Josh Poertner, CEO of Silca and former chairman of the Bicycle Wheel Technical Committee, on hookless rims on road bikes:

"I think it’s a scam. I think it’s way less safe than it needs to be, and it has absolutely zero performance advantage in any area of performance – and actually it likely has some performance detriment somewhere or another."

Stating the obvious.

https://www.bikeradar.com/news/josh-...ims-are-a-scam

I heard that on the Marginal Gains podcast and agree. It does save the manufacturer some money that hypothetically could save consumers money, but I do agree with Josh on this one.

So, is the hook on carbon rims just harder to make and a few grams heavier, or does it actually make the rim less strong?

The claim is hooked rims on mountain bikes (and presumably gravel bikes) can result in tubeless pinch flats. I am not even sure that is a thing, but it is a bit of a flimsy excuse. I never heard of hooks weakening the rim. I think it is just easier/cheaper to manufacture a carbon rim without hooks. There don't appear to be many aluminum hookless rims for some reason...

For higher-pressure road tubeless applications, a case can be made that hookless rims are less safe, in terms of tires blowing off.

I think the "scam" part is claiming hookless is superior, especially for higher-pressure road applications. Enve has a (rather short) list of tires it regards as safe and compatible with its hookless rims. That does imply a very small margin of error.

I'm reading the article now. I have those same Vittoria tires, set up with tubes, and one blew off my aluminum hooked box rim at 80 psi. Tires can be part of the problem (and in my case, it might have been user error). Fortunately, it was just sitting in the garage.

My understanding is harder to make, a few grams heavier, does NOT make the rim stronger (or weaker) but prevents blowouts.

Of course I am a retrogrouch and still riding clinchers so I don't have a horse in this race.

Slight thread derail, but when I install a new tire I like to give the tire/rim combo a "stress test" and blow it up to 10-15PSI above my usual to verify it's stable and safe. Then drop down to correct pressure.

There were early hookless aluminum rims. Back when few clincher tires were narrow and high pressure. I cannot give details even though I worked in a bike shop in that era. My excuses - I rode sew-ups exclusively and it wasn't until my last year that high performance clinchers were just starting to become popular and that was my post-head injury year of complete information overload. A clincher rim was a clincher rim. Now I studied those sewup ones!

Devising molds for straight-sided carbon rims is evidently a piece of cake compared to doing the same for rims with hooks. Remember, straight-sided rims meant for use with high-pressure tires had vanished from the market by around the mid-'80's. But when carbon rims became fashionable for high-performance road bikes, suddenly manufacturers were claiming that straight-sided rims were best ("Save 50 grams per pair of wheels!" or whatever it was).

A spokesman for DT, interviewed on the topic, said that they'd investigated the alternatives and chose chose to manufacture all their carbon rims with hooks. Paraphrasing: "We don't mind investing in the technology to build a safer and more reliable rim." Sick burn against the other rim manufacturers.

Hooks are easy to produce in aluminum. Make a die pattern that includes hooks. A one time cost. Extruding through a more complex die might be a touch harder but that's it. Bend your hooked rim to a circle, plug or weld. A touch of filing maybe and send it out the door.

CF - much harder. The mold has to come apart into several pieces just to remove each rim. Added labor, fit issues, probably shorter usable mold lives. So convincing the public that simpler, lighter and stronger is a no-brainer (at least in the stockholders' views).

Thank you Silca for your rational opinion not influenced by the fads of recent decades.

Yes.

I think you meant to write hooked rims are more likely to lead to pinch flats -- correct?

When I bought my BTLOS gravel wheels 18mo ago, I had the choice of hooked or hookless for the same cost.
It wasn't ever a second thought- I selected hooked rims.

There is 0 upside for how I ride- my bike, my weight, my riding distance, my riding frequency, and my interest in spending time on micro-psi adjustments.

Yes.

Thanks.

(I thought I caught that and edited it, but I guess not.)

Hooked rims are a good idea if you want to run a narrow tire at very high pressures, that's why they were introduced by manufacturers trying come up with high performance clincher tires to rival tubulars starting in the late 1970's.

But the days where people assume that narrow is faster, and higher pressure is faster, are happily long behind us, right?

I haven't done tubeless and in fact stepped back a few years to sewups. So this issue doesn't affect me. But if I were to go tubeless, I'd be thinking of that concept some of you have heard me talk of before, the "sacred path" of forces from the road to my hands. A path where failures really hurt and can even have life changing consequences. Having a front tire blow off the rim qualifies. That pro who suffered exactly that came out of if in good shape but that wasn't a given.

I did have a clincher blow and come off a few years ago. Rear tire so my injuries, while very extensive, were not serious. But it had me thinking "what if" every time I did a fast descent. Took all the fun out. Woke up to the nightmare of doing that at speed a few times. It was why I went back to sewups. Properly glued, you can roll to a stop at any speed after any blowout. Tire age or condition doesn't matter. (Yes, base tape glue does matter. I put that under "gluing".) I blew at least one sewup at real speed in my racing days. Such a non-event that I do not remember how many times, where I did it, front or rear. That one rear clincher coming off is etched into my brain for the rest of this lifetime and maybe the next.

For a given weight, and assuming the same materials the hooked rim is going to be less strong. The hook has to be strong enough to withstand the pressure of the tire, and tire irons used to mount the tire. It takes some material to make the hook sufficiently robust.

That’s material that otherwise could strengthen the rim overall. So a hooked rim is either going to be slightly heavier, or slightly weaker ( or use better materials and therefore more expensive). Whether the marginal difference is enough to matter is debatable.

Dollars to donuts, the tire wasn’t seated correctly. Likely the tube was under the bead. Did the tube end up with a nice rip in it?

Pretty much the way I remember it. IIRC, neither my “paperboy” bikes, nor my first 10 speeds had hooked rims.

It was discussed extensively on a thread a few years ago after one of those pro crashes with the PIZMET? owner. Someone needs to find the thread.

Here's one:

Is there an advantage to hookless rims?

Another:

Thomas DeGent no fan of hookless…

I think that might be the case (which is what I was referring to as user error), but I never found evidence. The tube wasn't definitive. The tire looked ok, and for several years has stayed put, so there is that. It still makes me cautious about riding that bike.

Using two 19 years old pairs of Mavic Cosmic Carbone SSC hooked rims with the most abolute satisfaction

Nothing has changed. It is still a bad application for road in particular and literally only has a benefit to the manufacturer.

The old aluminum Schwinn ones were an alloy rim with extremely stiff tires that have steel beads in them. Kind of like car tires.

Right now the market is trying to put the lightest of rims (least amount of material) together with the most supple tires using bead material and casings that stretch. They then put this near intended interference fit under "high" pressure.

Again the only reason to do it and the only winner is the manufacturer. It drops a ton of mold complexity and cost (scrap) from the process of manufacturing. Doubt it? Start listing all of the top performing high quality aluminum rim options that come hookless for road. I mean the market sells an order of magnitude more alloy rims than carbon even at the high enthusiast level. So why not have hookless performance alloy? The answer is because it is so easy and not expensive to include the hooks in the alloy mold. The response when asked would be, "why wouldn't you include the hooks?" Think about that.