See this link from Enve for a pretty good, illustrated explanation.
Thanks. Yea that pretty much jives with how I thought it worked. All the meaningful contact is on the inner portion of the tire bead against the bead shelf.
A tight fit is probably the best sign of hookless success.
2 Likes
Unfortunately thatâs very subjective. Bad technique can make even a loose fit hard to install.
I would instead try inflating with a floor pump without any sealant. If you can do that, chances are better that the inner diameter matches well. Measure wall height (G in the diagram above) before installing and see if it matches the table above. If both checks pass, thatâs something.
Iâm sticking with hooks though.
Agree with that. IMO if a tire wont seat and inflate with a floor pump something is seriously wrong.
Who even makes hooked disc wheels? Iâve been poking around various wheel manufacturerâs sites and I canât find any. Zipp, HED, etc.
I think Rovals are hookedâŚ.not 100%, though.
ETA - yes, Roval wheels are still hooked. Just checked.
Iâm sure there are others, as wellâŚ
2 Likes
Thanks
Itâs like when you push your tyre to the centre of the rim when you remove it, it gives you the maximum amound of slack to work with, increasing the inner diameter reduces the amount of possible slack, which is a issue as the tyre only has to come off in one place in order to âblowâ, it doesnât have to come of the entire outer diameter at the same time
(not advocating hookless, not arguing for , just explaining the âlogicâ, like everybody says, itâs a bodge)
1 Like
Thanks. I get it now. So the Extralight rim in question was undersized in every dimension. It also seems like the undersizing in multiple dimensions is additive.
It would have been interesting to know if the other rim he had was similarly undersized.
I would have also liked to see him swap tires front to back to see what happened.
2 Likes
From what I know 100%, Rovals road wheels and Shimanos road wheels are hooked. Scope also has models that are hooked 
Still plenty on the market, just a few that (annoyingly) are trying to push the âjust run 32mm at 3 bar so you can use our hookless wheelsâ
2 Likes
âBut then we donât make wide enough rims to be optimal for that. We optimize for 23 and 25mmâ
Reserve wheels are âsemi hookedâ according to their FAQ.
DT Swiss still make hooked disc wheels
1 Like
There is no reputable hookless wheel manufacturer optimising for 23mm tyres. Donât even think any of them are optimising for 25mm any more either, they mostly either explicitly say theyâre optimised for 28mm and/or have external widths of 30mm or wider which implies theyâre designed to be used with a wider tyre.
To touch back on importance of setup againâŚ
For you guys that are saying rim size and tire size must match exactly to a micron or whateverâŚdo you fee the same way about rim tape? Should there be some sort of regulatory commission to govern the thickness of rim tape as well? Because thereâs a pretty substantial difference in thickness. And the number of layers needs to be standardized tooâŚa second or third layer of tape makes a big difference in the fit vs 1.
AnywayâŚjust pushing back against those saying tire setup should not be customized for each setup. I think it needs to be. There are countless other things that need to be done this way on a bikeâŚtightened, cut, adjusted, etc, until itâs RIGHT, not to a random previously derived measurement.
No one is saying that and almost any âstandardâ has a + / - variation to it.
The issue is if companies are producing products that are outside the specification rangeâŚ.which is what Extralight did.
3 Likes
How far away from normal was this though? Would a few laters of rim tape really not fix it?
Why would you rely on adding rim tape until you get a tight enough fit (whatever that is), when you can instead buy a rim from a manufacturer who has actually adhered to the ETRTO standard and provides much clearer guidance on what tape to use (and/or ships their rims pre-taped) and what tyres, in what sizes, are compatible with what rims, and up to what pressure?
1 Like
Well, because I would never trust a manufacturer with anything over the actual tightness of the tire on the rim. Thatâs all that matters, and I can control that myself. I guess I dont understand why it matters what the manufacturer says regarding thisâŚ
If you start adding tape, you are effectively shortening the height of the rim wall that interfaces with the tire. You can thereby make it outside ERTRO specificationsâŚreduced interface between the tire and rim outside of spec increases your chances of a blowoff or catastrophic burb.