Zen Carbon Wheels Xiamen

[Matthew]

That's unfortunate. Stock Vaporlite Ultra's in 23 or 25? No extras requested?

No standard spec.

Guess that is what happens when smaller companies become popular, prices go up following the increased exposure and popularity.

[Rebel_Yell]

Love the wheels, they are great so far.

Specs in 2nd pic including price. 

[ZenCarbonBike]

Hi all,

We’re considering to develop a new 50mm carbon road rim and would really value some feedback from forum members

Concept Direction:
   •   50mm depth
   •   Modern U-shaped aero profile
   •   25mm internal
   •   ~32mm bead / ~34mm max external
   •   20 front / 20 rear
   •   Lightweight performance-focused rim


Rather than chasing extreme gravel-style numbers, we’re trying to optimise:
   •   Efficient U-shaped aero profile
   •   Lower overall rim weight
   •   Improved system load tolerance
   •   Better impact resistance than typical ultra-light race rims
   •   Compatibility with 28–32mm tyres (optimised around 30mm)

Spoke holes would likely be drilled with internal reinforcement for flexibility across hub types.

⸻

Open Questions:
   1.   Is 25mm internal still the right direction for 2026 road use?
   2.   Is ~34mm max width ideal for modern 30mm tyre setups?
   3.   Would you prioritise lower weight or higher load/impact margin?
   4.   20/20 rear — acceptable for modern road builds?
   5.   Any concerns with U-shape profiles at this width and depth?

Looking for constructive technical feedback rather than brand comparisons.

Appreciate any thoughts.

[NB87]

Hi all,

We’re considering to develop a new 50mm carbon road rim and would really value some feedback from forum members

Concept Direction:
   •   50mm depth
   •   Modern U-shaped aero profile
   •   25mm internal
   •   ~32mm bead / ~34mm max external
   •   20 front / 20 rear
   •   Lightweight performance-focused rim


Rather than chasing extreme gravel-style numbers, we’re trying to optimise:
   •   Efficient U-shaped aero profile
   •   Lower overall rim weight
   •   Improved system load tolerance
   •   Better impact resistance than typical ultra-light race rims
   •   Compatibility with 28–32mm tyres (optimised around 30mm)

Spoke holes would likely be drilled with internal reinforcement for flexibility across hub types.

⸻

Open Questions:
   1.   Is 25mm internal still the right direction for 2026 road use?
   2.   Is ~34mm max width ideal for modern 30mm tyre setups?
   3.   Would you prioritise lower weight or higher load/impact margin?
   4.   20/20 rear — acceptable for modern road builds?
   5.   Any concerns with U-shape profiles at this width and depth?

Looking for constructive technical feedback rather than brand comparisons.

Appreciate any thoughts.

I agree with the internal reinforcement for spoke holes for reliability reasons, but how does that help with flexibility across hub types?

My feedback to your questions:

   1.   Is 25mm internal still the right direction for 2026 road use?
Yes, I believe so. It relates to your second question. The combination of 25mm internal and 30mm tire width forms a round tyre profile, which improves predictable roll-over when leaning the bike from side to side. If you'd stuck a 25mm tire on 25mm internal width the profile is more flat which doesn't help with steering. Bigger internal width for road use does IMHO not bring any benefit.
   2.   Is ~34mm max width ideal for modern 30mm tyre setups?
Yes, that's perfect. 25mm internal width and a 30mm tire will sit nicely within 34mm external, making it aerodynamically a good match. I also believe that 30mm is the perfect width for fast road riding on most "typical" road surfaces. Bigger is only useful when the roads gets really rough.   
   3.   Would you prioritise lower weight or higher load/impact margin?
Balance is key. Personally, I don’t see much real-world benefit in sub-1000 g wheelsets. At ~85 kg rider weight, confidence in strength and impact resistance matters more to me. If a wheelset comes in around 1100–1200 g with solid durability margins, that’s an excellent compromise.
   4.   20/20 rear — acceptable for modern road builds?
Yes, provided lateral stiffness is sufficient. If the wheel can handle >1500 W sprint loads without feeling flexible, I’m comfortable with 20/20. Some degree of vertical compliance is desirable so the ride doesn’t feel harsh, but I realise that aspect is more subjective.
   5.   Any concerns with U-shape profiles at this width and depth?
No. U-shaped profiles at these dimensions are well proven aerodynamically and structurally, so I don’t have any concerns.

[Rolle2k]

Hi all,

We’re considering to develop a new 50mm carbon road rim and would really value some feedback from forum members

Open Questions:
   1.   Is 25mm internal still the right direction for 2026 road use?
   2.   Is ~34mm max width ideal for modern 30mm tyre setups?
   3.   Would you prioritise lower weight or higher load/impact margin?
   4.   20/20 rear — acceptable for modern road builds?
   5.   Any concerns with U-shape profiles at this width and depth?

1. I would say 25-26mm is perfect for road 2026..
2. i would like even wider rims, to be better for 32-35mm tires. The trend is wider, so wider OW is better. XMCS does have 26/33 wider wheels,and i would even liken even wider, maybe 34-35mm..
3. Lighter is always better, but not at cost of lateral stiffness or TO LOW impact resistance.. myself i would not buy wheels with specified load BELOW 110kg.
4.20/20 is perfect.. doesn't give much lower weight going down to 18 or even 16 spokes..
5. I think going more in the vein of DT-swiss profile is better when going for wider rims.. maybe 33mm around the tire bead, then going up to around 36 at it widest.
like this - https://d2a13k6araex7u.cloudfront.net/mat/00/00/00/00/00/00/00/10/00/00/06/00/6/DRW_GRC1100_50mm_24mm_discbrake_WEB_SHO_001.png

[ZenCarbonBike]

1. I would say 25-26mm is perfect for road 2026..
2. i would like even wider rims, to be better for 32-35mm tires. The trend is wider, so wider OW is better. XMCS does have 26/33 wider wheels,and i would even liken even wider, maybe 34-35mm..
3. Lighter is always better, but not at cost of lateral stiffness or TO LOW impact resistance.. myself i would not buy wheels with specified load BELOW 110kg.
4.20/20 is perfect.. doesn't give much lower weight going down to 18 or even 16 spokes..
5. I think going more in the vein of DT-swiss profile is better when going for wider rims.. maybe 33mm around the tire bead, then going up to around 36 at it widest.
like this - https://d2a13k6araex7u.cloudfront.net/mat/00/00/00/00/00/00/00/10/00/00/06/00/6/DRW_GRC1100_50mm_24mm_discbrake_WEB_SHO_001.png

Thank you, members.

Wider rims are definitely becoming more popular, but once we move beyond 25–26 mm internal we begin to overlap with gravel‑rim territory. There still needs to be a clear distinction between a modern road rim and a gravel rim in terms of width, structure and intended load range.

Lower spoke counts are also quite limiting. They reduce lateral stiffness and increase the load carried by each individual spoke, which raises stress at the nipple bed. This is especially true for lightweight rims where the rim bed and sidewalls are already optimised for weight. For a product to be suitable for a broad range of riders, spoke count and structural margins cannot be pushed too far.

Our goal is to create a rim with wide market appeal—balanced weight, stiffness, load capacity and compatibility—rather than something that only works for a very small group of ultra‑lightweight builds.

[Sakizashi]

Open Questions:
   1.   Is 25mm internal still the right direction for 2026 road use?
   2.   Is ~34mm max width ideal for modern 30mm tyre setups?
   3.   Would you prioritise lower weight or higher load/impact margin?
   4.   20/20 rear — acceptable for modern road builds?
   5.   Any concerns with U-shape profiles at this width and depth?

Looking for constructive technical feedback rather than brand comparisons.

Appreciate any thoughts.

Thanks for the opportunity to provide some feedback as a non customer.

   1.   Is 25mm internal still the right direction for 2026 road use? This is perfect for me. I think any wider and 30mm tires become non-conforming by the standards. This is both a potential liability issue for the future as well as a safety one as tire bead shapes, materials, etc still seem to be changing. If you are looking to sell to racers, you should consider going down to 24mm or even 23mm to conform to standards for 28mm or 29mm tires as a lot of people race with TT tires.
   2.   Is ~34mm max width ideal for modern 30mm tyre setups? Maybe? At 50mm depth, it might be too wide depending on your design. I would like to see a wider, more U-shaped front and a UV hybrid rear. The profile of the front should be more friendly to wider yaws and the rear more friendly to shallower ones. I know this means two rim molds, but I also think from a marketing perspective, a matched set would be more attractive. There are three reasons to do this. First, you want the rear to be more aero than the front to move the center of pressure away from the steering axis to the extent that it matters, as it can help with crosswind performance. Second, your front wheel needs to perform in wider yaw conditions. Third, your rear wheel is marginal in the greater scheme of the bike but is relevant in cross-tailwind conditions where the draft effect is reduced. It is also the place where most riders are likely to get dropped, so a race-oriented wheelset should account for this kind of scenario.
   3.   Would you prioritize lower weight or higher load/impact margin? Even at 56-60kg, a design that prioritizes retaining margin comparable to the brands used for racing at the higher levels is preferred. I regularly ride with groups that average 38-40km/h and will go 50km/h+ on flat sections. I don't race much on the road. I am too old and too small to want to deal with folks wanting to shoot non-existent gaps at those speeds, but I still do competitive fondos and the like, and usually get past 90km/h on the descents. I have not had this discussion with you as a customer yet, but many rim companies recommend their heavier T800 layups to me over T1000 or T1100 once I bring up this use. If you could design a lighter rim that fits this use case without reducing the margins, that would be ideal.
   4.   20/20 rear — acceptable for modern road builds? I am not qualified to answer this question in a technical sense with the information provided. I think it depends on wheel stiffness and the ability to absorb impact. I think 20/20 seems nice, for a wheel that's for like cafe rides and stuff, sure that sounds modern enough. But I wouldn't trust a wheel that I am not sure would hold up as well as I expect to hitting a pothole or road debris.
   5.   Any concerns with U-shape profiles at this width and depth? See answer to #2

[swatracing]

1. Is 25mm internal still the right direction for 2026 road use?
Yes, 25mm internal is perfect. It’s now clearly established that 30mm tires are becoming the standard, and many riders are already using 32mm and even 34mm. So 25mm internal width aligns very well with where modern road setups are heading.
2. Is ~34mm max width ideal for modern 30mm tyre setups?
Yes, exactly. With wider tires becoming the norm, having an external rim width of 34–35mm will be important from an aerodynamic perspective. This supports the tire properly and optimizes airflow around a 30–32mm setup.

3. Would you prioritise lower weight or higher load/impact margin?
Weight — especially rotating mass — is always critical. If I were Zen, I would definitely aim for a wheelset under 1000g. From a marketing perspective alone, this would position you as a benchmark manufacturer at the cutting edge of development and production.
At the same time, as you are already doing, I would offer a reinforced version for heavier riders. That way you cover both performance-focused customers and those who prioritize durability.

4. 20/20 rear — acceptable for modern road builds?
Fewer spokes can also bring aerodynamic benefits. An 18-spoke option could even be interesting, simply because very few brands offer it — that could be a differentiator.
For me personally, it’s only relevant if it delivers measurable aerodynamic gains without significantly compromising stiffness or durability.

5. Any concerns with U-shape profiles at this width and depth?
For 2026, rim shape is probably the most critical factor. It must handle crosswinds very well — this is where the real differences between brands become clear. Stability and predictable handling in wind are absolutely key.

[toxin]

You can't eyeball a shape and expect it to perform. If you want to do it right, you need to spend time and money to at least refine it in cfd. You can make great or terrible rims with small or large nose radii, but you need to test and refine them, otherwise you're just gambling on getting luck.

[ZenCarbonBike]

Many thanks for all feed back.

Please find attached customer set of VaporLite Ultra 50mm
Estimated weight 989g Actual 975g

[aeroskiii]

Hi all,

We’re considering to develop a new 50mm carbon road rim and would really value some feedback from forum members

Concept Direction:
   •   50mm depth
   •   Modern U-shaped aero profile
   •   25mm internal
   •   ~32mm bead / ~34mm max external
   •   20 front / 20 rear
   •   Lightweight performance-focused rim


Rather than chasing extreme gravel-style numbers, we’re trying to optimise:
   •   Efficient U-shaped aero profile
   •   Lower overall rim weight
   •   Improved system load tolerance
   •   Better impact resistance than typical ultra-light race rims
   •   Compatibility with 28–32mm tyres (optimised around 30mm)

Spoke holes would likely be drilled with internal reinforcement for flexibility across hub types.

⸻

Open Questions:
   1.   Is 25mm internal still the right direction for 2026 road use?
   2.   Is ~34mm max width ideal for modern 30mm tyre setups?
   3.   Would you prioritise lower weight or higher load/impact margin?
   4.   20/20 rear — acceptable for modern road builds?
   5.   Any concerns with U-shape profiles at this width and depth?

Looking for constructive technical feedback rather than brand comparisons.

Appreciate any thoughts.

need 18 spokes front for aero, specialized does it on the newest rapide and its significantly faster than higher spoke counts.

[kubackje]

need 18 spokes front for aero, specialized does it on the newest rapide and its significantly faster than higher spoke counts.

That's a pretty bold statement, could you elaborate bit more?

[aeroskiii]

That's a pretty bold statement, could you elaborate bit more?

no

[Sander2177]

no

Why no?
Because there is nothing to back it up with?
lol
Gotta love the marketing machine that is Specialized they are the best at what they do.
New SL9 is due this year probably 15watt faster stiffer more aero etc etc so I’m getting one

[toxin]

I mean it's pretty obvious that less of the same spoke will be more aero, but spoke count shouldn't be just blindly reduced for the sake of it. The newer, thinner carbon spokes are often less or similarly stiff as a cx-ray and should probably be built with the same spoke counts as most steel spoke wheels. If the aim is to reduce spoke count, regular thickness carbon spokes that we've had for years now should be used.