Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
tour, the UCI will investigate the safety of the design.

https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV

This follows on the heels of a statement by the president of the
Cyclistes Professionnels Associés (CPA) Adam Hansen "This crash is why
the CPA are 100 percent against hookless rims. Tires should not come off
a rim......There are a lot of people who want this banned out of the
peloton because you can actually take down other riders...We have heard
from some teams that they have put tires on before, they left them out
in the sun and their tires just pop off"

https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency

https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/

An organisation called "escape collective" (which I had never heard of
until reading the CyclingNews article) published a report on the issue
with respect to the ETRTO guidelines on hookless rims, implying that
Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
and tire. Lotto Dstny denies this, of course.

https://escapecollective.com/category/cycling/tech/

You'll have to pay for the publication from ETRTO, but Bikeradar has a
good write up here:

https://www.bikeradar.com/features/hookless-rims-road-tubeless

zen cycle <funkmasterxx@hotmail.com> wrote:
> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
> tour, the UCI will investigate the safety of the design.
>
> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>
> This follows on the heels of a statement by the president of the
> Cyclistes Professionnels Associés (CPA) Adam Hansen "This crash is why
> the CPA are 100 percent against hookless rims. Tires should not come off
> a rim......There are a lot of people who want this banned out of the
> peloton because you can actually take down other riders...We have heard
> from some teams that they have put tires on before, they left them out
> in the sun and their tires just pop off"
>
> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>
> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>
> An organisation called "escape collective" (which I had never heard of
> until reading the CyclingNews article) published a report on the issue
> with respect to the ETRTO guidelines on hookless rims, implying that
> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
> and tire. Lotto Dstny denies this, of course.
>
> https://escapecollective.com/category/cycling/tech/
>
> You'll have to pay for the publication from ETRTO, but Bikeradar has a
> good write up here:
>
> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>
Seems like a technology more suited to MTB than road and has been used for
quite some time I believe, I’ve yet to use tubeless on the MTB.

But I’d not be surprised if some team did something silly seems to have a
hard upper limit on pressures.

This said I’m not convinced that for road that a minor weight saving and
stronger rims are particularly important, Gravel and MTB yes you can hit
rims now and then, and run much lower pressures.

But my knowledge of this is limited so I may have missed something!

Roger Merriman

On 3/4/2024 7:02 AM, Roger Merriman wrote:
> zen cycle <funkmasterxx@hotmail.com> wrote:
>> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
>> tour, the UCI will investigate the safety of the design.
>>
>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>>
>> This follows on the heels of a statement by the president of the
>> Cyclistes Professionnels Associés (CPA) Adam Hansen "This crash is why
>> the CPA are 100 percent against hookless rims. Tires should not come off
>> a rim......There are a lot of people who want this banned out of the
>> peloton because you can actually take down other riders...We have heard
>> from some teams that they have put tires on before, they left them out
>> in the sun and their tires just pop off"
>>
>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>>
>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>>
>> An organisation called "escape collective" (which I had never heard of
>> until reading the CyclingNews article) published a report on the issue
>> with respect to the ETRTO guidelines on hookless rims, implying that
>> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
>> and tire. Lotto Dstny denies this, of course.
>>
>> https://escapecollective.com/category/cycling/tech/
>>
>> You'll have to pay for the publication from ETRTO, but Bikeradar has a
>> good write up here:
>>
>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>>
> Seems like a technology more suited to MTB than road and has been used for
> quite some time I believe, I’ve yet to use tubeless on the MTB.

I go back and forth. I have a tubeless wheelset and a tube wheelset for
both MTBs. Which set I take with me depends on the ride I have planned.
I do like the tubeless better, but not enough to dissuade me from riding
when the inevitable occurs - I don't ride MTB frequently enough, and the
tubeless set frequently has stagnated from lack of use - won't hold air,
needing the sealant refreshed. Fuck it, I'll ride the tubes. If I know
I'm heading out to somewhere I know tubeless has a distinct advantage
(local very rocky trails) I'll spend the time doing some wheel prep.

>
> But I’d not be surprised if some team did something silly seems to have a
> hard upper limit on pressures.
>
> This said I’m not convinced that for road that a minor weight saving and
> stronger rims are particularly important, Gravel and MTB yes you can hit
> rims now and then, and run much lower pressures.
>
> But my knowledge of this is limited so I may have missed something!

As far as I can tell, the gains are marginal. Maybe if I was a 20
something pro rider it would be worth it to me, but as a 60 something
with an FTP of 3.1, Id rather stick with what I know works :)

>
> Roger Merriman
>
>

--
Add xx to reply

On 3/4/2024 8:26 AM, Zen Cycle wrote:
> ... as a 60 something
> with an FTP of 3.1, Id rather stick with what I know works :)

As a 70-something rider with an unknown FTP, I heartily agree.

--
- Frank Krygowski

Zen Cycle <funkmaster@hotmail.com> wrote:
> On 3/4/2024 7:02 AM, Roger Merriman wrote:
>> zen cycle <funkmasterxx@hotmail.com> wrote:
>>> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
>>> tour, the UCI will investigate the safety of the design.
>>>
>>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>>>
>>> This follows on the heels of a statement by the president of the
>>> Cyclistes Professionnels Associés (CPA) Adam Hansen "This crash is why
>>> the CPA are 100 percent against hookless rims. Tires should not come off
>>> a rim......There are a lot of people who want this banned out of the
>>> peloton because you can actually take down other riders...We have heard
>>> from some teams that they have put tires on before, they left them out
>>> in the sun and their tires just pop off"
>>>
>>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>>>
>>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>>>
>>> An organisation called "escape collective" (which I had never heard of
>>> until reading the CyclingNews article) published a report on the issue
>>> with respect to the ETRTO guidelines on hookless rims, implying that
>>> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
>>> and tire. Lotto Dstny denies this, of course.
>>>
>>> https://escapecollective.com/category/cycling/tech/
>>>
>>> You'll have to pay for the publication from ETRTO, but Bikeradar has a
>>> good write up here:
>>>
>>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>>>
>> Seems like a technology more suited to MTB than road and has been used for
>> quite some time I believe, I’ve yet to use tubeless on the MTB.
>
> I go back and forth. I have a tubeless wheelset and a tube wheelset for
> both MTBs. Which set I take with me depends on the ride I have planned.
> I do like the tubeless better, but not enough to dissuade me from riding
> when the inevitable occurs - I don't ride MTB frequently enough, and the
> tubeless set frequently has stagnated from lack of use - won't hold air,
> needing the sealant refreshed. Fuck it, I'll ride the tubes. If I know
> I'm heading out to somewhere I know tubeless has a distinct advantage
> (local very rocky trails) I'll spend the time doing some wheel prep.
>
My MTB is fitted with Magic Mary & Hans combo which is fairly classic trail
set up, and being fairly burly tires even with tubes in they cope just fine
with rocks at 2bar or there abouts, which seems to be happy medium between
rolling sidewalls though berms which can load up and being rattled.

Tubeless should allow me to drop pressure for impacts but would be
same/worse for sidewall support so I’m uncertain how much gain I’d get.

But the main is tubes for me work and I don’t want any more maintenance
tubeless is a faff.
>>
>> But I’d not be surprised if some team did something silly seems to have a
>> hard upper limit on pressures.
>>
>> This said I’m not convinced that for road that a minor weight saving and
>> stronger rims are particularly important, Gravel and MTB yes you can hit
>> rims now and then, and run much lower pressures.
>>
>> But my knowledge of this is limited so I may have missed something!
>
> As far as I can tell, the gains are marginal. Maybe if I was a 20
> something pro rider it would be worth it to me, but as a 60 something
> with an FTP of 3.1, Id rather stick with what I know works :)

I’m a touch younger but like Frank never measured FTP, as I don’t race so
it’s not my thing.
>
>>
>> Roger Merriman
>>
>>
>
Roger Merriman

On Sun Mar 3 07:12:16 2024 zen cycle wrote:
> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
> tour, the UCI will investigate the safety of the design.
>
> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>
> This follows on the heels of a statement by the president of the
> Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
> the CPA are 100 percent against hookless rims. Tires should not come off
> a rim......There are a lot of people who want this banned out of the
> peloton because you can actually take down other riders...We have heard
> from some teams that they have put tires on before, they left them out
> in the sun and their tires just pop off"
>
> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>
> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>
> An organisation called "escape collective" (which I had never heard of
> until reading the CyclingNews article) published a report on the issue
> with respect to the ETRTO guidelines on hookless rims, implying that
> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
> and tire. Lotto Dstny denies this, of course.
>
> https://escapecollective.com/category/cycling/tech/
>
> You'll have to pay for the publication from ETRTO, but Bikeradar has a
> good write up here:
>
> https://www.bikeradar.com/features/hookless-rims-road-tubeless

I spent a full hour trying to mount a tubeless Corsa onto a clincher rim yesterday before giving up and mounting a Gatorskin in 10 minutes. So you can see why some people are willing to trade easier mounting for safety.

It is more difficult to mount tubeless tires on tubeless rims. When I was using full tubeless, I used a tire jack to get them on. I went up to the dentist this morning and on the freeway there were some potholes that went to China.

Tom Kunich <cyclintom@yahoo.com> wrote:
> On Sun Mar 3 07:12:16 2024 zen cycle wrote:
>> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
>> tour, the UCI will investigate the safety of the design.
>>
>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>>
>> This follows on the heels of a statement by the president of the
>> Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
>> the CPA are 100 percent against hookless rims. Tires should not come off
>> a rim......There are a lot of people who want this banned out of the
>> peloton because you can actually take down other riders...We have heard
>> from some teams that they have put tires on before, they left them out
>> in the sun and their tires just pop off"
>>
>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>>
>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>>
>> An organisation called "escape collective" (which I had never heard of
>> until reading the CyclingNews article) published a report on the issue
>> with respect to the ETRTO guidelines on hookless rims, implying that
>> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
>> and tire. Lotto Dstny denies this, of course.
>>
>> https://escapecollective.com/category/cycling/tech/
>>
>> You'll have to pay for the publication from ETRTO, but Bikeradar has a
>> good write up here:
>>
>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>
>
> I spent a full hour trying to mount a tubeless Corsa onto a clincher rim
> yesterday before giving up and mounting a Gatorskin in 10 minutes. So you
> can see why some people are willing to trade easier mounting for safety.

Technique trumps arm strength!

After all folks have managed with Marathon Pluses etc or if you really want
a fight on your hands some of the more burly MTB tires can be a pig to fit,
as they have reinforced sidewalls.
>
> It is more difficult to mount tubeless tires on tubeless rims. When I was
> using full tubeless, I used a tire jack to get them on. I went up to the
> dentist this morning and on the freeway there were some potholes that went to China.
>

Some rims/tires are tighter fitting but certainly road/gravel stuff seems
broadly the same, while I don’t own a pure road bike, I will now and then
fit folks spare tube and so on.

A airtight sidewall is still nowhere near the level of stiffness or weight
of Down Hill/Enduro casing even in trail form such tires are heavy and
really quite a step up from simply being tubeless.

For example most companies do tubeless and non tubeless versions of their
products with most the weight difference isn’t significant.

Roger Merriman

On 3/3/2024 7:12 AM, zen cycle wrote:
> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
> tour, the UCI will investigate the safety of the design.
>
> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>
> This follows on the heels of a statement by the president of the
> Cyclistes Professionnels Associés (CPA) Adam Hansen "This crash is why
> the CPA are 100 percent against hookless rims. Tires should not come off
> a rim......There are a lot of people who want this banned out of the
> peloton because you can actually take down other riders...We have heard
> from some teams that they have put tires on before, they left them out
> in the sun and their tires just pop off"
>
> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>
> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>
> An organisation called "escape collective" (which I had never heard of
> until reading the CyclingNews article) published a report on the issue
> with respect to the ETRTO guidelines on hookless rims, implying that
> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
> and tire. Lotto Dstny denies this, of course.
>
> https://escapecollective.com/category/cycling/tech/
>
> You'll have to pay for the publication from ETRTO, but Bikeradar has a
> good write up here:
>
> https://www.bikeradar.com/features/hookless-rims-road-tubeless

Zipp finally chimes in:
https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/

For the TLDR crowd, they diagnosed at a distance:
"It was their assessment that the nature of the impact would have caused
severe damage to the tire and rim regardless of the rim design. Images
circulating online indicate damage consistent with a severe frontal
impact,".

It's troublesome that Zipp would make such a statement based on
"circulated online images". I don't really have the time or patience to
do a deep dive for on-line images, but of the half-dozen stills and
single video I've seen, I don't see any evidence of a "severe frontal
impact" except when the bike actually hits the ground. When you consider
that they replaced the front wheel, jammed the left brifter back into
place, and sent him on his way on the same bike as seen in the video
below, it doesn't seem that any 'severe frontal impact' caused the crash.

https://youtu.be/GFyC9RKmMM4?si=1ftYiC3LVfx0TWF7

I also didn't see any visible damage to the front wheel.

De Gendt claims he hit a rock. At those speeds, hitting a rock could
easily cause the tire to dismount and and liner to pop out. Not sure why
Zipp thinks they need to do any more at this point but to state "As of
this moment, our design team in Indianapolis is still awaiting the
return of the wheel to confirm the failure mode and conduct additional
analysis"

--
Add xx to reply

On Thu Mar 7 14:17:19 2024 Zen Cycle wrote:
> On 3/3/2024 7:12 AM, zen cycle wrote:
> > Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
> > tour, the UCI will investigate the safety of the design.
> >
> > https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
> >
> > This follows on the heels of a statement by the president of the
> > Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
> > the CPA are 100 percent against hookless rims. Tires should not come off
> > a rim......There are a lot of people who want this banned out of the
> > peloton because you can actually take down other riders...We have heard
> > from some teams that they have put tires on before, they left them out
> > in the sun and their tires just pop off"
> >
> > https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
> >
> > https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
> >
> > An organisation called "escape collective" (which I had never heard of
> > until reading the CyclingNews article) published a report on the issue
> > with respect to the ETRTO guidelines on hookless rims, implying that
> > Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
> > and tire. Lotto Dstny denies this, of course.
> >
> > https://escapecollective.com/category/cycling/tech/
> >
> > You'll have to pay for the publication from ETRTO, but Bikeradar has a
> > good write up here:
> >
> > https://www.bikeradar.com/features/hookless-rims-road-tubeless
>
>
>
> Zipp finally chimes in:
> https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/
>
> For the TLDR crowd, they diagnosed at a distance:
> "It was their assessment that the nature of the impact would have caused
> severe damage to the tire and rim regardless of the rim design. Images
> circulating online indicate damage consistent with a severe frontal
> impact,".
>
> It's troublesome that Zipp would make such a statement based on
> "circulated online images". I don't really have the time or patience to
> do a deep dive for on-line images, but of the half-dozen stills and
> single video I've seen, I don't see any evidence of a "severe frontal
> impact" except when the bike actually hits the ground. When you consider
> that they replaced the front wheel, jammed the left brifter back into
> place, and sent him on his way on the same bike as seen in the video
> below, it doesn't seem that any 'severe frontal impact' caused the crash.
>
> https://youtu.be/GFyC9RKmMM4?si=1ftYiC3LVfx0TWF7
>
> I also didn't see any visible damage to the front wheel.
>
> De Gendt claims he hit a rock. At those speeds, hitting a rock could
> easily cause the tire to dismount and and liner to pop out. Not sure why
> Zipp thinks they need to do any more at this point but to state "As of
> this moment, our design team in Indianapolis is still awaiting the
> return of the wheel to confirm the failure mode and conduct additional
> analysis"
>
>
>
>
> --
> Add xx to reply
>

If Zipp claims that it was a collision with a rock that caused the crash exactly how do you suppose that the UCI is going to prove otherwise? Teams have the right to select their own equipment without interference from the governing boy save in making rules.

This year's Paris-Nice is whowing that the governing body is having trouble setting rules let alone somehow guarding riders from poor equipment choices.

Tom Kunich <cyclintom@yahoo.com> wrote:
> On Thu Mar 7 14:17:19 2024 Zen Cycle wrote:
>> On 3/3/2024 7:12 AM, zen cycle wrote:
>>> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
>>> tour, the UCI will investigate the safety of the design.
>>>
>>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>>>
>>> This follows on the heels of a statement by the president of the
>>> Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
>>> the CPA are 100 percent against hookless rims. Tires should not come off
>>> a rim......There are a lot of people who want this banned out of the
>>> peloton because you can actually take down other riders...We have heard
>>> from some teams that they have put tires on before, they left them out
>>> in the sun and their tires just pop off"
>>>
>>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>>>
>>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>>>
>>> An organisation called "escape collective" (which I had never heard of
>>> until reading the CyclingNews article) published a report on the issue
>>> with respect to the ETRTO guidelines on hookless rims, implying that
>>> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
>>> and tire. Lotto Dstny denies this, of course.
>>>
>>> https://escapecollective.com/category/cycling/tech/
>>>
>>> You'll have to pay for the publication from ETRTO, but Bikeradar has a
>>> good write up here:
>>>
>>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>>
>>
>>
>> Zipp finally chimes in:
>> https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/
>>
>> For the TLDR crowd, they diagnosed at a distance:
>> "It was their assessment that the nature of the impact would have caused
>> severe damage to the tire and rim regardless of the rim design. Images
>> circulating online indicate damage consistent with a severe frontal
>> impact,".
>>
>> It's troublesome that Zipp would make such a statement based on
>> "circulated online images". I don't really have the time or patience to
>> do a deep dive for on-line images, but of the half-dozen stills and
>> single video I've seen, I don't see any evidence of a "severe frontal
>> impact" except when the bike actually hits the ground. When you consider
>> that they replaced the front wheel, jammed the left brifter back into
>> place, and sent him on his way on the same bike as seen in the video
>> below, it doesn't seem that any 'severe frontal impact' caused the crash.
>>
>> https://youtu.be/GFyC9RKmMM4?sitYiC3LVfx0TWF7
>>
>> I also didn't see any visible damage to the front wheel.
>>
>> De Gendt claims he hit a rock. At those speeds, hitting a rock could
>> easily cause the tire to dismount and and liner to pop out. Not sure why
>> Zipp thinks they need to do any more at this point but to state "As of
>> this moment, our design team in Indianapolis is still awaiting the
>> return of the wheel to confirm the failure mode and conduct additional
>> analysis"
>>
>>
>>
>>
>> --
>> Add xx to reply
>>
>
>
>
>
> If Zipp claims that it was a collision with a rock that caused the crash
> exactly how do you suppose that the UCI is going to prove otherwise?
> Teams have the right to select their own equipment without interference
> from the governing boy save in making rules.

There is nothing stopping teams from using hooked vs hookless wheels bar
perhaps sponsorship deals.

Equally they could use tubes which will also work be that with hooked or
hookless rims, do need tubeless tires even so for hookless rims.
>
> This year's Paris-Nice is whowing that the governing body is having
> trouble setting rules let alone somehow guarding riders from poor equipment choices.
>

Roger Merriman

On 3/7/2024 1:17 PM, Zen Cycle wrote:
> On 3/3/2024 7:12 AM, zen cycle wrote:
>> Following a crash by Thomas De Gendt (Lotto Dstny) at
>> stage 5 of the UAE tour, the UCI will investigate the
>> safety of the design.
>>
>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>>
>> This follows on the heels of a statement by the president
>> of the Cyclistes Professionnels Associés (CPA) Adam Hansen
>> "This crash is why the CPA are 100 percent against
>> hookless rims. Tires should not come off a rim......There
>> are a lot of people who want this banned out of the
>> peloton because you can actually take down other
>> riders...We have heard from some teams that they have put
>> tires on before, they left them out in the sun and their
>> tires just pop off"
>>
>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>>
>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>>
>> An organisation called "escape collective" (which I had
>> never heard of until reading the CyclingNews article)
>> published a report on the issue with respect to the ETRTO
>> guidelines on hookless rims, implying that Lotto Dstny
>> didn't follow ETRTO guidelines for that combination of rim
>> and tire. Lotto Dstny denies this, of course.
>>
>> https://escapecollective.com/category/cycling/tech/
>>
>> You'll have to pay for the publication from ETRTO, but
>> Bikeradar has a good write up here:
>>
>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>
>
>
> Zipp finally chimes in:
> https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/
>
> For the TLDR crowd, they diagnosed at a distance:
> "It was their assessment that the nature of the impact would
> have caused severe damage to the tire and rim regardless of
> the rim design. Images circulating online indicate damage
> consistent with a severe frontal impact,".
>
> It's troublesome that Zipp would make such a statement based
> on "circulated online images".  I don't really have the time
> or patience to do a deep dive for on-line images, but of the
> half-dozen stills and single video I've seen, I don't see
> any evidence of a "severe frontal impact" except when the
> bike actually hits the ground. When you consider that they
> replaced the front wheel, jammed the left brifter back into
> place, and sent him on his way on the same bike as seen in
> the video below, it doesn't seem that any 'severe frontal
> impact' caused the crash.
>
> https://youtu.be/GFyC9RKmMM4?si=1ftYiC3LVfx0TWF7
>
> I also didn't see any visible damage to the front wheel.
>
> De Gendt claims he hit a rock. At those speeds, hitting a
> rock could easily cause the tire to dismount and and liner
> to pop out. Not sure why Zipp thinks they need to do any
> more at this point but to state "As of this moment, our
> design team in Indianapolis is still awaiting the return of
> the wheel to confirm the failure mode and conduct additional
> analysis"
>
>
>
>

That's because they are obviously amateurs at CYA.

The professionals appoint an investigatory committee to bury
the issue over a couple of years.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971

On Thu Mar 7 19:32:54 2024 AMuzi wrote:
> On 3/7/2024 1:17 PM, Zen Cycle wrote:
> > On 3/3/2024 7:12 AM, zen cycle wrote:
> >> Following a crash by Thomas De Gendt (Lotto Dstny) at
> >> stage 5 of the UAE tour, the UCI will investigate the
> >> safety of the design.
> >>
> >> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
> >>
> >> This follows on the heels of a statement by the president
> >> of the Cyclistes Professionnels Associs (CPA) Adam Hansen
> >> "This crash is why the CPA are 100 percent against
> >> hookless rims. Tires should not come off a rim......There
> >> are a lot of people who want this banned out of the
> >> peloton because you can actually take down other
> >> riders...We have heard from some teams that they have put
> >> tires on before, they left them out in the sun and their
> >> tires just pop off"
> >>
> >> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
> >>
> >> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
> >>
> >> An organisation called "escape collective" (which I had
> >> never heard of until reading the CyclingNews article)
> >> published a report on the issue with respect to the ETRTO
> >> guidelines on hookless rims, implying that Lotto Dstny
> >> didn't follow ETRTO guidelines for that combination of rim
> >> and tire. Lotto Dstny denies this, of course.
> >>
> >> https://escapecollective.com/category/cycling/tech/
> >>
> >> You'll have to pay for the publication from ETRTO, but
> >> Bikeradar has a good write up here:
> >>
> >> https://www.bikeradar.com/features/hookless-rims-road-tubeless
> >
> >
> >
> > Zipp finally chimes in:
> > https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/
> >
> > For the TLDR crowd, they diagnosed at a distance:
> > "It was their assessment that the nature of the impact would
> > have caused severe damage to the tire and rim regardless of
> > the rim design. Images circulating online indicate damage
> > consistent with a severe frontal impact,".
> >
> > It's troublesome that Zipp would make such a statement based
> > on "circulated online images". I don't really have the time
> > or patience to do a deep dive for on-line images, but of the
> > half-dozen stills and single video I've seen, I don't see
> > any evidence of a "severe frontal impact" except when the
> > bike actually hits the ground. When you consider that they
> > replaced the front wheel, jammed the left brifter back into
> > place, and sent him on his way on the same bike as seen in
> > the video below, it doesn't seem that any 'severe frontal
> > impact' caused the crash.
> >
> > https://youtu.be/GFyC9RKmMM4?si=1ftYiC3LVfx0TWF7
> >
> > I also didn't see any visible damage to the front wheel.
> >
> > De Gendt claims he hit a rock. At those speeds, hitting a
> > rock could easily cause the tire to dismount and and liner
> > to pop out. Not sure why Zipp thinks they need to do any
> > more at this point but to state "As of this moment, our
> > design team in Indianapolis is still awaiting the return of
> > the wheel to confirm the failure mode and conduct additional
> > analysis"
> >
> >
> >
> >
>
> That's because they are obviously amateurs at CYA.
>
> The professionals appoint an investigatory committee to bury
> the issue over a couple of years.
> --
> Andrew Muzi
> am@yellowjersey.org
> Open every day since 1 April, 1971
>

Peak Torque video on youtube tells it all and her claims that hookless rims are made for one purpose - to save money.

https://www.youtube.com/watch?v=bAgxTdNIOhA

On Mon Mar 4 10:12:21 2024 Frank Krygowski wrote:
> On 3/4/2024 8:26 AM, Zen Cycle wrote:
> > ... as a 60 something
> > with an FTP of 3.1, Id rather stick with what I know works :)
>
> As a 70-something rider with an unknown FTP, I heartily agree.
>
> --
> - Frank Krygowski
>

On YouTube Peak Torque analyzed hookless rims and came to the conclusion that the were designed to greatly reduce the cost of carbon mold and reduce the cost of the finishing on the rim when it is removed from the mold.

On Mon Mar 4 12:02:56 2024 Roger Merriman wrote:
> zen cycle <funkmasterxx@hotmail.com> wrote:
> > Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
> > tour, the UCI will investigate the safety of the design.
> >
> > https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
> >
> > This follows on the heels of a statement by the president of the
> > Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
> > the CPA are 100 percent against hookless rims. Tires should not come off
> > a rim......There are a lot of people who want this banned out of the
> > peloton because you can actually take down other riders...We have heard
> > from some teams that they have put tires on before, they left them out
> > in the sun and their tires just pop off"
> >
> > https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
> >
> > https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
> >
> > An organisation called "escape collective" (which I had never heard of
> > until reading the CyclingNews article) published a report on the issue
> > with respect to the ETRTO guidelines on hookless rims, implying that
> > Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
> > and tire. Lotto Dstny denies this, of course.
> >
> > https://escapecollective.com/category/cycling/tech/
> >
> > You'll have to pay for the publication from ETRTO, but Bikeradar has a
> > good write up here:
> >
> > https://www.bikeradar.com/features/hookless-rims-road-tubeless
> >
> Seems like a technology more suited to MTB than road and has been used for
> quite some time I believe, I?ve yet to use tubeless on the MTB.
>
> But I?d not be surprised if some team did something silly seems to have a
> hard upper limit on pressures.
>
> This said I?m not convinced that for road that a minor weight saving and
> stronger rims are particularly important, Gravel and MTB yes you can hit
> rims now and then, and run much lower pressures.
>
> But my knowledge of this is limited so I may have missed something!
>
> Roger Merriman
>
>

There is no weight savings. Forces are tranlated from pulling on the hooks to pushing on the sides so they have to be stregthened very slightly. The mold is reduced from something like 14 pieces to 4. The exact number depemd on the mold maker but it is substantial.

On Thu Mar 7 22:09:52 2024 Roger Merriman wrote:
> Tom Kunich <cyclintom@yahoo.com> wrote:
> > On Thu Mar 7 14:17:19 2024 Zen Cycle wrote:
> >> On 3/3/2024 7:12 AM, zen cycle wrote:
> >>> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
> >>> tour, the UCI will investigate the safety of the design.
> >>>
> >>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
> >>>
> >>> This follows on the heels of a statement by the president of the
> >>> Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
> >>> the CPA are 100 percent against hookless rims. Tires should not come off
> >>> a rim......There are a lot of people who want this banned out of the
> >>> peloton because you can actually take down other riders...We have heard
> >>> from some teams that they have put tires on before, they left them out
> >>> in the sun and their tires just pop off"
> >>>
> >>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
> >>>
> >>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
> >>>
> >>> An organisation called "escape collective" (which I had never heard of
> >>> until reading the CyclingNews article) published a report on the issue
> >>> with respect to the ETRTO guidelines on hookless rims, implying that
> >>> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
> >>> and tire. Lotto Dstny denies this, of course.
> >>>
> >>> https://escapecollective.com/category/cycling/tech/
> >>>
> >>> You'll have to pay for the publication from ETRTO, but Bikeradar has a
> >>> good write up here:
> >>>
> >>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
> >>
> >>
> >>
> >> Zipp finally chimes in:
> >> https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/
> >>
> >> For the TLDR crowd, they diagnosed at a distance:
> >> "It was their assessment that the nature of the impact would have caused
> >> severe damage to the tire and rim regardless of the rim design. Images
> >> circulating online indicate damage consistent with a severe frontal
> >> impact,".
> >>
> >> It's troublesome that Zipp would make such a statement based on
> >> "circulated online images". I don't really have the time or patience to
> >> do a deep dive for on-line images, but of the half-dozen stills and
> >> single video I've seen, I don't see any evidence of a "severe frontal
> >> impact" except when the bike actually hits the ground. When you consider
> >> that they replaced the front wheel, jammed the left brifter back into
> >> place, and sent him on his way on the same bike as seen in the video
> >> below, it doesn't seem that any 'severe frontal impact' caused the crash.
> >>
> >> https://youtu.be/GFyC9RKmMM4?sitYiC3LVfx0TWF7
> >>
> >> I also didn't see any visible damage to the front wheel.
> >>
> >> De Gendt claims he hit a rock. At those speeds, hitting a rock could
> >> easily cause the tire to dismount and and liner to pop out. Not sure why
> >> Zipp thinks they need to do any more at this point but to state "As of
> >> this moment, our design team in Indianapolis is still awaiting the
> >> return of the wheel to confirm the failure mode and conduct additional
> >> analysis"
> >>
> >>
> >>
> >>
> >> --
> >> Add xx to reply
> >>
> >
> >
> >
> >
> > If Zipp claims that it was a collision with a rock that caused the crash
> > exactly how do you suppose that the UCI is going to prove otherwise?
> > Teams have the right to select their own equipment without interference
> > from the governing boy save in making rules.
>
> There is nothing stopping teams from using hooked vs hookless wheels bar
> perhaps sponsorship deals.
>
> Equally they could use tubes which will also work be that with hooked or
> hookless rims, do need tubeless tires even so for hookless rims.
> >
> > This year's Paris-Nice is whowing that the governing body is having
> > trouble setting rules let alone somehow guarding riders from poor equipment choices.
> >
>
> Roger Merriman
>

Well, teams won't be able to decide for themselves if UCI elects to forbid hookless rims. Actually it is a complicate matter. Hookless rims have to run much lower pressures so teams use those foam tire liners to prevent rim damage which in turn gr4eatly reduces the actual air volume in the tire so that even small leaks rapidly cause full flats.

My analysis is that flats throwing the tire off of the rim are nearly guaranteed. Peak Torque's anaqlysis is that making hookless is all about profit. He thinks that they are too dangerous.

Tom Kunich <cyclintom@yahoo.com> wrote:
> On Thu Mar 7 22:09:52 2024 Roger Merriman wrote:
>> Tom Kunich <cyclintom@yahoo.com> wrote:
>>> On Thu Mar 7 14:17:19 2024 Zen Cycle wrote:
>>>> On 3/3/2024 7:12 AM, zen cycle wrote:
>>>>> Following a crash by Thomas De Gendt (Lotto Dstny) at stage 5 of the UAE
>>>>> tour, the UCI will investigate the safety of the design.
>>>>>
>>>>> https://www.uci.org/pressrelease/problems-arising-from-the-use-of-hookless-rims-with-tubeless-tyres-the-uci/643AahX42LzqziXz7OXKxV
>>>>>
>>>>> This follows on the heels of a statement by the president of the
>>>>> Cyclistes Professionnels Associs (CPA) Adam Hansen "This crash is why
>>>>> the CPA are 100 percent against hookless rims. Tires should not come off
>>>>> a rim......There are a lot of people who want this banned out of the
>>>>> peloton because you can actually take down other riders...We have heard
>>>>> from some teams that they have put tires on before, they left them out
>>>>> in the sun and their tires just pop off"
>>>>>
>>>>> https://www.cyclingweekly.com/news/uci-to-review-hookless-rims-as-a-matter-of-urgency
>>>>>
>>>>> https://www.cyclingnews.com/news/uci-statement-on-hookless-tyres/
>>>>>
>>>>> An organisation called "escape collective" (which I had never heard of
>>>>> until reading the CyclingNews article) published a report on the issue
>>>>> with respect to the ETRTO guidelines on hookless rims, implying that
>>>>> Lotto Dstny didn't follow ETRTO guidelines for that combination of rim
>>>>> and tire. Lotto Dstny denies this, of course.
>>>>>
>>>>> https://escapecollective.com/category/cycling/tech/
>>>>>
>>>>> You'll have to pay for the publication from ETRTO, but Bikeradar has a
>>>>> good write up here:
>>>>>
>>>>> https://www.bikeradar.com/features/hookless-rims-road-tubeless
>>>>
>>>>
>>>>
>>>> Zipp finally chimes in:
>>>> https://www.cyclingnews.com/news/zipp-releases-statement-on-hookless-rims-following-thomas-de-gendts-uae-crash/
>>>>
>>>> For the TLDR crowd, they diagnosed at a distance:
>>>> "It was their assessment that the nature of the impact would have caused
>>>> severe damage to the tire and rim regardless of the rim design. Images
>>>> circulating online indicate damage consistent with a severe frontal
>>>> impact,".
>>>>
>>>> It's troublesome that Zipp would make such a statement based on
>>>> "circulated online images". I don't really have the time or patience to
>>>> do a deep dive for on-line images, but of the half-dozen stills and
>>>> single video I've seen, I don't see any evidence of a "severe frontal
>>>> impact" except when the bike actually hits the ground. When you consider
>>>> that they replaced the front wheel, jammed the left brifter back into
>>>> place, and sent him on his way on the same bike as seen in the video
>>>> below, it doesn't seem that any 'severe frontal impact' caused the crash.
>>>>
>>>> https://youtu.be/GFyC9RKmMM4?sitYiC3LVfx0TWF7
>>>>
>>>> I also didn't see any visible damage to the front wheel.
>>>>
>>>> De Gendt claims he hit a rock. At those speeds, hitting a rock could
>>>> easily cause the tire to dismount and and liner to pop out. Not sure why
>>>> Zipp thinks they need to do any more at this point but to state "As of
>>>> this moment, our design team in Indianapolis is still awaiting the
>>>> return of the wheel to confirm the failure mode and conduct additional
>>>> analysis"
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Add xx to reply
>>>>
>>>
>>>
>>>
>>>
>>> If Zipp claims that it was a collision with a rock that caused the crash
>>> exactly how do you suppose that the UCI is going to prove otherwise?
>>> Teams have the right to select their own equipment without interference
>>> from the governing boy save in making rules.
>>
>> There is nothing stopping teams from using hooked vs hookless wheels bar
>> perhaps sponsorship deals.
>>
>> Equally they could use tubes which will also work be that with hooked or
>> hookless rims, do need tubeless tires even so for hookless rims.
>>>
>>> This year's Paris-Nice is whowing that the governing body is having
>>> trouble setting rules let alone somehow guarding riders from poor equipment choices.
>>>
>>
>> Roger Merriman
>>
>
>
>
>
> Well, teams won't be able to decide for themselves if UCI elects to
> forbid hookless rims. Actually it is a complicate matter. Hookless rims
> have to run much lower pressures so teams use those foam tire liners to
> prevent rim damage which in turn gr4eatly reduces the actual air volume
> in the tire so that even small leaks rapidly cause full flats.
>
> My analysis is that flats throwing the tire off of the rim are nearly
> guaranteed. Peak Torque's anaqlysis is that making hookless is all about
> profit. He thinks that they are too dangerous.
>

It’s probably down to limits and accuracy, ie if teams are running right on
the limits of the max pressures that hookless can cope with, the accuracy
of the gauge matters hugely as only got a 10% wiggle room.

Companies are claiming impact as is the rider, so perhaps would have been
same result with hooked.

This said doesn’t seem like a wise technology for road where you don’t
impact rims in general unlike MTB/gravel and might well want to run higher
pressures.

Roger Merriman