Trek Domane+ SLR 6 2023 first ride review: how discreet can an e-road bike be?

Are Trek going full-incognito with the new Domane+ SLR 6 2023? The American brand is the first one to use the new TQ-HPR50 motor, promising to combine an authentic road bike experience with discreet yet powerful motor assistance. According to Trek, the flagship model tips the scales at 11.8 kg. We tested the more affordable spec variant with a Shimano 105 Di2 drivetrain.

In the road bike segment, the e-ball hasn’t really started rolling yet and e-road bikes are still struggling to break into the mainstream. However, e-race bikes still offer several potential advantages for a wide range of riders – especially the latest generation, which promises to offer an unprecedented level of integration, ride feeling and design. Back in 2019, Trek unveiled the first generation of the Domane+, which came equipped with a powerful Bosch Performance mid-drive motor and big 500 Wh battery, tipping the scales at a whopping 17 kg. Two years on, the next iteration of Trek’s e-road bike featured a more discreet and significantly lighter FAZUA Ride 50 motor, which reduced the weight down to around 13 kg.

The new TQ HPR50 motor should enable a new generation of e-road bikes that replicate the handling and ride feel of analogue racers while at the same time maintaining a discreet look. With its fully integrated electric motor, several technical innovations and endurance-oriented riding position, the new Trek Domane+ SLR 2023 hits the road in incognito mode. But how did it fare in our test?

The beating heart of the Trek Domane+ SLR 2023: the new TQ-HPR50 motor

The motor system is the beating heart of an e-road bike and as such it has a big influence on the ride feeling, weight distribution and, of course, propulsion. Many modern e-road bikes rely on a rear hub motor, which might be a light and cost effective solution, but often results in uneven weight distribution and thus sluggish and less natural handling. For exactly this reason, Trek stuck to a mid-drive motor with the latest iteration of the Domane+, rounding off a proven concept with what appears to be the most consistent package thus far.

The TQ-HPR50 alone tips the scales at 1,850 g light. Including the battery, the new 2″ display integrated into the top tube and matching remote unit, the system weighs a total of 3,900 g (manufacturer’s specifications). As the name suggests, the TQ-HPR50 has a maximum torque of 50 Nm and maximum nominal output of 300 watts, while motor assistance can be adjusted in three support levels: ECO, MID and HIGH. Compared to most modern e-road bikes, the Domane+ has a bigger 360 Wh battery. However, this number alone shouldn’t entice you to draw conclusions about the range, because this is heavily dependent on countless factors including the rider’s weight, cadence, the selected assistance mode, gear choice, pedalling habits and, most importantly, the elevation profile of the route. Moreover, battery capacity can be expanded using Fazua’s optional 160 Wh range extender, which is about the size of a 500 ml water bottle and weighs around 900 g. The charging port is positioned above the bottom bracket, where it’s easy to reach.

TQ’s fully integrated top tube display provides excellent readability and shows all important riding data such as battery status, remaining range estimation and selected support mode. As a highlight feature, the system provides a real-time performance reading in watts, both for the motor and rider. Moreover, the TQ-HPR50 motor system can be connected to a smartphone and/or compatible bike computer via ANT+, while the TQ partner app allows you to access all crucial system data of the motor and customise the support levels.

Tucked away behind the hoods, the remote buttons of the motor system are easy to reach, allowing you to shift between support levels without having to take your hands off the bars. The robust-looking buttons provide good haptic feedback and make a discreet acoustic signal when pressed. Unfortunately, while the buttons themselves seem robust, the mounts seem quite flimsy.

Trek Domane+ SLR 6 2023 ­– features and design

Trek already did a pretty good job with the predecessor of the Trek Domane+ SLR, which we tested early last year. However, the upgrade to the new TQ-HPR50 system also brings some major changes: for example, the old 250 Wh battery was replaced with a bigger 360 Wh unit, which is permanently integrated into the frame, thus allowing Trek’s engineers to develop a thinner down tube to save weight. The new battery is mounted on its side in the down tube, presumably to preserve as much as possible of the analogue Domane’s design, and to reduce the width of the frame, allowing for a more conventional Q-Factor. However, the down tube still looks disproportionately big from the side, somewhat spoiling the overall sporty look of the bike.

Like the new analogue Domane, the Domane+ employs Trek’s proprietary Top Tube IsoSpeed system, which, together with the seatpost flex, ensures a good level of compliance for riders weighing in at around 75 kg. And while the new IsoSpeed system can no longer be adjusted to match the system weight, it’s 300 g lighter than its predecessor. Moreover, the system is neatly integrated into the frame and concealed by a magnetic cover. The new Domane+ also offers more tire clearance than its predecessor, allowing you to run tires up to 40 mm wide, which should improve comfort and broaden the range of applications of the bike, making it more appealing for light gravel, bikepacking and touring.

Spec, weight and geometry of the Trek Domane+ SLR 6 2023

Our € 8,999 Trek Domane+ SLR 6 2023 test bike tips the scales at 12.5 kg and comes equipped with a Shimano 105 Di2 groupset. The Domane+ SLR 9 eTap P1 flagship model sets you back € 14,499 and combines a SRAM RED eTap AXS groupset with higher-quality components, including better tires and a high-end saddle. The 2023 Domane+ range includes a total of six models and seven sizes, all of which come equipped with an electronic drivetrain from Shimano or SRAM. The new 2023 Domane+ SLR is also part of Trek’s Project One program, which allows you to customise the paint finish and spec of your bike down to the smallest detail using the Project One configurator. In addition, all available designs are premium, high quality finishes that stand out for their first-class texture, depth and style.

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According to Trek, the lightest variant with Shimano DURA-ACE Di2 breaks under the 12 kg barrier, tipping the scales at 11.8 kg. Our Trek Domane+ SLR 6 test bike in size 54 mm weighs 12.5 kg.

Geometry

True to its endurance roots, the Trek Domane+ SLR 2023 has a rather relaxed geometry, offering a comfortable, upright pedalling position. At the same time, the long wheelbase ensures good composure for long days in the saddle.

Size	50	52	54	56	58	60	62
Seat tube	450 mm	475 mm	500 mm	525 mm	548 mm	567 mm	586 mm
Top tube	519 mm	530 mm	542 mm	554 mm	567 mm	579 mm	593 mm
Head tube	130 mm	145 mm	160 mm	175 mm	195 mm	220 mm	245 mm
Head tube angle	71.1°	71.3°	71.3°	71.9°	72°	72.1°	72.1°
Seat tube angle	74.6°	74.2°	73.7°	73.3°	73°	72.8°	72.5°
Chainstay	430 mm	430 mm	430 mm	430 mm	430 mm	430 mm	430 mm
Wheelbase	1,007 mm	1,013 mm	1,021 mm	1,018 mm	1,027 mm	1,037 mm	1,047 mm
Reach	368 mm	371 mm	374 mm	377 mm	380 mm	383 mm	386 mm
Stack	546 mm	561 mm	575 mm	591 mm	611 mm	632 mm	656 mm
Stem lenght	80 mm	90 mm	90 mm	100 mm	100 mm	110 mm	110 mm
Bar width	400 mm	400 mm	420 mm	420 mm	440 mm	440 mm	440 mm
Crank lenght	170 mm	170 mm	172.5 mm	172.5 mm	175 mm	175 mm	175 mm
Wheelsize	700C	700C	700C	700C	700C	700C	700C

The new Trek Domane+ SLR 6 2023 on the road

Fire up the motor, swing your leg over the saddle and take off! With its relaxed, endurance-oriented riding position, the Trek Domane+ SLR 6 2023 makes you feel at ease from the get-go, coming across more as a sporty mile-muncher than a furious and agile tarmac rocket. Nevertheless, Trek’s e-road bike is still pretty nimble, which becomes particularly evident in corners, where the balanced weight of the mid-drive motor helps you turn with precision and control.. While the additional weight of the motor results in a higher moment of inertia compared to a conventional road bike, this is still significantly lower than with a rear hub motor e-bike. Bontrager’s 32 mm R3 tires also cut a good figure, ensuring a composed ride with their excellent damping qualities. That being said, we still recommend taking advantage of the 40 mm clearance and fitting wider tires for full-on off road riding.

Tuning tips: Wider tires for better off-road capabilities & handlebars with bigger contact surface

The TQ-HPR50 provides its assistance smoothly, ensuring a pleasant ride. In the standard configuration of the lowest support mode, the motor is hardly noticeable. On the other hand, the strongest support level provides a decent amount of artificial tailwind while still offering a very natural ride feeling, without jolting forward abruptly – providing you’re in the right gear. This is partly due to the slightly sustained response of the motor after you stop pedalling, ensuring an effective yet discreet and very natural feel. Even more discreet is the noise of the motor, which is barely perceptible while riding, making the Trek Domane+ SLR 6 2023 the ideal companion for chatty group rides. Moreover, the position of the remote buttons makes it easy to switch between support levels without having to take your hand off the handlebars.

Conclusions

The Trek Domane+ SLR 2023 almost gets away with claiming that it feels like an analogue road bike. In terms of handling, noise and motor integration, Trek’s e-road bike is unarguably raising the bar and setting a new benchmark – only the disproportionately thickdown tube gives away that it’s an ebike. The comfortable geometry, generous tire clearance and mudguard compatibility make Trek’s new e-road bike suitable for a huge range of applications, thus opening up a whole set of new possibilities.

​​For more info, visit trekbikes.com.

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Words: Martin Staffa Photos: Mike Hunger