The Ultra gets a Boost

Longer adventures, thanks to a longer battery life and the generous tire clearance of the Ultra frame. The new Boost is available in two versions: Dropbar and Flatbar.

Just over two years ago we published the post “A new era of e-gravel with the RaceMax Boost”, announcing 3T’s entry into the e-bike market with the release of a bike based on the RaceMax frame and equipped with a Mahle X-35 pedal assist system.

About a year later, just last summer, the release of the X-20 engine allowed us to present the evolution of that project. With more torque and a cadence sensor installed in the bottom bracket, this new motor was even smaller and lighter than its predecessor and boasted a more refined power delivery system. These innovations brought the new Boost even more in line with our goal: to offer a bike with pedal assistance indistinguishable from its standard version and with a nearly identical road feel due to weighing merely 3 kg more.

Today we are happy to present a product that joins the 2.0 version of the RaceMax Boost: the Ultra Boost.

The Bike

The engine body in the rear hub remains the same X-20, with its 55 Nm of power delivered according to three default modes to which each user can combine a completely custom one. Those who love long rides will love the drastically increased battery capacity from 236 to 350Wh. Due to the more generous tube sections characterising the Ultra frame compared to the RaceMax, we could house a larger battery and extend the autonomy range by nearly 50%. With relatively gentle power management, a rider under 75kg on a hilly fast gravel/paved route can comfortably ride more than 150km with 2000m of elevation gain (considering the EU 25km/h speed limit, of course). This is possible without compromising the handling and pedalling experience of a “standard bike” since the weight is only around 12 kg for the lightest assembly.

The battery life can also be extended even further with a simple battery extender on the seat tube, which adds a measly 1.1 kg, but gives a notable 173 Wh of additional autonomy. This possible upgrade makes the Ultra Boost even more capable of achieving one of the three purposes we started for this project: extend your adventures and ride according to the motto “The bigger the loop, the bigger the fun”.

We should probably add “epic” into the growing list of adjectives about the rides you can do given the generous clearance offered by the Ultra frame, which allows you to mount tires up to 42mm WAM/352mm RAM on 700c and up to 60mm WAM/353mm RAM on 650b (in combination with 1x groupsets).

Dropbar or Flatbar


Up until now, we have talked about “extended adventures”, but these represent only one of the types of rides that we had in mind when starting the e-bike project. There are a couple others:

  • Riding in a group of varying abilities can be frustrating. With a bit of extra support, nobody ever has to feel the pressure to keep up anymore. Perfect for road & off-road rides.
  • Commuting. The power support enables you to arrive at your destination without sweating through your clothes, but with the opportunity to have an adventurous workout on the way home.

Although both are possible with any version of the Ultra Boost, each is certainly better suited to a specific set-up: the first with the drop bar version, which is more performance-oriented, while the second flat bar version with its more relaxed upright fit and increased control.

More about the Mahle system

Nm and Wh are usually the two primary parameters considered in evaluating the performance of a pedal-assist system, obviously together with weight and size. However, the Mahle system goes further than this; it offers Bluetooth and ANT+ connectivity, so you can connect devices such as your Garmin cycle computer and other Bluetooth and ANT+ devices, or a heart rate monitor including the capacity to adjust  power delivery based on heart rate.

Furthermore, the MySmartBike app, in addition to allowing configuration of a fourth custom profile in addition to the three default ones, can keep track of ride history and a whole series of additional information.

Builds and prices

Ultra Boost is available with 700c or 650b wheels in both Dropbar (fitted with Rival XPLR AXS 1×12 groupset) and Flatbar (fitted with Force D1 AXS 1×12 or Force D1 AXS 1×12) versions, all offered at a list price of €5,999/$6,599 . The Flatbar version also offers a 3T i28 carbon rim upgrade for €6,999/$7,699.

All models are available to order now from 3T retailers and and start shipping today.