Rolling resistance/aero/weight net gain

[zefs]

Sounds like the second option would be more viable at your total weight, or you could get the 46mm wheels with 28c tires because the 50mm wheels seem a bit too wide and aimed more for gravel.

[Hexsense]

I'm trying to decide between:

Light Bicycle WR46 (46mm deep, 21C inner diameter, 28mm external, disc) paired with Conti GP5k TL 700x25C
Light Bicycle WR50 (50mm deep, 25C inner diameter, 32mm external, disc) paired with Conti GP5k TL 700x28C

Rider weight 85 kg (95-96 kg including bike & equipment). Typically 80-120 km rides on rolling terrain with various road quality, averaging 18-20 mph. Mostly solo, but a group ride here and there. No serious racing but can imagine grand fondo race or two yearly.

I guess I could run narrower set at 85/90 psi, and wider on 70/75 psi. How much speed can narrower set actually offer, at what comfort cost? How wide is too wide?

Those two are a bit too different. 25mm internal width is a bit too wide to use GP5k 25c. GP5k runs narrower than gp4000sII...
50mm 25mm internal force you to alway use 28c or wider. This would be the choice if you prefer to optimize performance on bad road.
46mm 21mm internal but with 28mm external means 28c maybe too wide for aero. While it is better for good road and still capable on rough terrain, when you actually need wider tire, it'll compromise aero a bit more.

How about 56mm 30mm external, 23mm internal?
This option is good for both 25c and 28c.
Use 25c front and 28c rear would be ideal everyday everywhere set.

[AJS914]

Agree with Hexsense. Also, breaking the 105% rule by a tiny bit is not a big deal.

[JoO]

Yes but go for a 10km climb instead of drum roll that power is not constant/weight plays a role and things change (for pros).
Doing attacks at high wattage will also be in favor of the lighter/higher psi tire.

And what would be the rationale for that?
Just curious to know your thoughts leading to this statement.

[zefs]

Because of softer spring and energy loss when applying power + extra weight. Unless you run the wider tire at high psi which is less comfortable.
At the same comfort level (which provides the same rolling resistance based on the test) I still think the wider tire will have softer spring because of it's wider nature and how air is distributed but I could be wrong.

[AJS914]

Wider is fastest? Hunt claims that it 34.3mm wide rim is the "most aerodynamic" below 50mm.

https://cyclingtips.com/2019/06/hunt-li ... -revealed/

[Nefarious86]

Wider is fastest? Hunt claims that it 34.3mm wide rim is the "most aerodynamic" below 50mm.

https://cyclingtips.com/2019/06/hunt-li ... -revealed/

Very curious about these. 2k aud landed with all the fruit apparently.

Sent from my SM-G977B using Tapatalk

[igs417]

How about 56mm 30mm external, 23mm internal?
This option is good for both 25c and 28c.
Use 25c front and 28c rear would be ideal everyday everywhere set.

These were actually my first option, but I got somewhat put off by the depth. I don't have any previous experience with aero wheels, so I got worried by the crosswinds. You ride those, right? How are they handling crosswinds? Not that we have anything above 20 mph here, and if we do I probably won't ride that day.

Would the viable option also be to combine WR46 with 25c on the front and WR56 with 28c on the rear?

[alcatraz]

Crosswinds aren't the problem if they are constant, it's the sudden gusts that can scare the crap out.

For me personally I can't say I've regretted buying deep wheels. I had about as scary a crosswind experience on 20mm box rims as I've had on 88mm and 58mm toroidal wide rims. It's more than just the depth, it's the shape. But I can't speak for everyone. Only myself...

[Hexsense]

68kg rider, using 56mm depth here. No problem with cross steady wind. My bike can move a bit in gusty surge wind but nothing scary yet.
The only thing i don't like about this depth is that there isn't a just right valve length exist.

If it is 50mm deep, i can use 60mm michelin latex tube. It's perfect fit.
If it is 64mm+, using 80mm valve or short valve+extender look about right.

But for 56mm, 60mm valve is too short, 80mm is too long. Short valve+ extender still isn't quite the right size as 60mm valve on 50mm deep rim.

[Beaver]

Wider is fastest? Hunt claims that it 34.3mm wide rim is the "most aerodynamic" below 50mm.

https://cyclingtips.com/2019/06/hunt-li ... -revealed/

Depends on the speed - for a time trial with 50kmph it's too much frontal area, with 25kmph and 28mm tires they should be fine. But it would be interesting how wide they are at the brake track. For 32mm a real 29mm tire width would be the limit, less is too narrow. But with 22.5mm inside it should work with most 25mm tires.

And as usual the U-shape won't be stable in crosswinds.

At least they are honest with the watt differences: https://cdn.shopify.com/s/files/1/0686/ ... O_DISC.pdf

[igs417]

The only thing i don't like about this depth is that there isn't a just right valve length exist.

So, what do you use?

What’s with tubeless valves that Light Bicycle offers with wheelset purchase? Also, get their tubeless tapa with the wheels or purchase something better and DIY?

[hambini]

I'm reading these comments with utter disbelief that the cycling industry has done such a good job on people they think "wider is faster".

Shaking my head...

[flying]

I'm reading these comments with utter disbelief that the cycling industry has done such a good job on people they think "wider is faster".

Shaking my head...

You beat me to it....
When I saw this in OP...

And then, where is all the "wider is faster" hype coming from?

I was going to say the hype comes from the usual suspects

[bikesrdangerousmmk]

I'm reading these comments with utter disbelief that the cycling industry has done such a good job on people they think "wider is faster".

Shaking my head...

If one’s interested in going fast in circles (crits) and enjoys the handling of more rubber contact with the ground, presumably those wider rims are better than 28-30mm lightbulb tire-rim set up.