Back when 3T debuted their new wider, more aero Exploro RaceMax last month, they teased the spec of the “world’s first aero gravel wheels” in the coming soon Discus 45|40 LTD carbon wheelset. Without any more official details at the time than depth & width dimensions in their name and a 29mm internal width, we’ve been waiting for more info. Now it’s here. We have the full specs, and you can order the wheels now…
3T Discus 45|40 LTD wide carbon tubeless aero gravel wheels
We could call 3T the driver behind the aero gravel concept, with the original Exploro introducing us to the “going slow, faster & going fast, slower“ idea. Their latest Exploro RaceMax takes it a step further with more refined aerodynamics. But their matching aerodynamic gravel wheels weren’t quite ready as quickly as the bike this summer.
It’s been made pretty clear now, that if tires are wider that their rims, much of aero gains are going to be lost. So mounting 40mm or even 35mm gravel tires to 3T’s older 25mm internal/32mm external Discus 45|32 LTD wheels (like I did this spring with 37s) meant losing out on potential aero gains from the start. But 3T has the solution in wider aero gravel wheels that don’t even sacrifice on weight.
What’s new in the Discus 45|40 LTD aerodynamics?
The new Discus 45|40 LTD wheels are optimized for real 35-40mm wide 700c tires, and thus get an overall rim width of 40mm. Inside, that’s a hooked tubeless width of 29mm, which is likely to grow most tires wider than labeled (since only modern MTB tires are designed for such wide rims.)
3T’s general aero gravel idea here is to make sure that rim & tire will be the same width. Developed between 3T’s own Gerard Vroomen & aero expert Dave Kennedy, they call it NoseTail design, which essentially boils down to the combination of rim+tire being equally aerodynamic whether the rim or the tire is on the leading edge, exposed to the wind. That is pretty logical, since every spinning wheel cuts into the wind with the tire on the front half, but the rear half of the wheel slices into the resulting turbulent wind with its rim first.
3T says NoseTail for the Discus 45|40 LTD effectively mimics a blunt-nosed 60mm deep shape in the wind. It’s all about compromise. A perfect leading edge aerofoil shape for a wheel won’t work nearly as well when flipped around on the back half, so NoseTail sacrifices a bit up front, to average out better overall. Of course, it still has to work with varying yaw angles too, which is said to dictate the final flat-ish, blunt-nosed rim profile.
Vroomen says aero wheels have such an impact for gravel riders, primarily because no other aero wheels come close to the 40mm+ tires that gravel racers are actually riding. It’s just that there is so much opportunity for improvement, even at lower gravel speeds. 3T still acknowledges that tread knobs aren’t going to do us all any favors from an aero perspective. But maybe you can make a compromise with a less knobby, but wider tire at lower pressures to get the grip you need, with much improved aero performance for those long solo rides & races out suffering in the wind alone?
Discus 45|40 – Tech details
- Wide enough externally to pick up the airflow from a 35-40mm WAM tire.
- Deep enough to realign that airflow and reduce the turbulence behind the profile.
- Wide internally to reduce lateral tire flop for more precise handling and give even a moderately sized tire a wider WAM.
The Discus 45|40 LTD uses an ultralight UD carbon construction for the 45mm deep, 40mm wide external, 29mm wide internal rim. The symmetrical carbon rims feature a hooked tubeless-ready bead to work with any tire, and get a tubeless bead lock shoulder ridge.
Wheels are built standard with 24 premium straight-pull aero bladed Sapim CX-Ray stainless steel spokes (front & rear) on made-in Italy Carbon-Ti 12mm thru-axle centerlock disc hubs, chrome-plated brass nipples & stainless steel washers to resist corrosion from sealant exposure, and Shimano 11 or SRAM XDR bodies. Total claimed wheelset weight is 1665g, just twenty-five grams more than the 45|32 wheels developed for the aero road Strada.
Discus 45|40 – Pricing, hub options & availability
The new Discus 45|40 wheels come only in a premium carbon LTD level for the time being, and sell for $2400 / 2400€ with the standard Carbon-Ti hubs in black. The new Discus 45|40 LTD aero gravel wheels were offered as a $1400 / 1400€ upgrade over the stock WTB or Fulcrum wheelsets on a number of complete RaceMax builds.
Additional Carbon-Ti anodized color options are apparently also possible on request, as are custom builds with even more colorful Industry Nine hubs (subject to availability, but for no extra charge.) Chris King hubs are also possible in a limited color selection for an extra $300€.
But currently, 3T has relatively limited stock of the new rims and they expect high demand, so picking from what is currently available from their online wheel selection tool with be the fastest way to make your gravel bike faster now.