seypat

You forgot about the sound. Ditch the crabon and you'll stop looking over your shoulder for that Pterodactyl that's swooping down to carry you off for dinner.

seypat

This, and my fat ass would have me hovering close to the danger zone. What hasn't been talked about yet is if one's weight flucuates 2 or 3lbs from day to day. The pressure and weight measurements better be precise. That 5-10lb range won't cut it.

surak

What's a more likely scenario in road cycling: A) an impact causes tire to deflate, which could lead to tire tire unmounting from the rim and breaking as it hits pavement or B) impact causes rim to crack, which could easily lead to a tire coming off?

Seems like the people saying the type of tire retention doesn't matter are assuming scenario B, but the tire being deflated at the beginning of scenario A is a lot more likely to me, and the hooked rim by design has a better chance of retaining that tire than hookless. This is the scenario the CPA is concerned about.

seypat

I'd vote for A.

DaveSSS 

Increasing the total bike/rider weight from 260 to 270 pounds only increases the recommended tire pressure by 1.3 psi. If I weighed that much I'd be on 32mm tires where there's a significant safety margin, not 28mm.

terrymorse 

Not very easily. I once rode on a fully deflated GP5000 clincher for a mile, because I didn't want to ruin my cleats by walking. The tire did not come off, until I worked it off with tire levers.

I've had a few sudden deflations while riding GP4000 and GP5000 tires. Never once did the tire bead come off the rim.

The makers of the tire and rim wouldn't have any vested interest in spinning the story, would they?

DaveSSS 

None of my BTLOS or Zipp carbon wheels ever made any noise.

seypat

A few years ago on a ride, I thought I heard a flock of turkeys take flight. I looked around/behind me and it was a rider with crabon wheels whooshing instead. I'm glad it wasn't a flock of seagulls. If it had been seagulls, I would have jumped off my bike and ran. I would have ran so far away. Even then, I probably couldn't get away.

Sy Reene

not really
as you'll calculate from the ETRTO chart above in post #247, a 32mm tire supposedly should only be inflated to a max of 65psi (450 x .145)

msu2001la

DeGent wasn't trying to ride a flat tire. He either hit something that caused him to crash, or his tire spontaneously blew off the rim and that caused him to crash. Tire retention after going flat has nothing to do with his situation.

DaveSSS 

The latest ETRTO guidelines limiting 30-34mm tires to 65 psi is more limiting than what's stamped on my 30 mm Pirelli tires. They say 73 is OK. I believe that ETRTO guidelines only apply to products manufactured by member companies who agree to abide by their recommendations, but I need to recheck that. Regardless, I'm going by what's printed on my tires. Weighing 135, it's not one of my concerns.

https://www.cyclingnews.com/features/changes-to-etrto-do-new-wheel-and-tyre-combination-recommendations-affect-your-safety/

msu2001la

This is part of the problem with hookless. The pressure is dependent on what size/type of rim the tire is being mounted to, and the pressure range on the sidewalls often doesn't align with the max recommended pressures from ETRTO or others.

My 30mm Specialized Turbo 2bliss T2/T5 are sidewall stamped as 65psi min - 95psi max. The Mavic chart above says 65.4psi max for this setup.

I run them around 55-60psi on 23mm ID hookless but I bet a bunch of folks are running these higher.

terrymorse 

Not sure that has been established for certain. He could have had a rapid loss of pressure (from an impact, or something else), followed very quickly by tire coming off the rim.

PeteHski

This is a good point. With a “normal” puncture, the foam insert should allow the tyre to run flat for miles. That’s the whole point of the insert and why they are so widely used at races like Paris Roubaix. Some teams not using inserts at Roubaix last year got caught out by flat tyres coming off rims. One of the Ineos riders was discussing this in a post-race podcast and criticised teams who were not using inserts with their tubeless tyres. There were no comments about hooked vs hookless though.

But in this particular crash the insert clearly didn’t work, which suggests that the tyre came off suddenly without warning. Whether that was from a severe impact or a spontaneous tyre blow-off depends on whether you believe the manufacturers or take a more cynical view. An impact seems more likely given the reported rim damage.

tomato coupe

Anybody here using inserts?

Yan 

I understand why you are lost, it's because you need to go back and read the entire thread. There was a long discussion in the earlier pages where people were attempting to justify hookless on cheaper price.

Yan 

What's with these ass backward poor logic posts saying "my friends and I have been riding hookless for x years and never had a downhill tire blow-off, so hookless is fine"?

​​​​​​The point is not how frequent downhill sudden flats are. Flats are rare and flats that just happen to coincidentally occur during a downhill are even rarer, because most of our riding minutes are not on downhills. The point is, what happens IF it occurs.

Neither you nor anyone you know have ever been in an airplane crash. Plane crashes are extremely rare, far rarer than downhill tire flats. If someone says you have a choice of two airplanes to fly in, a normal plane, or a plane with some safety features reduced because it was cheaper for Boeing to make, the world would rightly call you a moron if you chose the less safe plane on purpose.
.

• If the two plane tickets are the same cost, then you're a moron.
• If the less safe plane ticket is cheaper and you chose it to save money, then you're tighter than a dolphin's ass, cares more about money than your own safety

.
Either way it doesn't shine a good light on you.

mstateglfr 

face palm

Yan 

You're still confused or what?

DaveSSS 

This article has the best info I've read. I will continue to use 28mm tires on my BTLOS hookless 25mm IW rims. I've tested setups to 85 psi with no blow offs. I have used early model Michelin tubeless that were not approved for hookless for this reason - they suffer from bead stretch after 6-9 months of use. If deflated to add sealant, the beads dropped off the shelf and couldn't be reinflated with valve core in place. In contrast, Pirelli P-Zero TLR tires remain tight after more than a year of service. I briefly installed an old P-Zero with a tube and had a hard time getting the beads off the shelf when I took it off.

https://www.cyclingnews.com/features...t-your-safety/

For heavy riders who can't fit 32-35mm tires, it's probably best to stick with hooked, so you won't be buying Zipp or Enve wheels. Comparing a 31mm external width BTLOS rim to a hooked version of the same rim, the Zipp pressure calculator recommends about 8 psi higher pressure with the resulting 22mm IW, instead of 25mm. At least the pressure recommendation is well under what's allowed for a hooked installation.

​​​​​

tomato coupe

This seems like a good time to revisit Trakhak's earlier question. BTLOS wheels are available in both hooked and hookless, with the two version weighing the same and costing the same. If the hooked version gives you more flexibility with tire pressure (and therefore usable tire widths), what is the advantage of using the hookless version?

wayold

Not always true. I recently bought a set of BTLOS WM-i22 wheels for my gravel bike. Had they been available at the same weight with hooks I'd have bought them that way, but I'm not losing much sleep running them hookless. BTLOS does sell 22mm IW hooked wheels/rims, but they are of a different design and substantially heavier than the M-i22 (80g heavier per rim).

tomato coupe

Okay, then limit the question to the models that do weigh the same. In those cases, what is the advantage of hookless?

wayold

If they weighed the same and cost the same I'd buy hooked rims, just for that extra bit of reassurance. For lower pressure tubeless applications (MTB and gravel) I really don't think it makes much difference. I'll admit, though, that for road tubeless where the pressure might be within 10-20 psi of the rated maximum I'd be more comfortable with hooks.

DaveSSS 

I suggest reading the info at the Giant website regarding hookless rims. Apparently, they couldn't care less what ETRTO or ISO have to say. They're confident that their wheels and tires will work at higher pressures.

At some point, users will find that sealants don't work so well at higher pressures. There's an advantage to not needing as much pressure. My 30mm tires allow 87 psi with hooked rims, but punctures might not seal as well.

https://www.giant-bicycles.com/us/hookless-technology