Over the past couple of years, we’ve all watched as eBikes have gotten more and more ubiquitous. And, they now come in all shapes and sizes — from those teeny-wheeled folding bikes to monstrous fat bikes. However, as technology has advanced in both motors and batteries, the doors are opening to a more traditional aesthetic for both road and mountain eBikes. Hot on the heels of the Trek Fuel EXe and the new Domane SLR, Trek has launched the Domane+ and it’s one of the most integrated and sleek electric road bikes we’ve seen.
Trek Domane+ SLR 9 eBike Features:
- 50Nm TQ Harmonic pin ring motor with 28 mph max assist
- 360Wh integrated battery in downtube, 2 hour charge time
- TQ LED display with Bluetooth & ANT+ connectivity
- Utilizes 800 Series OCLV Carbon with rear IsoSpeed
- Shimano Dura-Ace Di2 12-speed drivetrain
- Praxis Carbon crankset
- Bontrager Aeolus RSL 37 OCLV Carbon wheels
- Bontrager Pro Iso-Core handlebar and a RCS Pro stem
- Bontrager R3 Hard-Case Lite 32mm tires (40mm max tire clearance)
- Up to 60 mile range (~2 hours)
- Updates delivered via Trek Central mobile app
- Weight: 26.16 lbs (56cm actual)
- MSRP: $12,999.99
The Domane+ SLR 9 shakedown
Absolutely incredible. There’s no other way to describe the new Trek Domane+ SLR 9. It looks so much like the traditional Domane SLR 9 that only a keen eye will sort them out. With both the Domane+ SLR and Domane SLR in for review at the same time, it’s been quite the treat comparing them head-to-head. But, once the Domane+ SLR arrived, it’s been getting the majority of the long weekend miles.
The Domane+ SLR features the same DNA as the standard Domane, so the setup was super easy. With a H2 fit, the stack/reach allows me to get situated without any spacers under the Bontrager RCS Pro Blender Stem. Bucking typical trends of top-shelf builds, Trek has opted for a separate bar/stem with cable routing underneath a removable cover on the underside of the stem. It works like charm by offering easy at-home maintenance. Should your fit require increased stack, the stem is available in a 7-degree model for $139.99.
This build features Shimano Dura-Ace R9200 Di2 and a Praxis Carbon crankset. And, the Bontrager Aeolus RSL 37 wheelset does the rolling duty with R3 32mm tires. But, the star of the show is the TQ Harmonic pin ring motor, housed neatly in the bottom bracket. The oversized downtube stores the 360Wh battery and the top tube features an integrated display that shows key data (watts, battery status, speed, distance). The system connects with various head units to display performance data in your device of choice. Or, you can connect everything to the Trek Central mobile app. Visit Trek learn out more about the TQ drive system.
Of course, the new Domane+ SLR utilizes the updated IsoSpeed design for a road-smoothing experience. Gone is the front IsoSpeed, but tire clearance is wide enough for 40mm rubber to smooth out the ride. In fact, Trek has two flavors of the Domane+ with Shimano-equipped models sporting a road spec and the SRAM-equipped models set up for all roads with 1x eTap AXS groupsets.
Unleashing the Power Pony
I’m gonna have to be honest here… eBikes haven’t really been my thing. And, it wasn’t until the Trek Fuel EXe mountain bike that I actually thought twice about riding one. Then, on the heels of the new Domane SLR, the Domane+ SLR arrives with the TQ motor and the eBike game suddenly became interesting. I nicknamed the Domane+ SLR 9 the Power Pony and she’s been quite a fun steed for winter training miles with tons of climbing.
The stealthy TQ harmonic pin ring motor is neatly built into the beautiful carbon frame and provides quiet power in three modes — depending on your needs. The ECO mode is honestly the ideal output for everyday riding. And, should the battery run out, it remains a capable road bike (albeit noticeably more sluggish than the regular Domane SLR). Speaking of that, my first ride was done without power due to a missing the magnetic rear rotor lock ring. Word to the wise… keep that lock ring on there or the system stops working.
The top tube-mounted TQ display allows you to rotate through power, speed, distance and battery modes. You can switch modes during the ride to show the metric of interest. I settled on the power mode, which shows your power output and the motor output simultaneously to give you an idea how much effort you’re making compared to the TQ motor. Throughout any given ride, I was always surprised by just how much power I could still provide while the motor chipped in the rest.
For starters, let’s cover what it’s like to climb on the Domane+ SLR. Living along Utah’s Wasatch Front, climbing is always on the menu with several pitches to choose from on my regular routes. I’ve recently been keen on a local climb that I call Three Falls Wall. Including the approach, it’s just over 2 miles and gains 700 ft. in elevation. Over the steepest parts, it maintains more than 10% grade, which pushes your limits — even on the Domane+. With that climb as the standard, I’ve been lapping it in all three modes for comparison. With that climb and every other climb I’ve done, you can still push yourself to the limit, but your time in the hurt locker is significantly reduced because of the increased speeds.
One one particular lap, a mountain biker stopped at a trail crossing looked at me as if I was Tadej Pogacar flying by, saying “go get it!” I just chuckled inside as he thought it was 100% me. I guess, for a few weeks, I’ve felt what it’s like to have a world-class VO2 max — pushing as fast and hard as a professional cyclist. It’s truly incredible just how smooth the TQ motor feels in concert with my own pedal strokes. You can hear it, but it’s merely a quiet hum. However, you can absolutely feel it. Standing climbs feel natural and smooth and that hourglass-shaped top tube stays out of your way.
Utilizing the three power modes is easy with the handlebar-mounted controls. Hit the right button to turn on or increase the power mode. The left button decreases the power and holding it down turns it off completely. To maximize battery duration, it may be wise to turn off the motor during flat sections. The one time I deliberately ran the battery out, I climbed 4000 ft over 38 miles in just over 2 hours to drain the tank. Interestingly, the mode didn’t automatically reduce, but instead let me continue with level 3 power until it was gone.
In short, climbing and crushing wide-open climbs is an absolute hoot. You can still push yourself to the limit, but climbs are done in significantly shorter times. To compensate for that, I’ve done most climbs on repeat or gone from one climb to another because you can seemingly get twice as much vert in the same amount of time as an acoustic road bike. On top of it all, the Domane+ SLR seems to turn winter training miles into absolute joy. It’s exhilarating to cover more miles on any given ride compared to a traditional bike, but I have had to adjust my mental clock so as not to get too carried away.
How does it descend?
After smashing one or twenty-one climbs, the Domane+ SLR 9 will gladly take you back down to the bottom. With a comfortable endurance geometry, you’d think balance would be off for aggressive descending, but you’re wrong. Body position and weight balance are spot-on for all terrain, and descents are particularly quick. With the extra weight and heft, the Domane+ really goes downhill like a rock.
One one hand, all that rolling speed is great because it remains a nimble and responsive handler, but it feels really damp, so all the speed can get away from you. The regular Domane SLR always feels lively and zippy, but the Domane+ SLR cruises along with a muted feel. Considering the TQ motor and battery, typical road chatter isn’t transmitted through the pedals or saddle. Interestingly, the IsoSpeed doesn’t feel as plush as the acoustic Domane SLR either. In spite of the added heft, it does still respond to rider input and navigates curves quite well. You can even hop over manholes or road debris at speed.
Yes, the added heft does make for faster descending, which can catch you by surprise. The Dura-Ace disc brakes are even more important as speeds are faster and overall weight is too. I’ve found myself needing more braking power to navigate the same curves, so prepare yourself to brake harder in order keep speed in check. If Shimano ever makes a 180mm Dura-Ace rotor, I would look into it. Note that power assist kicks off at 28mph, so speeds beyond that are purely due to the rider.
How about group rides or busy bike paths?
This is where things get interesting. Trek talks about riding the Domane+ on those fast group rides, but I say use caution until you’re 100% comfortable with the behavior of the power assist. While the TQ motor does help turn your power into super power, it doesn’t automagically make you a better bike handler. And, even an adept bike handler will be caught off guard by the added power during low-speed or tight situations.
You can absolutely maintain balance and control within a group or busy path, but just be prepared for the bike to occasionally lurch a little, which can be unsettling. If you aren’t a confident bike handler, I would not recommend riding the Domane+ on group rides. It’s sort of like giving your 16 yr old the keys to a new Porsche 911.
Something I have really appreciated about the Domane+ is its ability to get out of sketchy situations or quickly make it through intersections. As I’ve approached green lights, I typically go to full power to make it through as fast as possible. And, tricky road sections without comfortable shoulders can also be knocked out in a hurry that way. It feels like turning on the afterburners.
Overall spec mostly delivers
Shimano Dura-Ace shifting and braking feel as expected for their top-end groupset. Shifting is responsive and lever feel is smooth. Charging is simplified too, but adjustments are less intuitive than before and require the Shimano E-Tube mobile or Windows-based app. I haven’t had time to test it out, but still have a bad taste in my mouth from it bricking my Ultegra Di2 groupset in the past. I’m sure it’s improved, but Di2-specifc testing will have to wait for another bike.
Most of my testing has been done during cold weather with full-finger gloves. Compared to SRAM eTaP AXS paddle shifting, the tiny shift buttons leave something to be desired with winter gloves on. I struggled to shift reliably even with the tactile Castelli Mortirolo Gloves during the coldest rides (35 degrees).
The only miss for me are the Praxis cranks. They look off, considering the Dura-Ace groupset. And, for me, the pressed-in alloy washer surrounding the pedal threads popped off one side. Before it popped out, it had caused some cross-threading issues. Trek ensures that they haven’t seen this, but a replacement crankset was sent out just in case. Your local dealer would be able to do the same.
With the Bontrager Aeolus RSL 37 wheels, you’re getting their best all-around wheels. They excel on all terrain and all conditions. Crosswinds don’t faze them and they roll along nicely. With the 32mm Bontrager R3 tires, you can expect smooth grip and comfort. But, they aren’t the fastest-rolling tires on the block. They are wide enough to dabble in some light gravel if you’re so inclined (but I’d go wider if that’s really your jam).
I do have to mention the Bontrager Pro IsoCore VR-SF bars that are spec’d here. With a standard drop curve, they feel dated and out of touch with what a typical Domane rider would expect. I would like to see the VR-CF bars instead, with their shallower and comfier drops.
- TQ Harmonic motor amazes
- Climbing is an absolute gas
- Quiet, adjustable power on demand
- Looks and feels a lot like the regular Domane
- Turns winter training into a game
- Remains a nimble and responsive handler
- Can cover so much more terrain in the same amount of time
- Dura-Ace drivetrain offers smooth shifting
- Bontrager Aeolus RSL 37 wheels are outstanding
- Fit is great for non-racers
- Gravel capable with 40mm tire clearance (not tested)
- Can turn off the power completely in the flats to conserve battery
- Range extender is available, but you’ll lose a bottle cage
- Can pair with Wahoo or other head units
- I’d prefer the VR-CF bars instead
- IsoSpeed feels less cushy than the acoustic Domane SLR
- Requires an adept bike handler
- Power can get away from you in group settings or busy bike paths
- Lived with some minor creaking from the bottom bracket area because troubleshooting seems daunting
- Wished for a little more braking power and a 180mm front rotor
- Trek Central mobile app is so-so… it did lose its brains on one ride
- Pedal-based power meter needed for accurate power measurement
- Expect only about 2 hours on the battery if you climb a lot
The Bottom Line: 2023 Trek Domane+ SLR 9
As the first long-term test of a lightweight eBike, the Domane+ sets a high standard. The Domane+ SLR truly feels like a traditional road bike in almost every sense. The fit is comfortable and accommodating and it responds to rider input. With a quiet, TQ Harmonic motor, the Domane+ sits in a class on its own, but it does come with a hefty price tag. The bike is an absolute blast for winter training or hill repeats and seems to push me harder than I had anticipated because you want to put in even more work to see just how fast you can be with the help of a motor.
Buy Now: Visit TrekBikes.com or your local dealer
Well... the new Trek Domane+ SLR 9 has changed my mind about eBikes and set a new benchmark in the process. With an ultra-quiet TQ Harmonic motor and a traditional look and feel, the Domane+ has been a hoot when hammering out winter training miles. Hill repeats are so much fun while still allowing you to push yourself to the limit.
We have two on order to supplement our Domane acoustic bikes. These will be Project One in the custom shimmering blue color, SRAM, one 50 and one 56. We’re both turning 66 this year, in decent shape, but not quite as fast as we once were, so look forward to keeping up with the group.
David… you’re going to love how much more ground you can cover and vert you can climb in the same amount of time. It’s quite exhilarating to feel like a pro for a few hours. It has been a ton of fun, but you’ll definitely want to keep it in level 1 (eco mode) for group rides, once you get the hang of the added kick. It’s not like a sudden surge, but it can feel like the bike is getting away from you compared to an acoustic bike.
Excited for you to get on them and have some fun.
For someone weighing 210 lbs, and doing slower endurance rides in hilly terrain (1,000 feet of climbing every 10 miles), how long do you think the battery will last?
Jason, thorough review. Would you expect that I’d be able to take on climbs with less of my own power (rather than faster). Heart condition limits me to 100bpm which in turn translates to ~100 watts sustained.
Lou… when I pegged the battery at a two hour ride, that was almost 5k of steep climbing (10%+) over 40 miles at a very high pace. I’m 175 lbs, which would play into everything too. Hard to say for sure, but I’d like to think you could get more than 40 miles. In hindsight, I should have tested a rolling terrain ride to see how close to 60 miles I could get.
Hey Rob… it’s pretty awesome to have the Domane+ for a situation like yours. You can obviously put it into level 3 and meter your output based on heart rate. You’ll have to figure out the right cadence and effort, but it definitely seems doable.
What I’m hoping for. Thanks
Jason, nice review, thanks! You mention in the summary that a „Pedal-based power meter is needed for accurate power measurement“ but you did not comment further on that. Have you done a comparison? For a bike in that price range I‘d say it is unsatisfactory not to get correct watts shown…
Sorry for such a long delay. I was getting official information from Trek on the power measurement of the TQ Motor. As I mentioned, the power measurement isn’t optimized for training, so the output can vary wildly from 10-15% accuracy as opposed to most power meters being in the 1.5% range of accuracy. Your best bet is a pedal-based power meter, like the Wahoo POWRLINK Zero.
Thanks for review I’ve just read over here in the UK.
Motor assistance on ebikes in Europe is limited up to a speed of 15.5 mph so I’m wondering if a lot of benefit would be lost in UK.
I’m a fit 76 year old but now finding it hard to keep up with my group on hills ; they average 20yrs younger.
If motor cuts out at 15.5 mph and group is riding on flat terrain at say 18+ mph , I’d be pedalling a heavier machine.
So, my question is how did the bike perform on the flat with no motor assistance ?
I did just confirm the max assist you mentioned (15.5 mph in Europe), and that’s a bummer since typical riding speeds are in the 15-25 mph range. It will still help on climbs, for sure. So that’s a bonus.
Now to talk about unassisted rolling or flat terrain. It does move along just fine and you can ride it much like an acoustic bike, but you are pedaling another 10 lbs around and I’m not going to lie, it is noticeable. If the rides are rolling terrain where you might occasionally dip below 15 mph, it could be of partial benefit. Once you do get up-to-speed, it does maintain its momentum well. But, varying group speeds between 15-25 mph to keep pace might be taxing.
That said, if the group pace remains consistent, you can get up-to-speed with less effort and simply maintain pace reasonably well. It’s too bad the max assist hits at 15.5 mph — it’s just off the ideal pace for fast group rides.