The Orbea Denna M20I is an awesome gravel bike, a gravel bike that just happens to be paired up with an intuitive, powerful, efficient, responsive and impressively smooth motor system. Yep… It’s a good ‘un, and its frugal battery usage means that range anxiety isn’t an issue. The only thing you’ll probably need to allow for is a tyre upgrade for anything other than the driest, smoothest trail.
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Orbea Denna M20I – Technical details
The Denna uses Shimano's EP8-RS, which is an EP8 motor that Orbea has tuned using its own firmware known as RS or Rider Synergy. It delivers a max torque of 85 Nm, so it’s certainly got some punch to it. Also, while it is limited to a ‘continuous’ 250 watts of power as per UK law, for short bursts it can push out up to 350 watts.
Straight out of the box, the Denna comes with two pre-configured settings called Gravel and Gravel +. The first offers the most natural ride feel according to Orbea, and gives the longest battery range out of the two, while the Gravel + is ideal for looser surfaces, allowing more torque at lower cadences for added traction, says the brand.
Both offer three assist levels, with the Gravel mode being the one I used the most, putting out maximum torque of 20Nm on Eco, 27Nm on Trail and 42Nm on Boost. Using Shimano’s e-Tube app, you can configure the set-up however you like though giving you complete control. Switching modes and offering various data fields is the SC-EN600 display and Assist Switch, which easily lets you scroll, see things like battery range.
The ebike system also has plenty of compatibility with other systems, so the Di2 shifting runs off of the main battery, and the left-hand brake lever (UK setups) buttons change power modes. This lever is opened up due to the 1x drivetrain, making it redundant for gear-changing duties.
Fuelling the motor is a 420Wh battery, which I found to have an impressive range with just under 90 miles (145km) achievable on the Eco mode with the above settings, around 75 miles (120km) on Trail and 45ish miles on Boost, about 70km. Ramping up the torque will obviously reduce those figures, but I didn’t feel that I needed to change those standard outputs as they balanced rideability with range.
Charging is a doddle, too, and a full charge takes about four to five hours and costs about 20p to 25p according to my smart meter, so it’s pretty frugal too.
When it comes to sizing, Orbea offers six in total, which range from XS to XXL, covering top tube lengths of 531mm up to 599mm.
I’ve been riding the medium size with a top tube of 558mm, head tube of 152mm and a seat tube of 471mm. Combine that with a 71° head angle, a 73.5° seat angle and a trail of 67mm, and you get a stack and reach combination of 570mm and 395mm, and a wheelbase of 1,040mm.
The Denna’s frame is manufactured from OMR carbon fibre, as is the OMR ICR fork with its tapered steerer. Orbea describes the carbon as using high modulus and high strength fibres, and the moulding technologies they use prevent wrinkles and imperfections in critical zones. Both are designed for 12mm thru axles with 142mm spacing at the rear and 100mm for the fork – both of which seem to be the standard that has been widely adopted.
There is full internal cable routing for a clean look, plus there are a few mounting points on the frame, although not the fork, highlighting it’s more of a racer than an adventure machine.
Paint-wise, this model is available in three colours and the finish is completed to a high standard. In fact, everything about this bike's frame and fork looks and feels quality.
Tyre clearance is impressive at 50mm, and Orbea also sells a mudguard kit for the Denna too for a bit of riding in poor weather, so it can be considered quite a versatile machine.
Orbea Denna M20I – Componentry
The groupset is a bit of a mix and match between Shimano’s ebike, MTB and road lineups. We have Ultegra Di2 shifters and braking system, a Steps EM600 crank with a 42T chainring, an XT Di2 SGS Shadow Plus rear mech and a 10-51T 12-speed cassette. It may be a bit of a mouthful, but it all works very well together.
The cassette gives a great range of gears covering both the high and low end with ease, so I never felt compromised on either the uphills or the downhills, especially when you include the boost of the motor too. It also does a good job of filling in the gaps between the gears.
The shifting is crisp, even when the components are coated in mud or dust, and the braking set-up is more than enough to bring you to a controlled stop.
You can also adjust the power modes via the included handlebar controller, turn the unit on and off and scroll through the screen on the EN600 computer I mentioned before. I’ll point out that the computer is a £135 extra if you want it fitted.
As for the rest of the kit, you are getting a rather posh Easton EC90 AX carbon handlebar, which has a flat top section and a flare of 16 degrees, which aids stability when in the drops. It’s a bar I got on with very well indeed, and while the Denna isn’t a cheap bike, it’s still a bonus to find a carbon bar.
The stem is an OC Road Performance with an eight-degree drop, or you can have the same stem with a 15-degree rise for no extra cash. In fact, Orbea allows you to customise most parts on the bike, including the bar, seatpost, wheels and tyres.
The seatpost is carbon and comes in two setback options of 0mm or 15mm and comes with a Selle San Marco Shortfit 2.0 Start Up Off Road Xilite saddle. Not the catchiest name, but it is comfortable, although ours kept slipping in the saddle clamp unless it was done up as tight as possible.
The wheels are Oquo Road Control RC25TEAMs with carbon rims of 25mm in depth, as you no doubt can work out from the name. If you so desire, you can have a set of 45mm deep rims for no extra cost if aero and speed are your thing. The wheels took plenty of abuse over the rugged gravel trails I ride, and I was very impressed with their performance throughout.
For the tyres, you have the option of Pirelli’s P Zero Race X TLR 30mm or, as we have here, Vittoria’s Terreno Dry Gravel G2.0 TLRs in a 45mm width.
The Vittoria tyres were a good option for the dry, dusty conditions the test period covered, and they roll well on the road too. The compound is soft enough to give plenty of feel, but it’s a durable tyre too. The only issue I had was that the rear tyre decided after a couple of months that it didn’t want to seal on the rim anymore. I popped a tube in and had no issues, though, and puncture resistance was spot on.
Orbea Denna M20I – Performance
The biggest positive about the Denna M20I for me is the fact that it doesn’t ride like an e-bike when the motor isn’t in use. Even though it weighs north of 13kg, it never feels like a heavy bike to manoeuvre, even at slow speeds on technical trails, thanks to the weight of the motor sitting low down and not affecting your centre of gravity.
Shimano and Orbea have created a system that is very intuitive and complements how you are riding. It’s not just a matter of turning the pedals and the motor does all of the work. It delivers the power in a subtle way to assist you. The more you put in, the more you get back, dispelling the myth that e-bikes are cheating and that they do all the hard work.
This isn’t a system that allows you just to leave the bike in the hardest gear and expect a load of assistance to get you moving from a standing start. You need to use the gears to get the best out of it.
Anywhere the weight is an issue, like climbing or when pulling away, is counteracted by the motor, so the Denna just feels like you are riding a normal bike. The riding position I could achieve was performance-oriented, and it has a racy edge to it.
The tyres fitted didn’t have much tread, being designed for dry, hard-packed conditions, so on sections where the gravel was deep and loose, the Denna didn’t half squirm about, but the quick handling and ride position make for a very controllable bike, and a responsive one too.
It’s a bike you can chuck around, and while going for a course record on my gravel testing loop, I was pushing it very hard into the corners on the tracks, and not taking it easy either on the singletrack sections through the woods. It even feels quite nimble and flickable, not something I normally say about riding an e-gravel bike.
That large down tube that encases the battery and the oversized bottom bracket area that incorporates the motor means that the Denna has no issues with a lack of stiffness. Even with the combination of motor and leg power, there is no flex to be found, and thankfully, the fork doesn’t let the side down, coping well with heavy braking loads and hard turns.
A heavily sloped top tube results in a compact frame shape, and the amount of seatpost I was able to run on this size medium did add to the comfort.
In fact, the Denna is a comfortable bike in general from the front end to the rear and has been designed to give a great ride quality. The only slight niggle I had was that there was a bit of rattling from wires inside the frame, which could get a bit annoying on rough terrain.
Like most, I have to ride on a couple of miles of road to get to the nearest gravel, and the Orbea is no slouch on the asphalt either. The motor’s subtle nature means that I barely noticed it turning itself off when I reached the 15.5mph speed limiter, and I’d be easily rolling along at 20mph on the flat. In fact, to return the bike to our offices in the city of Bath, I rode my normal road route and set a course record with an average speed of 1mph faster than normal. With some fat slicks on it’d be even more efficient.
Overall, it’s just a belter of a bike to ride regardless of whether you take into account that it’s an ebike or not.
Orbea Denna M20I – Verdict
With no added extras, the M20I costs £7,299, and this exact bike would set you back £7,434 as it has the EN600 computer added. You could also add a 210Wh range extender battery for £395 and add mudguards for £69.
The range starts at just £3,499, though with an EP600-RS motor with the same battery, and a 1x10 Shimano Cues mechanical drivetrain. The range topper is the M10I, which has much the same build as our bike but with the Ultegra parts being swapped out for Dura Ace Di2 for £8,999.
From a comparison point of view in terms of value, I’ll kick off with Canyon’s Grizl:ONfly CF Trail, which is a bit more expensive at £7,449. It uses a Bosch Performance Line SX motor with a 400Wh battery and a SRAM X0 Eagle AXS transmission with 1x ‘mullet’ set up like the Orbea. You do get a few extras, though, like a wirelessly operated AXS dropper post and a RockShox Rudy XPLR gravel fork with 40mm of travel.
Specialized has the Turbo Creo 2 Expert for around the same sort of money as the Denna M20I at £7,500. It uses Spesh's own 1.2SL motor and 320Wh battery pack and comes with a mix of MTB and road components, although this time from SRAM. The gearing is pretty much the same as the Orbea, though with a 44T chainring and an 11-50T cassette. 32mm carbon wheels are also included in that price. You do get a dropper post, though, and Specialized's Future Shock 3.3 system adds a bit of squidge at the front.
After my time with the Denna, I came away thinking that this is one of the best all-around, capable gravel bikes that I have ridden. The motor system is excellent, both in the way it responds, delivers the power, and it covers an impressive range too.
On top of that, it rides brilliantly too. It feels very much like a gravel racer thanks to that light and nimble feel, but it feels really planted as well. It’s a laugh to ride, whether I was out for a short blast or going for a much longer route, and while this model is a big chunk of cash, it’s great to see Orbea offering such a large spread of builds and budgets.
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