terrain
Front: DD casing at 26psi
Rear: DH casing at 30psi
What's everyone doing running such low pressures? My bike feels like a wet noodle if I run any lower.
my setup = 26" wheels mavic crossmax sx with 21mm internal width running 2.35 onza ibex and onza cannis tyres. Ive hit tons of nasty rocks at speed. I dont do huge jumps but im a hefty 15 stone on a shortish travel full susser and its held up fine this long. Even if im not jumping far i do land heavy sometimes in bad ways and still good.......probbably gonna have a wheel explode on me now ive typed this.
dont know how everyone trashes so many tyres and wheels. I ride as often as poss in north wales were its nice and rocky and no issues with tyres and rims so far. Only thing is my wheel bearings wear out quicker than i like but thats it.
I think I'll stick with my tubes, not because it's better or worse, but because it's simple, no sealant, inserts, special tire pumps, and the extra weight really doesn't add up to be enough of a bother.
I'd pay someone else to do it for me. I'd consider it a good for $20.
Then the market can flood with fake bead-lock rims for all the scene-points idiots
When they become cheaper and easy to insert or easy to repair a flat on the trail.. ok... but at now.. no thanks
If the goal is to run lower pressure every year.. maybe producers have to change the tire concept...
I've got to say though, installing a tyres on a Cushcore is EXTREMELY hard
Particularly when you install it the first time and then blow it off the bead because you inflated it to 35 PSI :\
Weighs around 100g an end.
This is for trail and enduro application (and obviously not the perfect solution but for its cost its great)
DH and Park I switch to SG casing no questions asked.
Also still on 26" with tubeless and never experienced any of these issues
same here
Also, I'm 30 with a 20 year old mindset so sometimes I like to just send things that are probably beyond what I should be, so if I case or screw up somehow (not a rare occurrence) it's nice to have some insurance against smashing the shit out of my rims. If I ever become the better rider I hope I could be maybe they'll come back out, but until then, they will be front and back in the dh and trail bikes.
All that aside Code 4 is running awesome, need to go check out Prolapse. That will be a real test for the tires!