Hookless compatible tubeless tires?

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TobinHatesYou
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by TobinHatesYou

Jackofallgrades wrote:
Sat Jan 15, 2022 12:34 pm
Does anyone know, beyond what's been publicly stated, why 25c is often not approved for hookless use on wider ID (23ID for example)? Is it purely that most riders will be close to or indeed over the maximum ETRTO pressure of 72.5psi using that width of tyre? Therefore would that mean smaller riders running pressures much lower (60 for example) would be safe? Or is there another issue I'm missing? Will always be an element of 'at your own risk' but the pressure side of the equation seems fairly straightforward.

RyanW has mentioned putting 25c Conti's on multiple sets of hookless Zipps, which sparked these thoughts.

Wider rims = more volume = lower pressure required. It's not that.

It's more than likely due to the cross-section of the tire. When a tire takes a balloon/teardrop shape, some of the air is pushing the bead back toward the rim. If the tire takes on a U shape, there is more sidewall pressure pushing outward.

Jackofallgrades
Posts: 250
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by Jackofallgrades

I had thought that might be the case, but I've seen tests where approved tyres (in this case would be 28c and above) have been inflated over the maximum pressure, and have accordingly blown off the rim. This is because there is still a large portion of surface area pushing the tyre away from the rim, the underside of the tread. So whilst you're probably right that a balloon shape has more pressure pushing down into the rim walls, I don't think it's as significant as you suggest. Pressure seems the big player here?
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seinberg
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by seinberg

AggressiveBears wrote:
Sat Jan 15, 2022 1:08 pm
Jackofallgrades wrote:
Sat Jan 15, 2022 12:34 pm
Does anyone know, beyond what's been publicly stated, why 25c is often not approved for hookless use on wider ID (23ID for example)? Is it purely that most riders will be close to or indeed over the maximum ETRTO pressure of 72.5psi using that width of tyre? Therefore would that mean smaller riders running pressures much lower (60 for example) would be safe? Or is there another issue I'm missing? Will always be an element of 'at your own risk' but the pressure side of the equation seems fairly straightforward.

RyanW has mentioned putting 25c Conti's on multiple sets of hookless Zipps, which sparked these thoughts.
That is probably the reason. Zipp says I should use 28s at my weight. Their pressure calculator gives me JUST enough room to use 28s in dry conditions. Assuming you don't mind riding much lower (wet condition) pressures, it's probably less of an issue.
Yeah, I think this is right. There's a good Cycling Tips podcast where a product manager from Zipp (Sebastian something) goes into some detail on hookless rims and IIRC this came up.
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TobinHatesYou
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by TobinHatesYou

seinberg wrote:
Tue Jan 25, 2022 4:31 am

Yeah, I think this is right. There's a good Cycling Tips podcast where a product manager from Zipp (Sebastian something) goes into some detail on hookless rims and IIRC this came up.

That guy was awesome and very thorough. IIRC he also mentioned that the 73psi limit was merely in accordance with the ETRTO specification for TSS rims. He mentions their hookless rims are tested to the same pressures as their hooked clinchers and makes it clear that the hook doesn't actually do much for tire retention. He's basically saying if a tire blows off one of their hookless rims, it's probably the tire's fault and not theirs.
Last edited by TobinHatesYou on Tue Jan 25, 2022 9:04 am, edited 1 time in total.

warthog101
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by warthog101

He was good if this is it;

https://cyclingtips.com/2021/09/nerd-al ... confusion/

Makes a good case for hookless about 30min in.

MikeD
Posts: 1000
Joined: Thu Dec 11, 2014 9:55 pm

by MikeD

TobinHatesYou wrote:
seinberg wrote:
Tue Jan 25, 2022 4:31 am

Yeah, I think this is right. There's a good Cycling Tips podcast where a product manager from Zipp (Sebastian something) goes into some detail on hookless rims and IIRC this came up.

That guy was awesome and very thorough. IIRC he also mentioned that the 73psi limit was merely in accordance with the ETRTO specification for TSS rims. He mentions their hookless rims are tested to the same pressures as their hooked clinchers and makes it clear that the hook doesn't actually do much for tire retention. He's basically saying if a tire blows off one of their hookless rims, it's probably the tire's fault and not theirs.
It's interesting that my Mavic UST 28mm Yksilon Pro tires say 87 psi max. and 72 psi recommended pressure. I normally run 77 psi on the rear tire. That's also what the Silca pressure calculator recommends and seems to work fine for me. I wouldn't have hookless rims on my road bike.

seinberg
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by seinberg

warthog101 wrote:
Tue Jan 25, 2022 8:52 am
He was good if this is it;

https://cyclingtips.com/2021/09/nerd-al ... confusion/

Makes a good case for hookless about 30min in.
That's the one!
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Jackofallgrades
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by Jackofallgrades

Has anyone tried the Specialized Turbo 2Bliss? They seem a good option aside from giving up a few watts to Contis, reviewed as supple and same rubber compound as Turbo Cottons for good grip?
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allrandomletters
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by allrandomletters

I have the Spec Turbo 2Bliss in 26mm and 30mm on different bikes. Grip is top notch, every bit as good as the Corsa Control 2.0TLR 30mm and Corsa G2.0 TLR 28mm that I swapped from. BRR charts show the Turbos as the highest grip tubeless tire, and second only to the Veloflex Record overall. They are pretty supple and have great road feel too. In my experience, they run true to size, if not just a little small, so the drop off in rolling resistance at lower air pressure on the BRR charts might be more related to the real-world smaller sizing of these tires than any shortcomings in construction. The 30mm measure 31.5mm on my 25mm internal hookless rims.

In my opinion, the Spec Turbo's 2Bliss are the best combination of grip, rolling resistance, road feel, air retention, and ease of installation and upkeep. I think the only negative would be price, however other new tire releases are hard to find and inflated well above MSRP when in stock (like the new Conti 5ks), while my LBS has the Spec Turbos in stock at the normal MSRP.

Mocs123
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by Mocs123

Jackofallgrades wrote:
Sun Jan 30, 2022 11:22 am
Has anyone tried the Specialized Turbo 2Bliss? They seem a good option aside from giving up a few watts to Contis, reviewed as supple and same rubber compound as Turbo Cottons for good grip?
I haven't used them but a friend in my club had them and he had problems getting punctures with them that wouldn't seal. After 3-4 punctures that just kept bubbling sealant, he took them off and put Perelli's on and hasn't had the problem since. He thinks it's because the 2Bliss tires were thinner and didn't give the sealant much to adhere to. Of course, as with all punctures it could have just been bad luck, so your mileage may vary.

I will add that he uses Orange Seal Endurance sealant.
Last edited by Mocs123 on Mon Jan 31, 2022 7:54 pm, edited 1 time in total.
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Maddie
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by Maddie

I also had bad luck with the 2bliss tires. The only tubeless tires I had so far that didn't seal with Orange sealant. I had at least 2 dynaplugs in both front and rear tires before I finally tossed them. Riding quality was very good though.

yingyu
Posts: 87
Joined: Tue Jul 13, 2021 7:16 am

by yingyu

I also find orange seal (regular) doesn't seal my 28c 2bliss tires well. Had one dynaplug front and two rear before switching to gp5k s tr, which sadly appear to be more delicate -- rear had to be plugged in the beginning of its first ride. Nevertheless, I am sticking with gp5k because they feel slightly more supple and are reported to have aero tread patterns https://www.aero-coach.co.uk/aerodynam ... cing-tyres

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