Externally super Wide but Internally Not-so-wide rims?

[Kri]

Hello. I think I like the current trend of externally wider & deeper rims, to gain aero benefit for gravels.

But If the rims get too wide(external 42mm+~) to accomodate aero benefit for wider tires,
then Internal width gets waaay to wide(wider than 32mm) for 45c or even 2.0, 2.2 inch tires.

And seeing from the ETRTO perspective I think its borderline unsafe.

Some manufacturers seems to have found the solution, to make the sidewalls really thick and hollow.
So they has external of 44mm~ and internal width ~30mm, to maximise aero benefit and also have safe internal width to accomodate 45c safely
the attatched pictures below are from Duke rims and Reserve wheels.

Does any of Chinese carbon rim manufacturers do something simmilar?

[ckchriskohl]

based on my gravel wheelset list:
cadex maxgr
csixx gravel wide 45 or 65
Newmen Streem G-62G
Reserve 48/53 GR
Specialized Terra Aero CLX
Strada gravel Aero Plus 2
VoiceVelo GA450

i think some lightbicycle rims or sth similar has those "holes" under the rim bead. maybe it was just duke

[Serge_K]

Reply #38 on Conti GP 5000 35C: a new standard for road frames thread.
Reply #66 on Conti GP 5000 35C: a new standard for road frames thread.

A key topic of interest for me for the same reasons as you. Very confusing. POTOOO on the forum says he's tried a 35C on ETRTO compliant and non compliant rims, and he actually feels unsafe on the compliant ones, and vice versa.
We "know" that ETRTO is a bit of a shit standard, but it's a standard nonetheless, so i'm not comfortable just ignoring it. Also, chinese sellers push back quite hard if you tell them you want to mount a 35C on a wide rim, they point you straight to ETRTO.

Waiting for people smarter than me to come up with a consensus. I gave up on a wheelset purchase this summer precisely because i dont know what to buy that would be aero & safe.

[Kri]

based on my gravel wheelset list:
cadex maxgr
csixx gravel wide 45 or 65
Newmen Streem G-62G
Reserve 48/53 GR
Specialized Terra Aero CLX
Strada gravel Aero Plus 2
VoiceVelo GA450

Thanks for the lists!! Imo especially Newmen and Voicevelo looks good.
But also, as a hobbyist wheelbuilder, It would be better if there was rim-only options for those rims tho

A key topic of interest for me for the same reasons as you. Very confusing. POTOOO on the forum says he's tried a 35C on ETRTO compliant and non compliant rims, and he actually feels unsafe on the compliant ones, and vice versa.

Imo, That 'incompatibility' that POTOOO says(tyre losing bead sit, etc), I think it might be more of the rim bed shaping, and the actual bead sitting diameter 'errors', rather than wheel width itself
also for Gravel/MTB tires versus road tires, Tire can be too "square" and the side knobs would engage way too early if using with too wide rims

[Grailstore]

Very interested in this topic - following

[antoinesbikes]

interested as well!

[LittleBobcat]

I designed the rim profile of NOSIG HW-X gravel wheels and Voicevelo GA5450(They share the same profile but uses different carbon layups to accommodate different spokes system). the front profile is 30mm iw hookless & 44mm ow (with a 43mm ow at the hooks) 54mm deep. We use special layups to get a 6.5mm platform on either side of the hook to maximize aero performance & reduce tire crackings. You may choose same profile for front&rear or a 38mm ow 50mm deep lighter rim on the rear(just like standard voicevelo ones)

So far I think the profile is still one of the best on market. On NOSIG wheelsets Daan Soete just won the BK gravel 2026 in front of WVA last week and got 7th on Unbound 200 earlier this year.