eduskator

Com'hon...you can exceed the limit to seat the tire without damaging anything. Nothing's gonna blow or crack, I promise

Racing Dan

That's fine, but exceeding stated limits (or using tyres that isn't explicitly approved for hookless) you are experimenting and on your own. Object and argue all you want but I've been following these threads for some time now, and its always the same. - Disregarding stated limitations because reasons, extrapolating what tyres can be used even if not approved, ignoring the obvious fact that less tyre retention is worse not better, etc. While at the same time claiming hookless is "better" for nebulous reasons that feels entirely made up. Ie, you "can" run lower pressure as opposed to "must" run lower pressure, "can" run wide tyres as if the same tyre wouldn't fit on a hooked rim, claiming the rim is lighter while at the same time ignoring a tl tyre is much beefier than a clincher. Committing logical fallacies along the lines of."Ive been using hookles for x time and didn't die, thus its great and likely better than hooked rims" (hat also didnt kill the respondent). On and on and on :-)

eduskator

Are you familiar with the test protocol used to determine if a tire is safe to be used on hookless rims? You should read about this, it would really enlighten you.

My current tires are hookless compatible and rated up to 95LBS. I feel safe riding my bicycle knowing that I inflate them above my ideal 65PSI pressure for a minute or two once or twice a year when I swap them . In fact, I don't even think that my rims have a maximum pressure rating.

phrantic09

Not only that, but if you’re using something like an air shot you won’t get an appropriate size tire for a hookless rim to exceed 72 PSI. The volume of a 28c tire is something like 2.5x what the canister contains so it doesn’t hole enough air to get the tire pressure that high.

eduskator

Yep! My floor pump has a built-in compressor that can go up to 200PSI. I usually stop at 150-160, then I open the valve and it's enough to seat the tire. Pressure reading after the shot is around 40-45PSI.

People talking and arguing about things they don't know.

SoSmellyAir

Let me spell it out. You have not disputed the facts that (1) lower tire pressure comes from running tubeless, rather than hookless, even though you previously (in post #85) said lower tire pressure is an advantage of running hookless; and (2) hookless requires lower tire pressure (e.g., < 73 psi). You are merely disputing that the limitation in #2 is not a disadvantage, right?

For example, 700x25 Schwalbe Pro One TLE can be mounted on Zipp 303S: Hookless Tire Compatibility | Zipp (sram.com)

This is a relatively narrow tire size and some may want to > 73 psi. Thus, it is a disadvantage not to be able to inflate this tire > 73 psi. Just because you think a tire pressure > 70 psi is unnecessary for anyone < 200 lbs. does not eliminate this disadvantage.

Maelochs

Excuse me but ...


I weigh an eighth of a ton. I am probably not well-served by 16/20 wheels (I usually use 24/28). That doesn't mean that low-spoke-count wheels are bad but that I cannot safely use the benefits they offer.

Hookless wheels are not suited to every rider. Okay. Well, super-light climbing bikes are crap for pro downhill riders ... which should we ban? Climbing bikes, downhill bikes, downhill racers? Are downhill riders a step backward?

Hookless rims are an OPTION.

SoSmellyAir

Of course they are. As far as I can tell no one here has advocated for banning hookless rims. I was merely pointing out (mostly to eduskator) that the lower maximum tire pressure is a disadvantage rather than an advantage.

Carbonfiberboy 

I was once told by a rim manufacturer's rep that max tire pressures shown on the sidewall are derived by a calculation involving the casing size, measured rim to rim. There being an even pressure distributed on the casing, we see that force at the rim depends on this casing size. I was told that this calculation was done so as to not overstress the rim and had nothing to do with tire structure, tires always being engineered with a large factor of safety, as are rims of course, however rim braked rims wear out and tire structure essentially does not. Thus we see that heavy duty tires for the most part have a max pressure similar to that of the lighter duty tire.

Anyway . . . my point is that smaller tires should not need to have the same max pressure number as larger tires, since there's less tension at the (hookless) rim. Seems that way to me anyway. One wonders. One also does not want to die.

Kontact

I don't understand what the first paragraph has to do with the tire size stuff in the second paragraph.

Maelochs

I missed this o0n my first pass ....
Ummmmm .... what are you risking? Blow-off?


Of the Unmounted tire?

Look, people her seem to love to hate stuff they don't use. Often they go through some pretty weird mental/logical contortions to "prove" that their preferensc3s are "better." it is a little embarrassing.

Hookless rims are nto evil. They are no non-functional Not sure exactly what th benefits are, becasue I haven't bought wheels in several years, and haven't needed to do the research .... But ....

If the only complaint people have is that they are not made for high pressures .... that is NOT a "design flaw." They are specific parts made to operate under specific conditions, and the popel who want to use them that way, have the option.


If I want to run 70 psi in my 28s, not a thing wrong with hookless rims .... particularly if the are rated to 95 psi, as a poster who actually Rides Hookless and Survives, mentions above.

If I want to run 230s at 120, maybe tubeless in general is no my best bet .... so then, isn't Tubeles Also Evil?

Now we are into LarrySellerz territory ...... if I weigh 250 lbs, and find that more than a foot of exposed CF seat post is an excessive risk ... CF Seat posts Are Evil.

Hookless rims are only useful for certain riders in certain situations.

Guess what? The same can be said for studded tires, or tubulars.

Nothing wrong with a product with limited application.

"Show me on this bicycle model, exactly where the hookless rim touched you."

Racing Dan

You and others appear to still not understand that a 95psi rating does NOT apply when mounted on a hookless rim. 73 psi is the limit in hookless road application regardless of any other spec. printed on the tyre. - Except if the print says something less then 73 psi. Then that number apples. Too much confusion and possibilities of getting it wrong, IMO.

No one ever said hookless cant be made to work, just that hookless is worse, not better, than hooked in a number of ways. - If you still want to consider it a viable option, fine, but please stop inventing silly reasons. Just get it if you want it and abide by the limitations, or not, at your own discretion.

Maelochs

"Better" and "worse" are value judgments .... personal judgments. When dealing with engineering issues, value-free is the best way. it is what it is, it does what it does.

If a certain product doesn't meet You needs, it is not "bad," it is just not useful for you.

People are selling, buying, and riding hookless rims. They are actually working for some folks. For them .... they seem to be okay.

Not arguing that they are universally useful, or useful for you---or me. What I am saying .... I have already said.

pedal on, friend.

eduskator

What others do is none of my business, but the problem with people is they don't read instructions. You know, those few pages of information that comes with most of the goods you purchase. A hookless rim that has a maximum rated pressure of 5bar or less should not require additional pressure to properly mount tires on it. My TL tires are rated up to 95PSI and my hookless rims are rated up to 125psi (I checked this morning). Someone who wants a higher pressure should do his homework before buying a bike or rims, instead of buying the product and complaining after.

A few weeks ago, I read a thread here on DI2 chargers and the fact that they required at least 1A of current to properly work. People were blaming Shimano for bad engineering. When you read the instructions provided, it is written black on white to use a 1A or higher DC current. People are charging their DI2 with their laptop USB ports (0.9A or below) and are experiencing issues. Who's to blame? The manufacturer or the person that didn't read the instructions?

I just don't bite into the ''it should be made simple'' argument, regardless of what it is.

Carbonfiberboy 

I dunno. Read it again? 1st P is about how tire force at the bead or not-bead is calculated. 2nd P is why this should matter for hookless rims.

phrantic09

I’m not saying it’s better, I prefer the lower pressure that I can ride vs a hooked rim, but I also highly doubt that your typical hookless rim purchaser is going to have ANY confusion about tire compatibility and what to do. These aren’t wheels you get at Wal Mart for the average schmo. Someone buying Enve or Zipp has done their research.

terrymorse 

Yes, narrow tires can take more pressure than wide tires before failure.

The failure mode is blow off of the tire from the rim, whether hooked or hookless. Pressure rating for a tire accounts for that, with a substantial safety margin.

The force acting to blow off the tire can be modeled as the "hoop stress" of a cylinder, which is a linear function of pressure (P) and diameter (d) of the tire:





So yes, a wide tire will blow off at a lower pressure than a narrow tire. If you double the tire width, you halve the max pressure.

SoSmellyAir

By smaller and larger, are you referring to narrower and wider? If yes, note that narrower tires are often run at higher pressures than wider tires for a given wheel size.

SoSmellyAir

Everything I have read point to going tubeless as enabling lower tire pressure. If two tubeless wheels are same except one has a hooked rim and the other has a hookless rim, why would the hookless wheel be able to run at a lower pressure compared to the hooked version?

Kontact

I did. I just (still) don't see why the method of calculating rim tension has much to do with the safety numbers, since the pressure limit of 73psi isn't there to prevent rim failure, but to ensure the tire doesn't blow off. Hookless carbon beads should be stronger than hooked carbon.

The only rims that normally fail at the bead are ones that are worn thin by breaking. I've seen carbon rims fail from pressure (and bad execution), and the failure is generally toward the rim's center cross section.


Everyone is constantly looking to make stuff lighter, faster or sturdier. I don't care for road tubeless - but if you are someone who embraces it, hookless beads appear to be a way of getting a sturdier, more aerodynamic and lighter rim. And, if the tire is well constructed for the job, unlikely to be a problem even over 73psi. So much of the kvetching in this thread seems misplaced. If Continental can't get it right, use Schwalbes. They're lighter as well.

Kontact

I could be wrong, but I thought that the straight bead offers more surface area for the tire and sealant to maintain an airtight seal, even under more sidewall deformation found at lower pressures. Or, that the angles involved with the sidewall going straight into the bead rather than in a big curve offers better burp protection.

Maelochs

@Kontact: Hookless is the rim of Satan and if you defend it .....

BF told me so.

Racing Dan

Clearly you are wrong. 99% of all tyres out there are made with a hook in mind. Thus having a "slit" or rather a protruding bead for the hook to grab on to. (go take a look in your tyre collection) Mounting such a tyre on a straight wall rim Will leave a gap. - Un like the drawings in the marketing wank.

Chandne

I still use my rim-brake bit on steep fast Mtn descents. I have mountain biked for decades so learned to brake much less on the road. Maybe that is why I never had issues but I can feel the tire/air heating up on cold days. I switched to tubeless in front on that bike (hooked rims) and use much lower PSI in front when using that bike on the long and fast descents anyway. I have seen blowouts and they are scary as heck on mountain descents since most descents are twisty as well. One left the ride really badly injured since he flipped over the guardrail. Another resulted in a broken hip and road rash. Since I bought my newest bike, it is disc/tubeless and at 175 lbs currently, I use 55-65 PSI depending on terrain.