Hookless Rim Concerns

[scott43]

Some interesting stuff here, particularly around compatibility and safety. The compatibility issues are troubling with an apparent lack of agreement amongst mfgs even.

‘When Riders Express Concerns, It Worries Me:’ Hansen Welcomes Urgent UCI Review of Hookless Rims and Tires

Riders’ association president identifies several areas of concern he hopes the UCI will study as part of its review into hookless systems.

velo.outsideonline.com

 

[cantunamunch]

I am a total Vittoria fanboi, and they do have extremely clever liners that compensate for giant pressure spikes.

That said, given current slack standards around tire width and section profile (see other threads about 10%+ variance in width) , I don't see anyone setting a contact depth standard soon.

 

[Tom K.]

Interesting. I've been on hookless mtb rims forever. Pressures from 18 to 28.

But never remotely interested in going that direction for road wheels at higher pressures.

SIDE NOTE: This is such a great site. I was perusing comments on this subject on another site, and two commenters were sniping at each other about the practical pressure limit for hookless road rims, with one declaring it was 72 psi, and the other 73. Sheesh.

 

[scott43]

Way back, when the Specialized Turbo S folding tire came out, I broke more skin and tire levers trying to get those tires over the rim. Belief at the time I think was that with the Kevlar bead you had to have a very tight diameter to stay on the rim at 130psi, as was the style in the day. Jobst Brandt proved that the bead diameter was needlessly tight as the air pressure kept the bead in place. We cut beads with side cutters to prove it.

Fast forward, what's holding that tire on besides friction and diameter? Seems to be a greater chance of failure in certain conditions, especially with poorly understood tire diameter and rim width compatibility. I know people worry about burping road tires but I wonder how often this actually happens? And how many folks are running around with 90psi in their hookless rims obliviously?

 

[Tony Storaro]

We’ve been saying that all along. Ban the stupid hookless wheels already. This is tech that brings no benefits to consumers…as in NONE.

 

[Tony Storaro]

Interesting. I've been on hookless mtb rims forever. Pressures from 18 to 28.

But never remotely interested in going that direction for road wheels at higher pressures.

SIDE NOTE: This is such a great site. I was perusing comments on this subject on another site, and two commenters were sniping at each other about the practical pressure limit for hookless road rims, with one declaring it was 72 psi, and the other 73. Sheesh.

For MTBs it is fine, for road-absolutely not.

 

[cantunamunch]

We’ve been saying that all along. Ban the stupid hookless wheels already. This is tech that brings no benefits to consumers…as in NONE.

One might argue that it has leveled consumer prices in MTB, on the notion that MTB rims no longer need fussy and pricey un-automata ble hook moulds.

 

[cantunamunch]

Seems to be a greater chance of failure in certain conditions, especially with poorly understood tire diameter and rim width compatibility. I know people worry about burping road tires but I wonder how often this actually happens?

Are we counting events including cold weather and Stans, i.e.not specifically cold-formulated sealant?

 

[Tom K.]

Are we counting events including cold weather and Stans, i.e.not specifically cold-formulated sealant?

Not following. Stans and/or not cold-forumulated sealant add to the problem of keeping tires on rims?

My only cold weather experience is fat bike tires (max 10 psi, normal 4-7 psi) and hookless carbon rims. No problems in four seasons, N = 2 sets of wheels.

 

[cantunamunch]

Not following. Stans and/or not cold-forumulated sealant add to the problem of keeping tires on rims?

That's the roadie-pressure burping reports I know of. 40F, maybe below, and Stans, of unknown freshness.

 

[scott43]

I'm not sure sealant will help. If the burp is big enough and fast enough I don't know that it would be able to seal. I just saw a vid of a pro riding over a very very small lip in the road and popping a tire. I imagine those are hooked beads, likely riding over 75psi, and still appeared to burp. Could have been a puncture but didn't look like it..

 

[Tony Storaro]

That's the roadie-pressure burping reports I know of. 40F, maybe below, and Stans, of unknown freshness.

There are reports of tires blowing at all temperatures and sealants. This just needs to stop. One just cannot expect a tyre that can be folded 3 times, put in a box and then pumped to 6 bar to behave the same way as car tyre at 2.3.
This is just never gonna happen.

 

[cantunamunch]

I'm not sure sealant will help. If the burp is big enough and fast enough I don't know that it would be able to seal.

Ever taken a badly sealed glass jar and run sealant inside just to see what happens?

Anyway I think there is a notion that sealant develops an internal ring around the tire edge with some crude adhesive properties. The glass jar experiment might be a way to*cough* look into that.

 

[cantunamunch]

There are reports of tires blowing at all temperatures and sealants.

Not people I've ridden with *shrug*

 

[Tom K.]

There are reports of tires blowing at all temperatures and sealants.

Road, mtb, both? Hooked, hookless, both?

Not snarking, genuinely curious.

 

[Tony Storaro]

Not people I've ridden with *shrug*

Yes man, internet is full of anecdotal evidence of hookless rims being safe at even 7 bar, that doesn’t mean this tech isn’t utter useless shit that only brings benefits to the manufacturers.
if that wasn’t the case Specialized would not have reverted to hooked and Enve or was it Zipp wouldn’t have filed a patent for making hookless rims hooked again.

 

[Tony Storaro]

Road, mtb, both? Hooked, hookless, both?

Not snarking, genuinely curious.

I am only talking road here as this is what I care about. Hookless of course.

 

[scott43]

You can see the mfg superiority of hookless, cheaper for sure to mfg. I would argue the are also structurally more elegant. But yeah the safety issue is penalty not that well communicated to the masses.

 

[cantunamunch]

Yes man, internet is full of anecdotal evidence of hookless rims being safe at even 7 bar, that doesn’t mean this tech isn’t utter useless shit that only brings benefits to the manufacturers.
if that wasn’t the case Specialized would not have reverted to hooked and Enve or was it Zipp wouldn’t have filed a patent for making hookless rims hooked again.

Sorry, not buying the logic.

If I only know of very specific niche burps, that is what I am going to report on. It is not my burden to prove that other burps do not occur.

I don't trust the Internet for much.

We've seen marketing-driven and public opinion driven reversions before; reversion didn't prove that road disc was deadly and reversion doesn't prove that hookless is a faulty concept. Even if it is, reversion doesn't prove it.

And don't get me started on patent applications. The overwhelming majority of applications has nothing to do with real life. The ones that do mostly don't get allowed and just sit there as defensive pubs against someone else getting a patent. The ones that issue may or not stay in force depending on ... marketing and public opinion and legal slush fund availability. Technically a patent proves nothing.

 

[scott43]

I see it as similar to the press fit bb. They are, in my opinion, a superior design failed by poor mfg and implementation. Hookless is nice but there is a risk of incorrect application and failure. I do find it interesting that perhaps some mfgs have reverted. Maybe too much risk vs reward. Similar to press fit bb, maybe they just don't have the ability to manage the outfall.