3T will be closed for a winter break from December 24th to January 6th. Orders placed by December 19th will be processed starting from January 7th. For any inquiries, email us at info@3t.bike.

ULTRA

Designed to be unstoppable, without stopping to be fast

If you’re like us, you love riding in rough terrain but live in a more urban jungle. So you need a bike that is fast on-road and capable off-road. 

We designed the Ultra to fit 55-61mm wide 650b tires: the whole aero package is made around those to keep the on-road speed high. If you ride on less extreme terrain, you can also fit 700c tires up to 46mm WAM (With As Measured) on the Ultra. 

IT ALL STARTS WITH THE TIRE

To make the fastest possible gravel bike, you need to start with the tire. Tire choice determines comfort & grip. But it also determines how you can shape the frame to redirect the airflow.

To aerodynamically engineer the frame around the tires, you need to know what their REAL measurements are. Not what’s on the label, but how they really fit. That’s REALFAST aerodynamics. But it’s not easy, as the tire dimension depends on the rim you use, the pressure and of course how accurate the manufacturer’s claimed size is.

So we took hundreds of measurements to know the real tire widths (which we call WAM - Width As Measured and RAM - Radius As Measured) and use that to engineer the frame around.

Max clearance information can be found here.

SO WHAT TIRE DO YOU NEED?

The most important dimension is the WAM as that directly correlates to traction, puncture resistance, aerodynamics and rolling resistance. The WAM you need depends on three factors:

1. Terrain (traction, puncture resistance)

2. Rider skill (how much grip you need for control)

3. Rider speed (the slower you go, the more you bump/sink into the terrain)

The graph on the left indicates the WAM you need, and a more in-depth analysis can be found here.

Our favorite tires for the Ultra for each WAM and various rim widths are here.

Please note that running a front derailleur (especially an electronic version) will limit the tire width you can fit.

REALFAST AERODYNAMICS

The Ultra was one of our most difficult aerodynamic challenges. Start with massive 55-61mm (650b) tires and then make the bike aero. There’s nothing we can do about the tires, they’re big and the knobs don’t help. What we can do however, is take the messy airflow that comes off the front wheel and try to catch and redirect it. That’s why you will see the 60mm wide downtube tucked closely behind the front wheel, going even wider as it gets closer to the BB.  

Blending this into the headtube with an off-center aero profile along with loads of other tricks gives you a bike that feels so much faster than your brain can compute. Because let’s be honest, when you see those tires, your brain gets ready for that slow, boring paved performance of a mountain bike. But thanks to your riding position, the aerodynamics, the BB stiffness and the narrow Q-factor, the Ultra actually feels 100% like a road bike when you want to go fast. Even when muddy. 

ULTRA VERSUS RACEMAX, EXTREMA AND PRIMO 

Ultra compared to RaceMax (Integrale): similar geometry and fit, different soul. The RaceMax frameset is fastest with 35-46mm WAM tires. Set up like this, its top speed rivals the best road bikes out there (with a little help from the full integrated cables too) while still being compatible with the possibility to use up to 61mm WAM 650b tires. The Ultra is the reverse. It is aerodynamically optimized for 55-61mm WAM 650b tires thanks to its wider downtube near the front tire. If you prefer a smaller tire, you can run a 700c tire up to a 46mm WAM. In addition, the Ultra combines its aero seattube with a round seatpost so you can fit a standard, dropper or suspension post and cables are partially routed externally to keep it a little simpler when travelling and adventure calls. 

The Extrema is designed around massive 29” tires (optimum is 50-57mm) offering the same traction as a top of the line cross-country MTB and no compatibility with 650b. The rider fit is optimized for tougher terrain and, with its made in Italy frame, fork leg mounts and round seatpost it’s the perfect machine for tough races and fast adventures. 

The Primo frame features a more road inspired geometry, while still allowing for excellent wheel and tire versatility. Ride your faster days with 700c tires then swap to 650b when adventure calls. The perfect all-round bike. 

design in details

GEOMETRIES

Size 48 51 54 56 58 61
Rider Height (cm) 145-160 157-171 168-180 176-186 183-195 192 & up
Rider Height* (inches) 4'9"-5'3" 5'2"-5'7" 5'6"-5'11" 5'9"-6'1" 6'0"-6'5" 6'3 & up
Stack 520 542 564 584 604 632
Reach 351 362 373 381 388 399
"Road" Headtube 122 142 158 175 196 225
Headtube angle 68.5 69.5 71.0 72.0 72.5 72.5
Fork axle-crown 375 375 375 375 375 375
Front center 597 606 602 607 616 636
Rear center 419 419 419 419 419 419
BB drop 79 79 77 77 75 75
Toptube length 510 527 545 559 574 593
Seattube length 436 463 490 518 549 576
Seattube angle 74 74 74 74 74 74
* Rider heights are approximations. For more accuracy, compare stack/reach with your current bike or visit your 3T retailer.

** Ultra FORK length is equal to a standard road bike, so this HEADTUBE length can be compared to road bikes. To compare to gravel bikes with standard gravel forks, deduct 25mm from these “road" headtube lengths for a proper comparison.