(Hookless) What PSI do you run and have you ever blown a tire off?

[Tofast]

When I asked Vitoria if Corsa Pro 28mm would be approved on 25 mm IW they said no independent of hookless or hooked so it is surprising that the teams runs it.

I also sent the info to ZIPP and asked them to change their recommendation but they still haven't so that is quite bad from ZIPP:s side.

[mikehhhhhhh]

When I asked Vitoria if Corsa Pro 28mm would be approved on 25 mm IW they said no independent of hookless or hooked so it is surprising that the teams runs it.

I also sent the info to ZIPP and asked them to change their recommendation but they still haven't so that is quite bad from ZIPP:s side.

According to Zipp, their compatibility chart is based on tyre manufacturers reporting, so Vittoria approved it at one point.

To be fair, I don't see it published anywhere by Vittoria that the 28mm isn't suitable for 25IW

[naavt]

I can't imagine having dozens of bad experiences with tubeless.

That's what I call "leave it to chance!" I was one of the early adopters and believe me when I say that I had at least half a dozen of serious issues in a single year, not to mention all the life span of my tubeless experience.

The last one being a new pair of shoes and bibs (Lakes 238 and Sportfull bibs), all ruined by Silca's sealant which didn't came off no matter what. The hassle and expense when the system doesn't work doens't even come close to a simple job of replacing a tube on the road.

No more tubeless for me, at least until someone really offers a genuine system for the kind of tire pressures that road bikes use, and not only some system transported from mountain bikes (and on those the system works), to road.

[MikeD]

Not trying to be alarmist, but I've run Zipps new hookless iteneration and albeit being a comfortable ride (since it asks for very low pressures) I've ended selling them for 3 reasons:

1. It seems that some enginners question the tecnology when used by road bikes, even if pressures aren't that high (compared to hooked rims) stating that are some risks involved. We all know that Zipp and Enve - for instance - are well known brands and that they wouldn't risk their reputation on something that didn't work, but lets face it... Tecnology is new to road bikes and only time will tell if it works or not. For now, I do believe that marketing strategies play an important role on hookless rims.

2. Aero reasons. You can stand behind the notion that bigger tires have less roling resistance, but some tests argue that the RR benefits of a 30mm tire (28 when inflated on a hookless rim with a large inner width) won't cover for the loss in aerodynamics when compared with a smaller front area (25mm tire) and the difference will become even more visible when using modern road bikes with wider forks.

3. I've switched back to inner tubes after dozens of bad episodes with tubeless tires.

Regarding 2:
Not necessarily true. Depends how the rim profile was designed and for what width it was designed, depends on the rim width and transition.
A larger tire can have less drag than a smaller one if turbulent separation is controlled better, albeit having a larger frontal area.
The smaller tire can have a non-optimal transition to the rim and flow is separating earlier and more violently due to the rim edge being more prominent.
Additionelly it dependes on the surface roughness of the tire.

Do you have a reference that proves this? I was taught in Fluid Mechanics that frontal area dominates.

I teach fluid dynamics . Projected area includes rim, too. Look at tire from front and tell me whether a broader rim than the tire wouldn't make a difference

If rim width is 30mm outside and 22mm inside, a 25c tire could be smaller in width, transition therefore not smooth and the edge where the tire meets the rim could be causing strong separation, too.

The Cd-coefficient is determined by integrating stresses and pressure over the whole body (thus including form drag (pressure difference front/aft) and friction drag (viscous forces)). So the separation point + wake is important, too, to determine the form drag as well as friction drag.
Form drag is usually smaller for perfectly shaped objects like airfoils where the air is following the form smoothely without separation, but dominat for blunt bodies (think golf ball, for example).

You can even use turbulence to decrease wake/ form drag (e.g. dimples for golf ball) or by using a leading edge/toughness patch to trigger transition on purpose (or vortex generators in Formula one or on wings). This should be on the tire itself, not the rim, however. Swiss Side is working on that.

I've never seen a rim wider than the tire. That would be an unsafe combination i.a.w the ETRTO standard, especially where hookless rims are concerned.

[warthog101]

I can't imagine having dozens of bad experiences with tubeless.

That's what I call "leave it to chance!" I was one of the early adopters and believe me when I say that I had at least half a dozen of serious issues in a single year, not to mention all the life span of my tubeless experience.

The last one being a new pair of shoes and bibs (Lakes 238 and Sportfull bibs), all ruined by Silca's sealant which didn't came off no matter what. The hassle and expense when the system doesn't work doens't even come close to a simple job of replacing a tube on the road.

No more tubeless for me, at least until someone really offers a genuine system for the kind of tire pressures that road bikes use, and not only some system transported from mountain bikes (and on those the system works), to road.

Love tubeless. Have hooked and hookless.
Has drastically reduced my rate of punctures. Sold on it, sooo much better.

[cleanneon98]

https://youtu.be/GOgrig9JtFw?si=PlK9Gmvz7-SXJHfe

[Greny]

https://www.facebook.com/story.php?stor ... EQnXw&_rdr

Hookless rims are in the crosshairs of CPA (Association of Professional Cyclists) president Adam Hansen following Thomas De Gendt’s recent crash on stage 5 of the UAE Tour, with the Australian saying that the riders' association is "100 percent against" the technology.
About time , read the article, I had more then 25 years a high end bike shop....you need a hook for a tire...

[markyboy]

I ran the zipp 303 hookless for 2 months and hated it,I just didn't feel safe so got rid.

[HBike]

Regarding 2:
Not necessarily true. Depends how the rim profile was designed and for what width it was designed, depends on the rim width and transition.
A larger tire can have less drag than a smaller one if turbulent separation is controlled better, albeit having a larger frontal area.
The smaller tire can have a non-optimal transition to the rim and flow is separating earlier and more violently due to the rim edge being more prominent.
Additionelly it dependes on the surface roughness of the tire.

Do you have a reference that proves this? I was taught in Fluid Mechanics that frontal area dominates.

I teach fluid dynamics . Projected area includes rim, too. Look at tire from front and tell me whether a broader rim than the tire wouldn't make a difference

If rim width is 30mm outside and 22mm inside, a 25c tire could be smaller in width, transition therefore not smooth and the edge where the tire meets the rim could be causing strong separation, too.

The Cd-coefficient is determined by integrating stresses and pressure over the whole body (thus including form drag (pressure difference front/aft) and friction drag (viscous forces)). So the separation point + wake is important, too, to determine the form drag as well as friction drag.
Form drag is usually smaller for perfectly shaped objects like airfoils where the air is following the form smoothely without separation, but dominat for blunt bodies (think golf ball, for example).

You can even use turbulence to decrease wake/ form drag (e.g. dimples for golf ball) or by using a leading edge/toughness patch to trigger transition on purpose (or vortex generators in Formula one or on wings). This should be on the tire itself, not the rim, however. Swiss Side is working on that.

I've never seen a rim wider than the tire. That would be an unsafe combination i.a.w the ETRTO standard, especially where hookless rims are concerned.

Plenty. Many try to follow the 105% rule to optimize aerodynamics (although Swiss Side claims it has no merit). My Bontrager Aeolus RSL 51 is wider than the 28c tire mounted. Pretty normal

[Lina]

I can't imagine having dozens of bad experiences with tubeless.

That's what I call "leave it to chance!" I was one of the early adopters and believe me when I say that I had at least half a dozen of serious issues in a single year, not to mention all the life span of my tubeless experience.

The last one being a new pair of shoes and bibs (Lakes 238 and Sportfull bibs), all ruined by Silca's sealant which didn't came off no matter what. The hassle and expense when the system doesn't work doens't even come close to a simple job of replacing a tube on the road.

No more tubeless for me, at least until someone really offers a genuine system for the kind of tire pressures that road bikes use, and not only some system transported from mountain bikes (and on those the system works), to road.

You can't have been an early adopter if you had problems with the Silca sealant within a year of trying tubeless. At that point there had been actual years of user data to use Orange Seal and what tires are good. So it's clear that your issues are all user issues brought in from either refusing to use the tried and true products or refusing to do any research and insisting on experiencing all the same problems others before you have experienced for no good reason.

[naavt]

You can't have been an early adopter if you had problems with the Silca sealant within a year of trying tubeless. At that point there had been actual years of user data to use Orange Seal and what tires are good. So it's clear that your issues are all user issues brought in from either refusing to use the tried and true products or refusing to do any research and insisting on experiencing all the same problems others before you have experienced for no good reason.

Nowhere in my post you've read that I was using Silca from the start. What I told was that Silca ruined me some kit (take your time to see what I really have written "the LAST one being a pair of..."

Before Silca I've tried everything else! From OS to Stans and it's Schwalbe version... with many messy results.

But to each their own! I'm not trying to evangelize anyone. If it works for you... then great!

[nunokas]

I ran the zipp 303 hookless for 2 months and hated it,I just didn't feel safe so got rid.

Pardon my french but what's your weight and tire pressure?

More than 16k on mine, 50/55psi with p zeros and never had a problem with it.

[Lina]

You can't have been an early adopter if you had problems with the Silca sealant within a year of trying tubeless. At that point there had been actual years of user data to use Orange Seal and what tires are good. So it's clear that your issues are all user issues brought in from either refusing to use the tried and true products or refusing to do any research and insisting on experiencing all the same problems others before you have experienced for no good reason.

Nowhere in my post you've read that I was using Silca from the start. What I told was that Silca ruined me some kit (take your time to see what I really have written "the LAST one being a pair of..."

Before Silca I've tried everything else! From OS to Stans and it's Schwalbe version... with many messy results.

But to each their own! I'm not trying to evangelize anyone. If it works for you... then great!

Maybe you should pay some attention to what I wrote. I said you used it within a year of trying tubeless. That can't make you an early adopter in tubeless since Silca only released their sealant once tubeless was established technology. At that point I and many others had years of experience with tubeless. I've been on tubeless on all my bikes for over 5 years at this point. I was an actual early adopter of tubeless and sure, especially the first iterations weren't perfect, but even they were better than tubes. If you had constant issues with tubeless within a year of Silca launching their sealant it's entirely user issue caused by not knowing what you're doing because you didn't bother doing any research into the subject.

[naavt]

Maybe you should pay some attention to what I wrote. I said you used it within a year of trying tubeless. That can't make you an early adopter in tubeless since Silca only released their sealant once tubeless was established technology. At that point I and many others had years of experience with tubeless. I've been on tubeless on all my bikes for over 5 years at this point. I was an actual early adopter of tubeless and sure, especially the first iterations weren't perfect, but even they were better than tubes. If you had constant issues with tubeless within a year of Silca launching their sealant it's entirely user issue caused by not knowing what you're doing because you didn't bother doing any research into the subject.

I've read what you've written and I really won't even start a idiotic discussion about who was the first who did what!

On an end note, I really find it weird that almost all tubeless defenders do it by trashing the apparent ignorance of all others that don't defend the system!

Again... I'm not trying to evangelize anyone but I constantly see - and read - those "tubeless freaks" trying to evangelize everyone by calling others ignorants.

What can I say? Do you want a medal for doing things right? Given!

[BenCousins]

I can't imagine having dozens of bad experiences with tubeless.

That's what I call "leave it to chance!" I was one of the early adopters and believe me when I say that I had at least half a dozen of serious issues in a single year, not to mention all the life span of my tubeless experience.

The last one being a new pair of shoes and bibs (Lakes 238 and Sportfull bibs), all ruined by Silca's sealant which didn't came off no matter what. The hassle and expense when the system doesn't work doens't even come close to a simple job of replacing a tube on the road.

No more tubeless for me, at least until someone really offers a genuine system for the kind of tire pressures that road bikes use, and not only some system transported from mountain bikes (and on those the system works), to road.

I'm off tubeless too after trying it with both MTB and road.
- Hassle of installation
- Refilling of sealant
- I had two quite small punctures that did not seal, one half way up the Turini. €100 Uber ride home.

I'm also off TPU because of slow leaks and valve stems breaking under light pumping action.

Back to Latex, early 2000s style.