A simple slide guide to tubeless and hookless

[glepore]

Originally Posted by Onno

I just listened to latest Geek Warning podcast, and this is exactly the takeaway from their hour-long discussion of hookless road setups--that the margin of safety for hookless rims at road-racing air pressure is just too slim for it to make sense at the moment, and why it makes even less sense to go under the ISO standards (which is apparently what Lotto Destny has done by running 28mm tires on 25mm internal width rims). I don't have any hookless rims at the moment, and am not looking to buy any, but it is interesting to see an example of the genuinely greater risk that some new technology development can produce.

I don't have a dog in the fight either, as I don't even own a disk brake road bike or run anything tubeless at the moment, but yeah, I agree with Ronin-the issue isn't so much that user diligence is required as it is that tolerances can stack in such a way that a user gets burned.
That said, I think the slideshow is a great idea in that an informed consumer is a "safer" consumer. And I also suspect that the vast majority of users will never experience a problem. But my view remains that hookless is unnecessary for anyone not racing ProTour, and is of questionable benefit there, so there's no real reason to use it other than you don't have a choice if manufacturers abandon it.
Sorry to derail a bit Mike, your effort is recognized.

[NHAero]

My two sets of all road wheels from BTLOS are hookless. At the time I couldn't seem to find hooked carbon 650B rims, and maybe they were out there and I either missed them or they were from manufacturers where they cost 1.5-2.5x as much so I didn't look at the offerings. At 40 psi max pressure on 38 and 42mm tires I have about 8,000 miles without mishap. I have hit things, once or twice pretty darn hard, again, fortunately no mishap.

It's hard to know what constitutes acceptable risk. I mostly ride alone. In the events I've ridden such as D2R2 I haven't seen people with the type of failures we now are seeing in the Pro peleton, but most folks are on much wider tires at much lower pressures.

[fa63]

If you look at the table shared in post #20, you will see that the max. pressure for 35-39 mm tires on hookless rims is 400 kPa (58 psi) and for 40-44 mm tires, it is 350 kPa (51 psi). That means that the typical safety margin for wider tires on hookless is greater because most people aren't running anywhere near the max. pressure.

Originally Posted by NHAero

In the events I've ridden such as D2R2 I haven't seen people with the type of failures we now are seeing in the Pro peloton, but most folks are on much wider tires at much lower pressures.

[benb]

Originally Posted by fa63

If you look at the table shared in post #20, you will see that the max. pressure for 35-39 mm tires on hookless rims is 400 kPa (58 psi) and for 40-44 mm tires, it is 350 kPa (51 psi). That means that the typical safety margin for wider tires on hookless is greater because most people aren't running anywhere near the max. pressure.

What gets me with all this is I have 10+ years of being able to run these pressures in the 30-40psi range under my belt with tubes with absolutely minimal flats. I got my "gravel bike" in 2013 and I've had < 5 flats with it, and it most certainly has a ton of miles on it as up until last year it was basically my #1 bike for any training cause the weather is bad most of the time here and it was a cheaper bike. And I've rode MTB trails many times on that bike as one of my most favorite things has been to just ride that bike out of the garage to a trailhead, ride it, then hop back on the road and ride to another trailhead and ride there.

And my 8 year old road bike has had 1 flat with tubes and 26c tires and I've run the front tire into the 60s and the back tire into the 70s without issue. Again a bike that has seen gravel & dirt and tons of bad NE roads.

It's not like I hate tubeless, I have 20 years on tubeless on the MTB and have been extremely happy there. I've had 1 flat in 20 years on tubeless MTB, I tore the sidewall on a super weight weenie Hutchinson tire very early on. It was a substantial cut and yet Stan's actually got me back to the car with just having to keep topping the tire off.

But when I have to fix flats so rarely on road/gravel it's all meh.

For me the bottom line is sealant change happens more frequently for me than tubed flats, it doesn't take me that long to change sealant but it takes longer than changing a tube. That's with 1 bike with tubeless in the garage and 6 (including my wife and son's bikes) that have tubes. If I converted my road bike/gravel bike to tubeless I would have 3X as much work changing sealant and the # of flats I get would not change that much I think.

My son wants to convert his MTB to tubeless but I told him not until he saves the money and can do the maintenance himself. He is on his 2nd MTB with tubes and has yet to have a flat.

[NHAero]

Originally Posted by fa63

If you look at the table shared in post #20, you will see that the max. pressure for 35-39 mm tires on hookless rims is 400 kPa (58 psi) and for 40-44 mm tires, it is 350 kPa (51 psi). That means that the typical safety margin for wider tires on hookless is greater because most people aren't running anywhere near the max. pressure.

Exactly!

[bicycletricycle]

This is pure madness

[makoti]

Originally Posted by oldpotatoe

So...I've been away for a while..somebody tell me again...why are manufacturers making hookless rims?
Better? Cheaper? More reliable? Faster?

I'll take door #2, Bob. Cheaper

[flying]

Originally Posted by oldpotatoe

So...I've been away for a while..somebody tell me again...why are manufacturers making hookless rims?
Better? Cheaper? More reliable? Faster?

I've been here the whole time & still have a wealth of no idea why this mess was invented

[reuben]

Originally Posted by Baron Blubba

Sigh, I should have known this would cause another tubeless spitstorm.

Sadly, that was my first thought when I saw this thread. The internet is where good deeds are often punished, where experts abound, and a counterexample can be found to disprove anything.

[NHAero]

Originally Posted by Mark McM

That's actually the ISO maximum for that tire width on hooked rims (see table above). Interestingly, Zipp recommends 62 psi for the same rider, tire and inner rim width, if the rims have hooks.

Isn't that table for straight sided (aka hookless) rims?

[EB]

I remember in 2018 I rode the Tahoe Trail 100 XC race at Northstar, and day before we did a pre-ride with Levi Leipheimer himself to acquaint ourselves with the start and finish of the track.

We stopped for a bit and Levi led a long lively discussion of tire pressure. People were comparing and debating 21 psi, 22 psi, 23, 24 psi and so on.

Then one cranky gentleman "explains" that he's been running his mountain bike tires for years at 60 psi AND EVERYTHING IS JUST FINE, THANK YOU VERY MUCH <oldmanyellsatcloud.gif>.

Just goes to show you that operator error even with mature technology is inevitable, and sometimes, insisted upon.

[RoosterCogset]

I found the updated Mavic chart. IMO, the easiest way to see the ETRTO guidelines at a glance. Versus the 2yr old version, I do see they've taken 28mm tires out of the 25mm TSS rim width column.

https://technicalmanual.mavic.com/te...hemes/2_72.pdf

[El Chaba]

So….After all of this discussion and debate, we have gone over much of the methodology of installing and using tubeless and hookless….and precautions that should be taken with respect to rim/tire compatibility and pressures used with various combinations… The question that remains for me is, to what end? That is, can anybody concisely describe the advantages offered by said equipment?

[fa63]

It is lighter (by a few grams).
Manufacturers claim better aerodynamics, better rolling resistance, and more pinch flat resistance (the aero and rolling resistance claims in particular are dubious).
It is easier (and cheaper) to manufacture.

[Carbonita]

Good find! Is this the 2023 ETRTO standard year update?

Originally Posted by RoosterCogset

I found the updated Mavic chart. IMO, the easiest way to see the ETRTO guidelines at a glance. Versus the 2yr old version, I do see they've taken 28mm tires out of the 25mm TSS rim width column.

https://technicalmanual.mavic.com/te...hemes/2_72.pdf