Nextie 40mm wide gravelrim! NXT45AGX

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RDY
Posts: 2587
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

rulefive wrote:
Sat Dec 17, 2022 4:28 pm
My AGX45 wheelset is used for road and fast gravel. My opinion is that this is the primary use case for this style of rim - to provide stability and an aero friendly profile when using wider tyres.

My preference for running a 36mm tyre is that on the AGX45 it will end up measuring about 40mm which lines up nicely with the rim. Going to the 40mm tire is likely to negate at least some of the benefit of running the AGX45 as the tyre will end up a lot wider than the rim.

Also note that the Speedero should be faster than the Thundero because the knobs are lower profile and more aero, something that BRR et all don't test for.
No manufacturer is ever going to suggest running a 36mm tire on a 41mm external rim. Ever. Especially offroad. There's no way they function properly, as you've found, and rim damage is practically a given at some point. Much wider? Thundero 40mm measures at 43mm for me. That's 4.9% wider, or 1.5mm / 2.45% each side. The 105% rule isn't really a rule, and it's pointless following it for these rims as they're nowhere near deep enough relative to their width for it to be relevant. This rim is about stability, and arguably reducing tire deformation with less mushrooming, leading to lower rolling resistance (and potentially an aero gain that way).

If you're worried about the minute aero gain between the Speedero and Thundero, then presumably you wouldn't be running these rims, as they're way too wide.

If you want mixed road and gravel use, and want aero gains, then you'd have been much better with the ARX49 from Nextie, or similar rims from FarSports or LightBicycle. The 36mm Challenge HTLR tires should be fine on 31-32mm wide rims, unlike these monsters.

IMO the Panaracer GK 38s (40 ETRTO) are too narrow for the AGX. Thundero 40s are the narrowest I'd ever go.

rulefive
Posts: 4
Joined: Thu Nov 10, 2022 3:40 am

by rulefive

RDY wrote:
Sun Dec 18, 2022 11:30 am
No manufacturer is ever going to suggest running a 36mm tire on a 41mm external rim. Ever. Especially offroad. There's no way they function properly, as you've found, and rim damage is practically a given at some point. Much wider? Thundero 40mm measures at 43mm for me. That's 4.9% wider, or 1.5mm / 2.45% each side. The 105% rule isn't really a rule, and it's pointless following it for these rims as they're nowhere near deep enough relative to their width for it to be relevant. This rim is about stability, and arguably reducing tire deformation with less mushrooming, leading to lower rolling resistance (and potentially an aero gain that way).

If you're worried about the minute aero gain between the Speedero and Thundero, then presumably you wouldn't be running these rims, as they're way too wide.

If you want mixed road and gravel use, and want aero gains, then you'd have been much better with the ARX49 from Nextie, or similar rims from FarSports or LightBicycle. The 36mm Challenge HTLR tires should be fine on 31-32mm wide rims, unlike these monsters.

IMO the Panaracer GK 38s (40 ETRTO) are too narrow for the AGX. Thundero 40s are the narrowest I'd ever go.
I am sure you are correct where recommendations from tyre manufacturers are concerned as the AGX45 and 3T Discus 45/40 are rather niche wheelsets and not likely to be something tyre manufacturers care about. I will note that both the aforementioend rim manufacturers appear to take a different view to you on appropriate tyre width. 3T recommend a tyre size between 35-42mm WAM and Nextie 33-72mm. My 36mm Strade Bianca's measure 39.8mm at 30psi after about 500km on the road. I'm keen to hear personal experiences to the contrary, but otherwise think my issues are tied to tyre construction rather than their WAM relative to the width of the rim.

With respect to the likelihood of rim damage, I'm not a hack and have a different wheelset for singletrack, so am comfortable with the small risk that rim damage will result from the type of riding these wheels will see. I understand that everyone has a different risk appetite, but I'm not conviced that a tyre which is 3mm wider will significantly reduce the risk of damage.

Re aero gains, it is likely that we won't know for some time what the aero optimal setup for gravel wheels is, though resorting to running a rim like the ARX49 which is significantly narrower than the 36mm Strada Bianca appears contradictory to what we do know and I'm not sure why one would bother.

Will likely order some 36mm Speedero's in the coming weeks and report back once I have some time on them. In the interim, will be interested to hear any other experiences running tyres with a WAM close to the width of these rims.

by Weenie


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RDY
Posts: 2587
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

rulefive wrote:
Mon Dec 19, 2022 2:00 pm
RDY wrote:
Sun Dec 18, 2022 11:30 am
No manufacturer is ever going to suggest running a 36mm tire on a 41mm external rim. Ever. Especially offroad. There's no way they function properly, as you've found, and rim damage is practically a given at some point. Much wider? Thundero 40mm measures at 43mm for me. That's 4.9% wider, or 1.5mm / 2.45% each side. The 105% rule isn't really a rule, and it's pointless following it for these rims as they're nowhere near deep enough relative to their width for it to be relevant. This rim is about stability, and arguably reducing tire deformation with less mushrooming, leading to lower rolling resistance (and potentially an aero gain that way).

If you're worried about the minute aero gain between the Speedero and Thundero, then presumably you wouldn't be running these rims, as they're way too wide.

If you want mixed road and gravel use, and want aero gains, then you'd have been much better with the ARX49 from Nextie, or similar rims from FarSports or LightBicycle. The 36mm Challenge HTLR tires should be fine on 31-32mm wide rims, unlike these monsters.

IMO the Panaracer GK 38s (40 ETRTO) are too narrow for the AGX. Thundero 40s are the narrowest I'd ever go.
Re aero gains, it is likely that we won't know for some time what the aero optimal setup for gravel wheels is, though resorting to running a rim like the ARX49 which is significantly narrower than the 36mm Strada Bianca appears contradictory to what we do know and I'm not sure why one would bother.

Will likely order some 36mm Speedero's in the coming weeks and report back once I have some time on them. In the interim, will be interested to hear any other experiences running tyres with a WAM close to the width of these rims.
1) What we know is that we need a much deeper rim for air to stay attached when it gets significantly wider. The AGX45 can't hope to do this. What it can do is be more stable in strong, unstable wind and mushroom wide tires less. The AGX45 is probably quite a bit 'slower' in steady state or very light wind than an ARX30 would be. Slower in inverted commas because a lot of us rarely have light or steady winds to ride in. It's why I chose an ARX49 on the back, stability isn't an issue and it's not getting blasted by the (usually gusty) wind on the rear end, so a deeper narrower rim is more optimal when considering airflow as I stand to gain little from going really wide. Tbh I'd consider a 65mm on the rear if Alpina didn't refuse to sell Hyperlite spokes in shorter lengths at quantities of less than 1000 pieces.

2) It will probably work better than the SB HTLR 36, but again you're blowing out a tire on a really wide rim that it's not designed to sit on. I just don't see the point. Going too wide on the rim on too narrow a tire is probably worse than going too wide on the tire on too narrow a rim. Take a look at some articles on MTB tires.

emotive
Posts: 619
Joined: Tue Nov 01, 2016 10:40 am
Location: Melbourne, Australia

by emotive

rulefive wrote:
Sat Dec 17, 2022 7:54 am
Who has been running tires narrower than the width of their AGX45 rims and been happy with the handling?
I am running the Bon Jon Pass 35mm Extra Light. They have a WAM of 39.5mm. I am riding road and fast gravel on these tyres, the same as you. I am running a 38mm Barlow Pass Extralight on the rear. I use the Silca calculator to determine my pressure. For a 90kg system weight (rider + bike) I am running 43psi on the front for road use.

Very stable in strong wind, good cornering on road descents. 2200km in this setup so far. Tyres are showing some sidewall wear from rock contact, but I expect this will not shorten their life.

I also have a 31mm WAM tyres on my 32mm wide WR65 wheels for 100% road use. I have 14000km of use in this setup over 3 years. Again, there is evidence of sidewall contact from road irregularities but nothing to damage or shorten the life of the tyres.

hansotto089
Posts: 49
Joined: Sat Dec 26, 2020 7:44 pm

by hansotto089

... so anyone managed to find a discount code? :)

Edit: sometimes it's too easy: CNY2023 for 5% off until end of January.

emotive
Posts: 619
Joined: Tue Nov 01, 2016 10:40 am
Location: Melbourne, Australia

by emotive

Another tyre option with a good WAM match for this wheelset may be the new GP5000AS TR in 35mm. There are no real-world measurements yet to estimate the WAM on the AGX45, but it should be pretty close to 40mm.

HuwR
Posts: 3
Joined: Sun Mar 20, 2022 9:17 am

by HuwR

Currently off the bike due to bad leg break but have had a few different tyres on the axg45s during my ownership.

RH hurricane ridge EL 42mm WAM 43.5mm @40psi

Challenge strada Bianca 40mm WAM 42.5mm @ 50psi. (tried using these as winter road tyres, felt like steering a shipping container. Do not recommend)

Challenge getaway 40mm WAM 42.5mm @40 psi

Tufo Swampero 40mm WAM ~42mm @40psi

Conti gp5000TR 32mm WAM ~36mm (I like this tyre, but it has had so many punctures I might as well just use Swiss cheese)

I would really be interested in trying the new challenge getaways in 45mm but I suspect they would blow to ~47.8mm and not sure that will fit in the rear stays on my kanzo fast frame. Would be an expensive experiment if it failed!

RDY
Posts: 2587
Joined: Thu Jul 30, 2020 10:31 pm

by RDY

I just changed to Thundero 44mm front, from the 40mm. IMO given how hard it was to get the Thundero 40 on and off the rim, and that it measured 43mm and the Thundero 44 only 44.3mm, I'm now thinking this rim is a bit too wide for the Thundero 40 to perform optimally. The 44mm is way more supple even at the same pressures. I think the 40 was over stretched.

Tonsos
Posts: 14
Joined: Thu Feb 07, 2019 11:13 am

by Tonsos

Lightbicycle released their version of this rim now as well: https://www.lightbicycle.com/newsletter ... heels.html Interesting recommendations regarding minimum tire width (32c)

HuwR
Posts: 3
Joined: Sun Mar 20, 2022 9:17 am

by HuwR

Just to add to previous: Challenge Getaway 45mm blow up to 48.5mm at 22psi

First GRVL ride tomorrow

trackflack
Posts: 49
Joined: Thu Jul 20, 2023 11:16 pm

by trackflack

Tonsos wrote:
Thu May 11, 2023 2:30 pm
Lightbicycle released their version of this rim now as well: https://www.lightbicycle.com/newsletter ... heels.html Interesting recommendations regarding minimum tire width (32c)
Quite tempted by a set of these

satanas
Posts: 370
Joined: Sat Jul 04, 2020 5:45 pm

by satanas

Those considering these rims may find Josh's comments towards the end interesting:

https://www.slowtwitch.com/Products/Thi ... _8710.html

emotive
Posts: 619
Joined: Tue Nov 01, 2016 10:40 am
Location: Melbourne, Australia

by emotive

satanas wrote:Those considering these rims may find Josh's comments towards the end interesting:

https://www.slowtwitch.com/Products/Thi ... _8710.html
Brilliant. Thanks for sharing.

emotive
Posts: 619
Joined: Tue Nov 01, 2016 10:40 am
Location: Melbourne, Australia

by emotive

satanas wrote:Those considering these rims may find Josh's comments towards the end interesting:

https://www.slowtwitch.com/Products/Thi ... _8710.html
Brilliant. Thanks for sharing. These guys have immense experience and are way ahead of the standards, which just don’t cater for wheels with a 29mm internal width.

Tonsos
Posts: 14
Joined: Thu Feb 07, 2019 11:13 am

by Tonsos

satanas wrote:
Thu Aug 03, 2023 1:24 pm
Those considering these rims may find Josh's comments towards the end interesting:

https://www.slowtwitch.com/Products/Thi ... _8710.html
Very interesting discussion!

I guess my measurements are a little less relevant as Josh Poertner mentions pretty much the same combination in the article. AGX45 (hooked) with 32 mm GP5000S TR measures 35.5 mm. At 3.6 bar / 52 psi.

I have only ridden this combination for 400-500 km and use them as my All-Road wheelset. In my case that primarily means asphalt - also the poorly maintained kind - and a little bit of light gravel. I am very pleased with the combination so far! Rolls really well, is very comfortable and sooooo much fun when you encounter potholes and other poorly maintained surfaces. Rolls straight "through/over" the cracks and holes - and puts a big smile on my face. I could definitely use a pure road wheelset with narrower rims/tires for most of my rides and it surely would increase the avg. speed a little, but I honestly don't think it would make a big differnce - and I wouldn't have as much fun as I do on this wide setup.

The quality of the AGX45 (built with DT Swiss 350) seems really good. I am very happy with my set.

by Weenie


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