650b "Aero" Gravel Wheelset with 2.2 Tires

[coconutbuddha]

Hey guys,

I am sporting a Rose Backroad GRX 810 and I want to build a gravel specific wheelset with 2.2 Continental Speed King tires.

Basically, because I am riding in the Alps a lot and there are a lot of steep descents with realy narly, nasty and loose gravel. For this, I like to have the compliance and "protection" of a beefier tire. I rode the Speed Kings already on my old MTB and never had a puncture problem and according to bicyle rolling resistance they are faster than any gravel tires - they certainly feel this way.

So, right now I could identify some promosing 650b options:

Premium: https://www.3t.bike/en/products/wheels/ ... d-661.html

Budget/DIY: https://www.nextie.com/new-gravel-clincher-NXT27GR45

To achieve at least some aero gains the outer width should be more than 30/32mm. Any more suggestions?

Is an aero wheel worth it for 2.2 tires at all? I mean there must be a reason the guys at Dirty Kanza run it with their 42mm tires...handling? I will mostly/only climb and descend with the wheelset because there is not a single street straight in the alps - all up or down.

Thx for your help, guys!

[spdntrxi]

I'd say not worth it with 2.2s

[jayjay]

I'd say not worth it with 2.2s

+1

But you could save some weight with these LB rims instead of the Nextie rims:
https://www.lightbicycle.com/650b-road- ... lable.html

[jfranci3]

You'd want something not deep because of crosswinds. Just get a regular MTB 27.5 rim.
https://www.nextie.com/premium-mountain-asymmetric-27.5 Ask for road (12mm) hubs.
The 3T wheelset is $1000eur too much.

A 54c tire with a 45mm deep rim is about the same as a 25c tire with 74mm deep rim to crosswinds.

[justRideIt]

I've run Speed Kings on 650b DT Swiss GRC 1400. see link to my Specialized Diverge in my signature. Switched to Conti race kings for better grip.

I don't think it makes too much sense aerodynamically, you can literally hear the air resistance with the race kings knobs. Grip, suppleness and comfort of the Conti RaceSport are excellent though, while rolling fast.

[coconutbuddha]

I've run Speed Kings on 650b DT Swiss GRC 1400. see link to my Specialized Diverge in my signature. Switched to Conti race kings for better grip

Your bike looks fun. What's your frame size? Any steering trouble with such deep rims and the tires?

[justRideIt]

I've run Speed Kings on 650b DT Swiss GRC 1400. see link to my Specialized Diverge in my signature. Switched to Conti race kings for better grip

Your bike looks fun. What's your frame size? Any steering trouble with such deep rims and the tires?

Thanks!
Frame size 52.

That is exactly what I’m going for with the gravel bike: fun.
Not necessarily the fastest or lightest, but what puts a smile on my face.
Big part of the fun for me: I have to look at the bike and think “damn, I want to ride that thing”
Second big part is comfort. How I feel after multiple hours of unpaved roads.

I run the 2.2" tires at 20 PSI (64kg body weight) and it rides so smooth, like a magic carpet.

Regarding the gnarly gravel you mentioned - I've ridden this setup for three weeks around Garda Lake in Italy, also on MTB trails (difficulty S1 to S2 on singletrail scale) with all of the gnarly, loose, chunky gravel.

After almost 10.000 km on this setup, I've never said to myself: "Oh, I wish I had shallower wheels". So to answer your question reg. steering: I've not had issues steering with such deep rims. But also I'm used to riding deeper rims, e.g. 50mm on the road bike and 80mm on TT bike in aero position. I have them on all year round.

Sometimes, I also ride a shallow and lightweight 1.150g disc wheelset with 40mm wide Continental Terra Speeds (but measure 39mm).
And while these are definitely more agile on the uphill, for the overall ride I much, much prefer the DT Swiss + 2.2" MTB tires setup.
Descending trails and loose stuff with the Terra Speeds can be quite sketchy, the front-end is rather nervous where the MTB tires just bomb down with confidence. Also, the narrower tires with higher pressures to avoid hitting the rim, it beats you up after many hours of riding rough stuff.

The high volume MTB tires make me want to play with the bike, do some jumps, play with the cornering grip (drifting). However, the Speed Kings can be sketchy as well. In my experience, when the front Speed King slides out while cornering over loose stuff, you go down. Almost no side knobs to catch grip again.
Also when climbing around 20% inclines the rear wheel can start slipping, in the wet even earlier.

The Race Kings I find way more forgiving and fun overall. And they also roll quite fast (check bicyclerollingrestance.com ).

I've also run a setup with grippy Race King in front, fast rolling Speed King in the rear. Also a good combo.

But you have to try for yourself, your style of riding and riding conditions.
Hope this gives you some food for thought.

[Oms]

Hey guys,

I am sporting a Rose Backroad GRX 810 and I want to build a gravel specific wheelset with 2.2 Continental Speed King tires.

Basically, because I am riding in the Alps a lot and there are a lot of steep descents with realy narly, nasty and loose gravel. For this, I like to have the compliance and "protection" of a beefier tire. I rode the Speed Kings already on my old MTB and never had a puncture problem and according to bicyle rolling resistance they are faster than any gravel tires - they certainly feel this way.

So, right now I could identify some promosing 650b options:

Premium: https://www.3t.bike/en/products/wheels/ ... d-661.html

Budget/DIY: https://www.nextie.com/new-gravel-clincher-NXT27GR45

To achieve at least some aero gains the outer width should be more than 30/32mm. Any more suggestions?

Is an aero wheel worth it for 2.2 tires at all? I mean there must be a reason the guys at Dirty Kanza run it with their 42mm tires...handling? I will mostly/only climb and descend with the wheelset because there is not a single street straight in the alps - all up or down.

Thx for your help, guys!

Hiya - I've got a Rose Procross gravel which came with DT-Swiss P1800 650b wheels (standard on XS frames).

On the stock 38mm tyres, there's already a fair depth to them (compared to running say a 28mm road tyre) but never had a problem in any sort of wind. Add an aero rim and you'll end up with quite a lot of depth though. Worth considering the depth of the whole system if you're concerned about wind.

On a local road descent, I set my fastest time with my Rose gravel bike: wider/gripper tyres, confidence in brake discs and the extra weight all contributed towards that. Aero isn't everything I suppose.

Agreed, a wider rim is better for a wider tyre - on gravel and loose stuff, it's better to have some rim protection by having the tyre wider than the rim. A 2.2" tyre on a 32mm rim width will offer that. I know that I've bottomed out running my 38s at a lower pressure on rocky fire roads - saved the rim on few occasions. Also, a wider rim means more air volume... so you can run a marginally lower pressure.

Suppose with a more aero rim, you'll have shorter spokes and in theory a stronger wheel? If it's like for like construction anyway.

[coconutbuddha]

That is exactly what I’m going for with the gravel bike: fun.

However, the Speed Kings can be sketchy as well. In my experience, when the front Speed King slides out while cornering over loose stuff, you go down. Almost no side knobs to catch grip again.
Also when climbing around 20% inclines the rear wheel can start slipping, in the wet even earlier.

The Race Kings I find way more forgiving and fun overall. And they also roll quite fast (check bicyclerollingrestance.com ).

I've also run a setup with grippy Race King in front, fast rolling Speed King in the rear. Also a good combo.

But you have to try for yourself, your style of riding and riding conditions.
Hope this gives you some food for thought.

Have you ever tested the Specialized Pathfinder tires (since you have a diverge)? If so, how do they ride on steep uphill sections? Loss of traction? And how do they compare to the Speed King?

And yes the Speed King are sketchy when cornering on steep downhills and also on the flats in tight corners with loose gravel...I ride them on my MTB and until now I always managed to keep the bike upright when the tire decided to make vacation. Generally though, the grip is surprisingly good for a tire basically without any knobs. Just when the tiny rocks underneath your tire are start moving it's kind of like a dance on eggs.

[justRideIt]

Have you ever tested the Specialized Pathfinder tires (since you have a diverge)? If so, how do they ride on steep uphill sections? Loss of traction? And how do they compare to the Speed King?

The Pathfinder Pros were on the stock DT Swiss alloy wheelset, with which the Diverge was delivered. Have ridden them for a couple hundred kilometers.

Definitely not as supple and comfortable as the 2.2" high-volume Contis, but I'd say an overall great tire for mixed surfaces. Fast on tarmac with the slick center tread, good grip on dry hard pack gravel, but only okay on rocky sections and trails. You can descend with them, but it's not fun. Not great in the wet.

I mean, (ex-)professional riders win Unbound gravel on the Pathfinder Pros, so I guess it's a great tire for gravel application.
Since I like to rip trails with the Diverge, I much prefer MTB tires.