Coming soon: Hunt wheels 36mm outer width

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mpulsiv
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by mpulsiv

Source: https://bikerumor.com/2018/08/16/eb18-w ... e-in-color
I like the idea of super wide outer width (e.g. 36mm) but is it safe to mount 28mm tire? Isn't the sole purpose of making wheels this wide is for 35mm gravel tires to sit flush with the rim for aero benefit? Looks like they are targetting road discipline, 48mm deep on 28mm tire :noidea:
I think Reynolds ATR 700 at 32mm wide is a better choice for road discipline https://reynoldscycling.com/collections ... ts/atr-700

"The wheels use a unique low-density filler to create the extra width around the bead for a smooth transition to the tire without much weight penalty. From the side it looks similar to something you might have seen as a different brake surface material, although these are disc brake only. No word on an official name, weight, or pricing on these yet. But we are told that they will be finalized in the coming months and ready for order before the end of 2018."

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bm0p700f
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by bm0p700f

I have been testing a similar thing but I have not been marketing it.

The rim width I have been looking at is specific to IRC Formula Pro 28mm tyres. I suppose hunt will be suggesting the Schwalbe Pro one.

I also think gravel wheels need to evolve. I have been testing 30mm wide 25mm internal width carbon rims, hook less to for tubeless tyres only.

Hunt are on the right lines though. Wheels could be designed with tyres in mind more than they are at present. Some standardisation of bead to bead distance for a given width is sorely needed.

emotive
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by emotive

mpulsiv wrote:
Sat Aug 18, 2018 11:15 pm
I like the idea of super wide outer width (e.g. 36mm) but is it safe to mount 28mm tire?
The ratio of the inner rim width to the tyre width is what you need to look at for safety. The Hunt prototypes are 22.5C. Putting 28mm tyres on a 22.5C inner rim is not new.

22.5C is only 1.5mm wider than the current Rovals, and Specialized fit them with 26mm tyres, so the ratio is similar

22.5C is 2.5mm narrower than the Enve 4.5 AR which are 25C, and are commonly fitted with 28mm tyres.

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mpulsiv
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by mpulsiv

emotive wrote:
Sun Aug 19, 2018 5:55 am
mpulsiv wrote:
Sat Aug 18, 2018 11:15 pm
I like the idea of super wide outer width (e.g. 36mm) but is it safe to mount 28mm tire?
The ratio of the inner rim width to the tyre width is what you need to look at for safety. The Hunt prototypes are 22.5C. Putting 28mm tyres on a 22.5C inner rim is not new.

22.5C is only 1.5mm wider than the current Rovals, and Specialized fit them with 26mm tyres, so the ratio is similar

22.5C is 2.5mm narrower than the Enve 4.5 AR which are 25C, and are commonly fitted with 28mm tyres.
Inner diameter is not even a concern. I was asking about outer diameter, which is 36mm for 28mm tire. Taking a sharp corner can sweep the rim since tire is not wrapped around it.

Refer to THE BELL but even wider outside diameter.

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by Nefarious86

I'm more excited about the 981g tubs for £1090

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by JScycle

mpulsiv wrote:
Sun Aug 19, 2018 6:19 am
emotive wrote:
Sun Aug 19, 2018 5:55 am
mpulsiv wrote:
Sat Aug 18, 2018 11:15 pm
I like the idea of super wide outer width (e.g. 36mm) but is it safe to mount 28mm tire?
The ratio of the inner rim width to the tyre width is what you need to look at for safety. The Hunt prototypes are 22.5C. Putting 28mm tyres on a 22.5C inner rim is not new.

22.5C is only 1.5mm wider than the current Rovals, and Specialized fit them with 26mm tyres, so the ratio is similar

22.5C is 2.5mm narrower than the Enve 4.5 AR which are 25C, and are commonly fitted with 28mm tyres.
Inner diameter is not even a concern. I was asking about outer diameter, which is 36mm for 28mm tire. Taking a sharp corner can sweep the rim since tire is not wrapped around it.

Refer to THE BELL but even wider outside diameter.

With a small inner diameter compared to tyre size lots of roll and flex of the tyre can occur. Adding wider external width without changing internal width does not help stability.

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by emotive

Hunt's intent is to develop the first wheelset aero optimised for a 28mm tyre, and more specifically, the 28mm Schwalbe Pro One tubeless tyre.

See https://youtu.be/kdyRFGuK6_I

The inner width of 22.5C is to provide optimal support the 28mm tyre. This internal width will be as the WIDE RIGHT diagram above shows. I am riding 28mm Continental, S-Works, and Compass tyres on this sized inner wheel for 8000km. There is no roll and flex.

The outer width of 36mm is to provide optimal aero transition from the 28mm tyre to the wheel on the leading edge, and from the wheel back to the tyre on the trailing edge. On the 22.5C inner, the tyre will have a measured width of around 31mm.

Hunt tested a range of widths in the wind tunnel to find the best width, as per the youtube video above.

Striking the rim on a curb leaned over in a race may be a concern, but these wheels will only protrude 2.5mm wider than the 31mm tyre. The New Cannondale SystemSix KNOT64 wheels are 32mm wide, so they also protrude wider than the 26mm wide Rubino tyre, to get the optimal aero benefit

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by wheelsONfire

Easton 55 Aero have a leading edge of 28mm. It was tested as "most aero" with 22 to maximum 23mm tires.
BTW, that Hunt rim, it's possibly a really heavy rim.
Any numbers regarding weight?
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mpulsiv
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by mpulsiv

wheelsONfire wrote:
Mon Sep 03, 2018 8:37 pm
Easton 55 Aero have a leading edge of 28mm. It was tested as "most aero" with 22 to maximum 23mm tires.
BTW, that Hunt rim, it's possibly a really heavy rim.
Any numbers regarding weight?
Leading edge because of the width (e.g. 28mm) of the rim. Let's take a look at Hambini's data. There's a delta of ~6 watts when Conti GP4000S sits flush on the Enve 7.8 rim.
Easton 55 Aero holds then candle because of the rim profile. Based on the data, we can assume that anything between 28-30mm wide rim will perform as well or better.

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Last edited by mpulsiv on Fri Nov 02, 2018 9:17 pm, edited 1 time in total.
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by AJS914

Isn't wider slower in general (aero wise) because of more frontal area? You might make it up with less rolling resistance at lower pressures though.

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by Marin

Only at low yaw, which Hambini insists happens a lot less than we thought...

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mpulsiv
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by mpulsiv

AJS914 wrote:
Fri Nov 02, 2018 7:50 pm
Isn't wider slower in general (aero wise) because of more frontal area? You might make it up with less rolling resistance at lower pressures though.
To clarify things, I talk about wheel width only. I edit my reply above "Based on the data, we can assume that anything between 28-30mm wide rim will perform as well or better." At the end of the day, aim for "The Rule of 105%". Get the widest wheel you can afford https://silca.cc/blogs/journal/part-5-t ... rodynamics

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mpulsiv
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by mpulsiv

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