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Alloy hookless tubeless rims in 700c?
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I have been following slowman's articles on hookless wheels and tires with great interest. Supposing for a minute that I'm willing to try out the technology on my next build, but unable to justify spending top dollar on carbon fiber rims for non-racing applications, does anyone actually make aluminum alloy hookless rims in 700c?
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Re: Alloy hookless tubeless rims in 700c? [crmartin9] [ In reply to ]
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crmartin9 wrote:
I have been following slowman's articles on hookless wheels and tires with great interest. Supposing for a minute that I'm willing to try out the technology on my next build, but unable to justify spending top dollar on carbon fiber rims for non-racing applications, does anyone actually make aluminum alloy hookless rims in 700c?


Since eliminating hooks in a rim material that doesn't have issues with their formation (i.e. the extrusion die is no more or less complicated hooks or not), what would be the point? They aren't going to be any cheaper than they already are...and it would be a needless elimination of a key safety feature.

That said, Stan's NoTubes makes some aluminum rims that are mostly hookless (if you look closely at the profiles most have just a hint of a hook, though)...they also tend to be somewhat wide on the internal width measurement, so you'll be forced to also run somewhat wide tires to match.

http://bikeblather.blogspot.com/
Last edited by: Tom A.: Dec 1, 20 8:54
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Re: Alloy hookless tubeless rims in 700c? [crmartin9] [ In reply to ]
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I don't think I have seen any alloy hookless rim brake wheels. Not sure if I have seen disc brake ones either. Stans wheels have a barely-there hook which is the closest I have seen to a hookless alloy wheel. Their Grail road/gravel rims have a bead and the very similar Crest rim barely has a bead.

Others here have much more experience than I do though.

Edit: Tom A said a lot of the same info while I was typing the original reply.
Last edited by: dangle: Dec 1, 20 8:54
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Re: Alloy hookless tubeless rims in 700c? [Tom A.] [ In reply to ]
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Tom A. wrote:
crmartin9 wrote:
I have been following slowman's articles on hookless wheels and tires with great interest. Supposing for a minute that I'm willing to try out the technology on my next build, but unable to justify spending top dollar on carbon fiber rims for non-racing applications, does anyone actually make aluminum alloy hookless rims in 700c?


Since eliminating hooks in a rim material that doesn't have issues with their formation (i.e. the extrusion die is no more or less complicated hooks or not), what would be the point? They aren't going to be any cheaper than they already are...and it would be a needless elimination of a key safety feature.

That said, Stan's NoTubes makes some aluminum rims that are mostly hookless (if you look closely at the profiles most have just a hint of a hook, though)...they also tend to be somewhat wide on the internal width measurement.

+1

Most people have not yet recognized that hookless rims are a cost-reducer for carbon rims, not a performance enhancer.

-------------
Ed O'Malley
www.VeloVetta.com
VeloVetta is developing AERO cycling shoes with CFD and wind tunnel testing.
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Re: Alloy hookless tubeless rims in 700c? [RowToTri] [ In reply to ]
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RowToTri wrote:
Tom A. wrote:
crmartin9 wrote:
I have been following slowman's articles on hookless wheels and tires with great interest. Supposing for a minute that I'm willing to try out the technology on my next build, but unable to justify spending top dollar on carbon fiber rims for non-racing applications, does anyone actually make aluminum alloy hookless rims in 700c?


Since eliminating hooks in a rim material that doesn't have issues with their formation (i.e. the extrusion die is no more or less complicated hooks or not), what would be the point? They aren't going to be any cheaper than they already are...and it would be a needless elimination of a key safety feature.

That said, Stan's NoTubes makes some aluminum rims that are mostly hookless (if you look closely at the profiles most have just a hint of a hook, though)...they also tend to be somewhat wide on the internal width measurement.


+1

Most people have not yet recognized that hookless rims are a cost-reducer for carbon rims, not a performance enhancer.

The paradigm that a "high performance" bicycle rim needs to be made completely from carbon is continually quite the head-scratcher for me...especially since the best overall system performance (including cost) for a TT/Tri wheel system is still a "hybrid"-type construction of metallic rim bed/braking surface combined with a lightweight and shaped carbon "cap" (Hed Jet Black possibly the current high bar of that construction).

http://bikeblather.blogspot.com/
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Re: Alloy hookless tubeless rims in 700c? [crmartin9] [ In reply to ]
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Answering just for interest’s sake: the White Industries G25A rim is alloy and hookless.

http://www.whiteind.com/rimg25a

Why haven’t you heard of it? G presumably stands for gravel. It’s 20mm deep, not any type of aero section, 25mm internal and 29mm external width, suggested tire widths 40-54mm.

And yes, I have not heard of any other hookless alloy rim.
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Re: Alloy hookless tubeless rims in 700c? [RowToTri] [ In reply to ]
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RowToTri wrote:
Most people have not yet recognized that hookless rims are a cost-reducer for carbon rims, not a performance enhancer.

My understanding is that hookless can allow for stronger rim construction (w.r.t rim strikes, etc) and allow more flexibility in aerodynamic shaping. So not just cost.

Talking about carbon alone, here.
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Re: Alloy hookless tubeless rims in 700c? [trail] [ In reply to ]
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trail wrote:
RowToTri wrote:

Most people have not yet recognized that hookless rims are a cost-reducer for carbon rims, not a performance enhancer.


My understanding is that hookless can allow for stronger rim construction (w.r.t rim strikes, etc) and allow more flexibility in aerodynamic shaping. So not just cost.

Talking about carbon alone, here.

Can you provide an example? It is difficult for me to think of any meaningful way in which this would be true. It's true that you can get the depth of the lip where rim meets tire to be a little thinner without a hook. But will the aerodynamic difference be measurable? Is it worth the limitations it puts on tire construction and the safety issues? Everything I know about them leads me to believe that eliminating an expensive processing step from the manufacturing is the #1 driver for moving to hookless rims. I wouldn't have a problem with that, generally, except they seemed to roll out the rims before making it very clear to people that there are only certain tires that are safe to use with them. And even now I am not sure they make that clear enough.

-------------
Ed O'Malley
www.VeloVetta.com
VeloVetta is developing AERO cycling shoes with CFD and wind tunnel testing.
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Re: Alloy hookless tubeless rims in 700c? [Tom A.] [ In reply to ]
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Yeah... well... I have accepted that that ship has sailed and I just try not to think about it :)

When I totaled my bike in Nice WC, my crash replacement from Felt came with disc brakes, so... voila. I ride disc brakes now.

-------------
Ed O'Malley
www.VeloVetta.com
VeloVetta is developing AERO cycling shoes with CFD and wind tunnel testing.
Instagram • Facebook
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Re: Alloy hookless tubeless rims in 700c? [RowToTri] [ In reply to ]
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Probably just repeating what Slowman says. I've asked the same questions as you in some other hookless threads and received no answers from people who claim aero and strength benefits. I doubt either theoretical point has been quantified by anyone.
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Re: Alloy hookless tubeless rims in 700c? [RowToTri] [ In reply to ]
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RowToTri wrote:
Can you provide an example?

I'm not an expert here. But I'll do the best to explain my lay understanding.

First, strength. With images from Flo, below.

My understanding is that hookless rims can be made shorter and thicker. Both of those should allow for a more resilient rim to things like rim strikes. I guess part of that is just cost again. Because you can throw more money and costly material at that part of the rim to try to achieve the same strength as a cheaper hookless rim that's shorter and fatter. But I think it's still valid as inherently more durable.

For aero, the hook lip pushes the tire in, which makes it harder to get a smooth, continuous interface between the rim and tire. The shaded areas of the 2nd image show this difference. Yes, it's marginal. But it's there. And we're all about the extreme margins right?...like putting a Boa dial behind the heel of a shoe?

But I'll turn the argument around on you. Hookless is definitely cheaper, and possibly marginally better in some areas. What advantage do hooked rim have? The only one I can think of is "safety." At higher pressures. But we now know that even with 23mm tires, we should be running at far lower pressures than we used to. And most people don't even run 23mm anymore. I think 28mm is the new standard. At some point there's crossover where the safety benefit becomes all but irrelevant. My understanding is there was extensive safety testing with the new ETRTO standard, and basically we're not going to have tires blowing off the rim if everyone adheres to the standards.








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Re: Alloy hookless tubeless rims in 700c? [Tom A.] [ In reply to ]
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I have yet to see data showing / proving improved aero performance with hookless (not saying it's impossible - just that I haven't seen any data from any brand). When Slowman and I met with ENVE at their offices a year ago, they talked about doing some testing with wide gravel tires (35mm+, if I recall correctly) - and that there was some potential for an aero gain using hookless rims. It seemed to be an aero testing priority on their radar. I believe it had to do with the width of the overall rim/tire package, and the higher yaw angles experienced in gravel, due to the lower rider speeds.

At least with their products selling at that time, they noted a slight aero penalty with a hookless bead for road (i.e. 25-30mm tires), because it allows the tire to inflate to a larger size (think of the Rule of 105). But - they reported that the improvement in rolling resistance from this more than offset the aero loss. In other words, they reported a net gain in speed. Of course, I'm generalizing here and don't have any Crr/aero charts in front of me, so there are likely a lot of specific cases to understand - how this applies to various tires sizes, rim widths, yaw angles, and so on.

Greg Kopecky - Slowtwitch Tech Editor
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Re: Alloy hookless tubeless rims in 700c? [trail] [ In reply to ]
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Regarding the strength: the wall thickness and height is independent of the hook. Could be made made the same in either case. Why the hook would be a weak point (in theory), I understand. But do they break in practice? If they aren't breaking to begin with, then added strength isn't a benefit.

Regarding aero: the first picture is misleading by adding color at the tire. All setups should just be sized for 105% rule with no tire overhang. At the hook, maybe hookless is more flush and maybe not. If we use the top pictures as reference, it's not, because the wall was made just as wide as the hook. IF the wall thickness remained the same and only the hook was removed, then there may be some aero benefit (not adding strength in this case, though). But if the "marginal gain" is 0.05W, then I would argue not even the pickiest STers will care.

Both benefits are theoretical at best and non existent at worst.

Meanwhile a safety feature is being removed at the wheel and needs to be compensated for with stricter standards at the tire that will require stronger bead (heavier) and tighter tolerances (more expensive). So even the cost benefit could become a net loss to consumers even of the manufacturers decide to pass on the $25 manufacturing savings. Given that hooked rims can be purchased from reliable OEMs for under $150, I doubt the manufacturing savings can be more than $25-50 by eliminating the hook.
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Re: Alloy hookless tubeless rims in 700c? [BigBoyND] [ In reply to ]
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BigBoyND wrote:
Regarding the strength: the wall thickness and height is independent of the hook.


I'm not sure that's true, based on what I've read. But then again I only have a lay understanding and may have been reading industry "propaganda."
Last edited by: trail: Dec 1, 20 15:50
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Re: Alloy hookless tubeless rims in 700c? [trail] [ In reply to ]
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I'm also layman and just assuming they are mostly independent.

In the photos you posted it looks like the hookless rim basically filled in space below the hook, adding thickness.

In the diagram you posted it looks like the thickness stayed the same and the hook was removed.

Knight had thicker walls for better brake feel with hooks. I wonder if they'd look like the thick hookless picture, with hooks added on top of that.
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