Zen Carbon Wheels Xiamen

[Sander2177]

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.

I would think  the aero benefit of going 18/18 over 20/20 spokes is probably negligible and realistically insignificant.

I did look at regular carbon spokes for my latest wheelset (2.3 × 2 mm), but the lateral rigidity figures weren’t great even with a 21/24 hub. I also looked at  3.95 and 5.1 mm for  my use case, and considering I’m not putting out crit-level power, that felt unnecessary.

The 3.1 mm spokes I’ve chosen still perform better than Sapim CX-Ray in terms of stiffness, and for my weight and power output they should be more than adequate with a 21/24 hub.

If I were going with a 20/20 traditional hub, I might have to rethink it — unless there are spokes with better performance values available.

I think lower spoke counts will be a thing this year and the soon to be released No6 wheels are following suit with 16/20.

Serious engineering considerations for lower spoke counts but I’m assuming generally the rim hub and spokes are all designed seperatly and not as part of a total system.

[toxin]

The relevant part of a carbon spoke for stiffness is the round part at the end of the spoke (2.2 and 1.85 respectively on the pictures I attached) which tells you how much material is in the spoke. The flattening of the middle section should reduce tensile stiffness by some small amount, but not enough to worry about. This could be thrown out of whack by using different types of carbon, but so far, most seem to be sticking to similar material.

Most regular carbon spokes are 2.2mm in diametre and about 30% stiffer than a cx-ray, the lighter ones tend to be around 1.8mm and somewhere in the region of a cx-ray.

A 2:1 radially laced on the NDS, 18 spoke front wheel with the same spokes and similar hub dimensions should be laterally stiffer than a 20 spoke wheel. You gain a tiny bit of aero and weight from reducing spoke count, so it's an all-round win on paper, but you concentrate the same total stresses on the rim over fewer spokes and it's a case-by-case basis of how much reinforcement is needed to account for that. So you end up ahead in some respects but behind in others.

[peraal]

Speaking of spokes. I need some help from you guys and girls to select spokes. I am planning on buying a pair of wheels for climbing, and want them as light as possible, but also durable. The roads here are not so good, and I travel frequently with the bike. I got a quote form Zen with 3.1mm carbon spokes. I have never had carbon spokes before, so got a bit worried. Should I be worried, or am I just overthinking? When I asked for a quote with steel spokes, I got a quote with "sapim cx ray spokes". Is this the "normal"? A bit cheaper, but also a bit heavier. Please help a man who knows nothing about wheels. 

[kubackje]

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.

I know that, but calling it "significantly faster" is just silly. It's marginal if any.

[Sander2177]

Speaking of spokes. I need some help from you guys and girls to select spokes. I am planning on buying a pair of wheels for climbing, and want them as light as possible, but also durable. The roads here are not so good, and I travel frequently with the bike. I got a quote form Zen with 3.1mm carbon spokes. I have never had carbon spokes before, so got a bit worried. Should I be worried, or am I just overthinking? When I asked for a quote with steel spokes, I got a quote with "sapim cx ray spokes". Is this the "normal"? A bit cheaper, but also a bit heavier. Please help a man who knows nothing about wheels. 

Speaking of spokes. I need some help from you guys and girls to select spokes. I am planning on buying a pair of wheels for climbing, and want them as light as possible, but also durable. The roads here are not so good, and I travel frequently with the bike. I got a quote form Zen with 3.1mm carbon spokes. I have never had carbon spokes before, so got a bit worried. Should I be worried, or am I just overthinking? When I asked for a quote with steel spokes, I got a quote with "sapim cx ray spokes". Is this the "normal"? A bit cheaper, but also a bit heavier. Please help a man who knows nothing about wheels. 
[/quote]


I’ve been using carbon spokes since 2019 without any issues. I’m in the UK and, like many places, the roads are far from perfect — but whether I’m on steel or carbon spokes, I ride with the same level of care. I personally don’t see a problem unless you’re the type who’s constantly smashing into potholes without noticing.

Zen probably offered you the steel spoke option as a value alternative. Modern steel‑spoke wheels are still very light, and Sapim CX‑Ray is the standard “go‑to” spoke for high‑quality builds.

If you want something lighter than CX‑Ray but still steel, Zen also build with Alpina Hyperlite, which a lot of riders are choosing now — they’re lighter than CX‑Rays and still very reliable.

Carbon spokes are absolutely fine if you want maximum stiffness and weight savings, but steel is still a great option if you prefer something more traditional and a little cheaper.

[Sander2177]

I know that, but calling it "significantly faster" is just silly. It's marginal if any.

       


 
must be another 10kmh

[aeroskiii]

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

Info is proprietary but its significant for front wheels, rear wheels could use more spokes for pedaling stiffness. Don't have any data to give so I wont die on this hill.

[RLA]

Speaking of spokes. I need some help from you guys and girls to select spokes. I am planning on buying a pair of wheels for climbing, and want them as light as possible, but also durable. The roads here are not so good, and I travel frequently with the bike. I got a quote form Zen with 3.1mm carbon spokes. I have never had carbon spokes before, so got a bit worried. Should I be worried, or am I just overthinking? When I asked for a quote with steel spokes, I got a quote with "sapim cx ray spokes". Is this the "normal"? A bit cheaper, but also a bit heavier. Please help a man who knows nothing about wheels. 

For lightweight climbing wheels the 3.1mm carbon spokes are absolutely best option in my opinion. They are lighter but actually more durable (on paper at least). Been using different carbon-spoked wheels for 3-4 years now with no issues and don't see any reason to go back to steel.
If you still want to go with steel then CX-Ray is the popular choice. I have had to replace a few of those back in the days but nothing major.

[NB87]

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.

Aerodynamics is everything but obvious. It seems obvious that less of the same spoke will be more aero, but spokes create some kind of turbulance/disturbance of the windflow. It wouldn't surprise me if less spokes create less than ideal windflow.

Not saying he's wrong. But I agree that it's a bold statement that needs some backing up.

[peraal]

Thanks for the feedback regarding spokes, Sander and RLA. Appreciate it. Gives me something (more) to think about. 

[ZenCarbonBike]

Good Day Forum Members 


Thanks again for the feedback on the original post last week.

Some of the comments suggested looking at lower spoke counts, so we’ve been discussing whether 18 spoke front and rear might be feasible. However, this is still under consideration rather than a fixed decision.

With very lightweight rims (around ~340 g), spoke count becomes more important because the rim itself carries less material. The system needs to be considered as a whole — rim structure, spoke count, spoke tension and overall load limits — rather than just reducing spokes to save weight.

At the moment the rim design would still be based around 20/20 spoke drilling, with 18/18 being explored to see if it remains viable without compromising stiffness or load limits (target system weight around 120 kg).

Another trade-off we’ve been discussing with the manufacturer is rim profile vs weight.

Most of the current sub-1000 g wheelsets use rims around ~330 g, and they tend to be UV / hybrid profiles, largely because that shape uses less material and makes those weights achievable.

A fuller U-shape profile generally improves stability and tyre integration but tends to push rim weight higher as the wall thickness need to be thicker for this shape

So the current concept being looked at is roughly:

• ~50 mm depth 
• ~25 mm internal width 
• ~31 mm bead 
• ~34 mm max width 
• ~340 g rim target 
• ~120 kg system limit
• ~ Softer U/V Profile

[ZenCarbonBike]

Good day everyone,

We have been looking at two possible rim profile options for a lightweight aero wheelset concept.

Depth would likely be around 50 mm (possibly 51–52 mm), with 25 mm internal width, optimised for 30–32 mm tyres, and a 120 kg system weight limit.

Two rim profile directions are currently being considered:

Option 1 – Mild U/V hybrid profile
• ~50–52 mm depth
• Rim weight ~340 g

Option 2 – Full U-shaped profile
• ~50depth (additional 1mm or depth adds around 2.5g so a 52mm would be 355g)
• Rim weight ~350 g

Using the current hub and spoke setup:

Hub set: ~235 g
Spokes (40 total): ~84 g

Approximate wheelset weights:

• U/V hybrid profile: ~999 g
• Full U profile: ~1019 g

So roughly a 20 g difference for the complete wheelset.

The trade-off seems to be slightly lower weight with the hybrid U/V profile versus a fuller U-shape which may offer better tyre integration and crosswind stability, particularly with 30–32 mm tyres.

Interested to hear which direction people here would lean towards.

[Lotnik]

For mi U shape is the choice. 1000 - 1150 is very aceptable weight.

[kubackje]

I prefer wide u shape. For me this type is great in sidewinder, stability, speed.

[Dell]

Definitely U.