Massive rim failures in the pro peloton sparked a heated debate. Are hookless wheels safe, or nah? Here’s what your favorite wheel brands think.
Easier manufacturing was the primary reason, as far as I know. Molding the hooks for a rim requires a more complex mold and additional post molding finishing steps to ensure the hooks are shaped properly. Additionally, on MTBs, where there isn’t the same concern about having to retain a tire at high pressure, there is a potential benefit to durability with hookless, although I think that may be overstated, as it depends on the design. If material is added bringing up the whole sidewall thickness to the thickness that would normally be the hook, then yes, it could increase durability. But if the area where the hook would normally be is simply thinned to match the rest of the sidewall, then I think durability could even be worse. In other words, is the hookless shape achieved by adding OR subtracting material from a normal hooked setup. And of course some rims are a combo of the 2.
That’s not a real concern if rims and tires are made to ISO and/or ETRTO standards. The problem that exists now is the lack of compliance on those standards (with compliance including manufacturing to the correct tolerances) and the confusion in the marketplace re: those standards. It’s not helpful when companies like Zipp and Enve ignore the standards and tell their customers it’s safe to use 28mm tires on 25mm internal width rims.
You might want to check your facts. ETRTO applies to rims, tires, and valves for a variety of vehicles. The intent is to ensure safety of a complete system, when the components of the system are made by different suppliers. Both Enve and Zipp hookless rims are made to ETRTO standards for tubeless rims. So, it’s incorrect to say they both disregard standards. As for tire compatibility, until recently 28mm tires were approved. There was a recent change that increases the suggested width to 29mm. But, even with that, there is a provision for “past standard”, to cover this exact situation.
Peak torque did a great video explaining the differrences in how they make each.
https://www.youtube.com/watch?v=bAgxTdNIOhA
You can see the appeal from the maker’s perspective if they can get this right. I’ve always run hooked rims but bought some hookless recently. Too early to tell if they’ll be reliable but here’s to hoping!
As Peak Torque’s video on the topic states, hookless is specific to carbon wheels and rims.
Aluminum wheel manufacture is essentially extruding – squeezing the material out of a mold like toothpaste as it’s pushed along; the mold is the cross-section of the rim. You can’t do that with carbon fiber (unless perhaps if you go the forged route).
Carbon fiber manufacture involves lay-up of multiple plies of the material and sandwiching them with resin, and it’s the same for wheels. There are molds used, but they are different from the extrusion ones for aluminum. The molds for carbon fiber wheels are meant to hold the material in place as it’s baked in the autoclave.
How you make the rim hooks therefore is the big challenge. With an aluminum wheel the hooks are already accounted for in the extrusion process. With carbon, you need more molds to shape the carbon into the rim hook, and the molds themselves are consumable parts that cost money to make.
Stronger rim, a lot less weight, better tire to sidewall rim aero profile and shape of the tire in how it sits more flush on the outside edge. Read some articles from the big brands making them. It’s not just all about manufacturing costs, but it does help keep the MSRP from climbing like the rest of the industry. I’ve used hookless for 4 years and zero issues. Internet warriors will say otherwise, Pogacar doesn’t seem to mind them at the Giro.
FritzP: it’s cheaper because of competitive pressure and it’s lighter because the rim is wider. Even if hookless does shave 10 grams, I can also make a rim lighter by drilling holes in it, but I don’t think that weight loss through functional impairment should really count.
If you’re Zipp and you’re forced to sell at a lower price point, you will seek out ways to reduce costs to protect your margins. (Then you will hire shills to go on the internet and claim user benefit.) Pretty simple really.
The other fact that people need to keep in mind is that road hookless is often ONLY approved for tubeless use because the areas of pressure inside a tire are different with a tube vs no tube. Installing a tube increases the risk of the tire getting pushed off the rim, and so is explicitly frowned upon by many hookless rim manufacturers, so good luck getting home if you blow out and need to install a tube.
I’m not against the hookless design, but the industry is telling on themselves by suggesting the reduced cost in manufacturing will translate to reduced costs for us consumers. Companies that bet big on the hookless trend, like ENVE, Zipp, Cadex, to name a few, do not appear to have lowered the costs of their wheels substantially enough, so that’s not proving to be true as of yet. Yes, there are affordable offerings, but I was really disappointed in ENVE’s budget offering, the Foundation 65’s. I found them heavy, slow to spin up, unstable in even the slightest winds, which, I get, they’re 65mm deep, but I achieved faster speeds on my budget CRD 50mm wheels. Let’s keep it 100, we’re limited on tire choice, we’re limited on air pressure, and we’re limited on affordable high-end options. It’s clear the benefits aren’t for consumers.
